Neurology Flashcards
Causes of bilateral facial nerve palsy
- Infection
- meningitis
- Lyme’s disease - Granulomatous disease
- Sarcoid - Inflammatory disease
- guillan barre disease - Trauma
- base of skull fracture - Malignancy
- leukaemia
Differential diagnosis of chorea
- Genetic
- Huntington’s disease - anticipation of CAG trinucleotide
- Wilson’s disease - autosomal recessive –> more of a PD picture
- Ataxic telangiectasia –> more of a cerebellar picture - Drug induced chorea
- anti-convulsants
- levodopa
- anti-psychotics - Biochemical
- hyperglycaemia
- polycythaemia - Vascular
- usually unilateral –> hemi-ballismus: ischaemia in subthalamic nucleas - Systemic conditions
- SLE
- Anti-phospholipid
- Thyrotoxicosis - Pregnancy
- chorea gravidarum - Post infectious
- Syndenam’s chorea - post streptococcal infection/rheumatic fever - rare due to use of Abx
Management of Huntingdon’s chorea
MDT
- Neurologist - to manage symptoms
- Neuropsychiatrist - to manage mood + cognitive manifestations
- Neuropsychologist - as above and to help deal with devastating diagnosis
- Dietician - chorea increases basal metabolic rate and so malnutrition can occur
- PT/OT - manage mobility and adapt home + work environment
- Clinical geneticist - make diagnosis via blood test to look for trinucleotide repeat of CAG and offer support for diagnosis of family members
Clinical features of polyneuropathy
Inspection - distal symmetrical wasting - champagne legs in CMT - arched foot in CMT - Pes Cavus Tone - flaccid Power - reduced distal >proximal Reflexes - reduced/absent Sensation - reduced in all modalities including proprioception Coordination - not affected Gait - high step - bilateral foot drop
Differential diagnosis of peripheral polyneuropathy
- Inherited
- Charcot Marie Tooth
- CMT1 - most common, autosomal dominant inheritance, demyelinating pathology
- CMT 2 - autosomal dominant inheritance, axonal (non-demyelinating) pathology
- CMT 3 - autosomal dominant or recessive inheritance, demyelinating pathology - Nutritional deficiencies
- B1/thiamine = Beri Beri - seen in alcohol misues
- B6/pyridoxine - precipitated by isoniazid. Mainly sensory
- B12 = seen in vegan/vegetarian, pernicious anaemia, ileal disease (Crohn’s). Causes triad of Subacute Combined Degeneration of the Cord + optic neuropathy + dementia
- Vitamin E deficiency - Systemic diseases
- Diabetes
- CKD
- Paraneoplastic polyneuropathy - small cell lung cancer, myeloma with paraprotein
- CTD: SLE, rheumatoid arthritis, Sjogren’s
- Porphyria
- Sarcoid - Drugs
- Sensory: isoniazid (B6) + phenytoin
- Motor: amphotericin + gold + dapsone
- Sensorimotor: disulfiran + nitrofurantoin + vincristine - Toxins
- EtOH
- Lead
- Arsenic
- Glue sniffing
Investigations for polyneuropathy
- Nerve conduction tests
- differentiate between demyelinating + axonal disease in CMT - Sureal nerve biopsy
- Bloods
- HbA1c
- Renal function
- Vitamin levels
- ANCA, dsDNA, RF, anti-Ro + La, anti-CCP, anti-phospholipid screen, anti-cardiolipin
Differential diagnosis of spinal cord myelopathy
- Trauma
- Compression
- vertebral disc prolapse
- spinal abscess - staph aureas, Pott’s disease (TB) - Malignancy - primary or secondary cord compression, intra or extra medullary
- Vascular -
- anterior spinal artery thrombosis - may have preserved dorsal columns (proprioception, fine touch, vibriation)
- arterio-venous malformation haemorrhage
- vasculitis - polyarteritis nodosum, syphilis
- dissecting aortic aneurysm - Inflammatory - transverse myelitis
- multiple sclerosis
- SLE
- post viral demyelination
- sarcoid
- Sjogren’s disease - Metabolic
- subacute combined degeneration of the cord (B12 deficiency) –> loss of dorsal columns first, progresses to corticospinal tracts (UMN signs), preserved spinothalamic tract (anterior columns = pain, temperature)
- copper deficiency - Intrinsic lesions
- syringomyelia - Genetic
- Hereditary spastic paraplegia
Clinical features of MS
- Optic neuritis
- loss of central vision
- painful ophthalmoplegia
- pale disc
- relative afferent pupillary defect - Brainstem
- Internuclear ophthalmoplegia due to demyelination of the medial longitudinal fasciculus (MLF)
- -> loss of signal from VI to III via MLF - ABducting eye on side of lesion is slow compared to ADducting eye on contralateral side. Results in horizontal nystagmus on contralateral (to lesion) ADducting
- CN IX + X = dysphagia - Myelopathy
- UMN lesions –> spastic paraparesis/tetraparesis
- sensory deficit
- bladder dysfunction
- Lhermitte’s symptoms - Cerebellar - ataxia
MS - investigation
- MRI brain + spine: T2 weighted + Gad - hyperintense + gad enhancing lesions
- LP
- high protein
- mild lymphocytosis
- oligoclonal bands (not seen in serum) - Electrophysiology
- visual evoked potentials + auditory evoked potentials
Cerebellar syndrome - clinical findings
Inspection
- truncal ataxia
- staccato speech - dysarthria
- saccadic eye movements
- head tremor
Tone
- hypotonia
- rebound phenomenon: arms outstretched and arms pushed down - exaggerated upshoot of arms
Power
- normal
Sensation
- normal
- however Ix for sensory cause of ataxia: proprioception may be affected, Romberg’s positive
Reflexes
- normal
Co-ordination
- intention tremor
- past pointing
- dysdiadochokinesis +ve
- heel to shin
Eyes
- nystagmus
Cerebellar syndrome - causes
- Alcohol misuse
- Vascular
- ischaemic or haemorrhage - Malignancy - SOL
- Metabolic/nutritional
- B12 deficiency
- copper deposition in Wilson’s disease
- hypothyroidism - Drugs
- AED
- Lithium
- Barbituates
- Ketamine - Genetic
- Friedrich’s ataxia
- Spinocerebellar ataxia
- Ataxic telangiectasia
- Von Hippel-Lindau - Degenerative
- Multi-system atrophy (PD plus syndrome) - Paraneoplastic
- small cell lung cancer
- Gynae
- testicular
- breast
- Hodgkin’s
Differences between cerebellar and sensory ataxia
Cerebellar
- dysarthria
- nystagmus
Sensory
- proprioception deficit
- Romberg’s positive
- able to do coordination with eyes open but difficulty with eyes closed
- pseudoathetosis (writhing motion of arms/fingers with arms outstretched and eyes closed)
Ulnar palsy - clinical examination
Examination:
- Claw hand: paralysis of interosseous muscles resulting in extension of metacarpophalangeal joints and flexion of interphalangeal joints - most prominent in 4th and 5th fingers
- scar over ulnar aspect of risk: surgery or trauma
- check for scar behind elbow - ulnar nerve runs within olecranon groove behind medial epichondyle
- wasting in small muscles of the hand
Power:
- small muscles of the hand EXCLUDING LOAF (lumbricals, opponens pollicis brevis, abductor policis brevis, flexor policis brevis
- spread fingers apart and push in - weakness
- unable to hold piece of paper between fingers
- ABLE to keep thumb and forefinger in a ring despite examiner trying to break the ring - power of abductor policis brevis + flexor policis brevis
Sensory:
- loss of sensation/reduction in sensation/hyperalgesia in region of ulnar aspect 1.5 fingers anterior + posterior hand.
Difference between ulnar palsy + C8/T1 radiculopathy
Motor:
Abductor pollicis brevis is inervated by C8/T1 but NOT ulnar
- causes ABduction of thumb
Sensory:
C8/T1 innervates ULNAR side of hand/forearm
Ulnar innervates ULNAR side of hand only (not forearm) (1.5 fingers)
Management of neuropathic pain in nerve injury
- Start with TCA - Amitriptyline
2. Move on to gabapentin/pregabalin
Motor neurone disease - clinical examination
Examination:
- muscle wasting
- fasciculation - look at tongue “bag of worms”
- dysarthria
Tone:
- increased tone
Power:
- reduction
Reflexes:
- brisk + upgoing plantars
- brisk jaw jerk
- HOWEVER absent ankle jerk
Sensation
- intact
Coordination
- no sensory deficit but muscle weakness may result in difficulty performing coordination tests.
Gait
- spastic paraparesis
- bilateral foot drop
Causes of mixed upper + lower motor neurone disease
- Motor neuron disease
- Friedrich’s ataxia
- Subacute combined degeneration of the cord
- Tabes dorsalis
- Cervical radiculomyelopathy secondary to degenerative disease
- Dual pathology: myelopathy + peripheral neuropathy
- Syringomyelia
Types of MND
- Amyotrophic Lateral Sclerosis - most common form. UMN + LMN findings
- Primary lateral sclerosis - only UMN lesions
- Progressive muscular atrophy - only LMN lesions
Investigation and management of MND
Investigation
- EMG: evidence of UMN + LMN denervation
- MRI spine to exclude cervical myelopathy
Management = supportive/MDT
- Respiratory: NIV
- Nutrition - SALT + dietician assessment of swallowing and intake ?PEG
- Neurologist: Riluzole shown to prolong life by 3 months (SE: nausea, deranged LFTs)
- Psychologist
- OT/PT: mobility, home environment
Clinical findings syringomyelia
Examination:
- wasting of small muscles of hand
- Horner’s syndrome
- kyphoscoliosis
Tone
- increased
Power
- reduced
Sensation
- cape like dissociative sensory deficit - loss of anterior columns (pain + temp) with preservation of dorsal columns (light touch/vibration/proprioception)
Pseudobulbar palsy - definition, symptoms, causes
Definition:
Lesions of UMN innervating tongue + oropharynx
Symptoms: Spastic + hoarse voice Slow tongue movements Brisk jaw jerk Emotional lability
Causes:
MS
Brainstem stroke
MND
Bulbar palsy - definition, symptoms, causes
Definition:
Lesions of LMN affecting cranial nerves
Symptoms:
Nasal speech
Tongue wasting/fasciculations
Nasal regurgitation
Causes: Myasthenia gravis MND Neuropathy including GBS Myopathy e.g spinal + bulbar muscular atrophy (Kennedy's disease)
Kennedy’s disease
spinal + bulbar muscular atrophy
X linked progressive neuromuscular degenerative disease affecting LMN
Mutation in androgen disease - androgen insensitivity syndrome
Causes of facial nerve palsy
- Supranuclear lesion
- forehead sparing - Lesion at pons = stroke, MS, tumour
- also get CN VI involved = facial nerve weakness + lateral gaze palsy + contralateral weakness - Lesion at cerebellar pontine angle = acoustic neuroma meningioma, granulomatous disease
- CN VIII + CN VII + CN V + CN IX + CN X - Base of skull lesion
- Paget’s disease - Idiopathic = Bell’s palsy
- Ramsey Hunt
- Parotid disease
- tumour/mumps/sarcoid/swelling/trauma
Causes of myopathy
- Inherited
- Duchenne’s muscular dystrophy
- -> X linked, absence of dystrophin gene
- Becker’s MD
- Limb girdle myopathy
- Fascio-scapulo-humeral dystrophy
- McArdle’s syndrome - deficiency in myophosphorylase - Inflammatory
- inclusion body myositis - Infectious
- Endocrine
- hyperthyroidism
- cushings
- acromegaly - Acquired other
- myotonic dystrophy - Electrolyte
- deranged calcium
- hypokalaemia - Drugs
- statin
- steroids
- diuretics causing hypokalaemia
- amiodarone
Myotonic dystrophy clinical features
Autosomal dominent - demonstrates anticipation - CTG trinucleotide repeat
- Proximal or distal muscle weakness
- Myotonia - sustained contraction
- Myotonic facies - wasting of temporalis
- Frontal balding
- Bilateral ptosis
- Cataracts
- Learning difficulties
- Cardiomyopathy
- Gynaecomastia
- Bronchiectasis
Myaesthenia gravis examination
Inspection:
- ptosis
- snarling facies
- thymus resection scar
Demonstrate fatiguability
a) Proximal muslces
- move arms like a chicken
b) Bulbar
- listen to speech - nasal sounding
- count backwards from 100
c) ocular
- ophthalmoplegia
- continually blink
- maintain vertical gaze
- peek sign: close eyes –> >30 seconds eyes start to open
d) Respiratory
- test PEF + FVC
Cavernous sinus contents
- CN III
- CN IV
- CN V - ophthalmic + maxillary bracnhes
- CN VI
- Internal carotid artery
Lateral medullary syndrome/Wallenburgs syndrome clinical features and artery involved
Posterior inferior cerebellar artery
Sympathetic tract = Ipsilateral horners
CN V = ipsilateral facial numbness
CN X = ipsilateral bulbar palsy
Cerebellar punducles = ipsilateral ataxia/nystagmus/vertigo
Lateral Spinothalamic tract = contralateral loss of pain and pinprick
Weber’s syndrome
Clinical features and location of lesion
Midbrain
Ipsilateral CN III palsy - down and out, dilated pupil
Contralateral pyramidal weakness
Total anterior circulation stroke clinical features
NEED ALL 3 of the following:
- Contralateral motor +/- sensory loss of 2 or more of face/arm/leg
- Homonymous hemianopia
- Higher cerebral dysfunction I.e dysphasia, sensory inattention, apraxia
Partial anterior circulation stroke clinical features
2 or 3 of following but NO drowsiness
- Contralateral motor +/- sensory loss of 2 or more of face/arm/leg
- Homonymous hemianopia
- Higher cerebral dysfunction I.e dysphasia, sensory inattention, apraxia
OR
Higher dysfunction alone
OR
Motor and or sensory loss <2/3 of whole side of body
Lacunar circulation stroke (LAC) clinical features
Any of:
- Pure motor deficit
- Pure sensory (thalamic lesion)
- Sensorimotor
- Ataxic hemiparesis
Posterior circulation stroke clinical features
- Ipsilateral cranial nerve lesion and contralateral motor/sensory deficits
- Bilateral motor and sensory deficits
- Disorders of conjugate eye movements
- Cerebellar dysfunction without ipsilateral long tract deficits
- Isolated homonymous hemianopia
