U17 Flashcards

Question

Damage to the Corticobulbar tract

Answer 1

(UMN) Unilateral lesions usually results in mild muscle weakness due to bilateral nature. Few exceptions: * Hypoglossal nerve – Lesion to UMN for CNXIII -\> spastic paralysis of contralateral genioglossus so deviation of tongue. * Facial Nerve – Lesion to UMN for CNVII -\> spastic paralysis of muscles in contralateral lower quadrant of the face.

Answer 2

* Originate in brianstem, carryig motor fibres to spinal cord * involuntary and automatic control of all musculature including muscle tone, balance, posture + locomotion * Damage - common in degenerative diseases, encephalitis, tumours. Various types dyskinesias or disorders of involuntary movement. * 4 tracts: vestibulospinal + reticulospinal (don’t decussate, ipsilateral innervation) and rubospinal + tectospinal (decussate, contralateral innervation).

Answer 3

* Medial/lateral pathways. Arise from vestibular nuclei (input from organs of balance) -\> spinal cord. Remains ipsilaterally. * Control balance and posture by innervating ‘anti-gravity’ muscles via LMN.

Answer 4

Medial reticulospinal tract – from pons. Vol movements, increases muscle tone. Ipsilateral innervation Lateral reticulospinal tract – from medulla. Inhibits vol movements, reduces muscle tone.

Answer 5

* Originates from red nucleus (midbrain structure). Fibres emerge and decussate and descend to spinal cord. Contralateral innervation * Thought to play role in fine control of hand movements.

Answer 6

* Begins at superior colliculus of midbrain (receives input from optic nerves). Neurons quickly decussate and enter spinal cord and terminate at cervical levels spinal cord. Contralateral innervation. * Coordinates movements of head in relation to vision stimuli.

Answer 7

* Located posterior to the cerebral aqueduct. * Houses 4 colliculi * Inferior to collicul, trochlear nerve emerges

Answer 8

Occulomotor nerve exits between peduncles

Answer 9

Optic tract

Answer 10

Midbrain - level of inferior colliculus

Answer 11

Midbrain - level of usperior colliculus

Answer 12

Basilar artery and branches

Answer 13

Group of nerves that function as connection between cerebrum adn cerebellum.

Answer 14

* CNV – trigeminal – from lateral aspect mid pons * CN VI – abducent – pontomedullary junction, close to midline * CN VII- facial – cerebellopontine angle (more lateral aspect pontomedullary junction) * CN VIII – vestibulocochlear – lateral to facial nerve

Answer 15

* Ventral pons - coordinate movement * Tegmentum. form spart of reticular ofmraiton which is responsible for arpusal and attentiveness. Damage may result in anosognosia for hemiplegia (patients unaware paralysis)

Answer 16

Responsible for pain and temp sensation

Answer 17

Fine touch, vibration, proprioception

Answer 18

Voluntary motor control of face, head, neck

Answer 19

Voluntary motor contorl of body

Answer 20

Main sensory nucleus (somatosensory from face) + trigeminal motor nucleus = in midpons at level where fibres originate form lateral aspect of pons. 2 nuclei that receive sensory from trigeminal nerve: Spinal trigeminal nucleus and mesencephalic nucleus

Answer 21

controls abducens nerve (innervates ipsilateral lateral rectus muscle). Located on caudal pons.

Answer 22

Facial nucleus more anterior + lateral at same level to abducens nucleus. Controls muscles facial expression and fibres unusually loop around abducens nucleus before exiting brainstem

Answer 23

– dorsolaterally from inferior pons to superior medulla.

Answer 24

Most pons – pontine arteries (branches of basilar artery), smaller part from anterior inferior cerebellar artery and superior cerebellar artery (AICA and SCA)

Answer 25

Often place of intracranial growths which can lead to impairment of nearby structures. Symptoms start with mild impairment of cranial nerve in area (CNVIII).

Answer 26

Vestibular schwannomas (Acoustic Neuromas) are the most common growth in the area (lead to cerebllpontine angle syndrome) . They are benign and complications are from compression of structures. Slow growing and related to progressive ipsilateral hearing loss. * Ipsilateral hearing loss and tinnitus – due to compression of cochlear component of CN VIII * Disequilibrium. And more rarely vertigo – due to compression of vestibular component of CN VIII * Nystagmus – due compression of cerebella flocculus **Untreated leads to compression:** * Facial paralysis – due to compression of CN VIII * Reduced corneal reflex – due to involvement of both CN V and CN VII * Trigeminal palsy – due to compression of CN V * Ipsilaterally cerebellar signs Surgical resection guarantees a very good outcome mostly. *

Answer 27

Abducens arises (between pons and medulla), hypoglossal nerve (out of ventrolateral sulcus), CNIX,X,XI join medulla in posterolateral sulcus

Answer 28

Medulla - decussation of pyramids

Answer 29

Medulla - decussation medial lemniscus

Answer 30

Medulla - level of olives

Answer 31

Midbrain die to inferior colliculu, cerebral aqueduct and micky mouse

Answer 32

Pons - fourth ventricle, corticospinal tracts

Answer 33

Medulla - pyramids

Answer 34

* Abducens - caudal pons * Trigeminal motor - mid pons * Facial motor - caudal pontine tegmentu

Answer 35

* Direct pathway becomes less active due to damage to dopaminergic neurons at substantia nigra * Projection of dopaminergic neurons increase activity of striatum.

Answer 36

* Damage to caudate nucleus (part of striatum). * Damage evident post-mortem and on imaging. * Indirect pathway does not function as it should

Answer 37

Midbrain (posterior side)

Answer 38

Midbrian pontien junction

Answer 39

Pontine medulla junction

Answer 40

Glossopharyngeal, vagus, accesory. Anterior to olive is hypoglossal

Answer 41

**Lumbosacral spinal cord lesion**: Weakness, wasting, fasciculation of muscles, areflexia of the lower limbs (LMN lesion), incontinence, sensory loss below level of lesion and ‘sensory’ ataxia.

Answer 42

**Thoracic spinal cord lesio**n: Spastic paraparesis, hyperreflexia, and extensor plantar responses (UMN lesion), incontinence, sensory loss below level of lesion and ‘sensory’ ataxia.

Answer 43

**Lower cervical spinal cord lesion:** Weakness, wasting, fasciculation of muscles, and areflexia of upper limn (LMN lesion) . In addition, there is spastic paraparesis, hyperreflexia and extensor plantar responses(UMN lesion) in lower limbs, incontinence, sensory loss below level lesion and ‘ sensory’ ataxia.

Answer 44

High cervical cord lesion causes spastic tetraplegia with hyperreflexia, extensor plantar responses (UMN lesion), incontinence, sensory loss below level of lesion and ‘sensory’ ataxia.

Answer 45

* **Unilateral brainstem lesion** = can be caused by stroke, tumour or multiple sclerosis. Causes ipsilateral cranial nerve dysfunction, contralateral spastic hemiparesis, hyperreflexia and an extensor plantar response (UMN lesion), contralateral hemisensory loss and ipsilateral incoordination * **Bilateral lesions** = destroys the ‘vital centres; that control breathing and the circulation, leading to coma and death. This usually follows a massive stroke of the brainstem and is the end result of raised intracranial pressure, due to a space occupying lesion, which displaces the cerebellar hemispheres down through the foramen magnum to compress the upper brainstem .

Answer 46

1. Focal epileptic seizures 2. Sensory/motor deficits 3. Psychological deficits eg, language, memory etc.

Answer 47

Mental impairment (eg, aphasia), a contralateral spastic hemiparesis, hyperreflexia and extensor plantar response (UMN) and contralateral hemisensory loss. Vascular insult to the internal capsule, such as infarction or haemorrhage, leads to the rapid development of this syndrome (stroke)

Answer 48

* Focal seizures 'simple motor or Jacksonian seizures' * Sensory/motor deficity - weakness of face and UMN signs in the imbs on the opp side to the lesion (contralateral hemiplegia) * Psychological deficit - speech produced with great effort and poor articulation, in brief utterancs with word errors (paraphasia). Repition of words is impaired but powers of comprehension are relatively preserved. Brocas aphasia. There is also ipairment of reading and writing. Degenerative disease of left frontal lobe results in progressive non-fuent aphasia to Brocas aphasia.

Answer 49

LEFT Parietal lobe lesions

Answer 50

* Focal seizures - paroxysmal attacks of sensory disturbance affecting the contralateral side of body (simple sensory seizures) * Sensory/mnotor deficit - contralateral hemisensory loss and an inferior visual field loss * Psychological - inability to copy and construct designs because of spatial disorientation (constructional apraxia)

Answer 51

* Focal seizures - unresponsiveness (absences), purposeless behaviour (automatism), olfactory and complex cisual and auditory hallucinations and disturbances of mood and memory. Complex partial seixures * Sensory/motor deficit - contralateral superior visual field loss * Psycholoigcal deficit - Speech that is fluence and rapud but cpntains word errors (paraphasia) and is incomprehensible. There is profound word finding difficulty, impaired repetition of words and prodound loss of comprehension. Wernickes apahasia.

Answer 52

Bilateral lesions of Medial temporal gyri:

Answer 53

Bilateral lesions of temporal neocortex

Answer 54

* Focal seizures – paroxysmal visual hallucinations of simple, informed nature, such as lights and colours (simple partial seizures) * Sensory/motor deficit – contralateral visual field loss (contralateral homonymous hemianopia)

Answer 55

Bilateral occipital lobe lesions lead to cortical blindness, of which the patient is unaware (Anton’s syndrome). this occurs following cerebral hypoxia.

Answer 56

CNIII - occulomotor

Answer 57

CN IV - trochlear nerve lesion

Answer 58

6th CN VI - abducens

Answer 59

Combined unilateral palsies of cranial nerve III, IV, VI

Answer 60

Multiple sclerosis

Answer 61

Herpes zoster infection of sensory roots of trigeminal nerve (shingles) leads to pain and eruption of vesicles localised to dermatome supplied by one or other of ophthalmic, maxillary and mandibular branches. In syringobulbia – central cavitation of medulla caudal to the fourth ventricle leads to preferential compressive destruction of decussating trigeminothalmic fibres, causing selective loss of pain and temperature sensibility (dissociated sensory loss) in the face.

Answer 62

**Facial nerve**

Answer 63

Acoustic Neuroma – benign tumour of CN VIII that leads to compression of nerve and adjacent structures in the cerebellopontine angle. Attacks of dizziness and profound deafness. With expansion of tumour, ataxia and paralysis of cranial nerves and all 4 limbs. Unilateral and bilateral acoustic neuromas occur in inherited disease neurofibromatosis, in which tumours of peripheral nerves and skin (neurilemmoma and neurofibroma) can cause cosmetic blemish and deformity.

Answer 64

Motor neurone disease

Answer 65

CN IX, X, XI, XII can be damage dby compression in their peripheral course as they exit the cranium via the foramina of the skull base. Tumours in this area lead to dysphonia and depression of the gag reflex, together with unilateral wasting of the sternomastoid and trapezius muscles (jugular foramen syndrome) and unilateral weakness, wasting and fasciculation fo the tongue.

Answer 66

The right medial medulla

Answer 67

Left medial midbrain

Answer 68

Left lateral medulla.

Answer 69

Right lateral pons

Answer 70

* Posterior column- medial lemniscal pathwaydorsal columns * Somatosensory pathways conveying modalities of conscious proprioception, vibrtion and discriminative touch

Answer 71

* Somatosensory pathway converying modalities of pain, temperature and crude touch * Deccusate at ventral white commissure.

Answer 72

Contralateral hemiplegia

Answer 73

Hemiparesis

Answer 74

This patient has had a stroke, causing a right or left hemiplegia (lesion), which can be the result of either a vascular event, such as thrombosis, embolism, or haemorrhage, or a neoplasm of the brain (aetiology). This patient is limited by hemiplegia and hemianopia (functional status).

Answer 75

A stroke is a serious life-threatening medical condition that happens when the blood supply to part of the brain is cut off. A hemorrhagic stroke occurs when a weakened blood vessel ruptures.

Answer 76

**STROKE:** * Face – the face may have dropped on 1 side, the person may not be able to smile, or their mouth or eye may have drooped. * Arms – the person may not be able to lift both arms and keep them there because of weakness or numbness in 1 arm. * Speech – their speech may be slurred or garbled, or the person may not be able to talk at all despite appearing to be awake; they may also have problems understanding what you're saying to them. * Time – it's time to dial 999 immediately if you notice any of these signs or symptoms. Other signs and symptoms: Complete paralysis of 1side of the body, sudden loss/blurring of vision, dizziness, confusion, difficulty understanding what others are saying, problems with balance + coordination, difficulty swallowing (dysphagia). Also sudden and very severe headache resulting in blinding pain unlike anything experienced before, loss of consciousness.

Answer 77

Stroke related to the carotid artery and its cerebral branches are associated with focal epilepsy, a contralateral sensory/motor deficit and a psychological deficit (eg, aphasa) Recovery of function can occur, but it may take up to 2years and can be incomplete. • The internal carotid artery terminates lateral to the optic chiasm, giving rise to the anterior and middle cerebral arteries. * The anterior cerebral artery passes into the great longitudinal fissure and supplies the medial aspect of the cerebral hemisphere. * The middle cerebral artery passes into the lateral fissure and supplies the lateral aspect of the cerebral hemisphere. * The principal terminal branch of the basilar artery is the posterior cerebral artery, which supplies the occipital lobe of the cerebral hemisphere.

Answer 78

Right: Occlusion of the posterior choroidal artery, producing necrosis in part of the thalamus. Left: Multiple hemorrhages within the brain secondary to head trauma.

Answer 79

Hemiplegia (sometimes called hemiparesis) is a condition, caused by a brain injury, that results in a varying degree of weakness, stiffness (spasticity) and lack of control in one side of the body.

Answer 80

Head computed tomography showing two epidural hematomas in a 23-yr-old involved in a motor vehicle accident. Note air bubbles that are a result of linear fracture in the left temporal bone EDH between the outer layer of the dura mater and the inner table of the skull. The middle meningeal artery supplies most of the dura mater and the bones of the cranial vault. It is this artery or vein that is usually ruptured in an epidural hemorrhage. * CT appearance: Variable white to gray on brain windows * Location: Peripheral to brain, temporal region * Shape: Biconvex disc or lens * White swirl sign means active bleeding * Significance: May cause mass effect and herniation * Look for midline shift * Surgery to remove the blood clot and stop the bleeding/Release the pressure by craniotomy The swirl sign refers to the non-contrast CT appearance of acute extravasation of blood into a haematoma. The most important treatment when a midline shift is present is relieving the pressure that is pushing the brain off-center. If a collection of blood is the cause, such as a subdural hematoma, surgery will be needed to remove the blood clot and stop the bleeding

Answer 81

Epidural hematoma on magnetic resonance image. Brain MRI: More sensitive. Indicated in situations in which there is a strong clinical suspicion but no evidence of EDH on head CT. Coronal T2-weighted images show hypointense biconvex extraaxial collection in the left temporal region. • Note : Lumbar puncture (LP) is contraindicated in EDH due to risk of brain stem herniation.

Answer 82

Chronic subdural haematoma. (arrows) . A large haematoma causing mass effect with ventricular shift to the opposite side visualized with MRI. The accumulated subdural blood typically has a crescent shape, as it can flow freely in the subdural space. Larger SDHs, or those causing neurological dysfunction, require surgical drainage; smaller, asymptomatic SDHs can sometimes be followed expectantly.

Answer 83

Uncal herniation occurs when a space-occupying lesion in the temporal lobe displaces the uncus medially, forcing the uncus into the opening of the tentorium cerebelli. In turn, this compresses the midbrain, interfering with the function of the oculomotor nerve and consciousness (effect on ascending reticular activating system).

Answer 84

A large subdural hematoma displaced the right cerebral hemisphere, causing uncal herniation. Note the distortion of the shape of the lateral ventricles, and that both lateral ventricles and the third ventricle are to the left of the midline. An infarct of the posterior cerebral artery occurred secondary to uncal herniation.

Answer 85

The history and signs point to a progressive left hemisphere lesion. With a head injury preceding the onset, the first diagnosis is SDH. These are commoner in patients on warfarin or aspirin. Alternative diagnosis is a tumour unrelated to the injury.

Answer 86

Reduced arm swing is a typical early symptom of PD. Stiffness may lead the condition to be mistaken for a rheumatological disorder. The other symptoms and signs are also typical. One-third of patients have no tremor at presentation. There are no diagnostic investigations, but a careful history and examination may help to exclude other, rarer Parkinsonian syndromes.

Answer 87

**Sagittal MRI**: Left: Normal – Label it yourself Right: Pituitary tumor. Sagittal T1 magnetic resonance imaging (MRI) with contrast. Pituitary tumors account for approximately 10% of all intracranial neoplasms. Most are benign and slow growing. Symptoms result from the mass pushing on surrounding structures or hormonal hyposecretion or hypersecretion. Symptoms include headaches, nausea and vomiting, irregular menses and lactation, and sexual dysfunction. In addition, the person may have high blood pressure, increased blood glucose level, acromegaly (growth hormone disorder that begins in adulthood, causing gigantism with enlargement of the head, hands, feet), or Cushing's disease (excessive ACTH, causing fatigue, hypertension, osteoporosis, and abnormal deposits of facial and trunk fat). Because the tumor may compress cranial nerve 3, 4, or 6, the person may experience double vision. Bitemporal hemianopia (loss of both temporal visual fields is common with larger pituitary lesions because the axons cross in the optic chiasm directly above the pituitary gland.

Answer 88

**Lower motor neurone syndrome** * Weakness (paresis) or paralysis (plegia) of individual muscles. * Wasting of muscles. * Visible spontaneous contractions of motor units (fasciculation). * Reduced resistance to passive stretching (hypotonia). * Diminution or loss of stretch (tendon) reflexes (hyporeflexia or areflexia). **Upper motor neurone syndrome** * Weakness of specific muscles (‘pyramidal weakness’). * No wasting of muscles. * Hyperreflexia. * Spasticity. * Positive Babinski (extensor plantar) response. * Absent abdominal reflexes.

U17 Flashcards

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