1
Q
Causes of peripheral neuropathy
A
DAM IT BICH
- Drugs and toxins: isoniazid, vincristine, phenytoin, nitrofurantoin, cisplatinum, amiodarone, heavy metals
- Alcohol
- Metabolic: diabetes mellitus, uraemia, hypothyroidism
- Immune-mediated: Guillain-Barre syndrome
- Tumour – lung carcinoma, multiple myeloma
- B- Vitamin B12 or B1 deficiency
- Infiltrative: amyloid
- Connective tissues disease – SLE, polyarteritis nodosa
- Hereditary
2
Q
Causes of a predominantly motor neuropathy
A
- Guillain-Barre syndrome and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP)
- Hereditary motor and sensory neuropathy (Charcot-Marie-Tooth disease)
- Acute intermittent porphyria
- Diabetes mellitus
- Lead poisoning
- Multifocal motor neuropathy
3
Q
Causes of predominantly sensory neuropathy
A
- Diabetes
- Carcinoma (e.g. lung, ovary, breast)
- Paraproteinaemia
- Sjogren’s syndrome
- Syphilis
- Vitamin B12 deficiency
- Vitamin B6 intoxication
4
Q
Causes of a painful peripheral neuropathy
A
- Diabetes mellitus
- Alcohol
- Vitamin B12 or B1 deficiency
- Carcinoma
5
Q
Causes of mononeuritis multiplex
A
ACUTE
Diabetes mellitus
Polyarteritis nodosa or connective tissue disease – SLE, rheumatoid arthritis
CHRONIC Multiple compressive neuropathies: especially with joint-deforming arthritis Sarcoidosis Acromegaly Carcinoma
6
Q
Signs of a radial nerve lesion
A
- Wrist and finger drop (wrist flexion normal)
- Triceps loss (elbow extension loss) if lesion is above the spiral groove
- Sensory loss over the anatomical snuff box
- Finger abduction appears to be weak because of the difficulty of spreading the fingers when they cannot be straightened
7
Q
Features of hereditary motor and sensory neuropathy
A
- Pes cavus (short, high-arched feet with hammer toes)
- Clawing of the toes
- Distal muscle atrophy owing to peripheral nerve degeneration, not usually extending above the elbows or above the middle one-third of the thighs
- Absent reflexes
- Downgoing plantars
- Slight to no sensory loss in the limbs
- Thickened nerves (lateral popilteal)
- Optic atrophy; Argyll Robertson pupils (rare)
- Small muscle wasting of the hand and clawing
- Scoliosis
- High stepping gait
8
Q
Features of a complete brachial plexus lesion
A
- Lower motor neurone signs affect the whole arm
- Sensory loss (whole limb)
- Horner’s syndrome
9
Q
Features of an upper brachial plexus lesion (Erb’s C5 C6)
A
- Loss of shoulder movement and elbow flexion – hand is held in the ‘waiter’s tip’ position
- Sensory loss is present over the lateral aspect of the arm and forearm, and over the thumb
10
Q
Features of a lower brachial plexus lesion (Klumpke’s C8 T1)
A
- True claw hand with paralysis of all the intrinsic muscles
- Sensory loss along the ulnar side of the hand and forearm
- Horner’s syndrome
11
Q
Features of cervical rib syndrome
A
- Weakness and wasting of the small muscles of the hand (true claw hand)
- Sensory loss over the medial aspect of the hand and forearm
- Unequal radial pulses and blood pressures
- Subclavian bruit and loss of pulse on arm manoeuvring
- Palpable cervical rib in the neck
12
Q
Signs of a medial nerve lesion
A
- THUMB ABDUCTION LOSS: Loss of abductor pollicis brevis with a lesion at or above the wrist: ask patient to abduct thumb vertically
- Sensory loss over the thumb, index, middle and lateral half of the ring finger (palmar aspect only)
13
Q
Causes of carpal tunnel syndrome
A
- Idiopathic
- Arthropathy – rheumatoid arthritis
- Endocrine disease – hypothyroidism, acromegaly
- Pregnancy
- Trauma and overuse
14
Q
Signs of an ulnar nerve lesion
A
- Wasting of the intrinsic muscles of the hand
- Weak finger abduction and adduction (loss of interosseous muscles)
- Ulnar claw-like hand (a higher lesion cause less deformity, as an above-the-elbow lesion also causes loss of flexor digitorum profundus)
- Froment’s sign: grasp a piece of paper between the thumb and lateral aspect of the forefinger – the affected thumb will flex (loss of thumb adductor)
- Sensory loss over the little and medial half of ring finger (both palmar and dorsal aspects)
15
Q
Causes of wasting of the small muscles of the hands
A
1) Nerve lesions
- Median and ulnar nerve lesions
- Brachial plexus lesions
- Peripheral motor neuropathy (including hereditary motor and sensory neuropathy)
2) Anterior horn cell disease:
- Motor neurone disease
- Polio
- Spinal muscular atrophies
3) Myopathy
- Myotonic dystrophy – forearms more affected than the hands
- Distal myopathy
4) Spinal cord lesions
- Syringomyelia
- Cervical spondylosis
- Tumour
5) Trophic disorders
- Arthropathies (disuse)
- Ischaemia including vasculitis
16
Q
Signs of a femoral nerve lesion
A
- Weakness of knee extension (quadriceps paralysis)
- Slight hip flexion weakness
- Preserved adductor strength
- Loss of knee jerk
- Sensory loss involving the inner aspect of the thigh and leg
17
Q
Signs of a sciatic nerve palsy
A
Loss of power of all muscles below the knee causing a foot drop, so the patient may be able to walk, but cannot stand on the toes or heels
Knee jerk intact
Loss of ankle jerk and plantar response
Sensory loss along the posterior thigh and total loss below the knee
18
Q
Signs of a common peroneal nerve palsy
A
Foot drop and loss of foot eversion only
Sensory loss (minimal) over the dorsum of the foot
Normal reflexes
Weakness of extensor hallucis longus
19
Q
Causes of a foot drop
A
Common peroneal nerve palsy L4, L5 root lesion Sciatic nerve palsy Lumbosacral plexus lesion Peripheral motor neuropathy Distal myopathy Motor neurone disease Pre-central gyrus lesion
20
Q
Signs of subacute combined degeneration of the cord
A
- Symmetrical posterior column loss (vibration and position sense) causing an ataxic gait
- Symmetrical upper motor neurone signs in the lower limbs with absent ankle reflexes
- Peripheral sensory neuropathy
- Optic atrophy (occasionally)
- Dementia (occasionally)
21
Q
Causes of extensor plantar response but absent ankle jerk
A
- Subacute combined degeneration of the cord (Vitamin B12 deficiency)
- Conus medullaris lesion
- Combination of an UMN lesion with cauda equina compression or peripheral neuropathy (e.g. stroke plus diabetes)
- Neurosyphilis (Tabes dorsalis)
- Friedreich’s ataxia
- Motor neurone disease
22
Q
Signs of Brown Sequard
A
• Motor changes
o Upper motor neurone signs below the hemisection on the same side as the lesion
o Lower motor neurone signs at the level of the hemisection on the same side
• Sensory changes
o Pain and temperature loss on the opposite side of the lesion (the upper level of the sensory loss is usually a few segments below the level of the lesion)
o Vibration and proprioception loss on the same side
o Light touch is often normal
o There may be band of sensory loss on the same side at the level of the lesion (afferent nerve fibres)
23
Q
Causes of Brown Sequard syndrome
A
- Multiple sclerosis
- Angioma
- Glioma
- Trauma
- Myelitis
- Postradiation myelopathy
24
Q
Causes of spinothalamic loss only
A
- Syringomyelia (‘cape’ distribution)
- Brown-Sequard syndrome (contralateral leg)
- Anterior spinal artery thrombosis
- Lateral medullary syndrome (contralateral to the other signs)
- Peripheral neuropathy (diabetes mellitus, amyloid, Fabry’s disease)
25
Causes of dorsal column loss only
* Subacute combined degeneration
* Brown-Sequard syndrome (ipsilateral leg)
* Spinocerebellar degeneration (e.g. Friedreich’s ataxia)
* Multiple sclerosis
* Tabes dorsalis
* Sensory neuropathy or gangliopathy (e.g. carcinoma)
* Peripheral neuropathy from diabetes mellitus or hypothyroidism
26
Signs of syringomyelia
* Loss of pain and temperature over the neck, shoulders and arms (‘cape’ distribution)
* Amyotrophy (weakness, atrophy and areflexia) of the arms
* Upper motor neurone signs in the lower limbs
27
Causes of proximal muscle weakness
1. Myopathic
2. Neuromuscular junction disorder – myasthenia gravis
3. Neurogenic – motor neurone disease, polyradiculopathy
28
Causes of myopathy
```
Hereditary muscular dystrophy
Congenital myopathies
Acquired (PACE PODS)
- Polymyositis or dermatomyositis
- Alcohol
- Carcinoma
- Endocrine (hypothyroidism, hyperthyroidism, Cushing’s syndrome, acromegaly, hypopituitarism)
- Periodic paralysis
- Osteomalacia
- Drugs (steroids, statins)
- Sarcoidosis
```
35
Gait: Hemiparetic
the foot is plantarflexed and the leg swung in a lateral arc
36
Gait: Paraparetic
(scissor gait)
37
Gait: Extrapyramidal
(e.g. Parkinson’s Disease)
| o Hesitation in starting, shuffling, freezing, festination (patient hurries forward), propulsion/retropulsion
38
Gait: Cerebellar
gait that is wide-based or reeling on a narrow base; the patient staggers towards affected side
39
Gait: Apraxic
(prefrontal lobe): feet appear glued to the floor when erect, but move more easily when supine
40
Gait: Posterior column lesion
(clumsy slapping down of the feet on a broad base)(clumsy slapping down of the feet on a broad base)
41
Gait: Distal weakness
(high-stepping gait)
42
Gait: Proximal weakness
Waddling Gait
43
Causes of Unilateral Cerebellar Disease
1. Space-occupying lesion (tumour, abscess, granuloma)
2. Ischaemia (vertebrobasilar disease)
3. Paraneoplastic syndrome
4. Multiple sclerosis
5. Trauma
44
Causes of bilateral cerebellar disease
* Drugs (e.g. phenytoin)
* Friedreich’s ataxia
* Hypothyroidism
* Multiple sclerosis
* Trauma
* Arnold-Chiari malformation
* Alcohol
* Large space-occupying lesion, cerebrovascular disease
45
Causes of midline cerebellar disease
* Paraneoplastic syndrome
| * Midline tumour
46
Causes of cerebellar disease affecting the rostal vermis
Alcohol
47
Clinical features of Friedreich's Ataxia
* Cerebellar signs (bilateral) including nystagmus
* Posterior column loss in the limbs
* Upper motor neurone signs in the limbs (although ankle reflexes are absent)
* Peripheral neuropathy
* Optic atrophy
* Pes cavus, cocking of the toes and kyphoscoliosis
* Cardiomyopathy
* Diabetes mellitus
48
Causes of pes cavus
* Friedreich’s ataxia or other spinocerebellar degenerations
* Hereditary motor and sensory neuropathy (Charcot-Marie-Tooth)
* Neuropathies in childhood
49
Causes of spastic and ataxic paraparesis
* Multiple sclerosis
* Spinocerebellar degeneration
* Syringomyelia
* Bilateral upper pons or internal capsule infarction
* Lesion at the craniospinal junction
50
Causes of Parkinsonism
* Idiopathic (Parkinson’s Disease)
* Drugs (phenothiazines, methyldopa)
* Post-encephalitis
* Other: toxins (carbon monoxide), Wilson’s disease, Progressive Supranuclear Palsy, Multiple-System Atrophy, syphilis, tumour
51
DDx for action tremor
```
o Thyrotoxicosis
o Anxiety
o Drugs
o Familial
o Idiopathic (most common)
```
52
Causes of Chorea
* Huntington’s disease
* Sydenham’s chorea (rheumatic fever)
* Senility
* Wilson’s disease
* Drugs (OCP, phenytoin, L-Dopa)
* Vasculitis or connective tissue disease (e.g. SLE)
* Thyrotoxicosis
* Polycythaemia or other causes of hyperviscosity
53
Signs of an upper cervical spinal cord lesion
UMN signs in the upper and lower limbs
| Paralysis of the diaphragm occurs with lesion above C4
54
Signs of a C5 spinal cord lesion
LMN weakness and wasting of rhomboids, deltoids, biceps and brachioradialis
UMN signs affect the rest of the upper and all of the lower limbs
55
Signs of S3-S4 spinal cord lesion
No anal reflex
Saddle sensory loss
Normal lower limbs
56
Signs of a C8 spinal cord lesion
LMN weakness and wasting of the intrinsic muscles of the hand
UMN signs in the lower limbs
57
Signs of mid-thoracic spinal cord lesion
Intercostal paralysis (not clinically detected)
Loss of upper abdominal reflexes at T7 and T8
UMN signs in the lower limbs
Sensory level on the trunk
58
Signs of T10-T11 spinal cord lesion
Loss of lower abdominal reflexes and upward displacement of umbilicus on contraction
UMN signs in the lower limbs
59
Signs of L1 spinal cord lesion
Cremasteric reflexes lost
| UMN signs in the lower limbs
60
Signs of L4 spinal cord lesion
LMN weakness and wasting of the quadriceps
| Knee jerk lost
61
Signs of L5 and S1 spinal cord lesion
LMN weakness of knee flexion and hip extension (S1) and abduction (L5)
Knee jerk present
No ankle jerk or plantar response
Anal reflex present
62
Causes of a spastic paraparesis
```
MS
HIV
Trauma
Spinal cord tumour
MND
Syringomyelia
Subacute combined degeneration of the cord (associated peripheral neuropathy)
Tabes dorsalis
Transverse myelitis
Familial spastic paraplegia
OA of cervical spine
Metastatic carcinoma
Anterior spinal artery thrombosis
```
63
Signs of hereditary spastic paraplegia
Minimal weakness
Profound spasticity - increased tone, clonus, brisk reflexes
No sensory change
64
Signs of spinocerebellar ataxia
Different syndromes:
Roussy Levy: Atrophy of lower limbs, loss of deep tendon reflexes
Refsum's: Peripheral neuropathy, deafness, increased CSF protein
Machado Joseph disease: ophthalmoparesis, spasticity, dystonia, Parkinsonism
65
Signs of motor neurone disease
UMN and LMN involvement of either 2 limbs or more or 1 limb and bulbar
Fasciculations
Loss of reflexes
Upgoing plantars
Sensory and ocular movements not affected
Never cerebellar signs
66
Clinical pattern in amyotrophic lateral sclerosis
Flaccid arms and spastic legs
67
Clinical pattern in progressive muscular atrophy
Retention of deep tendon reflexes but severe muscular atrophy
68
Clinical pattern in primary lateral sclerosis
Progression from UMN to LMN weakness
69
Most common causes of lateral medullary syndrome
Occlusion of the intracranial vertebral artery
| Occlusion of posterior inferior cerebellar artery
70
Signs of a medial medullary syndrome
Ipsilateral paralysis and wasting of the tongue
Contralateral hemiplegia
Contralateral loss of vibration and joint position sense
71
CN 2 (Optic)
```
Pupils
Acuity
Fundoscopy
Fields
Blind spot
Color saturation
```
72
CN 3/4/6 (Oculomotor, trochlear, abducens)
Eye movements
| Accommodation
73
CN 5 (Trigeminal)
Corneal reflex (sensory component)
Facial sensation
Clenching teeth and open mouth
Jaw jerk
74
CN 7 (Facial)
Corneal reflex (blinking component)
Eyebrows up - check for symmetry of wrinkling
Eyes closed tight and try to open them up
Grin - assessing nasolabial folds
Taste on anterior 2/3rds of tongue
75
CN 8 (Vestibulocochlear)
Whisper screening test
Rinne
Weber
76
CN 9/10 (Glossopharyngeal, Vagus)
Uvula (Shy)
Gag reflex (CN 9 is sensation, CN 10 is the gagging)
Taste of posterior 3rd of tongue
Hoarse voice
77
CN 11 (Accessory)
Trapezius strength
| Sternocleidomastoid strength
78
CN 12 (Hypoglossal)
```
Tongue wasting/fasciculations
Tongue deviation (Proud)
```
79
CAUSES OF PUPIL DILATION
* Third nerve lesion
* Adie’s pupil
* Iritis
* Mydriatics
80
Features of Horner's Syndrome
Ptosis
Meiosis
Anhydrosis
81
Causes of a Horner's Syndrome
1. Carcinoma of the lung apex
2. Neck – thyroid malignancy, trauma
3. Carotid arterial lesion – carotid aneurysm or dissection, pericarotid tumour
4. Brain stem lesions – vascular disease (lateral medullary syndrome), syringobulbia, tumour
5. Retro-orbital lesions
6. Syringomyelia (rare)
82
Features of Lateral Medullary Syndrome
* Horner’s syndome
* Nystagmus (to the side of the lesion)
* Ipsilateral cranial nerve V (pain and temperature), IX and X lesions
* Ipsilateral cerebellar signs
* Contralateral pain and temperature loss over the trunk and limbs
83
Horner's Syndrome Exam
EYES: Partial ptosis and constricted pupil (reacts normally to light)
FOREHEAD: anhidrosis
CRANIAL NERVES V/IX/X: lateral medullary syndrome
VOICE: hoarseness (recurrent laryngeal nerve palsy)
HANDS: clubbing, finger abduction (lower trunk brachial plexus C8/T1 lesion)
NECK: cervical lymphadenop.athy, thyroid carcinoma, carotid aneurysm or bruit
RESPIRATORY EXAMINATION: apical lung tumour
UPPER LIMB NEUROLOGICAL EXAM: dissociated sensory loss (syringomyelia)
84
Causes of Bilateral Anosmia
```
URTI
Meningioma of olfactory groove (late)
Ethmoid tumours
Head trauma (including cribiform plate fracture)
Meningitis
Hydrocephalus
Congenital (Kallman's syndrome)
```
85
Causes of Unilateral Anosmia
Meningioma of the olfactory groove (early)
| Head trauma
86
CAUSES OF ABSENT LIGHT REFLEX BUT INTACT ACCOMMODATION REFLEX
1. Midbrain lesion (e.g. Argyll Robertson pupil)
2. Ciliary ganglion lesion (e.g. Adie’s pupil)
3. Parinaud’s syndrome
4. Bilateral afferent pupil defects
87
CAUSES OF ABSENT CONVERGENCE BUT INTACT LIGHT REFLEX
* Cortical lesion (e.g. cortical blindness)
| * Midbrain lesions
88
CAUSES OF PUPIL CONSTRICTION
* Horner’s syndrome
* Argyll Robertson pupil
* Pontine lesion (often bilateral but reactive to light)
* Narcotics
89
CAUSES OF PUPIL DILATION
* Third nerve lesion
* Adie’s pupil
* Iritis
* Mydriatics
90
Adie's Syndrome Cause and Signs
CAUSE
• Lesion in the efferent parasympathetic pathway
SIGNS
• Dilated pupil
• Decreased or absent reaction to light (direct and consensual)
• Slow or incomplete reaction to accommodation with slow dilation afterwards
• Decreased tendon reflexes
• Patients are commonly young women
91
Cause of Argyll Robertson Pupil
```
• Lesion of the iridodilator fibres in the midbrain, as in:
o Syphilis
o Diabetes mellitus
o Alcoholic midbrain degeneration
o Other midbrain lesions
```
92
Signs of Argyll Robertson Pupil
* Small, irregular, unequal pupil
* No reaction to light
* Prompt reaction to accommodation
* If tabes is associated (syphilis), decreased reflexes
93
Causes of Papilloedema
* Space-occupying lesion (causing raised intracranial pressure) or a retro-orbital mass
* Hydrocephalus (associated with large ventricles)
* Benign intracranial hypertension
* Hypertension (grade IV)
* Central retinal vein thrombosis
* Cerebral venous sinus thrombosis
94
Causes of Hydrocephalus
o Obstructive
o Communicating
Increased formation of CSF – choroid plexus papilloma
Decreased formation of CSF – tumour causing venous compression, subarachnoid space obstruction from meningitis
95
Causes of Benign intracranial HTN
```
Idiopathic
Drugs:COCP, Nitrofurantoin, tetracycline, steroids
Addison’s disease
Vitamin A
Lateral sinus thrombosis
```
96
Causes of optic atrophy
```
Chronic papilloedema or optic neuritis
Optic nerve pressure or division
Glaucoma
Ischemia
Familial - retinitis pigmentosa, Leber's disease, Friedreich's ataxia
```
97
CAUSES OF OPTIC NEUROPATHY
* Multiple sclerosis
* Toxic: ethambutol, chloroquine, nicotine, alcohol
* Metabolic: Vitamin B12 deficiency
* Ischaemia: diabetes mellitus, temporal arteritis, atheroma
* Familial – Leber’s disease
* Infective – infectious mononucleosis
98
CAUSES OF PTOSIS
| WITH NORMAL PUPILS
* Senile ptosis
* Myotonic dystrophy
* Fascioscapulohumeral dystrophy
* Ocular myopathy, e.g. mitochondrial myopathy
* Thyrotoxic myopathy
* Myasthenia gravis
* Botulism
* Fatigue
* Congenital
99
CAUSES OF PTOSIS WITH CONSTRICTED PUPILS
* Horner’s syndrome
| * Tabes dorsalis
100
Causes of a unilateral 6th nerve palsy
Central:
- Vascular
- Tumour
- Wernicke’s encephalopathy
- Multiple sclerosis
Peripheral
- Diabetes, other vascular lesions
- Trauma
- Idiopathic
- Raised intracranial pressure
101
CAUSES OF PTOSIS WITH DILATED PUPILS
• Third nerve lesion
102
Cause of jerky vertical nystagmus
Brain stem lesion:
- Upbeat nystagmus suggests a lesion in the floor of the fourth ventricle
- Downbeat nystagmus suggests a foramen magnum lesion
Toxic – phenytoin, alcohol (may also cause horizontal nystagmus)
103
Features of a Third Nerve Palsy
* Complete ptosis (partial ptosis may occur with an incomplete lesion)
* Divergent strabismus (eye ‘down and out’): limited adduction and elevation
* Dilated pupil unreactive to direct or consensual light and unreactive to accommodation
104
How to Exclude a 4th nerve palsy in a 3rd nerve palsy
• Always exclude a fourth (trochlear) nerve lesion when a third nerve lesion is present. Do this by:
o Tilting the patient’s head to the same side as the lesion. The affected eye will intort if the lesion is intact
o Asking the patient to look down and across to the opposite side from the lesion and look for intortion
105
Causes of a 3rd nerve palsy
Central
- Vascular (e.g. brain stem infarction)
- Tumour
- Demyelination
- Trauma
Peripheral
Compressive lesions:
-Aneurysm (usually on the posterior communicating artery)
-Tumour causing raised intracranial pressure
-Nasopharyngeal carcinoma
-Orbital lesions
-Basal meningitis
Infarction: diabetes mellitus, arteritis (pupil is usually spared)
Trauma
Cavernous sinus lesions
106
CLINICAL FEATURES OF A SIXTH NERVE PALSY
* Failure of lateral aBduction
* Affected eye is deviated inwards in severe lesions
* Diplopia – maximal on looking to the affected side; the images are horizontal and parallel to each other; the outermost image is from the affected eye and disappears on covering this eye
107
Causes of a bilateral 6th nerve palsy
Trauma
Wernicke’s encephalopathy
Raised intracranial pressure
Mononeuritis multiplex
108
CAUSES OF BILATERAL LOWER MOTOR NEURONE FACIAL WEAKNESS
* Guillain-Barre syndrome
* Bilateral parotid disease (e.g. sarcoidosis)
* Mononeuritis multiplex (rare)
109
Cause of Jerky horizontal nystagmus
o Vestibular lesion – chronic lesions cause nystagmus to the side of the lesion
o Cerebellar lesion – unilateral disease causes nystagmus to the side of the lesion
o Internuclear ophthalmoplegia – nystagmus is in the abducting eye, with failure of adduction on the AFFECTED SIDE. This is the result of a medial longitudinal fasciculus lesion. The most common cause in young adults with bilateral involvement is multiple sclerosis; in the elderly consider brainstem infarction
110
Features of a supranuclear palsy and how it is distinguished from 3rd/4th/6th nerve palsy
• Loss of vertical upward gaze and sometimes downward gaze. Clinical features (distinguishing from third, fourth and sixth nerve palsy)
o Both eyes affected
o Pupils often unequal
o No diplopia
o Reflex eye movements (e.g. on flexing and extending the neck) intact
111
Features of progressive supranuclear palsy
o Loss of vertical downward gaze first, later vertical upward gaze and finally horizontal gaze
o Associated with pseudobulbar palsy, long tract signs, extrapyramidal signs, dementia and neck rigidity
112
Features and Causes of Parinaud's Syndrome
Loss of vertical upward gaze often associated with convergence-retraction nystagmus on attempted convergence and pseudo-Argyll Robertson pupils
Causes:
Central: pinealoma, multiple sclerosis, vascular lesions
Peripheral: trauma, diabetes mellitus, other vascular lesions, idiopathic, raised intracranial pressure
113
Causes of a 5th nerve palsy
Central (pons, medulla and upper cervical cord)
- Vascular
- Tumour
- Syringobulbia
- Multiple sclerosis
Peripheral (posterior fossa)
- Aneurysm
- Tumour (skull base, e.g. acoustic neuroma)
- Chronic meningitis
Trigeminal ganglion (petrous temporal bone)
- Meningioma
- Fracture of the middle fossa
Cavernous sinus (associated third, fourth and sixth nerve palsies)
- Aneurysm
- Thrombosis
- Tumour
Other
- Sjogren’s syndrome
- SLE
- Toxins
- Idiopathic
114
Causes of a 7th nerve palsy
Upper motor neurone lesion (supranuclear)
- Vascular
- Tumour
Lower motor neurone lesion
- Pontine (often associated with nerves V, VI): Vascular, tumour, syringobulbia, multiple sclerosis
- Posterior fossa: Acoustic neuroma, Meningioma
- Petrous temporal bone: Bell’s Palsy, Ramsay Hunt Syndrome, Otitis media, Fracture
- Parotid: Tumour, Sarcoid
115
Interpretation of Rinne's Test
* Normal – the note is audible at the external meatus
* Nerve deafness – the note is audible at the external meatus (air and bone conduction reduced equally)
* Conduction (middle ear) deafness – no note is audible at the external meatus – negative result
116
Interpretation of Weber's test
* Normal – sound is heard in the centre of the forehead
* Nerve deafness – sound is transmitted to the normal ear
* Conduction deafness – sound is heard louder in the abnormal ear
117
Causes of Sensorineural deafness
Degeneration (Presbycusis)
Trauma (high noise exposure, fracture of the petrous temporal bone)
Toxic (aspirin, ETOH, streptomycin)
Infection (Congenital rubella/syphillis)
Tumor (acoustic neuroma)
Brain stem lesions
Vascular disease of the internal auditory artery
118
Causes of conductive deafness
Wax
Otitis media
Otosclerosis
Paget's disease of the bone
119
Causes of 9th and 10th nerve palsies
Central
o Vascular: e.g. lateral medullary infarction
o Tumour
o Syringobulbia
o Motor neurone disease (vagus nerve only)
```
Peripheral (posterior fossa)
o Aneurysm
o Tumour
o Chronic meningitis
o Guillain-Barre syndrome (vagus nerve only)
```
120
Causes of 12th nerve palsy (UMN lesion)
o Vascular
o Motor neurone disease
o Tumour
o Multiple sclerosis
121
Causes of 12th nerve palsy (Unilateral LMN lesion)
Central
- Vascular – thrombosis of the vertebral artery
- Motor neurone disease
- Syringobulbia
Peripheral (posterior fossa)
- Aneurysm
- Tumour
- Chronic meningitis
- Trauma
- Arnold-Chiari malformation
- Fracture or tumour of the base of the skull
122
Causes of a 12th nerve palsy (Bilateral LMN lesion)
o Motor neurone disease
o Arnold Chiari malformation
o Guillain-Barre syndrome
o Polio
123
Causes of multiple cranial nerve palsies
Think of Cancer first!
* Nasopharyngeal carcinoma
* Chronic meningitis (carcinoma, tuberculosis, sarcoidosis)
* Guillain-Barre syndrome, including Miller-Fisher variant
* Brain stem lesions – usually vascular disease causing crossed sensory or motor paralysis (i.e. cranial nerve signs on one side and contralateral long tract signs)
* Arnold-Chiari malformation
* Trauma
* Lesion of the base of the skull
* Mononeuritis multiplex (e.g. diabetes mellitus)
124
Upper limb reflexes
* Biceps: C5, C6
* Triceps C7, C8
* Supinator C5, C6
* Finger: C8
125
FACIO-SCAPULO-HUMERAL SYNDROME
* Inspection: wasting of the masseter and temporalis muscles
* Winging of the scapulae
* Foot drop
* Facial weakness (inability to close eyes tightly, whistle or puff out the cheeks)
126
Signs of a pseudobulbar palsy
```
Stiff and spastic tongue
Slow thick and indistinct speech
Brisk jaw jerk
UMN lesions of the limbs
Emotional lability
```
127
Causes of pseudobulbar palsy
Stroke
Multiple sclerosis
MND
Creutzfeldt-Jakob disease
128
Signs of a bulbar palsy
```
Flaccid tongue with fasciculations
Nasal speech
Prominent nasal regurgitation
Normal or absent jaw jerk
Normal effect
```
129
Causes of a bulbar palsy
```
MND
Polio
GBS
Myasthenia gravis
Myopathy
```
130
CAUSES OF UPPER LIMB DRIFT
* Upper motor neurone weakness (usually downwards owing to muscle weakness)
* Cerebellar lesion (usually upwards owing to hypotonia)
* Posterior column loss (any direction owing to joint position sense loss)
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Upper Limb myotomes
* Shoulder abduction: C5,6
* Shoulder adduction C6, C7, C8
* Elbow flexion: C5, C6
* Elbow extension: C7, C8
* Wrist flexion: C6, C7
* Wrist extension C7, C8
* Fingers extension: C7, C8
* Finger flexion C7, C8
* Finger abduction: C8, T1
132
Causes of a sciatic nerve lesion
Pressure
Trauma
Vasculitis
Tumour
133
Causes of weakness of all muscles of the foot
Peripheral neuropathy
Root or plexus lesion - Cauda equina
Anterior horn cell disease - MND
Sciatic nerve lesion
134
Signs of LMN lesion
Weakness
Wasting
Decreased or absent reflexes
Fasciculations (prominent in anterior horn cell disease unless far advanced)
135
Features of Myotonic dystrophy
Autosomal dominant
distal wasting and weakness in all 4 limbs
hyporeflexia
frontal baldness
partial ptosis - failure to bury the eyelashes
horizontal smile
weak neck flexion (cf. extension)
Iridescent cataracts from subcapsular fine deposits
tests
- make a tight fist and then open the fingers as rapidly as possible - if fingers unfurls slowly = myotonia
- tap the thenar eminance - if thumb slowly abducts then falls back to original position = percussion myotonia
Ask for Glycosuria - diabetes
136
Signs of UMN lesion
Weakness more marked in upper limb abductor and extensor muscles and lower limb flexor muscles
Spasticity
Clonus
Increased reflexes and extensor plantar response
137
Causes of Fasiculation
```
Benign idiopathic fasciculation
Motor neuron disease
Motor root compression
malignant neuropathy
Spinal muscular atrophy/bulbospinal muscular atrophy (Kennedy Syndrome)
Any motor neuropathy (less likely)
```
138
Signs of a lateral medullary syndrome
- Nystagmus
- Ipsilateral Horner's syndrome
- Ipsilateral involvement of 5th, 6th, 7th and 8th cranial nerves
- Bulbar palsy
- Ipsilateral cerebellar signs
- Contralateral pain and temperature sensory loss
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Causes of an INO
Lesion in the medial longitudinal fasiculus
```
MS
Vascular disease
Tumour (pontine glioma)
Inflammatory lesions of the brain stem
Drugs (phenytoin, carbamazepine)
```
140
Signs of an INO
Adduction of the eye is impaired on the affected side
Nystagmus in the non affected eye on abduction
141
Impairment with conductive aphasia
Can read, write, and speak normally
| CANNOT repeat words/phrases
142
Causes of hemiplegia
Cerebral infarction resulting from thrombotic or embolic occlusion of a cerebral artery (80%)
Intra-cerebral or subarachnoid haemorrhage (20%)
```
Elderly:
Vascular event
Tumour
Subdural haematoma
Syphilis
```
```
Young:
MS
Tumour
Trauma
Embolism (AF, valvular heart disease)
Connective tissue disorder
Syphilis
Intra-cranial infection
```
143
Foster Kennedy Syndrome
Optic atrophy on affected side with and papilloedema in the opposite fundus
Seen in Frontal lobe tumors
144
Site of lesion for receptive aphasia
Wernicke's area
| -Posterior part of the first temporal gyrus in the dominant lobe
145
Site of lesion for expressive aphasia
Broca's area
| -Posterior part of the frontal gyrus in the dominant lobe
146
Site of lesion for conductive aphasia
Arcuate Fasciculus
| -Connection between Broca's and Wernicke's areas
147
Site of lesion for nominal aphasia
Angular gyrus in the temporal lobe
| Other causes: encephalopathy, pressure effect rom a space occupying lesion
148
NCS: Amplitude
How many axons are excited
| -Low amplitude = axonal problem
149
NCS: Latency
Represents velocity of the fastest conducting fibres
| -Increased latency = demyelinating problem
150
EMG: Neurogenic pattern
Fibrillations and positive sharp waves
Fasciculations
Morphology: Large amplitude, increased duration
Recruitment: Decreased
151
EMG: Myopathic pattern
Fibrillations and positive sharp waves
Morphology: Small amplitude
Recruitment: Increased
152
Myasthenia Gravis Investigations
- Acetylcholine receptor AB positive (Associated with thymoma - Consider CT chest)
- Muscle specific kinase antibody positive
- EMG: Decrement in amplitudes with repeated nerve stimulation
