Neurology Flashcards
Causes of blackouts - 7
Vasovagal (neurocardiogenic) syncope
Situational syncope ie cough or micturition
Carotid sinus syncope
Epilepsy
Stokes-Adams sacks - transient arrhythmia
Hypoglycaemia
Orthostatic hypotension
What is vasovagal syncope, onset and what happens during
Reflex bradycardia with or without peripheral vasodilation provoked by emotion, pain, fear, standing
Onset over seconds, preceded by nausea, pallor, sweating, closing in of visual fields
Unconscious for around 2 mins, may have brief clonic jerking of limbs (reflex anoxic)
May have urinary incontinence
Post ictal recovery rapid
Differentiate reflex anoxic jerks in vasovagal from epilepsy - 4
No stiffening
No tonic - clonic sequence
No tongue biting
Rapid post-ictal recovery
What is situation syncope
Sx same as vasovagal - preceding nausea, pallor, sweating, unconscious +- reflex anoxic myoclonic jerks, urinary incontinence
Caused by cough, effort (exercise, from cardiac origin ie aortic stenosis) or micturition (mostly men at night)
What is carotid sinus syncope
Hypersensitive baroreceptors cause excessive reflex bradycardia +- vasodilatation on minimal stimulation eg head turning
Features of LOC suggestive of epilepsy - 8
When asleep or lying down Aura Identifiable trigger Altered breathing, cyanosis Tonic-clonic movements Tongue biting Urinary incontinencce Prolonged post-ictal drowsiness, confusion, amnesia and transient focal paralysis
What is syncope related to arrhythmia and features, and how often?
Stokes-Adams attacks - transient arrhythmia eg bradycardia from complete heart block, reduces CO and causes LOC
Often with no warning except palpitations
Pale, slow/absent pulse
Recovery within seconds, with flushing, pulse speeding up and consciousness returns
Can be several times a day and in any posture
What is a cause of sudden fall with no LOC in the elderly - 3
Drop attacks - sudden weakness in legs, generally older women
Benign and spontaneously resolves after a few attacks
Cataplexy - triggered by emotion
Hydrocephalus - may not be able to get up for hours
What makes orthostatic hypertension more likely? - 4
Inadequate vasomotor reflexes: Elderly Autonomic neuropathy Antihypertensives, overdiuresis Multi system atrophy
Features of anxiety attack - 7
Hyperventilation Tremor Sweating Tachycardia Paraesthesia Light headed ness No LOC
What exams to do for LOC - 3
Cardiovascular
Neurological
BP standing and lying
Investigation for LOC
ECG +-24h for arrhythmia, long qt; echo UE, FBC, glucose Tilt table test EEG, sleep eeg CT/MRI brain PaCO2 - low = hyperventilation
What is vertigo?
Illusion of movement, often rotator, of patient or surroundings
Always worsened by movement
Associated sx with vertigo - 4
Difficulty walking or standing
Relief on sitting still or lying
NV, pallor, sweating
Hearing loss or tinnitus = labyrinth or CN8 involvement
Anatomical locations of causes of vertigo - 4 most common
Labyrinth
Vestibular nerve
Vestibular nuclei
Central connections
7 common causes of vertigo
- Benign paroxysmal vertigo due to canalolithiasis
- Acute labyrinthitis/vestibular neuronitis
- Ménière’s disease
- Ototoxicity - aminoglycosides, loop diuretics, cisplatin - also dizziness
- Vestibular schwannoma (also known as acoustic neuroma incorrectly)
- Traumatic damage of patrons temporal bone or cerebello-pontine angle affecting auditory nerve
- Herpes zoster - eruption of external auditory meatus
Features of BPV and treatment
Canalolithiasis - debris in semicircular canal disturbed by head movement, resettles causing vertigo for a few seconds after movement
Nystagmus on performing Hallpike manoeuvre = diagnostic
Cleared by Epley manoeuvre
What is acute labyrinthitis and features
Abrupt onset of severe vertigo, NV +- prostration
No deafness or tinnitus
Caused by virus or vascular lesion
Severe vertigo subsides in days, complete recovery in 3-4w
Treat = reassure, sedate
What is Ménière’s disease, 3 features and treatment
Endolymphatic hydrops causing 1. recurrent attacks of vertigo lasting >20m +- nausea, 2. fluctuating sensorineural hearing loss (may be permanent), 3. Tinnitus with sense or aural fullness
Treat with bed rest and reassurance, and antihistamine if prolonged
What causes ototoxicity
Aminoglycosides
Loop diuretics
Cisplatin
Features of vestibular schwannoma
Unilateral hearing loss Vertigo occurs later Progresses to affect ipsilateral CN5, 6, 9, 10 and ipsilateral cerebellar signs Late = signs of RICP A type of cerebello-pontine angle tumour
How does traumatic damage cause vertigo
To petrous temporal bone or cerebello-pontine angle, affects auditory nerve, causing vertigo, deafness, tinnitus
What infection can cause vertigo and what else does it cause?
Herpes zoster - herpetic eruption of external auditory meatus, causes facial palsy +- deafness, tinnitus, vertigo = Ramsay Hunt syndrome
What causes related to the brain stem, cerebellum and cerebello-pontine angle can cause vertigo and what other sx are there
Also nystagmus and CN lesions MS Stroke/TIA Haemorrhage Migraine Vestibular schwannoma
Management and progress of vestibular schwannoma
Serial MRIs for a few years to predict growth
30% don’t progress, 50% grow slowly and 20% grow quickly
Malignancy rare
Microsurgical removal can cause damage to CN7
Causes of conductive deafness and finding on tuning fork test
Wax, otosclerosis, otitis media or glue ear
Weber - localises to ear with conductive loss
Rinne = negative = bone conduction louder than air conduction
Causes of sensorineural deafness - 3 chronic 8 acute
Chronic - accumulated environmental noise toxicity - presbyacusis (loss of higher frequency sounds from age 30) - inherited disorders Acute - V vasculitis - V stroke - I mumps - I TB - T noise exposure - A MS - I toxin eg gentamicin - N acoustic neuroma
Tests for sudden sensorineural deafness
ESR, FBC, LFT Viral titres and TB Evoked response audiometry CXR MRI Lymph node and nasopharyngeal biopsy for malignancy and TB culture
Result of tuning fork tests for sensorineural hearing loss
Tuning fork = 512hz
SNAC-RIP
Sensorineural loss and Normal ears, Air Conduction better - Rinne Is Positive
Weber localises sound to contralateral ear from affected ear in sensorineural loss
Causes of tinnitus
Focal hyper-excitability in auditory cortex
Viral
Presbyacusis, Meniere’s, hearing loss
Excess noise, wax
Head injury
Septic otitis media
Hypertension
Drugs - aspirin, loop diuretic, aminoglycosides
Psychological - diverse
Pulsatile = carotid artery stenosis or dissection, AV fistulae
Investigate tinnitus
Pulsatile may be audible with stethoscope
MRI
If unilateral, exclude vestibular schwannoma
Complications of tinnitus
Depression, insomnia
Manage tinnitus
Psychological support, reassure
Hypnotics at night
White noise through noise generator like a hearing aid
Cochlear nerve section if disabling - causes deafness
Repetitive transcranial magnetic stimulation of auditory cortex
Key questions for weak legs - 6
- Onset gradual or sudden
- Progressing at what rate
- Spastic or flaccid legs
- Sensory loss. Level = spinal cord disease
- Loss of sphincter control
- Signs of infection - spinal tenderness, raised WCC, eg extradural abscess
Sx in progressive weakness
Spinal or root pain first
Then leg weakness and sensory loss
- arm weakness is less severe as suggests cervical cord lesion
Bladder sphincter involvement is late = hesitancy, frequency then painless retention (neurogenic)
Signs:
- motor, reflex and sensory level - normal above, LMN signs at level, UMN signs below level
- tone and reflexes are usually reduced in acute cord compression
Causes of progressive weakness due to cord compression - 7
Most common = secondary malignancy - breast, lung, prostate, thyroid, kidney - in spine
Infection - epidural abscess
Cervical disc prolapse, atlanto-axial subluxation
Haematoma (warfarin)
Intrinsic cord tumour, myeloma
Differentials for progressive weakness (not due to cord compression)
Transverse myelitis
MS, Guillaun-Barre
Spinal artery thrombosis, dissecting aneurysm
Trauma
Investigations for cord compression
MRI sine
Biopsy or surgical exploration to investigate mass
CXR for primary lung malignancy, secondaries or TB
Screening bloods - FBC, ESR, B12, LFTs, syphilis, UE, PSA
Serum electrophoresis
treatment cord compression
Dexamethasone IV 4mg/6h if malignancy then consider C/RT, decompressive laminectomy
Surgical decompression and abx if epidural abscess
Main difference in sx of cauda equina/conus medullary lesions and higher up lesions
Leg weakness is flaccid and areflexic instead of spastic and hyperreflexic
Clinical features of conus medullary lesions
Mixed UMN/LMN leg weakness
Early urinary retention and constipation
Back pain and sacral sensory disturbance
Erectile dysfunction
Clinical features of cauda equina
Back pain and radicular pain down legs
Asymmetrical, atrophic, areflexic paralysis of legs
Sensory loss in root distribution
Reduced sphincter tone
Sensation of dorsal column damage
Hypersensitive or vibratory feelings
Causes of unilateral foot drop - 5
Diabetes Common peroneal nerve palsy Stroke Prolapsed disc MS
Causes of weak legs with no sensory loss - 2
MND
Poliomyelitis
Causes of chronic flaccid paraparesis - 2
Peripheral neuropathy
Myopathy
Causes of spastic paraparesis - 5
MS Intrinsic cord tumours Cord mets MND Syringomyelia
Causes of absent knee jerks and extensor planters - 5
Cervical and lumbar disc disease Conus medullaris lesions MND Friedreich’s ataxia Subacute combined degeneration of cord - vit B12 deficiency
Spastic gait appearance
Stiff, circumduction of legs
Scuffing of foot
Extrapyramidal gait disorder
Flexed posture, shuffling feet, slow to start, postural instability
Parkinson’s
Apraxia gait disorder
Feet glued to floor or wide based unsteady gait with tendency to fall
Caused by normal pressure hydrocephalus or multi-infarcts
Ataxic gait
Wide based, falls, cannot walk heel to toe
Caused by
- cerebellar lesions (MS, alcohol)
- proprioceptive sensory loss (sensory neuropathy, B12 def)
Worse in dark or eyes closed
Myopathic gait abnormality
Waddle - hip girdle weakness
Cannot climb stairs or sit from standing
Psychogenic gait abnormalities
Bizarre, not conforming to pattern
Can’t stand despite no signs when examined
Tests for gait disorders
Spinal X-ray, MRI FBC, ESR, syphilis serology, B12, UE, LFT PSA, serum electrophoresis CXR LP EMG, muscle +- sural nerve biopsy
Examples of symptoms movement disorders
Ataxia Dystonia, dyskinesia Gait problems Parkinsonism Chorea Myoclonus Spasticity Tics and tremor
3 things to note on tremor
Frequency
Amplitude
Exacerbating factors eg stresss, fatigue
4 types of tremor
Rest - abolished on voluntary movements, caused by Parkinsonism
Intention tremor - irregular, large amplitude, worse at end of purposeful act eg finger-pointing, caused by cerebellar damage (MS, stroke)
Postural tremor - absent at rest, present on maintained posture eg arms outstretched , may persist but not worse on movement, caused by benign essential tremor, thyrotoxicosis, anxiety, B agonist
Re-emergent tremor - postural, developing after delay of 10s (Parkinson’s). Can be helped by surgery or deep brain stimulation
What is chorea and 7 causes
Non-rhythmic jerky purposeless movements eg facial grimacing, raising shoulders
Caused by basal ganglia lesion (Huntingdon’s, stroke), strep, SLE, wilson’s, neonatal kernicterus, drugs (L-dopa)
What is the chorea which causes significant large amplitude proximal muscle movements
Hemiballismus, contralateral to vascular lesion on subthalamic nucleus
Unilateral proximal joint
Recover spontaneously in a few months
What is common in cerebral palsy and often confused with chorea
Athetosis - slow, sinuous, confident, purposeless writhing movements - also known as dystonia.
Caused by lesion in putamen
What are tics?
Brief, repeated, stereotyped movements, most common in children and usually resolve
Tourette’s = motor and vocal
Manage = psych support, clonazepam, clonidine if severe
What are sudden involuntary focal/general jerks, and its 2 main types
Myoclonus, from cord, brain stem or cerebral cortex
In metabolic problems, neurodegenerative disease, CJD
Benign essential myoclonus - childhood onset, may respond to valproate or clonazepam
Asterixis/metabolic flap - jerking 1-2/s of outstretched hands with wrists extended, from loss of extensor tone - caused by liver/kidney failure, gabapentin
What is the complication of antipsychotics long term
Tardivesyndromes - chronic exposure to dopamine antagonists (antipsychotics and antiemetics)
Can be permanent
Can be dyskinesia (choreiform), dystonia (twisting spasms), akathisia (inner restlessness), myoclonus, tourettism or tremor
What antipsychotics are less likely to cause tardive dyskinesia?
Quetiapine, olanzapine, clozapine - atypical antipsychotics
Cause of acute dystonia, presentation and treatment
From starting drugs eg neuroleptic and antiemetics (metoclopramide, cyclizine)
Torticolis, trismus (oromandibular spasm), oculogyric crisis
Sx disappear with anticholinergic procyclidine IM
Risk factors for drug induced acute dystonia
Male
Young
Previous acute dystonia
Recent cocaine use
Which tracts transmit which sensations in the spinal cord?
Anterolateral/spinothalamic - pain and temperature
Dorsal columns - joint position and vibration sense
What results from hemicord lesions?
Brown-Sequard syndrome - dorsal column (proprioception and vibration) loss on side of lesion and contralateral spinothalamic (pain and temperature) loss
What is dissociated sensory loss?
Cervical cord lesion causes loss of pain ad temperature with sparing of proprioception and vibration
Caused by syringomyelia or cord tumour
Sensory loss in cortical lesions?
Confined to discriminating sensory functions eg 2 point discrimination
Where can an UMN lesion be?
Motor nerve cells in precentral gyrus of frontal cortex Internal capsule Brain stem Cord Anterior horn cells in cord
Pattern of weakness/spasticity with UMN lesion
Stronger muscles become spastic - arm flexors and leg extensors, with weakness in opposing muscles
Loss of skilled fine finger movements
Findings on exam for UMN lesion
Spasticity is velocity dependent so can suddenly be overcome, eg clasp-knife
Hyperreflexia
Positive babinski (upgoing plantars)
Clonus
Where is damage that causes LMN lesions?
Anterior horn cells in cord
Nerve root
Plexus
Peripheral nerves
Features of LMN lesion
Wasting, fasciculation
Hypotonia, flaccidity
Reduced reflexes
Flexor plantars
Differentiate between LMN and primary muscle disease eg myasthenia gravis
Muscle disease - symmetrical, reflexes lost later, no sensory loss
Myasthenia gravis = fatiguability, little wasting, normal reflexes, no sensory loss
Muscle weakness grading
MRC classification: Grade 0 = no muscle contraction 1 = flicker 2 = some active movement 3 = active movement against gravity 4 = active movement against resistance 5 = normal power
3 impairments causing difficulty speakign
Dysphasia - impairment of language
Dysarthria - difficulty articulating due to incoordination or weakness of musculature for speech, language is normal
Dysphonia - difficultly with speech volume due to weakness of resp muscles or vocal cords
Dysphasia associated with difficulty saying words, location of lesion
Broca’s/expressive - non-fluent, malformed words. Reading and writing impairment but comprehension relatively intact. understand question, attempts to convey meaningful answer
Lesion = inferolateral dominant frontal lobe
Dysphasia associated with meaningless speech and location of lesion
Wernicke’s/receptive - empty fluent speech with neologisms, oblivious of errors, inappropriate speech
Reading, writing, comprehension all impaired
Lesion = posterior superior dominant temporal lobe
2 types of aphasia which are not expressive or receptive
Conduction - interrupted communication between Broca’s and Wernicke’s. Impaired repetition, some comprehension and fluency
Nominal - all fine except naming objects, Posterior dominant temperoparietal lesions
What to assess in assessment for dysphasia - 4
- Comprehension - follow 1/2/3 step commands
- Repetition
- Naming
- Reading and writing
Assessing dysarthria and 4 causes and their features
Diffficuty with articulation due to incoordination/weakness of musculature of speech. Repeat phrase eg British constitution
- Cerebellar disease - slurring and irregular volume, scanning speech
- Extrapyramidal diseases - soft, indistinct, monotonous speech
- Pseudobulbar palsy - spastic dysarthria (UMN), slow, nasal and effortful, from MND or severe MS
- Bulbar palsy - LMN eg facial nerve palsy or guillain-barre - palatal paralysis gives nasal speech
Identifying dysphonia and what causes it?
Weakness of resp muscles/cords, precipitated in myasthenia by counting to 100
Dysarthria and dysphonia in Parkinson’s
What is dyspraxia and 4 types
Poor performance of complex movements despite ability to do each component, eg mime object’s use
Dressing - unsure of orientation of clothes on body. Nondominant hemisphere lesions
Constructional - difficulty drawing 5 point star - nondominant hemisphere lesions or hepatic encephalopathy
Gait - bilateral frontal lesions, posterior temporal region or hydrocephalus
Treat chorea
Dopamine antagonist tetrabenazine
Cerebellar signs
DANISH
Dysdiadochokinesia and fingerto nose tests
Ataxia - broad based gait, fall to side of lesion
Nystagmus
Intention tremor
Slurred/staccato speech
Hypotonia andreduced power
Test for ataxia
Romberg test - stand with eyes closed
- pos (loses balance) = posterior column disease
- neg = cerebellar disease
Findings on exam for complete optic nerve lesion
Ipsilateral blindness and no direct pupillary reflex
Indirect pupillary reflex intact
Findings on exam for optic chiasm lesion
Bitemporal hemianopia as fibres from nasal halves both retinas will be involved
Normal direct, consensual light reflex and accommodation reflex
Findings on exam for optic tract lesion
Homonymous hemianopia: right side optic tract lesion = right nasal. And left temporal hemianopias
Normal direct, consensual light and accommodation reflexes
Optic radiation lesion findings
Homonymous hemianopia, or inferior quadrantinopia if more posterior to cortex
Visual cortex lesion
Homonymous hemianopia
Pupils react normally to reflex stimuli
Macula often spared due to posterior/middle cerebral artery anastamosis
Scotoma found with glaucoma
Arcuate scotoma
Unilateral horizontal hemianopia cause - 3
Arterial occlusion, retinal vein thrombosis, inferior retinal detachment
Cause of central scotoma - 2
Macular degeneration or macular oedema
Test for macular disease - 2
Central scotoma
Amsler grid for distortion in central vision
Pituitary tumour findings and why
Disrupts chiasm so bitemporal field defects, can superimpose central optic nerve. Defect icon onesidemore
Process from optic nerve to brain
Optic chiasm Optic tract Lateral geniculate body Optic radiations Visual cortex
Temporal lobe tumour visual defect
Contralateral upper homonymous quadrantinopia
Causes of visual cortex field defects
Ischaemia - TIA, migraine, stroke AVM Glioma, meningioma Abscess Drugs - ciclosporin
What is dementia
Progressive global decline in cognitive function
2 types of dementia and causes of each
Degenerative - AD, PD, multi-infarct, Lewy body, Huntingdon’s, Wilson’s
Reversible - brain (SDH, NPH), drugs, infections (HIV, neurosyphilis), metabolic (low T4, low B12, high calcium) [DIM]
Inv for dementia?
Confusion screen:
Collateral history, MMSE
Bloods - FBC, UE, LFT, TFT, haematinic (ferritin, B12), bone screen (calcium), glucose
Other fluids - urine mcs
X-ray - cxr, CT head (small vessel disease = variant on multi infarct dementia)
[BOX]
Manage areas in dementia
Social - Activity, Adl help (mobility, nutrition, continence), Anticipatory planning
Psycho - Ask about depression
Bio - Address reversible, Ad drugs (acetylcholinesterase inhibitor, NMDA antagonist)
[6As]
Adv and disadvantages of MMSE
Adv - quick and easy, monitor changes
Dis - bias against blind or uneducated, poor sens for mild dementia