Neuro Flashcards
Median nerve palsy (carpal tunnel is common cause)
Thenar eminence wasting Thumb ABduction (reduced power) LOAF = motor innervation of median nerve Lateral 2 lumbricals Opponens pollicis Abductor pollicis brevis Flexor pollicis brevis
Phalen test
Wrist held in flexion for 60 seconds causing parasthesia
Tinel test
Repeatedly percuss over carpal tunnel
Ulnar nerve palsy
Hypothenar eminence wasting
Partial claw hand of little and ring finger
Finger ABduction (reduced power)
Usually caused by damage to elbow (funny bone)
Froment’s sign
Straight thumb and index finger pinching paper and try and keep hold as you pull away; would flex DIP if positive showing weak ADductor pollicis
Radial nerve palsy (or C7 radiculopathy)
Wrist drop
Reduced power extending wrist and fingers
NB C7 sensation though is index and middle fingers so would had motor deficit of radial nerve and median nerve sensation loss
Carpal tunnel syndrome causes
Idiopathic Pregnancy RA Hypothyroidism Diabetes Acromegaly
Radial nerve palsy causes
Humeral shaft #
Saturday night palsy (compression of radial nerve when sleeping causing dead arm)
T1 lesion causes
Causes:
Cervical spondylosis
Pancoast tumour
Plexus trauma/birth trauma (Klumpke’s)
T1 lesion features
Total claw hand
Wasting of small muscles in hand
Sensory loss in medial forearm
Horner’s syndrome may co-exist
Supinator catch
Early sign of hypertonia in upper limb, difficulty pronating/supinating
Erb’s palsy
Lesion of C5-6
Atrophy of the deltoid, biceps, and brachialis muscles
Medially rotated arm with extended and pronated forearm with flexed wrist
Klumpke’s palsy
C8-T1 lesion
Claw hand occurs
Wasting on small muscles in hand
Shoulder ABduction
C5 (axillary)
Elbow flexion
C5/C6 (musculocutaneous)
Elbow and finger extension
C7 (radial)
Wrist extension
C6 (radial)
Finger flexion
C8 (medial + ulnar)
Thumb ABduction
T1 (median)
Finger ABduction
T1 (ulnar)
Biceps jerk
C5/6 (same as elbow flexion)
Triceps jerk
C7 (same as elbow extension)
Supinator jerk
C5/6 (biceps does so same as elbow flexion)
Extrapyramidal lesion
Rigid tone Normal power Normal reflexes Plantars down Co-ordination down (THINK PARKINSON'S)
Spinothalamic pathology
Syringomyelia = expansion of spinal cord central canal due to CSF blockage
Anterior spinal artery occlusion
MS
Dorsal columns pathology
Tabes dorsalis
Folate/B12 deficiency (SDSC)
MS
Spinothalamic
Pain
Temp
Crude touch
Dorsal columns
Vibration
Propriaception
Fine touch
Syringomyelia
Loss of pain and temp in cape-like distribution over arm and shoulder
LMN signs in upper limbs and spastic paraparesis of lower limbs
Dorsal column signs develop in late syringomyelia
If affects brainstem called syringobulbia
Flexion of upper limb
C5 - elbow flexion (musculocutaneous = makes sense as biceps innervated by this)
C8 - finger flexion (median and ulnar)
Extension of upper limb
C6 - wrist extension (radial)
C7 - elbow extension and finger extension (radial)
Hip flexion
L1/2
Hip extension and knee flexion
L5/S1
Knee extension
L3/4
Ankle dorsiflexion
L4 (peroneal)
Hallux extension
L5 (peroneal)
Ankle plantarflexion
S1 (tibial)
Knee jerk
L3/4 (same as knee extension)
Ankle jerk
S1 (same as ankle plantarflexion)
Peripheral neuropathy DDx
DM (sensory mainly) B12/folate deficiency (called subacute degeneration of spinal cord) Alcohol Thiamine deficiency (Wernicke's) Uraemia (sensory mainly) SLE Guillain-Barre (motor mainly) Charcot-Maries-Tooth Lead poisoning (motor mainly) Amyloidosis Paraneoplastic
Unilateral leg weakness DDx
UMN: stroke, tumour, MS
LMN: root lesion, nerve lesion
Subacute degeneration of spinal cord
B12/folate deficiency Features: UMN - Spastic paraparesis & upgoing plantars LMN - reduced reflexes \+ dorsal columns loss
Mixed LMN and UMN
MND (e.g. ALS Amyotrophic lateral sclerosis)
SDSC
Bilateral leg weakness DDx
UMN (spastic) - bilateral strokes; acute spinal cord compression (eg disc prolapse, trauma, tumor, MS); syringomyelia (LMN signs in upper limb)
LMN (flaccid) - Guillain Barre; lead poisoning; Charcot-Marie-Tooth
Positive Romberg’s (dizziness when eyes shut)
Dorsal columns loss: tabes dorsalis; SCDC; MS
Sensory peripheral neuropathy
MND features
UMN: spasticity, brisk reflexes
LMN: weakness, wasting, fasciculation
Foot drop
Common peroneal nerve palsy Stroke L4/L5 nerve root lesion MND Charcot-Marie-Tooth
Olfactory lesion
Trauma
Frontal lobe tumour
Meningitis
Bitemporal hemianopia
Pituitary adenoma
Internal carotid artery aneurysm
Homonymous hemianopia
Anything behind chiasm
Stroke/tumour/abscess
Trigeminal lesion
Trigeminal neuralgia (idiopathic)
Acoustic neuroma
Herpes zoster
Facial lesion
LMN: Bell’s, malignant parotid tumour, Ramsay Hunt (herpes), sarcoid (usually bilateral)
UMN: stroke, tumour
Hearing loss
Excessive noise Conductive loss Meniere's Furosemide Gentamicin
Bulbar balsy (LMN)
MND Diptheria Polio Myasthenia gravis Guillain Barre syndrome Syringobulbia
Pseudobulbar palsy (UMN)
MND
Bilateral stroke
MS
Cavernous sinus thrombosis
III, IV, VI lesion (mainly VI)
V - pain (ophthalmic)
Corneal reflex lost
Headache, periorbital oedema, proptosis (exopthalmus)
CN III palsy
Down and out eye
Ptosis
Dilated pupil if complete (not diabetes)
Opthalmoplegia
Myasthenia gravis Cranial nerve palsy (III, IV, VI) Grave's Wernicke's Progressive supranuclear palsy
Internuclear opthalmoplegia (INO)
Disorder of conjugate lateral gaze due to lesion in medial longitudinal fasciculus (MLF), which ADducts that eye
Means that if you have LEFT LESION, your LEFT EYE cannot ADduct and so you cannot look to the RIGHT
Causes of INO
MS (esp in young pt)
Stroke
Lyme disease and TCA overdose
Bulbar palsy (LMN) features
Tongue appearance:
Flaccid
Wasted
Fasciculating
Tremulous lips as well as drooling and dysphonia
Pseudobulbar palsy (UMN) features
Tongue appearance:
Spastic
Contracted
Emotionally labile as well as drooling and dysphonia
Parkinson’s
TRAP Tremor Rigidity Akinesia (bradykinesia initially) Postural instability
Parkinson’s DDx
Benign essential tremor
Wilson’s (with psych illness, hepatotoxicity and Kayser-fleischer rings)
Parkinson-plus syndromes
Multi-system atrophy (autonomic failure)
Corticobasal degeneration (alien hand syndrome and apraxia)
Progressive supranuclear palsy (ocular features including vertical gaze failure)
Lewy-body dementia
Parkinson’s Rx
L-dopa Dopamine agonist - ropinerole Anticholinergics - procyclidine COMTi - entacapone MAO-Bi - selegiline Glutamate antagonists - amantadine Sleep commonly affected and mirtazapine works best
Causes of cerebellar disease
Stroke: vertebrobasilar Tumour at cerebello-pontine angle MS Congenital (e.g. Arnold-Chiari) Friedrich's ataxia Alcohol abuse Thiamine deficiency Anti-epileptic medication (phenytoin)
Wernicke’s triad
Acute confusion
Ataxia
Ophthalmaplegia (especially upgaze)
Dysarthria Differentials
Facial nerve palsy CNVII Bulbar palsy eg MND Pseudobulbar palsy eg MS MG Cerebellar disease
Lateral Medullary syndrome
posterior inferior cerebellar artery (PICA) infarct
DANVAH = dysphagia, ataxia, nystagmus, vertigo, anaesthesia, Horner’s
[] ipsilateral: ataxia, nystagmus, dysphagia, facial numbness, cranial nerve palsy e.g. Horner’s
[] contralateral: limb sensory loss
Weber’s syndrome
ipsilateral III palsy
contralateral weakness
Abulia
Pathological laziness, seen with anterior cerebral artery infarct (with this face spared usually)
Cerebellopontine angle syndrome
Causes: acoustic neuroma, meningioma, astrocytoma and mets (e.g. breast)
Effect: ipsilateral CN 5, 6, 7, 8 palsies (pons) and cerebellar signs
Subclavian steal syndrome
subclavian artery stenosis proximal to origin of vertebral artery leading to syncope/headache raising arms and BP difference >20 between arms
Anterior spinal artery/Beck’s syndrome
Supplies ventral 2/3 spinal cord caused usually by aortic aneurysm or dissection / surgery
Symptoms: paresis with impaired pain and temperature sensation but preserved dorsal columns as these antero-lateral
Locked-in syndrome
Everything paralysed but eye muscles
Causes = ventral pons infarct from basilar artery or central pontine demyelination
Millard-Gulber syndrome
Pontine infarct
6 and 7 CN palsy and contralateral hemiplegia
Parkinson’s plus
Progressive supranuclear palsy
Corticobasal degeneration
Multi system atrophy (shy drager)
Lewy body dementia
Hearing loss conductive causes
WIDENING Wax or foreign body Infection: otitis media, OME Drum perforation Extra: ossicle discontinuity – otosclerosis, trauma Neoplasia: carcinoma INjury: e.g. barotrauma Granulomatous: Wegener’s, Sarcoid
Hearing loss sensorineural causes
DDIVINITY Developmental - Alport's; TORCH Degenerative - Presbyacusis Infection - VZV, measles Vascular - internal auditory artery Inflammation - vasculitis, sarcoid Neoplasm - cerebellopontine angle tumour Injury - trauma / noise Toxins - gentamicin, frusemide LYmph - Perilymphatic fistula
Action tremor causes
BEATS
Benign essential tremor
Endocrine: thyroxicosis, ↓glucose, phaeo
Alcohol withdrawal (or caffeine, opioids…)
Toxins: β-agonists, theophylline, valproate, PHE
Sympathetic: physiological tremor may be
enhanced: e.g. in anxiety
Bell’s sign
Eyes move up on trying to close eyelid in bell’s palsy
Miller Fisher sydrome
Variant of GBS
Triad of:
Ophthalmoplegia + sensory ataxia + areflexia
