Neurology Flashcards
UL examination - how to elicit cerebellar signs
1) Rebound test:
Arms outstretched, push one arm down, will oscillate back to normal position
2) May see titubation in head/trunk (truncal ataxia)
3) Speech: scanning characteristic
4) Coordination: intention tremor, past pointing DDK
Causes of cerebellar signs:
Metabolic causes:
- alcohol excess
- B12 deficiency
- Hypothyroidism
Vascular eg posterior circ stroke
SOL in posterior fossa
Demyelination eg MS
Iatrogenic causes: Phenytoin (gingival hypertrophy)
Genetic causes: Freidrich’s ataxia, ataxia telangiectasia
Also paraneoplastic syndrome: look for signs of lung Ca
Approach to cerebellar examination
1) Gait: ataxic
2) Arms:
- Outstretched
- Test for rebound tenderness
- Test for pronator drift
3) Face:
- Nystagmus (fast phase towards side of lesion)
- Loss of smooth pursuit of eye movements
- INO: think MS
- Scanning speech
4) Hands:
- Intention tremor
- DDK
Myotonic dystrophy: UL examination
Inspection:
- Face: frontal balding, temporal wasting, bilateral ptosis, expressionless
- Hands: Thenar wasting
- PACEMAKER
- Feeding tube (oesophageal dysmotility)
Tone: Slow hand grip release
Power: Reduced distally > proximally
Coordination: intact
Reflexes: reduced.
- PERCUSSION MYOTONIA (thenar eminence)
Sensation: intact
DDx for ptosis
Bilateral ptosis:
- hypothyroidism
- myasthenia pathology: myasthenia gravis, Lambert-Eaton syndrome
- inherited neuromuscular disorders: Myotonic dystrophy, Facioscapulohumeral dystrophy
Unilateral:
- 3rd nerve palsy
- Facial nerve palsy (Bell’s palsy)
- Horner’s syndrome
- Congenital
Pathophysiology of myotonic dystrophy?
Autosomal dominant
Trinucleotide expansion results in myotonia.
Investigations for myotonic dystrophy
Bedside:
- ECG: cardiomyopathy/conduction delays
- CBG or urine dip: diabetes
Blood tests:
- HbA1c
- CK may be raised
Specialist testing:
- EMG
- Genetic testing
- Echocardiogram (cardiomyopathy)
- If concerns re: swallow - consider a barium meal
Complications of myotonic dystrophy
Top to toe:
- Eyes: cataracts
- Cardiac: conduction delays, cardiomyopathy
- GI: impaired swallow, oeseophageal dysmotility
- QOL: fatigue, psychiatric
Signs of ulnar neuropathy:
Inspection:
- Scars at wrists of elbows
- “Ulnar claw”: flexion of 4th and 5th fingers
Power: Weakness of finger abduction
- Thumb abduction maintained if no median nerve involvement
Sensation:
- Split ring finger sensation
Causes of ulnar neuropathy
Trauma e.g. fracture
Ulnar nerve nerve entrapment
- Functional e.g. repetitive elbow flexion and extension (builder)
- Associated with other conditions e.g. acromegaly
Iatrogenic e.g. surgery
Inflammatory neuropathy e.g. vasculitis
How to differentiate pure ulnar neuropathy from C8/T1 nerve root lesion?
In C8/T1 nerve root lesion, there would be:
- Loss of sensation at T1 (inner upper arm)
- Involvement of radial nerve: wrist extension
- Involvement of median nerve: thumb abduction
- Involvement of posterior interosseous nerve: finger extension
Investigations for ulnar neuropathy
Neurophysiology: Electromyography (EMG)
- Can give an indication of prognosis
MRI neck if concerned about cervical radiculopathy
Causes of chorea
Basal ganglia
Acute onset: always consider stroke (usually unilateral)
Metabolic: hypoglycaemia, uraemia
Drug-related: dopamine agonists (L-dopa), amphetamines
Post-infection: Sydenham’s chorea
Vasculitis: SLE
Neurogenetic: Huntington’s disease, Wilson’s disease
Complications of Huntington Disease
- Impaired motor function
- Cognitive impairment
- Neuropsychiatric disturbance
- Malnutrition - due to 1) increased calorific requirement secondary to involuntary movements and 2) impaired swallow
Post Polio Syndrome - examination features
Look for asymmetric wasting, weakness, arreflexia with usually preserved sensation
Inspection:
- Walking aids, splints
- Possible scars
- Leg length discrepancy
- Muscle wasting
Tone: Hypotonia
Power: Reduced
Reflexes: Absent
Sensation: usually preserved
Management of Huntington Disease
- MDT approach aiming to achieve symptomatic control
- Led by consultant with special interest
- Neuropsychiatrist
- Specialist nurses
- Dietitian
- Psychosocial support
- Genetic counsellors
If there is LMN weakness with sensory involvement, the lesion could be in the…
Nerve root
Plexus
Peripheral nerve
If there is LMN weakness with sensory involvement, the lesion CANNOT be…
Muscle
NMJ
Anterior horn
(these are all pure motor)
Motor neuron disease - definition
Progressive disease characterised by axonal degeneration of both upper and lower motor neurons
Motor neuron disease - examination
Inspection: Wasting, fasciculations
Tone: Can be spastic or flaccid (more commonly spastic)
Power: Reduced, often asymmetric
Reflexes: Mixed
Coordination: Intact
Sensation: NORMAL
Motor neuron disease DDx
Causes of pure motor pathology (without sensory involvement)
- Demyelination (GBS/CIDP/MS)
- Muscular dystrophy
- NMJ disorders: myasthesia gravis/LEMS
Causes of mixed UMN and LMN signs (but these would all have sensory involvement:
- Cervical Myelopathy (UMN signs from spinal cord involvement + LMN signs from nerve root involvement)
- Dual pathology (eg: cervical myelopathy and peripheral neuropathy)
- Inherited disorders e.g. Friedrich’s ataxia: progressive ataxia with mixed UMN/LMN signs
How does MND present?
- Asymmetric progressive weakness
- Rapid disease course
- Cognitive dysfunction - associated with frontotemporal dementia
MND subtypes
Amyotrophic lateral sclerosis:
- Both UMN and LMN involvement
- typically spastic paraparesis
Primary lateral sclerosis:
- Predominantly UMN
Progressive muscular atrophy:
- Predominantly LMN
Progressive bulbar palsy:
- Lower cranial nerves and suprabulbar nuclei
Investigations for cerebellar ataxia
Acute onset - investigate for stroke
- CT Head in first instance
More chronic onset
- think about Metabolic or Demyelinating causes
- Serum B12, thyroid function
- Alcohol history
- Consider LP for MS
- In all cases - MRI Brain is the optimal imaging for the cerebellum
How to differentiate sensory ataxia from cerebellar ataxia
Cerebellar ataxia will have additional features:
- Scanning speech
- Nystagmus
Sensory ataxia will have positive Romberg’s
Management of ataxic syndromes
1) Address underlying cause
2) MDT approach:
- PT/OT
- Neurology
Aiming to preserve functional abilities
Which subtypes of motor neuron disease have the best/worst prognosis?
Best prognosis: Primary lateral scleosis (typically UMN only)
Worst prognosis: Progressive bulbar palsy
Motor neuron disease - investigations
Electrophysiology: EMG would show fasciculations and fibrillations
MRI spine to rule out cervical myelopathy
Motor neuron disease - management
MDT approach led by a consultant with special interest in MND, alongside specialist nurses, physiotherapists etc.
Cause:
- Pharmacological management - Riluzole (adds a few months to prognosis)
Symptoms:
- Pain management
Complications:
- Mobility - PT, OT
- Feeding and minimising aspiration risk e.g. artificial feeding
- Monitor respiratory function +/- ventilatory support
- Neuropsychiatric screening
- Psychosocial support
Complications of MND
- Motor functional impairment
- Cognitive decline (frontotemporal dementia)
- Impaired swallow - may need artifical feeding
- Respiratory muscle weakness - may need respiratory support e.g. NIV
How does Brown Sequard syndrome present?
- Unilateral spastic paraparesis
- There is ipsilateral spasticity and loss of dorsal column sensation
- Contralateral loss of spinothalamic tract
So the affected leg will have:
- spastic weakness
- loss of vibration/proprioception
- preserved pinprick sensation (other leg loses pinprick sensation)
Causes of spastic paraparesis
Acute spastic paraparesis:
- Cord compression
- Trauma
- Anterior spinal artery occlusion
- Stroke (but usually hemiplegia rather than paraparesis)
Acquired causes with more subacute-chronic onset:
1) Compression of the spinal cord
- Disc herniation
- Spinal stenosis
- Malignant cord compression
2) Demyelination: Multiple sclerosis, transverse myelitis
3) Metabolic: B12 deficiency → SACD
4) Autoimmune: SLE, sarcoidosis
5) Inherited causes: Friedrich’s ataxia
6) Infection: HIV
In general the acquired causes can be asymmetric
Causes of absent ankle jerks and upgoing plantars?
- Subacute combined degeneration of the cord
- Friedrich’s ataxia
- Conus medullaris syndrome
- Combined pathology e.g. diabetic neuropathy and stroke
Neuropathic pain management
1) Tricyclic antidepressant - amitryptilline
2) Anti-epileptic e.g. gabapentin
3) SNRI - duloxetine
TCA side effects
Drowsiness
Dry mouth
Headache
Causes of peripheral sensory neuropathy
Metabolic - DBAT
- Diabetic neuropathy
- B12 deficiency
- Alcohol
- Thyroid (Hypothyroidism)
- Uraemia
Drugs
- Chemotherapy
- Isoniazid (TB)
Inflammatory causes
- Vasculitis
Genetic causes e.g. hereditary sensorimotor neuropathy
Further bedside tests if you see peripheral neuropathy
- Fundoscopy to assess for diabetic retinopathy
- CBG
- Urinalysis to test for glycosuria
Investigations for peripheral sensory neuropathy
Bedside: fundoscopy, urinalysis, CBG
Bloods:
- FBC, U+Es, LFTs
- HbA1c
- B12
- TFTs
- Autoimmune screen
Special tests:
- EMG
- Nerve conduction studies - assess whether it is demyelinating or axonal
IF UMN signs e.g. in SACD, MRI spine too
Management of diabetic neuropathy
Treat cause: Tight glycaemic control
- Patient education
- DSN involvement
Treat symptoms:
- Neuropathic pain: stepwise approach (TCA)
Treat complications:
- Regular podiatry/foot clinic for foot care
- Physiotherapy for gait stability
Causes of peripheral motor neuropathy (flaccid paraparesis)
Think: Nerve, Muscle, NMJ
ACUTE ONSET:
Nerve = Guillain Barre syndrome
- ascending flaccid paralysis
- typically sensory only, but some subtypes have motor involvement
SUBACUTE OR CHRONIC:
Nerve = Chronic Inflammatory Demyelinating Polyradiculopathy
Muscle
- Muscular dystrophy (Becker)
- Polymyositis
NMJ = Myasthenia gravis (would expect fatiguability)
Other:
Hereditary sensorimotor neuropathy (would expect sensory loss, distal wasting and pes cavus)
Diabetic neuropathy (predominantly sensory but can have some motor component)
Vasculitis e.g. polyarteritis nodosa
Charcot Marie Tooth - examination
Inspection:
- Ankle-foot brace
- Distal wasting
- Pes cavus
Gait: high stepping gait
-Romberg’s +ve
Tone: flaccid
Power: reduced, mainly distal weakness
Reflexes: reduced distally
Coordination: intact
Sensation: Reduced in all modalities
Charcot-Marie-Tooth inheritance
Autosomal dominant
Charcot-Marie-Tooth specific investigations
Neurophysiology
- EMG and nerve conduction studies
- Type 1 is demyelinating
Genetic testing
Anterior circulation stroke - features
Total anterior circulation stroke: 3 H’s
- Hemiplegia (legs > arms)
- Homonymous hemianopia
- Higher cortical dysfunction
Partial anterior circulation stroke:
- 2 of the above
Friedrich’s ataxia - inheritance
autosomal recessive
frataxin gene mutation
Friedrich’s ataxia - examination
- Inspection: mobility aid, distal wasting, truncal ataxia, may notice dysarthria
- Tone: normal or spastic
- Power: reduced globally
- Reflexes: absent with upgoing plantars
- Coordination: ataxic
- Sensation: loss of vibration and proprioception
Friedrich’s ataxia DDx
- Spinocerebellar ataxia
- Subacute combined degeneration of the cord*
- Cervical myelopathy*
- Combined pathology e.g. spinal cord compression with peripheral neuropathy*
*Wouldnt expect cerebellar signs
Friedrich’s ataxia investigations
Bedside: ECG (Arrhythmia), urine dip for glycosuria
Bloods: FBC, U+Es, CRP, B12, vitamin E, HbA1c
Imaging: MRI brain and whole spine, echo
Neurophysiology: nerve conduction, EMG
Genetic testing
Friedrich’s ataxia management
- No pharmacological management
- MDT approach: neurology, specialist nurses, PT, OT, orthotics, psychiatry
- Serial ECGs, echo +/- cardiology reviews
- Monitor for diabetes
- Palliative care for symptom control
Friedrich’s ataxia complications
- Cardiomyopathy (HOCM leading cause of death)
- Diabetes mellitus
- Sensorineural deafness
- Functional limitations
- Psychological impact
Rinne’s and Weber’s test
First do Webers:
Louder in one ear means there is either
- conductive loss in that ear
- sensorineural loss in the other ear (because the louder ear’s nerve is able to compensate)
Then do Rinne’s on the louder ear.
- AC > BC = not conductive hearing loss
- BC > AC = conductive hearing loss
If inconclusive: do Rinne’s on the quieter ear.
- If AC > BC, this is sensorineural hearing loss.
Myasthenic gravis - examination
Fatiguability testing -
Cranial nerves: sustained upwards gaze leading to diplopia and partial ptosis
Upper limbs: Repeated shoulder abduction/adduction leading to weakness
Myasthenia gravis UL examination - differential
Proximal myopathy
Myasthenia gravis Investigations
Bloods:
- anti-acetylcholine receptor antibodies (80%)
- anti-musc antibodies (15%)
Imaging: CT Chest to assess for thymoma
Neurophysiology: Nerve conduction shows fatiguability
FVC (<1.5L needs referral to HDU)
Myasthenia gravis management
Myasthenic crisis:
- IV steroids
- Measure FVC and ABGs
- FVC <1.5L warrants referral to HDU
Stable patients:
- Pyridostigmine (acetylcholinesterase inhibitor)
- Steroid sparing agents
- Consider referral for monoclonal Abs e.g. rituximab
- Consider thymectomy
Multiple sclerosis - examination
Patchy, mixed sensory and motor involvement in asymmetric pattern
Inspection; may have mobility aid
Tone: Typically spastic
Power: Asymmetric weakness
Reflexes: Brisk or normal
Coordination: intact, unless cerebellar involvement
Sensation: May have patchy parasthesia
Multiple sclerosis: investigations
- MRI brain + whole spine
- LP: oligoclonal bands
Multiple sclerosis management
MDT approach
Acute relapse: high dose IV steroids for 5 days
Maintenance: DMARD e.g. beta-interferon or natalizumab
Symptom control e.g. baclofen for spasticity; intermittent self cath for urinary retention
Supportive: PT, OT, psychological
Stroke territories
Anterior circulation stroke (ACA or MCA)
- TACS: Hemiplegia, Homonymous hemianopia and Higher cortical dysfunction
- PACS: 2/3 of the above
- Anterior cerebral artery: Legs weaker than arms
- Middle cerebral artery: Arms weaker than legs
Homonymous hemianopia DDx
With macular sparing: Posterior circulation stroke
Without macular sparing: Anterior circulation stroke
(Use Humphreys visual field testing to confirm)
Extra-neurological examination in stroke
Pulse (AF)
Carotid Bruits
Heart auscultation for murmurs
Blood pressure
Stroke investigations
Acute:
CT Brain to rule out Haemorrhage
Longer term:
- Blood pressure
- Lipids, HbA1c
- Holter (24 or 72h tape)
- Echocardiogram
- Ultrasound doppler of carotids - stenosis >50% for carotid endarterectomy
Stroke management
Acute:
- Refer to HASU
- Thrombolysis (within 4.5h)
- Thrombectomy (within 24h including wake up strokes)
Chronic:
- Secondary prevention; Clopidogrel + ACEi + statin
- Manage risk factors: BP, HTN, diabetes, lipids
- Consider carotid endartectomy if >50% stenosis
Neurofibromatosis1 features
Chromosome 17
CAFE NOIR
- Cafe-au-lait spots: 6 x 15mm
- Axillary freckling
- Fibromas (2+ neurofibromas)
- Eyes: 2x Lisch nodules*(iris harmatomas)
- Neoplasm (CNS tumour/phaeochromocytoma)
- Ortho - scoliosis, kyphosis
- IQ reduced
- Renal artery stenosis
Needs 2 of the above OR
1 + family history
Drug induced parkinsonism causes
Dopamine antagonists
Neuroleptic agents: Quetiapine, risperidone
Anti emetics: metoclopramide
Tuberous sclerosis complex features
“Remember Tuberous Sclerosis Complex”
Renal: angiomyoplipoma, RCC
Tumours: brain
Skin: peri-ungual fibromas, ashl-leaf macules, shagreen patches
Cardio: Rhabdomyoma
Tuberous sclerosis inheritance
Autosomal dominant
Tuberous sclerosis investigations
Bloods: standard + genetic testing
ECG
Imaging:
- Echo
- MRI brain
- US KUB +/- MRI renal
Neurofibromatosis type 2 features
- Acoustic neuromas (hearing aids)
- Meningiomas
- Seizures
Complications of neurofibromatosis
HTN: ‘CPR’
- Coarctation of aorta
- Phaeochromocytoma
- Renal artery stenosis
Neurological:
- Seizures
- Brain tumours
- Hearing loss in type 2
