1
Q
Patient with a stroke in the middle cerebral artery, which areas are lesioned?
A
- The motor and sensory cortices (upper limb and face)
- Temporal lobe (Wernicke area)
- Frontal lobe ( Broca area)
2
Q
What symptoms present with a stroke of the middle cerebral artery?
A
- Contralateral paralysis and sensory loss of the face and upper limb
- Aphasia if in dominant (usually left) hemisphere
- Hemineglect if lesion affects the nondominant (usually right ) hemisphere.
3
Q
What is aphasia?
A
- A higher order language deficit
- The inability to understand, speak, read or write
4
Q
What is dysarthria?
A
- The motor inability to speak
- Movement deficit due to muscle weakness
5
Q
What is Hemineglect or spatial neglect?
A
- Inability to report, respond or orient to stimuli in the contralesional space
- Ex. Patient with a stroke of the right middle cerebral artery completely ignores everything on the left side because they can not recognize it
6
Q
What visual symptoms is Wernicke aphasia associated with in a stroke?
A
Right superior quadrant visual field defect due to temporal involvement of
7
Q
Patient with a stroke in the anterior cerebral artery, which area is lesioned?
A
- Motor and sensory cortices (lower limb)
8
Q
What symptoms present with a stroke of the anterior cerebral artery?
A
- Contralateral paralysis and sensory loss of the lower limbs
9
Q
Amyotrophic lateral sclerosis
A
- Commonly known as Lou Gehrig’s
- Combined degeneration of UMN and LMN with no sensory or bowel/bladder deficits (due to loss of cortical and spinal cord motor neurons, respectively)
- Can be caused by superoxide dismutase 1
- Presents with asymmetric limb weakness (hands/feet), fasciculation’s, eventual atrophy
- Fatal
- Treatment is with Riluzole
- Increases survival by decreased glutamate excitotoxicity via unclear mechanism
10
Q
What are common UMN symptoms seen in ALS?
A
Some of the following seen in combination with LMN symptoms
- Babinski sign
- Hyperreflexia
- Spasticity
- Hypertonia
- Clasp knife reflex
- Pronator drift (when eyes closed and hands supinated)
11
Q
What are common LMN symptoms seen in ALS?
A
Some of the following seen in combination with UMN symptoms
- Fibrillations
- Fasciculations
- Hypotonia
- Hyporeflexia
12
Q
What is the treatment for ALS?
A
Riluzole
- It increases survival by decreased glutamate excitotoxicity via an unclear mechanism
13
Q
Hypertrophic Cardiomyopathy is caused by?
A
60-70% are familial, autosomal dominant - Due to mutations in genes encoding sarcomeric proteins such as myosin binding protein C , Beta-myosin heavy chain and Troponin C May be associated with friedreich ataxia - Neurodegenerative disease - Autosomal recessive
14
Q
What are the complications of prolonged hypertension on the heart?
A
Left ventricular hypertrophy
- May hear S4, systolic murmur (during contraction)
- Mitral regurgitation due to impaired mitral valve closure (crescendo decrescendo murmur)
- This is because hypertrophic ventricle dilates and opens the mitral valve annulus
- May lead to left ventricular heart failure
15
Q
What are the symptoms and findings seen in hypertrophic cardiomyopathy?
A
- Causes syncope during exercise
- May lead to sudden cardiac death in athletes do to ventricular arrhythmia
- S4, systolic murmur is heard (crescendo-decrescendo)
- May see mitral regurgitation due to impaired mitral valve closure
- Leads to diastolic dysfunction
- Leads to concentric hypertrophy (sarcomeres are added in parallel) - septal predominance
- Myofibrill disarray and fibrosis
16
Q
What is hypertrophic obstruction cardiomyopathy?
A
- A subset of hypertrophic cardiomyopathy
- Asymmetric septal hypertrophy of the left ventricle and systolic anterior motion of the mitral valve lead to an obstruction of the blood leaving the left ventricle
- Leads to dyspnea and possible syncope
- Causes crescendo decrescendo murmur
- If person squats, systemic vascular resistance increases, this increases the force needed to increases blood out of the ventricle, increasing afterload
- This stretches the ventricle out a little more, leading to reduced obstruction of the outflow tract, a less intense murmur is then heard
- If the person stands up or does Valsalva, it decreases venous return, causing less blood to enter the ventricle, leading to more obstruction of the outflow tract, a more intense murmur is heard
17
Q
How is hypertrophic cardiomyopathy treated?
A
- Cessation of high intensity athletics
- Beta blockers or Non-Dihydropyridine Ca2+ blockers (verapamil)
- Implantable cardioverter defibrillator if patient is high risk
18
Q
What are the causes of dilated cardiomyopathy?
A
- Often idiopathic or familial
- Alcohol abuse (chronic)
- Wet beriberi (Thiamin deficiency - B1)
- Cocaine
- Coxsackie B viral myocarditis
- Chagas disease
- Doxorubicin / Daunorubicin toxicity
- Duchen muscular dystrophy
- Hemochromatosis
- Sarcoidosis
- Peripartum cardiomyopathy (Due to HTN in pregnancy)
19
Q
What are the findings seen in dilated cardiomyopathy?
A
- Heart failure (weak contractions, less stroke volume)
- S3 result of blood rushing in and slamming into thew wall during disatole
- Systolic regurgitant murmur (mitral or tricuspid) is due to stretching out the valves allowing blood to leak back
- Holosystolic murmur
- Dilated heard on CXR or echocardiogram
- Systolic dysfunction ensues due to weak contractions
- Leads to eccentric hypertrophy (sarcomeres are added in series)
20
Q
What is takotsubo cardiomyopathy?
A
- Broken heart syndrome
- Ventricular apical ballooning likely due to increased sympathetic stimulation
- Stressful situations or emotional situations
21
Q
What are the medications used to treat tuberculosis?
A
RIPE
- Rifampin
- Isoniazid
- Pyrazinamide
- Ethambutol
22
Q
Isoniazid
- Uses
- MOA
- Side effects
A
Uses
- Mycobacterium Tuberculosis
- Used as solo prophylaxis against TB
- Used as monotherapy for latent TB
- Combined with other medications to treat primary TB
MOA
- Inhibits mycolic acids in cell wall of mycobacterium
- Decreases synthesis of mycolic acids
- Must be activated by bacterial catalase peroxidase (KatG)
- KatG converts it to active metabolite
- Resistance occurs when KatG is down regulated
Side effects
- Mainly causes injury to nerves and hepatocytes
- Peripheral neuropathy
- Metabolized by N-acetyltransferase
- Slow acetylators increased risk for toxicity
- May lead to seizures
- B6 is given alongside to prevent toxicity
- Hepatocyte dysfunction is common
- Increased LFTs
- Drug induced lupus
- Anion gap metabolic acidosis
- Inhibits cytochrome P450 increasing levels of other drugs ( Increases WEPT)
23
Q
Rifampin or Rifabutin
- Uses
- MOA
- Side effects
A
Uses
- Mycobacterium tuberculosis
- Mycobacterium leprae, delays resistance to dapsone when used in combination
- Meningococcal prophylaxis and chemoprophylaxis in contacts of children with H. influenzae type B
MOA
- Inhibits DNA-dependent RNA polymerase
- Inhibits RNA synthesis
- Resistance to drug when used alone or when RNA polymerase binding site is prevented
Side effects
- Hepatitis when used with other RIPE drugs
- Urine, tears, sputum, feces and CSF may turn orange
- Induces (revs up) cytochrome P-450 (decreases WEPT)
- Rifabutin preferred in HIV patients due to less cytochrome P-450 stimulation
24
Q
Pyrazinamide
- Uses
- MOA
- Side effects
A
Uses
- Mycobacterium tuberculosis
MOA
- Uncertain
- Works best at acidic pH (host phagolysosome)
Side effects
- Hyperuricemia and needle shaped uric acid crystal formation that may precipitate gout
- Hepatotoxicity leading to liver necrosis
25
Ethambutol
- Uses
- MOA
- Side effects
```
Uses
- Mycobacterium tuberculosis
MOA
- Blocks arabinosyl transferase
- Inhibits carbohydrate formation at the cell wall of mycobacterium
- Stops polymerization (bacteriostatic)
Side effects
- Optic neuropathy- red green color blindness
- Loss of visual acuity
```
26
Where does primary tuberculosis typically presen in the lungs?
In the Ghon complex
- The hilar nodes
and
- The Ghon focus (mid/lower lobes)
27
What is normocytic, normocromyc anemia?
- Can be nonhemolytic or hemolytic
- Can be intravascular or extravascular
- Can
28
What is Chronic Granulomatous Disease?
- X- linked recessive defect in NADPH oxidase
- Disorder of phagocytic cells
- Defect in bactericidal mechanism
- Usually young boys that get recurrent bacterial and fungal infections
- Recurrent catalase positive infections
> Staphyloccocus aureus
> Serratia Marcescens
> Pseudomonas
> Nocardia
> Aspergillus
> Candida
> E. coli
> Enterobacteriaceae (Klebsiella)
29
What test is used to diagnose chronic granulomatous disease?
Nitroblue Tetrazolium Test (NBT)
- Detects NADPH oxidase
- If it does not change enzyme to blue and it stays yellow, indicates that NAPH oxidase deficiency
- Negative test
Dihydrorhotamine Flow Cytometry Test
- Activation of neutrophils with phorbol myristate acetate (PMA) results in oxidation of DHR to a fluorescent compound, rhodamine 123, which can be measured by flow cytometry
30
When does sickling of RBC's occur in patient with sickle cell disease?
- Dehydration (Acidosis)
- Deoxygenation
- High altitudes
31
What causes sickle cell anemia?
- HbS point mutation causes a single amino acid replacement in Beta chain
- Substitutes Glutamic Acid with Valine
- Leads to extravascular and intravascular hemolysis
32
When is sickle cell disease first diagnosable?
- After the first 6 months of life
- Because infants are protected by HbF
- HbF levels are reduced by 6 months of age
33
What is the most common clinical manifestation of sickle cell anemia?
- Vaso occlusive crisis that can present as:
- Dactilytis: painful and swollen hands and feet
- Priapism: prolonged erection
- Acute chest syndrome
- Acute abdomen
- Avascular necrosis
- Stroke
34
Are heterozygotes with sickle cell trait resistant to malaria?
Yes
35
What is seen on skull x-ray of patients with sickle cell anemia?
Where else is this seen?
Crew cut
- Produces perpendicular radiations characterized as hair on end appearance
- Due to marrow expansion from increased erythropoiesis
36
What are complications seen in sickle cell disease?
1. Aplastic crisis (due to parvovirus B19)
2. Autosplenectomy leads to increased risk of infections by encapsulated organisms
- Howell-Jolly bodies on smere (nuclear remnant)
- Some killers have nice capsules
- S. Pneumonia
- Klebsiella
- H. Influenzae
- Pseudomonas
- N. Meningitidis
- Cryptococcus
3. Splenic infarct/ sequestration crisis
4. Salmonella Osteomyelitis
5. Painful crisis (most common)
6. Renal papillary necrosis and microhematuria
- Decreased Po2 in papilla causes necrosis
- Medullary infarcts lead to microhematuria
37
How is sickle cell anemia diagnosed?
Hemoglobin electrophoresis
38
What is the treatment for Sickle cell disease?
1. Hydroxyurea
- Increases HbF
- increase in fetal hemoglobin retards gelation and sickling of RBCs
- Reduces levels of circulating leukocytes, which decreases the adherence of neutrophils to the vascular endothelium
- In turn, these effects reduce the incidence of pain episodes and acute chest syndrome episodes.
2. Hydration
39
What is restrictive cardiomyopathy?
- Heart muscle is restricted and less compliant
- Cant stretch and there is less filling
- Less blood is pumped out to the body
- Leads to diastolic heart failure (filling failure)
40
What causes restrictive cardiomyopathy?
1. Amyloidosis
- Misfolded proteins that are insoluble
- Become deposited in many organs including the heart
- Can be familial or senile (TTR becomes deposited)
2. Sarcoidosis
- Formation of granulomas in the heart tissue
3. Endocardial fibroelastosis
- Thick fibroelastic tissue in the endocardium of young children
4. Loffler Syndrome
- Endomyocardial fibrosis with a prominent eosinophilic infiltrate
- Leads to inflammation of the myocardium
5. Hemochromatosis
- Iron becomes deposited in the hear
6. Postradiation fibrosis
41
What are the four pyruvate metabolic pathways and their cofactors?
1. Alanine aminotransferase
- B6 is the cofactor
- Alanine carries amino groups to the liver from muscle
2. Pyruvate Carboxylase
- Biotin is the cofactor
- Oxaloacetate can replenish TCA cycle or be used in gluconeogenesis
3. Pyruvate dehydrogenase
- B1, B2, B3, B5 and Lipoic acid are cofactors
- Transition from glycolysis to the TCA cycle
4. Lactic acid dehydrogenase
- B3 is the cofactor
- End of anaerobic glycolysis
- Major pathway in RBCs, WBCs, kidney medulla, lens, testes and cornea
42
What is primary disease prevention?
| Give an example
Preventing the disease before it occurs
| - Ex. HPV vaccination
43
What is secondary disease prevention?
Screen early for and manage existing but asymptomatic disease
- Ex. Pap smear for cervical cancer
44
What is tertiary disease prevention?
Treatment to reduce complications from disease that is ongoing or has long-term effects
- Ex. Chemotherapy to cure cancer
45
What is quarternary disease prevention?
Identifying patients at risk of unnecessary treatment, protecting from the harm of new interventions
- Ex. Electronic sharing of the patient records to avoid duplicating recent laboratory and imaging studies
46
The axillary nerve
Arises from?
Exits the axilla through the?
Innervates which structures and muscles?
- Arises from posterior cord (C5, C6)
- Quadrangular space
- Gives rise to superior lateral cutaneous nerve of arm which innervates the skin over the lower deltoid (regimental badge area)
- Innervates teres minor and deltoid muscles
47
Fractures of the surgical neck of humerus or anterior dislocation of humerus damages which nerve?
Axillary nerve (C5, C6)
48
Which nerve is injured in the following presentation?
Flattened deltoid
Loss of arm abduction at shoulder ( > 15 degrees)
Loss of sensation over deltoid muscle and lateral arm
Axillary nerve (C5, C6)
49
```
What structures make up the quadrangular space?
Superior border
Inferior border
Lateral border
Medial border
```
- Subscapularis
- Teres major
- Surgical neck of humerus
- Long head of triceps brachii
50
The musculocutaneous nerve
Arises from?
Leaves the axilla by?
Innervates which structures and muscles?
- Arises from lateral cord (C5, C6, C7)
- Leaves the axilla by piercing through the coracobrachialis near the humerus
- Innervates the coracobrachialis, biceps brachii and brachialis
- Gives rise to the lateral cutaneous nerve of the forearm which innervates the skin on the lateral surface of the forearm
51
Upper trunk compression of the brachial plexus damages which nerve?
Musculocutaneous nerve (C5, C6, C7)
52
Which nerve is injured in the following presentations?
| Loss of forearm flexion and supination or loss of sensation to the lateral forearm
Musculocutaneous nerve (C5, C6, C7)
53
The radial nerve
Arises from?
Leaves the axilla by?
Innervates which structures and muscles?
- Arises posterior to the axillary artery from the posterior cord (C5-T1)
- Exits the axilla inferiorly through the triangular interval supplying the long and medial heads of the triceps. It descends down the arm through the radial groove
- Descends wraping around the medial head of the triceps accompanied by the brachial artery
- Travels anteriorly over the lateral epicondyle of the humerus
- Innervates most of the skin of the posterior side of forearm and dorsal surface of the lateral palm and lateral three and a half digits (sensory)
- innervates triceps brachii (extends elbow) and the majority of the extensor muscles in the forearm (extends wrist and fingers and supinates the forearm)
54
Midshaft fracture of the humerus or compression of the axilla, due to crutches or sleeping with arm over chair (Saturday night palsy) causes injury to which nerve?
Radial nerve (C5-T1)
55
The following presentations cause injury to which nerve?
Wrist drop: loss of elbow, wrist and finger extension
- Decreased grip strength (wrist extension for maximal action of flexors)
Loss of sensation over the posterior arm/forearm and dorsal hand
Radial nerve (C5-T1)
56
Median nerve
Arises from?
Travels by?
Innervates which structures and muscles?
- Arises from medial and lateral cords of the brachial plexus (C5-T1)
- Exits the axilla, travels lateral to the brachial artery
- Halfway down the arm it crosses over the brachial artery and it becomes situated medially
- It enters the anterior compartment of the forearm via the cubital fossa
- Travels between the flexor digitorum profundus and flexor digitorum superficialis
- Gives rise to anterior interosseous nerve and the palmar cutaneous nerve
- It enters the hand via the carpal tunnel where it dives into the recurrent branch and the palmar digital branch
Motor Innervation
- Innervates the flexors of the anterior compartment of the forearm except flexor carpi ulnaris and only half of flexor digitorum profundus
- Innervates the thenar muscles and the lateral two lumbricals in the hands.
Sensory innervation
- Palmar cutaneous branch which arises from forearm, innervates the lateral aspect of the palm, does not pass through carpal tunnel
- Palmar digital cutaneous branch which arises in the hand, innervates the palmar surface and fingertips of the lateral three and a half digits
57
Supracondylar fracture of the humerus (proximal lesion) or carpal tunnel syndrome and wrist lacerations (distal lesion) cause injury to which nerve?
The median nerve (C5-T1)
58
The following presentations cause injury to which nerve?
- Ape hand
- Popes blessing
- Loss of wrist flexion
- Loss of flexion of the lateral fingers
- Loss of thumb opposition
- Loss of lumbricals of 2nd and 3rd digits
- Loss of sensation over the thenar eminence and dorsal and palmar aspects of lateral 3.5 fingers with proximal lesion
- Tingling on percussion of the carpal tunnel
The median nerve (C5-T1)
59
The ulnar nerve
Arises from?
Travels by?
Innervates what?
- Arises from C8-T1, a continuation of the medial cord
- Descends down the medial side of the upper arm
- At elbow it passes posterior to the medial epicondyle of humerus
- In the forearm it pierces the two heads of the flexor carpi ulnaris and travels along the ulna
Three branches arise in the forearm
- Muscular branch, palmar cutaneous branch and dorsal cutaneous branch
- At the wrist it travels superficial to the flexor retinaculum
- Enters the hand via guyon canal
Innervates
- The flexor carpi ulnaris and the flexor digitorum profundus medial half
- The hypothenar muscles
- Medial two lumbricals
- Adductor pollicis
- Interossei of the hand
- Palmaris brevis
60
Fracture of the medial epicondyle of the humerus (funny bone) or fractured hook of hamate causes injury to which nerve?
The ulnar nerve
61
The following presentations are injury to which nerve?
- Ulnar claw on digit extension
- Radial deviation of wrist upon flexion (proximal lesion)
- Loss of wrist flexion
- Loss of flexion of medial fingers
- Loss of abduction and adduction of fingers (Interossei)
- Loss of action of medial 2 lumbrical muscles (MCP flexion)
- Loss of sensation over the medial 1.5 fingers including hypothenar emminence
The ulnar nerve (C5-T1)
62
Recurrent branch of the median nerve is injured when?
Superficial laceration of the palm
63
Injury to the recurrent branch of the median nerve presents as?
- Ape hand
- Loss of thenar muscle group which include opposition, abduction and flexion of the thumb
- No loss of sensation
64
```
Patient presents with winged scapula
What nerve is injured?
What can cause the injury?
What muscle is deficit?
What are the symptoms?
```
- Lesion of long thoracic nerve
- Axillary node dissection from mastectomy
- Stab wounds
- Serratus anterior deficit
Symptoms
- Can not anchor the scapula to thoracic cage
- Can not abduct the arm above the horizontal plane
65
What is thoracic outlet syndrome?
What causes it?
Which muscles are affected?
What are the symptoms?
- Compression of the lower trunk of the brachial plexus and of the subclavian vessels
- Caused by a cervical rib (extra) or a pancoast tumor (tumor of pulmonary apex)
- Intrinsic hand muscles: lumbricals, Interossei, thenar and hypothenar
- Symptoms are atrophy of the intrinsic hand muscles, ischemia, pain and edema due to vascular compression
66
What is klumpke palsy?
What are the causes?
What are the muscle deficits?
What are the symptoms?
- Traction or tear of the lower trunk (C8-T1) roots
- In infants, due to upward force on arm during delivery
- In adults, due to fall and trying to grab on with on arm
- The intrinsic hand muscles: lumbricals, Interossei, thenar and hypothenar
- Symptoms are total claw hand, lumbricals flex the MCP joints and extend the DIP and PIP joints
67
What is Erbs palsy?
What are the causes?
What are the muscle deficits?
What are the symptoms?
- Waiters tip (Erb-er Trunk)
- Traction or tear of the upper trunk (C5-C6)
- In infants due to traction on neck during delivery
- In adults due to trauma
- Deltoid, supraspinatus, infraspinatus and biceps are affected
- Supraspinatus and Deltoid unable to abduct arm so it hangs by the side
- Infraspinatus unable to laterally rotate the arm so it stays medially rotated
- Biceps unable to flex and supinate arm so it stays extended and pronated
68
Lesion to the upper trunk of the brachial plexus causes?
Erbs palsy
69
Lesion to the lower trunk of the brachial plexus causes?
- Klumpke's palsy (claw hand)
70
Lesion to the posterior cord of the brachial plexus causes?
- Wrist drop
71
Lesion to the Long Thoracic from T1 of the brachial plexus causes?
- Winged scapula
72
Lesion to the axillary nerve of the brachial plexus causes?
- Deltoid paralysis
73
Lesion to the radial nerve of the brachial plexus causes?
- Wrist drop (Saturday night palsy)
74
Lesion to the musculocutaneous branch of the brachial plexus causes?
- Difficulty flexing the elbow joint and loss of lateral forearm sensation
75
Lesion to the median branch of the brachial plexus causes?
- Popes hand, unable to use thumb, flex hand and sense in lateral 3.5 fingers
76
Lesion to the ulnar branch of the brachial plexus?
- Ulnar claw hand, unable to use the intrinsic hand muscles
77
What is conns syndrome?
- Primary Hyperaldosteronism
- Due to adrenal adenoma
- Increased aldosterone levels that are nonsuppressible
- Decreased renin levels
- Hypokalemia with kaliuresis
- Hypernatremia
- Metabolic alkalosis
- Leads to hypertension and water retention
- Normal plasma and urine cortisol
78
What is addisons disease?
- Primary Adrenal Insufficiency (chronic)
- Due to adrenal atrophy or destruction by disease
- Autoimmune destruction is most common in western world
- TB is most common in the developing world
- Deficiency in aldosterone and cortisol production
- Hypotension due to hyponatremic volume contraction
- Hyperkalemia
- Metabolic acidosis
- Skin and mucosal hyperpigmentation due to increased MSH (byproduct of ACTH from propiomelanocortin {POMC})
79
How does acute primary adrenal insufficiency present?
- Sudden onset
- Due to massive hemorrhage
- May present with shock in acute adrenal crisis
80
What is waterhouse Friderichsen syndrome?
- Acute primary adrenal insufficiency due to adrenal hemorrhage associated with septicemia, DIC, endotoxic shock
- Usually caused by N. meningitidis
81
What are the features of secondary adrenal insufficiency?
- Seen with decreased pituitary ACTH production
- No skin or mucosal hyperpigmentation
- No hyperkalemia because aldosterone synthesis is preserved due to intact Renin-Angiotensin-Aldosterone axis.
82
What are the features of tertiary adrenal insufficiency?
- Seen in patients with chronic exogenous steroid use precipitated by abrupt withdrawal
- Aldosterone synthesis is unaffected
83
Diabetes insipidus
- Intense thirst and polyuria with inability to concentrate urine due to lack of ADH (central) or failure to respond to circulating ADH (nephrogenic)
84
Central Diabetes Insipidus
- Etiology
- Findings
- Water deprivation test results
- Treatment
- Due to pituitary tumor, autoimmune disease, trauma, surgery, ischemic encephalopathy or idiopathic
Findings
- Decreased ADH
- Urine specific gravity < 1.006
- Serum osmolality >290 mOsm/kg
- Hyperosmotic volume contraction
Test Results
- Greater than 50% increase in urine osmolality after administration of ADH analog
Treatment
- Intranasal desmopressin acetate and hydration
85
Nephrogenic Diabetes Insipidus
- Etiology
- Findings
- Water deprivation test results
- Treatment
```
Etiology
- Hereditary (ADH receptor mutation)
- Secondary to hypercalcemia, lithium, demeclocycline (ADH antagonist)
Findings
- Normal ADH levels
- Urine specific gravity < 1.006
- Serum osmolarity > 290 mOsm/kg
- Hyperosmotic volume contraction
Water deprivation test results
- Minimal change in urine osmolarity, even after administration of ADH analog
Treatment
- HCTZ, indomethacin, amiloride, hydration
```
86
Syndrome of inappropriate antidiuretic hormone
- Excess free water retention
- Euvolemic hyponatremia with continued urinary Na+ excretion
- Urine osmolality > serum osmolality
- Body responds to water retention with decreased aldosterone (hyponatremia) to maintain near normal volume status
- Very low serum Na+ levels can lead to cerebral edema or seizures.
- Correct slowly to prevent osmotic demyelination syndrome (central pontine myelinolysis)
Causes
- Ectopic ADH (small cell lung cancer)
- CNS disorders/head trauma
- Pulmonary disease
- Drugs (cyclophosphamide)
Treatment
- Fluid restriction, IV hypertonic saline, Conivaptan, tolvaptan, demeclocycline
87
What does aldosterone mainly do?
- Primarily regulates ECF volume (blood plasma) and Na+
- Responds to low volume states (via AT II)
- Also responds to hyperkalemia by increased K+ excretion
88
How does aldosterone produce its actions?
- Increases Na+ channel insertion and increases activity of Na+/K+ pump in the DCT
- Enhances K+ and H+ excretion by way of principal cell K+ channels and alpha-intercalated cell H+ ATPases
- Na+ is reabsorbed and water follows
- Leads to increased blood volume without changing osmolarity (Volume and osmoles increase)
89
What does ADH mainly do?
- Primarily regulates osmolarity, it responds to increased plasma osmolarity
- It also responds to low blood volume states
90
How does ADH produce its actions?
- Increases aquaporin insertion in the principal cells of the collecting duct
- Increases H2O reabsorption
91
Type I Diabetes
- Autoimmune destruction of beta cells
- Insulin is always necessary
- Patients usually diagnosed before age 30
- Not associated with obesity
- Genetic predisposition is 50% (weak)
- Associated with HLA-DR3 and DR4
- Glucose intolerance is severe
- Insulin sensitivity is high
- Ketoacidosis is common
- Beta cell numbers in the islets are decreased
- Serum insulin level is low
- Polyuria, polydipsia, polyphagia and weight loss are common
- Histology shows islet Leukocytic infiltrate
92
How do you differentiate between diabetes insipidus and psychogenic polydipsia?
- In DI the urine can not be concentrated during the water deprivation test
- In psychogenic polydipsia the urine becomes concentrated during the water deprivation test
93
Type II Diabetes
- Increased insulin resistance leads to progressive pancreatic Beta-cell failure
- Insulin may be required
- Patients are usually diagnosed after age 40
- Associated with obesity
- Genetic predisposition is >90% (strong)
- Not associated with HLA
- Glucose intolerance is mild to moderate
- Insulin sensitivity is low
- Ketoacidosis is rare
- Beta cell numbers in islets are variable with amyloid deposits
- Serum insulin levels are variable
- Sometimes presents with classic polydipsia, polyuria, polyphagia and weight loss
- Histology shows islet amyloid polypeptide (IAPP) deposits
94
What are the acute manifestations of diabetes?
- Polydipsia, polyuria, polyphagia, weight loss
- DKA in type I
- Hyperosmolar hyperglycemia in type II
95
What are the chronic complications of diabetes?
1. Due to nonenzymatic glycation:
- Small vessel disease (thickening of the basmement membrane) leads to retinopathy (hemorrhage, exudates, microaneurysms, vessel proliferation), glaucoma, neuropathy, nephropathy (nodular glomerulosclerosis aka Kimmelstiel-Wilson nodules) leads to progressive proteinuria and arteriosclerosis which leads to hypertension and chronic renal failure
- Large vessel atherosclerosis, CAD, peripheral vascular occlusive disease, gangrene can lead to limb loss, cerebral vascular disease andf MI is most common cause of death.
2. Due to osmotic damage (sorbitol accumulation in organs with aldose reductase and decreased or absent sorbitol dehydrogenase)
- Neuropathy (motor, sensory and autonomic degeneration)
- Cataracts
96
How do cells convert glucose to sorbitol?
How do cells convert sorbitol to fructose?
Which cells have both enzymes?
Which cells have only aldose reductase?
1. Aldose reductase
- NADPH => NADP+
2. Sorbitol Dehydrogenase
- NAD+ => NADH
3. Liver, ovaries and seminal vesicles
4. Lens, Retina, Kidneys and Schwann cells
97
In diabetics, insulin deficiency or insensitivity leads to what three main metabolic complications?
1. Decreased serum glucose uptake
- Leads to hyperglycemia, glycosuria, osmotic diuresis, electrolyte depletion
- Leads to dehydration, +/- acidosis
- Can lead to coma, death
2. Increased protein catabolism
- Leads to increased plasma amino acids, nitrogen loss in urine
- Leads to hyperglycemia, glycosuria, osmotic diuresis, electrolyte depletion
- Leads to dehydration, +/- acidosis
- Can lead to coma, death
3. Increased lipolysis, with insulin deficiency only
- Leads to increased plasma FFA, ketogenesis, ketonuria and ketonemia
- Leads to dehydration, +/- acidosis
- Can lead to coma, death
98
How do you diagnose diabetes?
- HbA1c > 6.5
- Fasting plasma glucose > 126 mg/dl
- 2 hr glucose tolerance test > 200 mg/dL
99
What are the signs and symptoms of diabetic ketoacidosis?
- Delirium/psychosis
- Kussmaul respirations (rapid/deep breathing)
- Abdominal pain, nausea or vomiting
- Dehydration
- Fruity odor breath (due to exhaled acetone)
100
What are the lab findings for DKA?
- Hyperglycemia
- Increased H+, decreased HCO3- (anion gap metabolic acidosis)
- Increased blood ketones
- Leukocytosis
- Hyperkalemia but depleted intracellular K+ from decreased insulin and acidosis
101
How do you treat DKA?
- IV fluids
- IV insulin
- K+ to replace intracellular stores
- Glucose may be necessary to prevent hypoglycemia
102
What is hyperosmolar hyperglycemic state?
Profound hyperglycemia-induced dehydration and increased serum osmolality
- Classically seen in the elderly of type II diabetes with limited ability to drink
- Thirst, polyuria, lethargy, focal neurological deficits (seizures) and can progress to coma or even death
- Labs show hyperglycemia over 600 mg/dL, increased serum osmolality ( > 320 mOsm/kg), pH usually greater than 7.3 ( no acidosis)
- Treat with IV fluids and insulin
103
What is a glucagonoma?
- Tumor of alpha pancreatic cells
- Overproduction of glucagon
- Presents with dermatitis (necrolytic migratory erythema), diabetes (hyperglycemia), DVT, declining weight, depression.
- Treat with octreotide (inhibits glucagon, insulin, gastrin, cholecystokinin, secretin, pancreatic polypeptide, VIP and 5-Ht3) and surgery
104
What is an insulinoma?
- Tumor of beta cells
- Overproduction of insulin
- Hypoglycemia
- Whipple triad: low blood glucose, symptoms of hypoglycemia (lethargy, syncope, diplopia) and resolution of symptoms after normalization of glucose levels
- Labs show decreased blood glucose and increased C peptide
- 10% associated with MEN type 1
105
What is carcinoid syndrome?
- Syndrome caused by carcinoid tumors
- Most common malignancy in small bowel
- Made of neuroendocrine cells
- Metastatic small bowel tumors that secrete high levels of serotonin (5HT)
- Symptoms include: recurrent diarrhea, cutaneous flushing, asthmatic wheezing, right sided valvular heart disease (tricuspid regurgitation or pulmonic stenosis)
- Increased 5-hydroxyindoleacetic acid in urine
- Niacin deficiency (pellagra)
- Treat with surgery and a somatostatin analogue (octreotide)
Rule of 1/3
- 1/3 metastasize
- 1/3 present with 2nd malignancy
- 1/3 are multiple
106
What is a somatostatinoma?
Tumor of pancreatic delta cells
- Overproduction of somatostatin
- Leads to decreased secretin, cholecystokinin, glucagon, insulin, gastrin and gastric inhibitory peptide (GIP)
- May present with diabetes/glucose intolerance, steatorrhea, gallstones, achlorhydra (decreased HCL)
- Treat surgically then somatostatin analogs for symptom control (octreotide)
107
Insulin lispro, aspart and glulisine
- Rapid acting
- Onset is 10-15 min
- Peaks at 1-1.5 hrs
- Lasts 3-5 hrs
- Usually for post prandial control
108
Regular insulin
- Short acting
- Onset is 30-45 minutes
- Peaks at 2-3 hrs
- Lasts 6.5 hrs
- Used for hyperkalemia and stress hyperglycemia
109
Insulin NPH
- Intermediate acting
- Onset is 1-3 hrs
- Peaks at 5-8 hrs
- Lasts 14-18 hrs
110
Insulin detemir and glargine
- Long acting
- Onset is 1-2 hrs
- Does not peak
- Lasts 22-24 hrs
- Used for basal glucose control
111
Canagliflozin
Dapagliflozin
Empagliflozin
Sodium-glucose co-transporter 2 inhibitors (SGLT2)
- Block reabsorption of glucose in PCT leading to its excretion in the urine
- Side effects: glucosuria, UTI's, vaginal yeast infections, hyperkalemia, dehydration. weight loss
112
Linagliptin
Saxagliptin
Sitagliptin
Dipeptidyl Peptidase-4 inhibitors (DPP-4)
- Inhibit DPP-4 enzyme that normally deactivates glucagon like peptide-1 (GLP- 1)
- Thereby increases glucose-dependent insulin release, decreases glucagon release, decreases gastric emptying and increases satiety.
- Side effects: Mild urinary and respiratory infections
113
Exenatide
| Liraglutide
Glucagon like peptide-1 analogs (GLP-1)
- Increase glucose dependent insulin release, decreases glucagon release, decreases gastric emptying and increases satiety
- Side effects: Nausea, vomiting, pancreatitis; modest weight loss effects
114
Chlorpropamide, tolbutamide
| Glimeperide, glipizide, glyburide
Sulfonylureas
- First generation
- Second generation
- Stimulate release of endogenous insulin in type 2 DM, require some islet function (not for type I)
- Close K+ channel in beta cell membrane, the cell depolarizes and insulin is released via Ca2+ influx
- Side effects: Hypoglycemia in patients with renal failure, weight gain, first generation have a disulfram like effect
115
Pioglitazone
| Rosiglitazone
Glitazones/Thiazolidinediones
- Increase insulin sensitivity in peripheral tissues
- Bind PPAR-gamma nuclear transcription regulator
- PPAR regulates fatty acid and glucose metabolism
- Increases levels of adiponectin
- Side effects: Weight gain, edema, HF, increased risk of fractures
- Can be used as monotherapy in type 2 DM or combined with others
- Safe to use in renal failure
116
Nateglinide
| Repaglinide
Meglitinides
- Stimulates postprandial insulin release by binding to K+ channels on beta cell membranes (different site than sulfonylureas)
- Side effects: Hypoglycemia (increased risk with renal failure) and weight gain
117
What is acromegaly?
Excess GH
| - Usually caused by pituitary adenoma
118
What are the findings in acromegaly?
- Increased GH in children leads to increased linear bone growth (gigantism)
- Large tongue with deep furrows, deep voice, large hands and feet
- Coarsening of facial features with aging
- Frontal bossing (protruding of head)
- Diaphoresis (excessive sweating)
- Impaired glucose tolerance (insulin resistance)
- Increased risk of colorectal polyps and cancer
- HF is most common cause of death
119
How is acromegaly diagnosed?
- Increased serum IGF-1 (Insulin-like growth factor or somatomedin C)
- Failure to suppress GH following oral glucose tolerance test
- Pituitary mass seen on brain MRI
120
How is acromegaly treated?
- Pituitary adenoma resection
- If not cured, treat with octreotide (somatostatin analog) or Pegvisomant (GH receptor antagonist)
- Can also treat with dopamine agonist (Cabergoline)
121
Octreotide
- Long acting somatostatin analogue
- Inhibits action of many splanchnic vasoconstriction hormones
- Used for acute esophageal varices, acromegaly, carcinoid syndrome, Gastrinoma, glucagonoma, VIPoma
122
What is Zollinger-Ellison syndrome?
- Gastrin secreting tumor (Gastrinoma) of pancreas or duodenum
- Acid hypersecretion leads to ulcers in duodenum and jejunum
- Presents with abdominal pain, diarrhea
- Positive secretin stimulation test: gastrin levels remain elevated after administration of secretin which normally inhibits gastrin release
- May be associated with MEN 1
123
Glucose 6 Phosphate Dehydrogenase Deficiency
X-linked recessive disorder
The most common human enzyme deficiency
- More prevalent among African Americans
- Increases malarial resistance
- Decreased NADPH
- NADPH is necessary to keep glutathione reduced
- Glutathione detoxifies free radicals and peroxides
- Decreased NADPH in RBCs leads to hemolytic anemia due to poor RBCs defense against oxidizing agents
- Oxidizing agents include fava beans, sulfonamides, primaquine, antituberculosis drugs.
- Infections are most common cause to precipitate hemolysis because inflammatory response produces free radicals that diffuse into RBCs causing oxidative damage
-Heinz bodies, due to denatured Hemoglobin that precipitates within RBCs due to oxidative stress
- Bite cells, results from phagocytic removal of Heinz bodies by splenic macrophages
124
Trimethoprim
- Inhibits bacterial dyhydrofolate reductase
- Stops dihydrofolic acid from turning into tetrahydrofolic acid
- Bacteriostatic
- Used in combination with sulfonamides
- Trimethoprim-Sulfamethoxazole
- Together causes sequential block of folate synthesis
- Combo treats UTIs, Shigella, Salmonella
- Pneumocystis jirovecci pneumonia treatment and prophylaxis
- Toxoplasmosis prophylaxis
- Side effects: Megaloblastic anemia, leukopenia, granulocytopenia
- Side effects may alleviate with folic acid
125
Sulfonamides
Sulfamethoxazole, sulfisoxazole, sulfadiazine
- Inhibits folate synthesis
- Para amino benzoic acid (PABA) antimetabolites inhibit dyhydropteroate synthase .
- Bacteriostatic (bactericidal when combined with trimethoprim)
- Dapsone used to treat Lepromatous leprosy is closely related and inhibits folate synthesis
- Treats gram positives, gram negatives,
- Nocardia, Chlamydia
- UTI
- Causes hypersensitivity reactions
- Hemlysis if G6PD deficiency
- Nephrotoxocity ( tubuleinterstitial nephritis)
- Photosensitivity, kernicterus in infants, displaces other drugs from albumin (warfarin)
- Resistance occurs with altered enzyme of bacterial dyhydropteroate synthase, decreased uptake or increased PABA synthesis
126
Type IV Hypersensitivity
- Delayed hypersensitivity (takes 48-72 hrs)
- T cell mediated (CD 4 and CD 8)
- T cells encounter antigen and then release cytokines
- Leads to macrophage activation
- No antibodies involved
Examples
- Transplant rejections
- TB test
- Contact dermatitis (Poison IV, Nickle, etc.)
- Diabetes type I
- Multiple sclerosis
- Rheumatoid arthritis
127
Type III Hypersensitivity
- Mediated by immune complexes
- Antibodies bind to soluble antigens (not bound on cells)
- Antigen-antibody complexes float in the blood longer and deposit in blood vessel walls
- Lead to inflammation and tissue damage
- Leads to basement membrane leakage, edema and vasculitis
- Large amounts of complement are activated and used up (Especially C3 and C4)
- Glomerulonephritis
- Rheumatoid Arthritis
- Systemic Lupus Erythematosus: In lupus IgG is directed to DNA
- Serum sickness: Antibodies against antivenom antibodies that were created after a person got bit by a snake and was treated twice with antivenom, leads to vasculitis and cycle repeat
128
Type II Hypersensitivity
- Cytotoxic (antibody mediated)
- IgM, IgG bind to a fixed antigen on enemy cell and lead to cellular destruction
1. Opsonization and phagocytosis
2. Complement and Fc- receptor mediated inflammation
3. Antibody mediated cellular dysfunction
- Direct and Indirect coombs test
MAC attack kills cell
129
Hemochromatosis leads to which cardiomyopathy?
- Restrictive cardiomyopathy is classic
| - Dilated cardiomyopathy is reversible
130
Hemochromatosis
- Autosomal Recessive
- Mutation in HFE gene
- C282Y > H63D, chromosome 6, associated with HLA-A3
- Leads to abnormal iron sensing, increased intestinal absorption
- Increased ferritin, increased iron, decreased TIBC lead to increased transferrin saturation
- Iron overload can also be secondary to chronic transfusion therapy such as Beta-thalassemia major
- Iron accumulates in liver, pancreas, skin, heart, pituitary, joints
- Hemosiderin (iron) can be identified on MRI or biopsy with Prussian blue stain
- Disease presents after age 40 when total body iron is > 20 g
- Iron loss through menstruation slows progression in women
- Classic triad of cirrhosis, diabetes mellitus and skin pigmentation.
- Causes restrictive cardiomyopathy (classic) or dilated cardiomyopathy (reversible)
- Hypogonadism
- Arthropathy due to calcium pyrophosphate deposition, especially metacarpophalangeal joints
- Hepatocellular Carcinoma is most common cause of death
- Treatment: repeated phlebotomy, chelation with deferasirox, deferoxamine, oral deferiprone
131
Chrons Disease
Location
- Inflammatory bowel disease that causes patchy inflammation throughout the GI tract with skip lesions of normal bowel
- Usually in the ileum and colon, skips the rectum
Gross Morphology
- Transmural inflammation (all layers)
- May lead to fistulas
- Cobblestone mucosa, creeping fat, bowell wall thockening (string sign), linear ulcers and fissures.
Microscopy
- Noncaseating granulomas and lymphoid aggregates (Th1 mediated)
Complications
- Malabsorption, malnutrition, colorectal cancer
Fistulas, phlegmon/abcess, strictures leading to obstruction and perinanal disease
Manifestations
- Diarrhea may be bloody or not
- Rash (pyoderma gangrenosum, erythema nodosum)
- Eye inflammation (episcleritis, uveitis)
- Oral ulcers (aphthous stomatitis)
- Arthritis (peripheral, spondylitis)
- Kidney stones (calcium oxalate)
- Gallstones
- May show + ASCA
Treatment
- Corticosteroids
- Azathioprine
- Antibiotics (ciprofloxacin, metronidazole)
- Infliximab
- Adalimumab
132
Ulcerative Colitis
```
Location
- Colon inflammation
- Continuous lesions always with rectal involvement
Morphology
- Mucosa and submucosa only
- Friable mucosa with superfiial or deep ulcerations
- Loss of haustra "lead pipe appearance"
Microscopy
- Crypt abscesses and ulcers, bleeding, no granulomas (Th2 mediated)
Complications
- Malabsorption, malnutrition, increased risk of colorectal cancer
- Fulminant colitis
- Toxic megacolon
- Perforation
Manifestations
- Bloody diarrhea
- Rash
- Eye inflammation
- Oral ulcerations
- Arthritis
- Primary Sclerosing cholangitis
- PANCA
Treatment
- 5-aminosalicylic preparations (mesalamine)
- 6-mercaptopurine
- Infliximab
- Colectomy
```
133
Primary Sclerosing Cholangitis
Unknown cause of onion skinning of the bile duct or fibrosis
- Alternating strictures and dilation with beading of intra and extrahepatic bile ducts on ERCP, MRCP
- Usually in middle aged men with IBD
- Associated with ulcerative cholitis
- p-ANCA +
- Increased IgM
- Can lead to secondary biliary cholangitis
- Increases risk of cholangiocarcinoma and gall bladder cancer
134
What is found on biopsy for whipple disease?
- PAS +
| - Foamy macrophages in intestinal lamina propia or mesenteric nodes
135
Whipple disease?
- Tropherma Whipplei
- Cardiac symptoms, arthralgias and neurologic symptoms are common
- Most often occurs in older men
136
Where are B cells located in lymph nodes?
- In the outer cortex in follicles
- Primary follicles are dense and dormant
- Secondary follicles have pale germinal centers and are active
137
Where lymphocytes and plasma cells located in the lymph nodes?
- In the medulla in medullary cords
| - Connect with medullary sinuses where reticular cells and macrophages are located
138
Where do you find T cells in the lymph nodes?
- In the Paracortex
- Between the follicles and the medulla
- Contain high endothelial venules through which T and B cells enter the blood
- Paracortex enlarges with viral infections
139
Spleen
- White pulp contains WBCs ( B cells and T cells)
- T cells are in the periarteriolar lymphatic sheath
- B cells are in the follicles
- Red pulp contains RBCs
- Protected by the 9th-11th ribs
140
Splenic dysfunction in sickle cell disease or splenectomy leads to what?
- Decreased IgM
- Decreased compliment activation
- Decreased C3b opsonization
- Increased susceptibility to encapsulated organisms
141
Postsplenectomy findings?
- Howell-jolly bodies (nuclear remnants)
- Target cells (Mexican Hat)
- Thrombocytosis (loss of sequestration and removal)
- Lymphocytosis (loss of sequestration)
142
Hyper IgM Syndrome
- Defect?
- How does it present?
- What are the findings?
- Defective CD40L on Th cells causes class switching defect
- X-linked recessive (increased in boys)
- Presents as severe pyogenic infections early in life, opportunistic infection with Pneumocystis, Cryptosporidium and CMV
- Labs show normal or increased IgM,
- Decreased IgG, IgA and IgE
- Failure to make germinal centers
143
Bruton agammaglobulinemia
- Defect
- How does it present?
- Findings?
- X-linked recessive ( increased in boys)
- Defect in BTK (tyrosine kinase gene) leads to no B cell maturation
- Recurrent bacterial and enteroviral infections after 6 months (once maternal IgG decreases)
Findings are absent peripheral B cells in peripheral blood
- Decreased Ig of all classes
- Absent or scanty lymph nodes and tonsils
- Live vaccines are contraindicated (MMR, Varicella, Rotavirus, Flu (mist), Yellow fever, Adenovirus, Typhoid, BCG, old polio (sabin)
144
Pagets Disease of the Bone or Osteitis Deformans
- Common localized disorder of bone remodeling
- Increased osteoblastic activity followed by increased osteoclastic activity
- Forms poor quality boone
- Serum Ca2+, phosphorus and PTH normal
- Increased alkaline phosphatase
- Mosaic pattern of woven and lamellar bone (osteocytes within lacunae in chaotic juxtapositions)
- Long bone chalk-stick fractures
- Increased blood flow form arteriovenous shunts may cause high output HF
- Increased risk of osteogenic sarcoma
145
What are the findings in pagets disease of bone?
What are the stages?
How is it treated?
- Hat size can be increased due to skull thickening
- Hearing loss is common due to auditory foramen narrowing
- Lytic stage: osteoclast predominance
- Mixed - Osteoclast + osteoblast proliferation
- Sclerotic - osteoblast predominance
- Quietscent - minimal osteoclast/osteoblast activity
- Treated with bisphosphonates
146
Bisphosphonates
- Medications
- MOA
- Uses
- Side effects
- Alendronate, ibandronate, risedronate and zoledronate
- Pyrophosphate analogs, bind hydroxyapatite in bone and inhibit osteoclast activity
- Used in osteoporosis, hypercalcemia, paget disease of bone, metastatic bone disease and osteogenesis imperfecta
- Side effects: Esophagitis, osteonecrosis of jaw and atypical stress fractures
147
What is the treatment for a healthcare worker that has a needlestick from a hepatits infected patient?
- Hepatitis B vaccines if they have not received it
| - Hepatitis B IVIG
148
What is the treatment for Influenza virus?
- Oseltamivir (Tamiflu)
| - Treat supportively
149
Influenza Virus (Orthomyxovirus)
- Enveloped
- Negative sense, single stranded RNA
- 8 segment genome
- Contains hemagglutinin which binds sialic acid and promotes viral entry
- Also contains neuraminidase antigens which promotes progeny virion release
- Patients are at risk for fatal bacterial superinfection from S. aureus, S. pneumoniae and H. influenzae
150
What is genetic/antigenic shift?
- Causes pandemics
- Reassortment of genome segments
- When human flu A reasserts with swine flu A
- More deadly
151
What is genetic/antigenic drift?
- Causes epidemics
- Minor changes based on random mutation in hemagglutinin or neuraminidase
- Less deadly
152
Macrolides
MOA
- Inhibit protein synthesis by blocking translocation
- Binds 23S rRNA of the 50S ribosomal subunit
- Bacteriostatic
Uses
- Atypical pneumonias (Mycoplasma, Chlamydia and Legionella)
- STIs (Chlamydia)
- Gram + cocci (Strep for those allergic tp PCN)
- Bordatella pertussis
Side effects (MACRO)
- Motility GI issues
- Arrhythmia caused by prolonged QT interval
- Cholestatic hepatitis (acute)
- Rash
- eosinophilia
- Increases concentration of WEPT (Inhibit cytochrome P450)
153
What is an aneurysm?
Abnormal dilation of an artery due to weakening of vessel wall
154
Saccular (berry) aneurysm
- Occurs at bifurcations in the circle of Willis
- Most commonly in the anterior communicating artery and the anterior cerebral artery
- Associated with Autosomal dominant polycystic kidney disease or Ehlers-Danlos syndrome
- Other risk factors are advanced age, hypertension, smoking and African-American race
- Usually clinically silent until rupture that leads to a subarachnoid hemorrhage
- Presents as worst headache of my life or thunderclap headache and leads to focal neurological deficits or can cause symptoms by compression of surrounding structures
155
Anterior communicating artery aneurysm?
- A saccular berry aneurysm
- Usually causes compression of the optic chiasm
- Leads to bitemporal hemianopia; visual acuity deficits
- Then it ruptures
- Leads to ischemia in the anterior cerebral artery distribution
- That causes contralateral lower extremity hemiparesis and sensory deficits
156
Middle cerebral artery aneurysm?
- A saccular berry aneurysm
- Usually ruptures
- Leads to ischemia in the middle cerebral artery distribution
- Causes contralateral upper extremity and facial hemiparesis and sensory deficits
157
Posterior communicating artery aneurysm?
- A saccular berry aneurysm
- Usually compresses
- Causes ipsilateral CN III palsy
- Midriasis (blown dilated pupil)
- May also see ptosis, down and out eye
158
Autosomal Dominant Polycystic Kidney Disease
- Numerous cysts I'm cortex and medulla cause bilateral enlarging of kidneys that ultimately destroy the parenchyma
- Presents with flank pain, hematuria, hypertension, urinary infection and progressive renal failure in 50%
- Mutation in PKD1 on chromosome 16 (85%) or PKD2 on chromosome 4 (15%)
- Death associated with berry aneurysms, mitral valve prolapse, benign hepatic cysts and diverticulosis
- Treat with ACE inhibitors or ARBs
159
Upper Motor Neuron Lesion
- Destruction of motor cortex or connection between motor cortex and facial nucleus in the pons
- Leads to contralateral paralysis of lower muscles of facial expression
- The forehead is spared due to its bilateral UMN innervation
160
Lower motor neuron lesion
Destruction of facial nucleus or CN VII anywhere along its course
- Leads to ipsilateral paralysis of upper and lower muscles of facial expression
- Hyperacusis and loss of taste sensation in the anterior 2/3 of tongue
161
Bells Palsy
- Most common facial nerve palsy
- Lower motor neuron lesion
- Ipsilateral paralysis of upper and lower muscles of facial expression
- Caused by lyme disease, herpes simplex, herpes zoster, sarcoidosis, tumors (parotid gland) or diabetes
- Treat with corticosteroids, acyclovir
- Most patients gradually recover function
162
Glioblastoma multiforme (Grade IV astrocytoma)
- Common, highly malignant primary brain tumor
- Has 1 year median survival
- Found in the cerebral hemispheres
- It can cross the corpus callosum and from a "butterfly glioma"
- Tumor is of astrocyte origin and GFAP +
- Pseudopalisading pleomorphic tumor cells that border central areas of necrosis and hemorrhage
163
What is the treatment for chlamydia?
- Azithromycin
164
What is the treatment for gonorrhea?
- Ceftriaxone and Azithromycin to cover for chlamydia co-infection
165
What causes CN III damage?
Motor output of extraocular muscles
- Affected by vascular disease such as diabetes (glucose => sorbitol) due to decreased diffusion of oxygen and nutrients to the interior fibers from compromised vasculature that resides on the outside of the nerve
- Leads to ptosis (down and out gaze) due to SO (CN IV) and LR (CN VI) unopposition
Parasympathethic output
- Fibers on periphery are first affected by compression
- Can be from PCom aneurysm or uncal herniation
- Laads to diminished or absent pupillary light reflex, there is a blown pupil often with down and out gaze
166
Trichomoniasis
- Cause
- Findings
- Treatment
- Caused by trachomonas vaginalis
- A gram variable bacterium associated with bacterial vaginosis
- Leads to foul smelling, greenish discharge, itching and burning
- Transmitted via sexual contact
- Can not survive outside of the body because it cannot form cysts
- Mobile trophozoites seen on wet mount
- May cause strawberry cervix, inflamed, red
- Treat with metronidazole, must treat partner as well
167
Celiac Disease
- Autoimmune-mediated intolerance of gliadin (the gluten protein found in wheat)
- Leads to malabsorption and steatorrhea
- Findings are anti-endomysial, anti-tissue transglutaminase and anti-gliadin antibodies
- Blunting of villi and lymphocytes in the lamina propia
- There is moderate increased risk of T cell lymphoma
- Decreased mucosal absorption affects the distal duodenum and proximal jejunum
- Treat with gluten free diet
168
Acute post streptococcal glomerulonephritis
Most frequently seen in children
- Occurs 2 weeks after group A streptococcal infection of pharynx or skin
- Presents with peripheral and periorbital edema, cola colored urine and hypertension
- Can check ASO titers to see if they had recent infection
- Resolves spontaneously
- Light microscopy: glomeruli enlarged
169
Basal Cell Carcinoma
- Most common skin cancer
- Sun exposed areas of the body
- Locally invasive but rarely metastasizes
- Pink pearly nodules commonly associated with telangiectasias, rolled borders, central crusting or ulceration
- Can also appear as nonhealing ulcers with infiltrating growth or as a scaly plaque
- Have palisading nuclei
170
Squamous cell carcinoma
- Second most common skin cancer
- Due to excessive exposure to sunlight
- Appears on face, lower lips and ears and hands
- Locally invasive, may spread to the lymph nodes and will rarely metastasize
- Ulcerative red lesions with frequent scale
- Associated with chronic draining sinuses
- Histology shows keratin pearls
171
What is actinic keratosis?
A scaly plaque that can lead to squamous cell carcinoma
172
Squamous cell carcinoma of the lung?
- Central (Hilar mass arising from bronchus)
| - Cavitation, Cigarretes and Hypercalcemia (PTHrP)
173
Adenocarcinoma
- Peripheral
- Most common in non smokers and overall
- Mutations include KRAS, EGFR and ALK
- Associated with hypertrophic osteoarthropathy
- It is a Bronchioalveolar subtype (adenocarcinoma in situ)
- CXR shows hazy infiltrates similar to pneumonia which indicates better prognosis
- Bronchial carcinoid and Bronchioalveolar cell carcinoma have lesser association with smoking
- Histology shows glandular pattern and stains mucin +
- Bronchioalveolar subtype grows along alveolar septum, apparent thickening of alveolar walls , tall columnar cells containing mucus
174
Small cell carcinoma
- Central
- Undifferentiated, very aggressive
- May produce ACTH (Cushing syndrome), SIADH or Antibodies against presynaptic Ca2+ channels (Lambert Eaton-Myasthenic Syndrome) or neurons (paraneoplastic myelitis, encephalitis, Subacute cerebellar degeneration)
- Amplificvation of MYC oncogenes is common
- Managed with chemo and radiation
- Histology shows neoplasm of neuroendocrine Kulchitsky cells (small dark blue cells), Chromogranin A + and neuron specific enolase +
175
What is carcinoid syndrome?
Flushing, diarrhea and wheezing
- Due to increased Serotonin
- Can be caused by bronchial carcinoid tumor
176
Most common causes of lobar pneumonia?
| Characteristics?
- S. pneumoniae
- Legionella
Characteristics
- Intraalveolar exudate leads to consolidation
- May involve the entire lobe or lung
177
Most common causes of bronchopneumonia?
- S. pneumoniae, S. aureus, H. influenzae, Klebsiella
- Acute inflammatory infiltrates from bronchioles into adjacent alveoli
- Patchy
178
Microcytic Anemia
MCV <80
- Iron Deficiency
- Anemia of chronic disease
- Alpha and Beta Thalassemia
- Sideroblastic anemia
179
Macrocytic Anemia
MCV > 100
1. Megaloblastic
- Folate deficiency B9
- Cobalamine deficiency B12
2. Nonmegaloblastic
- Liver disease
- Alcoholism
- Reticulocytosis
- Drugs
180
Normocytic Anemias
```
Nonhemolytic
- Blood loss < 1 week
- Early stage iron deficiency
- Early stage anemia of chronic disease
- Aplastic Anemia
- Renal disease
- Malignancy
Hemolytic
1. Intrinsic RBC defect
- Membrane defects
>Hereditary spherocytosis
>Hereditary eliptocytosis
>Paroxysmal nocturnal hemoglobinuria
2. Abnormal hemoglobin
>Sickle cell disease
3. Deficienct Enzymes
- G6PD deficiency
- Pyruvate kinase deficiency
2 Extrinsic RBC defect
- Blood loss > 1 week
- Immune hemolytic anemias
- Micro/macroangiopathic hemolytic anemia
- Malaria
```
181
HLA B27 is associated with?
Spondyloarthropathies
182
Antiphospholipid Syndrome?
- Primary or Secondary autoimmune disorder (most commonly due to SLE)
- Anticardiolipin antibodies
- Anti-beta2 glycoprotein antibodies
- Lupus anticoagulant
- Patients usually have history of thrombosis (venous or arterial) or spontaneous abortion
- Treat with anticoagulation
183
SLE presents as?
- Rash, joint pain and fever
- Most common in a female of reproductive age and of African decent
- Lupus nephritis (type III hypersensitivity)
- Can be nephritic or nephrotic
184
What are the lab findings in lupus?
- Antinuclear antibodies (ANA) (sensitive, not specific)
- Anti-dsDNA (Specific, poor prognosis (renal disease)
- ANti-smith (Specific, not prognostic)
- Antihistone (sensitive for drug induced lupus)
- Decreased C3, C4 and CH50 due to immune complex formation
185
How is lupus treated?
NSAIDS
- Steroids
- Immunosuppressants
- Hydroxychloroquine (inhibits rheumatoid factor and acute phase reactants)
186
Lepromatous mycobacterium elicits which response?
Humoral TH2 response (CD4+ T Cells)
| - IL-4, IL-5, IL-6, IL-10 and IL-13
187
Tuberculoid mycobacterium elicits which response?
Cell mediated TH1 response (CD8+ T cells)
| - IL- 2, IFN-gamma and TNF-alpha
STEP
flashcards
Decks in class (28)
# Cards
-
Musculoskeletal10
-
Pediatrics21
-
Vitamins, Minerals and Trace Elements49
-
Amino Acids36
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Drug Abuse9
-
UWORLD Review30
-
Emergency Medicine42
-
Behavioral Health59
-
Infectious Disease134
-
Hematology59
-
Dermatology21
-
Neurology92
-
Gynecology28
-
Gastrointestinal137
-
Genetics/Embryology23
-
Immunology145
-
Opthalmology54
-
General Principles29
-
Urology/Nephrology201
-
Respiratory33
-
Endocrinology31
-
Cardiovascular120
-
Ear, Nose and Throat37
-
General Pharmacology16
-
Public Health5
-
Preventative Medicine1
-
Professional Exam Study Guide187
-
Metabolism Disorders11
