Neurology Flashcards
Which nerve roots supply the musculocutaneous nerve
C5, C6, C7
Which nerve supplies sensation to the lateral forearm
Musculocutaneous nerve
Which nerve supplies flexion of the elbow (biceps, brachialis)
Musculocutaneous nerve
What are the clinical features of musculocutaneous nerve palsy
Sensory: numbness over lateral forearm
Motor: very weak elbow flexion and forearm supination, absent biceps reflex
Deformity: wasting of anterior compartment of arm, elbow held in extension
Note: musculocutaneous nerve palsy is rare - may be damaged by trauma
Which nerve roots does the axillary nerve arise from
C5, C6
What is the sensory function of the axillary nerve
“Sergeant’s patch” - lower part of deltoid
What is the motor supply of the axillary nerve
Shoulder muscles - deltoid, teres minor
Which nerve roots does the radial nerve arise from
C5, C6, C7, C8, T1
Which nerve supplies sensation to the posterior arm and forearm
Radial nerve
Which nerve supplies sensation to the lateral 2/3 of dorsum of hand
Radial nerve
Which nerve innervates the triceps muscle
The radial nerve
Which nerve innervates extension of wrist and fingers
Radial nerve
Which nerve innervates abduction of thumb
Median nerve
Which nerve palsy causes a wrist drop
Radial nerve - wrist flexion, forearm pronation, thumb adduction
Which nerve roots supply the median nerve
C5, C6, C7, C8, T1
What is the sensory innervation of the median nerve
Skin over thenar eminence
Lateral 2/3 palm of hand
Palmar aspect of lateral 3.5 fingers
Dorsal fingertips of lateral 3.5 fingers
(thumb, index, middle and half of ring finger)
What is the motor innervation of the median nerve
Anterior compartment of the forearm - wrist flexion and abduction, finger flexion, thumb flexion
Intrinsic muscles of hand - LOAF
Lateral two lumbricals
Opposes thumb
Abducts thumb
Flexes thumb
Which nerve palsy is caused by carpal tunnel syndrome
Median nerve
Which nerve palsy causes hand of benediction (unable to flex index or middle fingers)
Median nerve
Which nerve roots supply the ulnar nerve
C8, T1
Which nerve supplies sensation to the hypothenar eminence, medial 1/3 of palm of hand and medial 1.5 fingers
Ulnar nerve
What is the motor supply of the ulnar nerve
Flex ring and little fingers
Abduct little finger
Finger abduction and adduction
Medial two lumbricals
Thumb adduction
Which nerve palsy causes “claw hand” (fixed flexion of ring and little fingers)
Ulnar nerve
What is the dermatome testing point of C5
Seargent’s patch (lateral antecubital fossa just proximal to elbow joint)
What is the dermatome testing point for C6
Palmar side of thumb
What is the dermatome testing point for C7
Palmar side of middle finger
What is the dermatome testing point for C8
Palmar side of little finger
What is the dermatome testing point for T1
Medial antecubital fossa just proximal to elbow joint
What does pronator drift indicate
Contralateral corticospinal tract lesion
Which myotome is assessed with shoulder abduction
C5 (axillary nerve)
Which myotome is assessed with shoulder adduction
C6/7 (thoracodorsal nerve)
Which myotome is assessed with elbow flexion
C5/C6 (musculocutaneous and radial nerve)
Which myotome is assessed with elbow extension (triceps)
C7 (radial nerve)
Which myotome is assessed with wrist extension
C6 (radial nerve)
Which myotomes are assessed with wrist flexion
C6/C7 (median and ulnar nerves)
Which myotome is assessed with finger extension
C7 (radial nerve)
Which myotome is assessed by finger abduction
T1 (ulnar nerve)
Which myotome is assessed by thumb abduction
T1 (median nerve)
Which myotomes are assessed by biceps reflex
C5/C6
Which myotomes are assessed by brachioradialis reflex
C5/C6
Which myotome is assessed by triceps reflex
C7
Which spinal column does pin-prick sensation involve
Spinothalamic tracts
Which tests involve the dorsal columns
Vibration, proprioception, light touch
What is myotonic dystrophy
Autosomal dominant multisystem disorder
Progressive muscle weakness, myotonia and early onset cataracts (+ many more)
What are the 2 types of myotonic dystrophy
Type 1: CTG trinucleotide repeat that demonstrates anticipation
Type 2: tetranucleotide repeat, doesn’t show as much anticipation
Both AD
What is myotonia
Inability of a contracted muscle to relax
E.g. difficulty letting go of something after grasping, difficulty opening eyes after closing
What are the clinical features of myotonic dystrophy
Frontal balding, bilateral ptosis, temporalis and masseter weakness (myopathic face)
May have CPAP machine by bed (resp muscle weakness)
Eyelid myotonia - close eyes very tight for 5s then ask to open, pt will have difficulty opening
What is the clinical difference between type 1 and 2 myotonic dystrophy
Type 1: distal weakness
Type 2: proximal weakness
How can you assess myotonia
Ask pt to grip your fingers for 5 seconds then relax - difficulty relaxing
What causes a RAPD
Any cause of unilateral optic nerve damage:
- Optic neuritis (MS, NMO)
- ischaemic optic neuropathies (GCA)
- glaucoma
- sarcoid, SLE, Sjögren’s
- infection (cat scratch disease, syphilis, Lyme, CMV etc)
- hereditary (eg Leber’s)
Unilateral retinal causes:
- ischaemic retinal disease (CRVO, CRAO)
- retinal detachment
- severe macular degeneration
- retinal infection (CMV, HSV)
What is the driving advice after a first seizure
6 months
What is the driving advice after an epileptic seizure
1 year
What is the difference between optic neuropathy and optic atrophy
Optic neuropathy = optic nerve not working
Optic atrophy = optic nerve permanently and irrecoverably damaged (looks pale on fundoscopy)
What can transiently make MS symptoms worse
Increased body temperature (hot showers, going for a run) - Uhthoff phenomenon
Where is the lesion typically found in INO
Brainstem
- affected side will fail to adduct on lateral gaze, other side will develop nystagmus
Where is the lesion usually found in a RAPD
Optic nerve
What is the NIHSS used for
Quantify severity of stroke
What is the modified rankin scale used for
Measure the degree of disability after a stroke
What are the features of an occulomotor nerve palsy
Ptosis
Strabismus - down and out gaze
Ophthalmoplegia - failure to adduct
Dilated pupil - if surgical nerve palsy
What are the first line medical options for Parkinson’s disease
- Co-beneldopa/co-careldopa
- MAO-B inhibitors e.g. selegiline
- dopamine agonists e.g. ropinirole, pramipexole, rotigotine
Which Parkinson’s meds increase risk of impulse control disorders
Dopamine agonists
What are the complex management options for Parkinson’s disease
Deep brain stimulation, apomorphine infusion, duodopa (gel version of dopamine into jejunum via PEJ)
What will happen during Weber’s test in conductive hearing loss
Heard in the bad ear
What will happen during Weber’s test in sensorineural hearing loss
Heard in the good ear
What happens during rinne’s test in conductive hearing loss
Bone conduction > air conduction
What happens during rinne’s test in sensorineural hearing loss
Air conduction > bone conduction
What does a positive rhomberg’s indicate
Loss of proprioceptive (or vestibular) function
(Does not assess cerebellar function)
What are the nerve roots of the femoral nerve
L2-L4
What are the motor functions of the femoral nerve
Anterior thigh muscles (flex hip, extend knee)
What is the sensory function of the femoral nerve
Anteromedial thigh, medial leg
What are the nerve roots of the sciatic nerve
L4-S3
What is the motor function of the sciatic nerve
Posterior thigh
Whole leg (tibial + common fibular nerve branches)
Whole foot (tibial + common fibular)
What is the sensory function of the sciatic nerve
No direct sensory innervation
Tibial branch - posterolateral leg, lateral foot, sole of foot
Common fibular - lateral leg, dorsum of foot
What nerve damage causes foot drop
Common or deep fibular nerve
Where will wasting and weakness be seen most in myotonic dystrophy
Distal muscles (type 1 most common)
What are the extra-neurological features of myotonic dystrophy
Frontal balding
Cataracts
Cardiomyopathy
Diabetes
Testicular atrophy
Dysphagia
What will show up on EMG in myotonic dystrophy
‘Dive-bomber’ potentials
What are the common causes of bilateral ptosis
- Myotonic dystrophy
- Myasthenia Gravis
- Oculopharyngeal muscular dystrophy
- Chronic progressive external ophthalmoplegia (Kearns-Sayre)
- Congenital
What are the common causes of unilateral ptosis
Third nerve palsy, Horner’s syndrome
In a cerebellar lesion, which way does the fast-phase of nystagmus go in relation to the lesion
Towards the lesion
In a CNVIII/vestibular lesion, which way does the fast-phase of nystagmus go in relation to the lesion
Away from the lesion
What are the causes of cerebellar syndrome
Paraneoplastic
Alcoholic
Sclerosis (MS)
Tumour
Rare (Freidrich’s, ataxia telangiectasia)
Iatrogenic (phenytoin toxicity)
Endocrine (hypothyroidism)
Stroke
What are the common cranial nerve findings in MS
INO (can be bilateral), optic atrophy, reduced visual acuity, any other cranial nerve palsy
What are the common limb nerve findings in MS
UMN spasticity, weakness, brisk reflexes, altered sensation
What will be seen on visual evoked potentials in MS
Delayed velocity but normal amplitude (evidence of previous optic neuritis)
What are the DMARDS used in MS
Interferon-beta (reduces relapse)
Alemtuzumab (anti-CD52) and Natalizumab (blocks T-cell trafficking) - slow progression
Which drugs are useful in acute attack of MS
- Methylprednisolone - shortens duration
- anti-spasmodics e.g. baclofen
What is MRC grade 2 power
Moves with gravity neutralised
What extended investigations should be considered in a young person with CVA
- echo
- MRI/A/V (dissection, VST)
- clotting screen inc APLS
- vasculitis screen
What is Gerstmann’s syndrome
Dominant parietal lobe cortical syndrome:
- dysgraphia, dyslexia, dyscalculia
- L-R disorientation
- finger agnosia
What is the most common brainstem vascular syndrome
Lateral medullary (Wallenberg) syndrome
Which artery is occluded in lateral medullary (Wallenberg) syndrome
Posterior inferior cerebellar artery (PICA)
What are the clinical signs associated with lateral medullary (Wallenberg) syndrome
- Ipsilateral cerebellar signs
- Ipsilateral nystagmus
- Ipsilateral Horner’s
- Ipsilateral loss of trigeminal pain and temperature sensation
- contralateral loss of pain and temperature sensation
What are the causes of retinitis pigmentosa
- Usher’s syndrome
- Bardet-biedl syndrome
- Kearns-Sayre syndrome
- Refsum’s disease
- Abetalipoproteinemia
- Familial isolated vit E deficiency
Which condition presents with a lower motor neuropathy and peri-oral faciculations
Kennedy’s disease
What is the inheritance of Kennedy’s syndrome
X linked recessive
What exam features can distinguish between ALS and Kennedy’s disease
Fasciculations around mouth/neck in Kennedy’s syndrome
Kennedy’s is only LMN, ALS is UMN+LMN
What features in the history can differentiate between ALS and Kennedy’s
- ALS has rapid progression over months, Kennedy’s is gradual over years
- Kennedy’s will have family Hx
Which myotome assesses ankle dorsiflexion
L4/L5 (deep peroneal nerve)
Which myotome is assessed with big toe extension
L5 (common peroneal nerve)
Which nerve roots are assessed with knee jerk
L3, L4 (quadriceps - femoral nerve)
Which myotome is assessed with ankle jerk
S1
Where is the lesion in foot drop with preserved eversion
Deep branch of common peroneal nerve
Where is the lesion in foot drop if the only sensory loss is 1st webspace
Deep branch of common peroneal nerve
Which nerve does the common peroneal arise from
Sciatic nerve
What are the 4 lacunar syndromes
- Pure sensory
- Pure motor
- Sensorimotor
- Ataxic hemiparesis (Ipsilateral cerebellar-like ataxia)
Which condition can cause a pseudo-INO due to fatiguability of the ocular muscles
Myasthenia gravis
What side is the lesion on in INO
The side of the eye that fails to ADduct
What are the causes of simultaneous bilateral optic disc swelling
- Malignant hypertension
- Raised ICP (papilloedema)
What does rebound phenomenon indicate
Cerebellar syndrome (inability for arm to move back to original position after pushing downwards with pts eyes closed)
Which drugs result in a cerebellar syndrome
Phenytoin
Lithium
Carbemazapine
Chemotherapy agents
What is the significance of ankle jerk in foot drop
- Unaffected in common peroneal nerve palsy
- depressed in motor neuropathy
How can a common peroneal nerve palsy and L5 nerve root lesion be differentiated as a cause of foot drop
- positive SLR with L5 lesion
- weakness of inversion and eversion with L5 lesion (only eversion with CPN)
- sensory loss extends to lateral thigh with L5 nerve lesion
What is the most common cause of an L5 nerve root lesion
L4-L5 disc prolapse
What are the causes of a mononeuritis multiplex
- diabetes
- vasculitis (PAN, EGPA, GPA)
- Rheum (RA, SLE, Sjögren’s)
- infiltrative (sarcoid, amyloid)
- malignancy
- infection (Lyme, Leprosy)
What is the DDx of depressed knee and ankle jerks with extensor plantars
- Combination of conditions (eg peripheral neuropathy + stroke, or cervical + lumbar spondylosis)
- SCD (B12 deficiency)
- Tabes dorsalis (syphilis)
- Freidrich’s ataxia
- MND
- Lesion of conus medullaris
What are the extra-neuronal features of Freidrich’s ataxia
- Hypertrophic cardiomyopathy (50%)
- Optic atrophy (25%)
- Diabetes (10%)
- Sensorineural deafness (10%)
What does the presence of pyramidal, cerebellar and/or dorsal column signs point towards
Multiple sclerosis
What is the classic triad of miller fisher syndrome
Ophthalmoplegia, ataxia and areflexia
What are the causes of Lhermitte’s sign
- MS
- cervical myelopathy
- cervical cord tumour
- SCD
What are the causes of CSF oligoclonal bands
- MS (present in 80% of cases)
- Neurosarcoidosis
- Neurosyphilis
- CNS lymphoma
- NMO
- GBS
- SSPE
What is a scissoring gait suggestive of
Spastic paraparesis
What are the common causes of spastic paraparesis of the lower limbs
- multiple sclerosis
- cervical myelopathy
- trauma to spinal cord
- MND
What are the upper limb signs in syringomyelia
- weakness and wasting of small muscles of hands
- absent reflexes
- loss of pain and temp, normal dorsal columns
What are the common causes of Charcot joints
- tabes dorsalis
- diabetes
- syringomyelia
What are the neurological causes of pes cavus
- HSMN (CMT)
- cerebral palsy
- Freidrich’s ataxia
- spinal cord lesions
- poliomyelitis
- ALS
- leprosy
- Huntington’s
What causes weakness, dramatic wasting, areflexia and lower limb shortening
Polio
What does pes cavus suggest
Chronic neuromuscular disease, usually one that started in childhood
What are the cardinal components of pseudobulbar palsy
Dysphagia, dysarthria, emotional apathy
What causes a Donald-duck ‘nasal’ like speech
Bulbar dysarthria (LMN) causing palatal weakness
What are the causes of a bulbar palsy of CN IX, X and XII (LMN)
- MND
- Syringobulbia
- GBS
- Neurosyphilis
What are the causes of a pseudobulbar palsy of CN IX, X and XII (UMN)
- bilateral stroke affecting the internal capsule
- Multiple sclerosis
- MND
What is the speech like in bulbar palsy
Nasal speech - Donald Duck (LMN)
Which neurological conditions demonstrate anticipation
- myotonic dystrophy
- Huntington’s chorea
- freidrich’s ataxia
What is the pattern of sensory loss in syringomyelia
Loss of pain and temp in upper limb, preserved joint position and vibration
Which muscles are most commonly affected in inclusion body myositis
Proximal muscles (quadriceps) and finger flexors
What is the differential for MND with a pure LMN presentation
- multifocal motor neuropathy with conduction block
- spinobulbar muscular atrophy (kennedy’s)
- motor-predominant CIDP
- benign fasciculations
- inclusion body myositis
- spinal muscular atrophy
What is the differential for MND with a pure UMN presentation
- primary progressive MS
- hereditary spastic paraparesis
- vitamin B12 deficiency
What is the differential for MND with a mixed UMN and LMN presentation
- cervical myelopathy
- syringomyelia
- B12 deficiency
What does the “on off phenomenon” associated with levodopa describe
Phases of improved Parkinson symptoms followed by sometimes abrupt wearing off of dopamine effect, associated with dyskinesias
What are the non-motor features of Parkinson’s
- Anosmia
- REM sleep disorder
- constipation
- pain
- orthostatic hypotension
- mood disturbance
- cognitive impairment
- visual hallucinations
What determines urgency of MRI spine in patients with myelopathy
- Onset and rapid progression of symptoms
- severity of symptoms
What are the 3 cardinal signs of Friedrich’s ataxia
- Bilateral cerebellar ataxia
- Dorsal column signs
- Leg wasting with absent reflexes and bilateral upgoing plantars
Other than the 3 cardinal features, what are the other signs of Friedrich’s ataxia
- wheelchair/ataxic gait
- pes cavus
- optic atrophy
- HOCM
- diabetes
- high arched palate
- sensorineural deafness
What is the inheritance pattern of Friedrich’s ataxia
Autosomal recessive
What are the causes of extensor plantars and absent knee reflexes
- Friedrich’s ataxia
- SCD
- MND
- tabes dorsalis
- conus medullaris lesions
- concurrent UMN+LMN pathologies
What are the skin changes associated with tuberous sclerosis
- facial adenoma sebaceum
- periungual fibromas
- shagreen patches
- ash leaf macules
What are the renal manifestations of tuberous sclerosis
- renal angiomyolipomas
- renal cysts
- renal carcinoma
(genes for TSC and AKPKD both on Chr 16 so some overlap)
What are the CNS features of tuberous sclerosis
- Epilepsy in 80%
- Low intelligence in 50%
What condition is associated with retinal phakomas on fundoscopy
Tuberous sclerosis
What are the investigations into tuberous sclerosis
- urine dip
- bloods inc UEs
- CT/MRI head - tuberous masses
- abdo USS - renal cysts
How can ocular myaesthenia be tested for on exam
Sustained upwards gaze will cause worsening ptosis and diplopia
What is the speech like in pseudobulbar palsy (UMN)
‘Hot potato’ strangling speech due to spastic tongue
What are the causes of a postural tremor (worse with hands outstretched)
- benign essential tremor
- anxiety
- thyrotoxicosis
- C02 retention, hepatic encephalopathy
- alcohol
What are the causes of painful diplopia
Restrictive causes: trauma, myositis, thyroid
What are the causes of painless diplopia
Neurological causes (CN III, IV, VI palsies, MG)
What are the cutaneous manifestations of neurofibromatosis
- Cutaneous neurofibromas (>=2)
- Cafe au lait patches (>6, >15mm)
- Axillary freckling
- Lisch nodules in eyes
What are the visceral findings associated with neurofibromatosis
- Hypertension (phaeochromocytoma, renal artery stenosis)
- Lung fibrosis
- Neuropathy
- Reduced visual acuity (optic glioma)
What are the complications of neurofibromatosis
Epilepsy
Intellectual disability (10%)
Hypertension (phaeochromocytoma, renal artery stenosis)
Sarcomatous change (5%)
Scoliosis (5%)
What is the inheritance of neurofibromatosis
Autosomal dominant
What are the causes of chorea
- Huntington’s
- Wilson’s
- Rheumatic fever
- Stroke
- Drugs (levodopa, phenytoin, carbamazapine)
- SLE
What are the 5 screening tools that can be used at the start of UL neuro exam
- Pronator drift
- Tight grip and release
- Finger tapping
- Touch chin
- Hands forward and feel scapulae
What are the 3 tests of motor function in the hands for the 3 main nerves
Radial - finger extension
Ulnar - finger abduction
Median - thumb abduction
What is the difference between spasticity and rigidity
Spasticity (pyramidal) - velocity dependent
Rigidity (basal ganglia) - velocity independent
What are the differentials for cerebellar + UMN signs
- spinocerebellar ataxia
- MS
- B12 deficiency
- vascular (multiple strokes)
- paraneoplastic
- Friedrich’s ataxia
How can a resting tremor be exaggerated in PD
Ask patient to count backwards from 20 during initial inspection
List the Parkinson plus syndromes
- MSA
- PSP
- Drugs - antipsychotics, antiemetics
- Wilson’s, Huntingtons
- Vascular - symmetrical, LLs
- Corticobasal degeneration
- Toxins - MPTP
What are the causes of a bilateral cerebellar syndrome
- alcohol
- B12 deficiency
- toxins/drugs (eg phenytoin)
- paraneoplastic
- neuroinflammatory (eg MS)
- genetic (SCA, Friedrich’s, AT)
What are the 3 types of tremor
- Resting - PD
- Postural (worse when arms out)
- Intention - cerebellar
What are the causes of a bilateral spastic scissoring gait
- cortical: parasagittal meningioma, CP
- brainstem: stroke, inflammatory
- spinal: tropical infection, neuroinflammatory, compression, vascular, metabolic
What does difficulty with tandem gait but negative rhomberg’s suggest
Cerebellar ataxia
What does difficulty with tandem gait and positive rhomberg’s suggest
Sensory ataxia
What question can be used to determine if diplopia is monocular or binocular
Does the double vision resolve with closing either eye?
What is the difference in presentation of optic neuritis in MS vs NMO
MS: red vision loss, painful eye movements
NMO: under 20, female, rapid and profound bilateral vision loss
What are the key investigations for myaesthenia gravis
- antibodies (AchR Ab, MUSK)
- repetitive nerve stimulation
- single fibre EMG
- CT Thorax
+ thyroid Abs/TFTs
Which sensory modalities do large fibres carry
Vibration, proprioception
What are the acute causes of a lower motor neuropathy
- Guillian Barre
- Botulism
- Transvere myelitis/cauda equina
Chronic causes = HSMN, CIDP, Lead poisoning, porphyria
What is the difference between type 1 and type 2 HSMN on neurophysiology
Type 1: demyelinating
Type 2: axonal
What are the differentials for a typical myaesthenia gravis presentation
- LEMS
- Botulism
- Inclusion body myositis
What is the first line management of stable myasthenia gravis
Pyridostigmine
(Consider corticosteroid as adjunct)
Which drugs can worsen myasthenia gravis
Penicillamine
Quinidine
Gentamicin
+ BASIC LM (b-blockers, acetazolomide, statins, Iodine, CCB, Lithium, Magnesium)
What is the clinical hallmark of multifocal motor neuropathy with conduction block
Finger drop
What are the features of transverse myelitis
- sensory/motor/autonomic dysfunction
- no evidence of cord compression
- bilateral signs/symptoms
- clearly defined sensory level
- CSF inflammation/T2 signal change on MRI
What is the usual onset of transverse myelitis
Hours to days
What are the causes of transverse myelitis
- Demyelination (MS, NMO, ADEM)
- Infection (HSV, Hep, CMV, EBV, TB..)
- Inflammatory (SLE, sarcoid, Sjögren)
- Paraneoplastic (Anti-GAD, anti-Hu)
- Nutritional (B12, copper)
Which manouvres can be performed during examination to look for meningism
- kernig’s sign (pain on straightening knee)
- brudzinski sign (flex knee on neck flexion)
What are the central causes of Horner’s syndrome
- Brain/brainstem - stroke, SOL, brainstem demyelination
- Spinal cord - trauma, syringomyelia
What are the causes of a surgical third nerve palsy
- PCA aneurysm
- Cavernous sinus pathology
- Uncal herniation
What are the causes of a medical third nerve palsy (normal pupil)
- mononeuritis multiplex (e.g. DM)
- midbrain infarct
- midbrain demyelination (e.g. MS)
How will brown-sequard syndrome present
- Ipsilateral asymmetrical spastic paresis
- Ipsilateral loss of vibration and proprioception
- contralateral loss of pain and temperature
What are the causes of a brown-sequard syndrome
- Compressive: disc herniation, tumours, spinal stenosis
- AI: MS, lupus, sarcoid
- Infectious: HIV, VZV
- Nutritional: B12 deficiency
What are the differentials for a partial seizure
- migraine with aura (lasts hours)
- TIA (negative symptoms)
- Transient global amnesia (elderly)
When is a CT head indicated in suspected TIA
- anticoagulated
- residual neurology
- headache
Otherwise, can start aspirin and refer to TIA clinic for MRI brain