Neurology Flashcards
1
Q
Causes of ptosis with normal pupils
A
senile ptosis myotonic dystrophy fascioscapulohumeral dystrophy ocular myopathy thyrotoxic myopathy myasthenia gravis congenital
2
Q
Causes of Horners
A
Pancoast tumour (tumour in apex of lung) Neck malignancy eg - thyroid brachial plexus lesion carotid artery lesion eg - aneurysm brainstem lesion eg - lateral meduallary syndrome
3
Q
Features of third nerve palsy
A
Ptosis
Eye is down and out (divergent strabismus)
Mydriasis, unreactive to light or accommodation
4
Q
Causes of CN3 palsy - by location
A
Problem at the nucleus - infarct, haemorrhage, mass
Problem at the fascicles - infarct, tumour, fasicles, demyelination
Problem in the subarachnoid space - Aneurysm (PCOmm)
Problem at the cavernous sinus - tumour, inflammation, carotid aneurysm
5
Q
Causes of CN3 palsy - central or peripheral
A
Central causes - brain stem infarct, tumour, demyelination, trauma
Peripheral causes - Compression by eg aneurysm, tumour, raised intracranial pressure. Infarct from microvascular ischaemia (eg from diabetes, GCA), trauma, cavernous sinus lesion
6
Q
Features of CN6 palsy
A
At rest - if severe affected eye adducted
Looking towards the lesion - affected eye unable to abduct, horizontal nystagmus
Looking away from lesion - normal
7
Q
Causes of CN6 palsy
A
Vascular cause - infarct, haemorrhage, basilar artery aneurysm
Space occupying lesion in the pons
Demyelination - MS
Inflammatory - sarcoid, giant cell arteritis
Cavernous sinus lesion
Mononeuritis multiplex
Trauma
Central - vascular, tumour, Wernicke’s encephalopathy, MS
Peripheral - microsvascular ischaemia (eg - diabetes), trauma, raised intracranial pressure
8
Q
Causes of jerky horizontal nystagmus
A
Vestibular (peripheral) - unidirectional with fast component is away from the side of the lesion
Vestibular (central) - bidirectional, left beating on left gaze, right beating on right gaze
Cerebellar - fast component towards the side of the lesion
Toxins - phenytoin, alcohol
9
Q
Causes of jerky vertical nystagmus
A
Brain stem lesion
- Upbeating: lesion at floor of 4th ventricle
- Downbeating: lesion at foramen magnum
Toxins - phenytoin, alcohol
10
Q
Causes of mononeuritis multiplex
A
Rheumatologic conditions - Sjogrens, SLE, RA
Vasculitis - PAN, giant cell arteritis
Other chronic conditions - diabetes, neurosarcoid, amyloidosis
Paraneoplastic
Infections such as HIV
11
Q
Causes of peripheral neuropathy
A
D - drugs and toxins like isoniazid, vincristine, platinum based chemo
A - Alcohol, amyloid
M - Metabolic like diabetes, thyroid, uraemia
I - Immune mediated like GBS
T - tumour, lung carcinoma, paraproteinaemia
B - vitamin B12 deficiency
I - Idiopathic
C - Connective tissue disease or vasculitis
H - Hereditary motor and sensory neuropathy
12
Q
Signs of median nerve lesion
A
- Weak thumb abduction
- Wasting of the thenar eminence
- Hand of benediction if more proximal lesion
- Sensory loss to the palmar aspect of thumb, index and middle (and half of ring)
13
Q
Signs of a radial nerve lesion
A
- Wrist drop/finger drop
- Sensory loss over the anatomical snuffbox
- Weak elbow extension if high enough
- Absent triceps jerk
14
Q
Signs of ulnar nerve lesion
A
- Wasting of the hypothenar eminence
- Weak abduction and adduction
- Claw hand when trying to straighten
- Sensory loss over the dorsal and palmar little and half of ring finger
15
Q
How do you distinguish a C8 nerve root lesion/lower trunk brachial plexus lesion from ulnar nerve lesion?
A
- sensory loss of a C8 root/lower trunk plexus extends above the wrist
- Thenar wasting with C8 root/lower trunk plexus
16
Q
Signs of femoral nerve lesion
A
- Weak knee extension
- Loss of sensation over inner thigh and leg
- Strong adduction
- Slight weak hip flexion
17
Q
Signs of sciatic nerve lesion
A
- Foot drop
- Knee Extension weakness
- loss of sensation in posterior part of thigh and all of lower leg
- Loss of power to all muscles below knee
- Unable to stand on toes or heels
- Loss of ankle jerk
18
Q
Common peroneal nerve lesion
A
- Foot drop
- Loss of sensation to the dorsum of foot
- Weak eversion
- Normal power inversion (L5 nerve root will be all of above and weak inversion)
19
Q
Nerve fibre types for motor and sensory
A
Motor - Large myelinated nerve fibres
Proprioception and vibration - large myelinated nerve fibres (A-beta)
Pain and temperature - small myelinated and unmyelinated fibres
Autonomic - small fibres
20
Q
Nerve fibre types for motor and sensory
A
Motor - Large myelinated nerve fibres
Proprioception and vibration - large myelinated nerve fibres (A-beta)
Pain and temperature - small myelinated and unmyelinated fibres
21
Q
Which nerve pathways carry pain/temperature vs vibration/proprioception
A
DCML - fine touch, proprioception and vibration
Lateral spinothalamic tract - pain and temperature
22
Q
Causes of mononeuritis multiplex
A
Metabolic causes - Diabetes Vasculitis - PAN, Churg-Strauss, Wegeners Connective tissue - RA, SLE, Sjogrens Sarcoid Amyloid Paraneoplastic
23
Q
Tests to order for peripheral neuropathy
A
Bloods - FBC, ESR, CRP, U and E, TFTs, HbA1c, B12, Serum protein electrophoresis, Autoimmune profile Urine - Bence jones, glucose Nerve conduction Genetic testing Nerve biopsy
24
Q
Peripheral neuropathies that are predominantly motor
A
CIDP GBS CMT Porphyria Lead poisoning
25
Axonal vs demyelinating polyneuropathy
Axonal - more distal sensory loss, wasting and weakness of hands/feet
Demyelinating - vibration/proprioception (large myelinated fibres) loss > pain/temp, weakness can be more generalised
26
Demyelinating vs axonal neuropathy features on NCS
Demyelinating - slow nerve conduction velocities, prolongation of distal latencies
Axonal - reduced amplitude of evoked compound action potentials, relative preservation of the nerve conduction velocity
27
If there is wasting of the hand in a neuro exam, when can the pathology originate from?
Anterior horn cell, nerve root or the lower motor neurons that arise from C8 to T1
28
Clinical features of Charcot Marie Tooth disease
1. Pes cavus - high arch, short foot, hammer toe
2. Inverted champagne bottle legs
3. Distal muscle atrophy and weakness - mainly hands and feet. Get weak eversion
4. Absent reflexes
5. Foot drop
6. Thickened nerves - esp lateral popliteal nerve
7. Sensory loss - vibration and proprioception
8. Claw hand
9. Optic atrophy
29
Nerve conduction studies in CMT disease
Can be motor and sensory involved
Can be predom axon or demyelinating or mixed
Demyelinating - get decreased conduction velocities
Axonal - get decreased amplitudes
30
Differentiating neuropathy from myopathy
Myopathy - usually more proximal, no fasciculations, no sensory loss, deep tendon reflexes intact unless severe, can have mm tenderness
Neuropathy - usually more distal, fasciculations, can have sensory loss, loss of reflexes
31
What are the main clinical features of myotonic dystrophy?
Face - frontal balding, facial muscle atrophy (temporalis, masseter, sternomastoid), high arched palate (some), ptosis, cataracts
Neck - weak neck flexion
Hands - grip myotonia, percussion myotonia
Wasting UL and LL esp intrinsic hand mm
32
What are some of the systemic features of myotonic dystrophy?
Cardiac - arrythmias, heart block, mitral valve prolapse, cardiomyopathy
GIT - dysphagia, hypomotility, reflux, delayed gastric emptying
Endocrine - diabetes, hypogonadism, nodular thyroid involvement
33
What is the EMG finding in myotonic dystrophy?
Characteristic "dive bomber" sound of myotonia
34
What is the blood supply to the different parts of the brainstem?
Medulla - vertebral arteries
Pons - Basilar artery
Midbrain - either the PCA or the superior cerebellar
35
Where is the lesion in intranuclear ophthalmoplegia ?
Medial longitudinal fasciculus (heavily myelinated tract that in simple terms connects ipsilateral CN III with contralateral CN VI and is involved in the control of conjugate eye movements
36
Describe the clinical features of an INO?
Unilateral INO (eg - affecting the right medial longitudinal fasciculus) - when looking to the left, the right eye will not adduct, nystagmus in the left eye, diplopia
Bilateral INO - when looking to the right the the left eye cannot adduct, when looking to the left the right eye cannot adduct, opposite eye may have nystagmus
The adduction becomes normal when contralateral (abducting) eye is covered
37
What are cerebellar eye signs?
nystagmus towards the side of the cerebellar lesion, hypo/hypermetric saccades, broken smooth pursuit
38
What are the most common causes of an INO?
1. MS - can be unilateral or bilateral
2. Brainstem lesion
3. Wernicke's encephalopathy
4. SLE
5. Miller Fisher Syndrome
6. Drug overdose
39
which cranial nerves are in which part of the brainstem?
```
I and II - from the cerebrum
IV - posterior side of midbrain
III - midbrain-pontine junction
V - pons
VI - VIII - pontine-medullary junction
IX-XII - medulla
(V, VII, VIII) - cerebellopontine angle
```
40
Bulbar vs pseudobulbar palsy
Bulbar (LMN affecting X, XI, XII) - absent gag reflex, wasted tongue with fasciculations, absent or normal jaw jerk, nasal sounding voice, limb fasciculations
Pseudobulbar (UMN affecting X, XI, XII) - increased or normal gag reflex, spastic tongue, increased jaw jerk, spastic dysarthria, limb UMN signs, labile emotions
41
CN III, IV, V, Vi affected, where may the lesion be?
Cavernous sinus
42
CN V, VII, VIII affected, where may the lesion be?
Cerebellopontine angle
43
Unilateral Ix, X, XII affected, where may the lesion be?
jugular foramen
44
Visual field deficits - where is the lesion?
Bitemporal hemianopia - optic chiasm
HH - optic tract to occipital cortex
Upper HQ - temporal lobe
Lower HQ - parietal lobe
45
What are the major causes of myopathy?
Inflammatory causes - polymyositis, dermatomyositis, inclusion body myositis, vasculitis
Endocrine - hypo/hyperthyroidism, Cushing's
Drugs - steroids, alcohol, statins
Inheritied causes - muscular dystrophy
Electrolyte disturbances
46
Which conditions can cause both proximal myopathy and peripheral neuropathy?
Alcohol
Endocrine
Paraneoplastic
Connective tissue diseases
47
What are the clinical features of dermatomyositis?
```
Heliotrope rash
Periorbital oedema
Gottron papules
Periungual telangectasia
Mechanics hands
hyperpigmentation and telangectasias in sun-expose areas (shawl sign)
Symmetrical proximal muscle weakness
Arthritis
Signs of interstitial lung disease
```
48
Parkinson's disease vs Parkinson's plus differentiation
```
Clinically
- Parkinson plus more symmetrical, early onset postural instability, early onset autonomic dysfunction (shy drager), pyramidal signs, cerebellar signs (MSA-C), gaze palsies (PSP), more axial rigidity in PSP, limb apraxia and cortical sensory loss in corticobasal degeneration
Other
- Poor response to levodopa
- Early onset dementia
- early onset hallucinations
```
49
What are the Parkinson Plus syndromes
Progressive supranuclear palsy
Multiple Systems atrophy
Corticobasal degeneration
50
What is most commonly seen on nerve conduction studies in CMT?
Reduced nerve conduction velocities indicating a demyelinating pattern
51
What are the causes of pronator drift?
Downwards drift - UMN pyramidal weakness
Upward drift - cerebellar lesion
Posterior column - Drift in any direction from proprioception loss
52
Which cranial nerves are affected in a cerebellopontine angle lesion?
CN 5, 6, 7 and 8 (CN 6 palsy may or may not be present)
53
What are the clinical features of a cerebellopontine angle lesion?
Possible CN 6 palsy
Weakness of muscles of facial expression (CN7)
Loss of sensation over face (CN5)
Loss of corneal reflex (CN5)
Weakness of mm of mastication (CN5)
Sensorineural hearing loss (CN8) (Rinnes normal, Weber's decreased on affected side)
CN IX-XII spared
54
What are the 2 most common causes of a cerebellopontine angle lesion?
Acoustic neuroma
| Meningioma
55
Spinal cord lesion motor signs?
Weakness, spasticity, increased reflexes, Babinski in muscle groups innervated below the level of the lesion
Can also get LMN signs in a myotomal distribution at the specific level of involvement
56
Motor neuron disease features on clinical examination
Bulbar or pseudobulbar palsy
Mix of upper and lower motor neuron signs
No or very minimal sensory loss
57
DDx for motor neuron disease
Cervical radiculomyelopathy - would get UMN signs below level of lesion and LMN signs at the level. Get sensory loss as differentiator
Syringomyelia - UMN signs in legs and LMN signs in arms
Other spinal cord injury - may cause UMN signs, would get sensory signs
Multifocal motor neuropathy - LMN, slowly progressive distal weakness and atrophy
CIDP - LMN, get autonomic dysfunction and may get sensory loss
Spinal muscular atrophy - LMN, can get bulbar palsy
58
Causes of cerebellar syndrome
```
Demyelinating disease
Post circulation stroke
Haemorrhage
Alcoholic cerebellar degeneration
Friedrich's ataxia
Posterior fossa space occupying lesion
Paraneoplastic
Drugs
Hypothyroidism
MSA-C
```
59
If in peripheral neuropathy you get pain and temperature loss, what may you also test?
Postural BP - pain and temperature is small fibre neuropathy, autonomic nerves also small fibre
60
What type of neuropathy do you get with diabetes?
Can be motor, sensory or sensorimotor
| Autonomic neuropathy
61
What type of neuropathy do you get with B12 deficiency?
Predominantly sensory neuropathy
62
What type of neuropathy do you get with alcohol?
Sensory or sensorimotor
63
What are the causes of the demyelinating polyneuropathies?
```
GBS
MGUS/myeloma
CIDP
CMT (type 1 and 3)
HIV
Multifocal motor neuropathy
```
64
Peripheral neuropathy. How would you like to investigate?
Bloods - B12, BSL, LFTs, Autoimmune and vasculitic screen, TFTs, EPG/IEPG
Urine - glucose, bence jones protein
Nerve conduction studies
65
Common peroneal nerve palsy signs
```
High stepping gait
Foot drop
Weak DF, big toe ext and Eversion
Inversion spared
Ankle reflex spared
Sensory loss over lateral calf and dorsum of foot sparing 5th toe
```
66
L5 nerve root lesion
High stepping gait
Foot drop
Weak DF, big toe ext, eversion and inversion
Weak hip abduction
Reflexes not affected
Sensory involvement lateral calf and dorsum of foot, can extend to thigh
67
Causes of foot drop
L5 nerve root lesion
Lumbosacral plexus
Sciatic nerve
Common peroneal nerve
LMN - MND, other causes of motor neuropathies
Muscular - distal myopathies such as myotonic dystrophy
NMJ - Myasthenia Gravis
68
Friedreich's ataxia signs
Signs of cerebellar syndrome (bilateral)
Pes cavus, kyphoscoliosis, high arched palate
Pyramidal weakness
Distal wasting
Absent LL reflexes
Upgoing plantars
Impaired vibration and proprioception with positive Rombergs
69
What is pyramidal weakness?
In upper limbs extensors weaker than flexors, In LLs flexors weaker than extensors
70
What systemic features do you get in Friedreich's ataxia?
Optic atrophy, diabetes, HCOM, sensorineural deafness
71
Signs of hereditary spastic paraparesis
```
LL > UL
Spasticity
Weakness
Increased reflexes
Upgoing plantars
Spastic gait with scissoring
Can get loss of proprioception and vibration
Can get pes cavus
```
72
Muscular dystrophies - Duchenne's (less likely to appear as more severe) and Becker's
```
Proximal > distal weakness
Neck flexion > neck extension
Pseudohypertrophy of the calf
Weak tibialis anterior and wrist extensors
contractures and kyphoscoliosis
Waddling gait
```
73
Facioscapulohumeral dystrophy features
Myopathic facies with generalised wasting and weakness of the muscles
Inability to close eyes tightly, smile or whistle
Weakness of the shoulder and upper arm muscles
Protrusion of the trapezeii muscles
Deltoid sparing
Riding of the scapulae upwards and winging
Forward jutting of the medial ends of the clavicles when the arms are abducted
Forearm muscles usually spared
Weakness of the lower abdominal muscles
74
CIDP clinical features
symmetric sensorimotor polyneuropathy (motor predominant)
both proximal and distal muscle weakness
Foot drop
Sensory impairment - more vibration and temperature
Sensory ataxia
Can have decreased reflexes
Autonomic dysfunction
75
Weakness pattern in facioscapulohumeral dystrophy
Facial muscle weakness with characteristic myopathic facies (without ptosis)
Weakness at the shoulder girdle
Protrusion of the trapezius
Scapula winging
Wasting of the pectoral muscles with sparing of deltoid
Forward jutting of the clavicles with arm abduction
Wasting of biceps and triceps with sparing of the forearm
Weakness of the lower abdo muscles with abdo protrusion
Upward deflection of the umbilicus with neck flexion (Beevor's sign)
Weakness in distal LL with possible foot drop
76
Pattern of weakness in Duchenne's and Becker's muscular dystrophy?
```
Proximal > distal
Legs first then arms and neck
Neck flexors > extensors
Facial musculature sparing
Calf pseudohypertrophy
```
77
On examination you find features of muscular dystrophy. if you had more time what else would you want to test for?
Cough
Forced exp time/spirometry
Cardiovascular exam - can get myocardial involvement
78
Syringomyelia signs
Lower motor neuron signs in the upper limb distal > proximal - fasciculations, weakness, areflexia
Sensory dissociation - loss of pain and temperature bilaterally but not loss of vibration or proprioception
Upper motor neuron signs in the lower limbs
Kyphoscoliosis from weakness to the paraspinal muscles
79
Explanation of signs in syringomyelia
Syrinx - fluid filled tubular cavity in the central spinal cord - can expand up and down and outwards
Anterior horn cells of spinal cord get affected - damage to LMN at those levels
The decussating fibres of the spinothalamic tract get affected - loss of pain and temperature
The UMNs of the corticospinal tracts get affected - LL UMN signs
The DCML fibres are spared - sparing of vibration and proprioception
80
What is the function of CN4 in the primary position and in adduction of the eye?
In primary gaze, CN4 (superior oblique) intorts the eye
| In adduction, CN4 (superior oblique) depresses the eye
81
CN4 palsy
contralateral eye is slightly hypertropic on primary gaze
In the adducted position, difficult to depress the eye
Head tilt away from the affected eye
