Neurology Flashcards
Astrocyte and oligodendroglial tumours
new classification system WHO 2016. Classified on basis of IDH mutation or not. ISOCITRATE DEHYDROGENASE and other genetic snp mutations. No longer histopathological basis. High grade glioma managed surgical resection plus post op radiotherapy plus systemic chemo. TEMOZOLAMIDE
Guillan bare synrome
Definition: Progressive ascending motor weakness and areflexia ascending weakness pain sensory loss
AI attack on myelin sheath of peripheral nerves
Presentation:
EARLY = BACK PAIN radiating to lower limbs ?proximal nerve root inflammation
proximal weakness
symmetrical CN palsy / diaphragmatic weakness / autonomic dysfunction - tachycardia
Pathology:
70% post infective: compylobacter jejuni classic or LRTI
Investigation:
CSF: raised protein late
nerve conduction: multifocal demyelination late
Management:
Monitor FVC - ITU if <1.2L - anaesthetic and elective intubation
RX:
plasma exchange
IV Ig
Lambert Eaton - Lambert Eaton Myaesthenic Syndrome
Definition
Myaesthenic like syndrome - AI abs VS Voltage gated calcium channels - PRESYNAPTIC
Association:
50-70% underlying malignancy
majority SCLC
Presentation:
SLOW PROGRESSIVE PROXIMAL MYOPATHY
LOSS OF DEEP TENDON REFLEXES
FACILITATION AND RETURN OF DTR = PATHOGNOMIC
autonomic features more present than in myaesthenia = poor salivation and erectile dysfunction
Bulbar and resp are preserved unlike myaesthenia
Also responds to facilitation unlike myaesthnia due to increase calcium in cleft from repeated stimulation
MITOCHONDRIAL DISORDERS
EPILEPSY DEAFNESS OPTHALMOPLEGIA OPTIC NEURITIS HEART DISEASE SHORT STATURE LEARNING DIFFICULTIES
inherited from mother (mitochondrial)
examples: Kearns-Sayre Leigh MELAS: mitochondrial encephalopathy lactic acidosis and stroke like episodes NARP: Neuropathy and Retinitis Pigmentosa MNGIE: Mitochondrial neuro gasto intestinal encephalopathy PEO: Progressive external opthalmoplegia
Freidreich’s Ataxia
Pattern:
Autosomal Recessive
Presentation: gait disturbance pes cavus scoliosis diabetes
Huntington’s disease
Pattern:
Autosomal Dominant INHERITANCE
Definition:
Huntington gene chr 4 codes for HUNTINGTIN cand contains a CAG triplet repeat coding for glutamine. Normal = 11-34 repeats
Expansion of this triplet results in abnormal protein which seems to damage brain cells
Demonstrates Anticipation with paternal inheritance
Alternate presentation:
Teenage years with parkinsonian symptoms - WESTPHAL VARIANT
Presentation: Early: mood / mental acuity MIDDLE: ataxia uncoordinated jerky choreoform movements / athitosis LATE: mental decline to dementia FT lability loss of speech loss of mobility due to worsening ataxia and poor coordination
Miller-Fisher - SUB-TYPE OF GBS
DEFINITION:
Sub-type of GBS
Anti-Gq1b antibody specificity
AI demyelination of peripheral nerves
Presentation:
Opthalmoplegia
Ataxia / coordination
Loss of deep tendon reflexes
Spinocerebellar Ataxia - SCA
Defintion: 4 subtypes genetic disorder SLOW PROGRESSIVE UNCOORDINATED GAIT UNCOORDINATED SPEECH, HAND AND EYE MOVEMENTS
SCA 4:
Autosomal Dominant
associated sensory neuropathy
B12 neuropathy
Presentation:
Sensory loss and sensory ataxia
Motor Neurone Disease = MND
Definition:
Pure Motor neurone features
Cognitive impairment and labile mood overlapping with FT dementia also seen
Amyotrophic lateral sclerosis:
Mutation in SOD-1 - superoxide dismutase
Presentation: Increasingly clumsy Slow hand movements wasting of small muscles of the hands UMN sgns: - loss of CNS inhibition Fasciculations in lower limbs Spasticity weakness brisk reflexes
Investigation:
EMG: active denervation in affected muscle
MRI may be normal
need to rule out SOL
Headache
Red flags: Vision changes / FAST Thunderclap New onset progressive Early morning headaches ABOVE NEED CT IMAGING ESP IN >50s
Raised ICP: Extradural SOL Venous sinus thrombosis BIH / IIH
Ix:
CT head / CT or MRI venogram
MRA for SAH
LP once confirmed no raised ICP
BIH / IIH - no longer BIH as associated with visual loss
Defintion:
Raised ICP without obvious cause
Demographic:
overweight female
child bearing age
Presentation:
visual obscurity
pulsatle tinnitus
postural headaches
exam: bilateral papilloedema enlarged blind spot impaired acuity VI palsy
Ix: Ct head to exclude SOL / causes ICP CSF: opening pressure >25cm LP improved symptoms opthalmology review for regular retinal photography and visual field assessment
management:
weight loss
acetazolamide or topiramate reduced CSF production
surgical - optic nerve sheath fenestration to allow drainage or CSF shunts
major morbidity = visual loss due to papilloedema
Stroke prevention
Secondary prevention:
rate control / rhythm control if AF / ablation / anticoag rivarox / apixaban
INTERNAL CAROTID ST >50%
consider endarterectomy
>70% - European carotid surgery trial - the greater the baseline risk the greater the patient has to gain from surgery vs conservative medical managstement
e.g. male sex / hemispheric event / unstable plaque / worsening comorbidity
Northamerican symptomatic carotid endarterectomy trial = >50%
Endarterectomy advised
Aspirin 75mg
TIA on Aspirin –> Add clopidogrel 75mg
Increasing aspirin dose does not reduce stroke risk but increases UGIB RR
Aspirin and dipyridaomle was treatment of choice for secondary prevention post ESPS-2 study. However clopidogrel now superseded original guidance
Meningitis
Definition:
Bacterial or viral inflammation of the meninges
Infectoin may spread to parenchyma and brainstem
Presentation: Meningo-encephalitic picture headache pyrexia nausea cranial nerve palsy neck stiffness photophobia drowzyness / depressed GCS altered behaviour seizures
Pathogens: Elderly and immunosupressed: Listeria monocytogenes Gram positive rods mortality >60% CSF 50% sensitivity
Ix:
Ct head
LP
neuro obs
Mx: unknown aet: cefotaxime + aciclovir listeria / gram +ve = ampicillin and gent TB suspect: cefotaxime and rifampicin MDR pneumococcal - cefotax and rifamp pneumococcal = cefotaxime and dex paeds = cefotax and dex evidence of oedema = dexamethasone
Pen Ax = chloramphenicol
Peroneal Nerve Palsy
Definition:
Common entrapment neuropathy
Cause:
pressure at fibular head / plaster casts and immobilisation
Diagnosis:
EMG studies
CK levels
presentation:
weakness of ankle flexion and toe extension
Foot Inversion is preserved
Foot eversion is lost
L5-S1 lesion would lose inversion as well
Anti-GM1 antibodies
seen in:
multifocal moto neuropathy with conduction block
brachial neuritis
definition
inflammation of brachial plexus
presentation:
classic post vaccination
symptoms:
winging of scapula
weakness in any distribution of plexus supply
cerebral abscess
Definition:
abscess (walled off focal infection primary or seeded) seen in the brain which may exhibit focal neurology
CT:
Ring enhancing lesion demonstrating encapsulation and non resolution
precipitant:
mastoiditis / sinusitis / dental infection
neonatal meningitis
fungal > in immunocomp e.g. HIV / DM
symptoms: headache fever encephalopathy depressed GCS FAST +VE specific symptoms dependent on the site of the lesiont
site:
most common corticomedullary junction frontoparietal region
Mccardle’s disease - mycophosphorylase disease
effects muscle
glycogen storage disorder V
Defintion:
impaired glycogen storage and metabolism in skeletal muscle
Inheritance:
autosomal recessive
PYGM gene chromosome 11
presentation: teens
impaired early exercise tolerance / fatigue / cramping
fixed weakness
prolonged bouts of exercise lead to myoglobin release and dark urine - myoglobin urea
Testing: second wind phenomenon - rest - delivery of oxygen and fatty acids and switch to non aerobic metabolism myoglobinuria raised CK muscle biopsy
MX:
high carb diet
sucrose before exercise
Beckers Muscular Dystrophy
Definition:
X linked muscular dystophy
Any female offspring will be carriers at least
presentation
later than Duchennes an variable anywhere from age 3 to middle age
likely to manifest arrythmias
Muscular Dystrophy
Definition:
Group of muscle disorders that result in progressive muscle weakness and muscle breakdown over time
Affects dystrophin gene product
examples:
Duchennes
Beckers
Vertebral Artery Dissection
Definition
Dissection of intima layer of vertebral artery resulting in occlusion of the arterial lumen
presentation: Posterior inferior cerebral artery occlusion
traumatic
vertigo / nausea / weakness / depressed GCS / ataxia
Benign paroxysmal positional vertigo
Definition:
Acute onset bouts of vertigo / nausea worse on head movement brought on by loose ortoliths.
Presentation:
commonly anyone with a history of head injury
manifestation: DIX HALLPIKE
Hold head to the right 45 degrees
rapidly move from sitting to lieing
Treatment:
Prochlorperazine
EPLEY MANEOUVRE:
Turn head to affected side as for DH
SLOW and SMOOTH go from sit to lieing and allow patients head to rest off end of cough still supported for 30secs
turn head towards unaffected side and remain for 30secs head still off couch - chin on shoulder
Patient now turns onto side to face unaffected side - head still supported off couch
sit up slowly keeping head supported chin on shoulder
Turn head to face forward and move chin to chest in one movement 30 secs
DONT DRIVE FOR 2 HOURS
DONT LIE FLAT FOR 2 NIGHTS
SLEEP ON GOOD SIDE FOR 5 NIGHTS WITH SUPPORT TO PREVENT ROLLING
Hepatic Encephalopathy
Definition:
Encephalopathy manifest by depressed GCS secondary to liver failure
precipitants: HEPATICUS HYPOGLYCAEMIA ELECTROLYTE DISTURBANCE PROTEIN MEAL - GI BLEED ALCOHOL / ANALGESIA TUMOUR INFECTION CONSTIPATION URAEMIA SURGERY
EEG: TRIPHASIC REPEATS
mX: Treat cause abx itu laxatives rifaximin fluids
5 stages - 0 - nil
1 - altered sleep wake cycle / mild confusion / alt behaviour
2 - moderate confusion / dorwzy / ataxia / asterixis
3- stupor / sleeping / incoherent speech
4 - coma
Myotonic Dystrophy type 1
Definition:
Inherited muscular dystrophy resulting in progressive muslce weakness and muscle wasting
Unlike Beckers and DMD, it is not x linked but is autosomal dominant and MD1 is the most common.
Mutation:
trinucleotide repeat disorder like Huntington’s
affects dystrophia myotonica protein kinase (DMPK)
ANTICIPATION
Diagonsis:
Muscle EMG - wax and wane “dive bomber pattern”
Presentation: adulthood bilateral ptosis frontal balding cataracts (not seen in DMD or BMD) progressive weakness loss of TDR facial wasting smooth muscle wasting abdo pain dysphagia resp muscle weakness
Parkinson’s Disease
Defintion:
Longterm neuro-degenerative disorder of the substantia nigra causing a reduction in dopamine release resulting in involuntary tremor like movements / bradykinesis and stiffness
Early:
Disturbnce in REM sleep due to a lesion within the PONS is a recognized feature of early onset idiopathic PD - this results incomplete relaxation during REM sleep and classically patients are seen fighting or verbalising with invisible individuals.
Chronic Inflammatory Demyelinating Neuropathy:
inherited - charcot marie tooth
drug related - amiodarone
paraprotein
Definition:
Chronic demyelinating sensorimotor neuropathy
EMG:
latency
F waves
slowed conduction
treatment:
oral steroid
IV Ig
azathioprine as a steroid sparing agent
Periodic Paralysis
thyrotoxicosis with periodic hypokalaemic paralysis
Definition:
periodic attacks of global motor weakness usually starting in the second half of the night following strenuous exercise the day before or a high carb meal
common:
chinese / japanese heritage
associated:
thyrotoxicosis
hypokalaemic paralysis
Mx:
potassium chloride supplements restore muscle power
euthyroid state prevents further attacks
Basilar stroke
Definition
Ischaemic occlusion of middle / proximal / distal basilar artery affecting brainstem function
risk factors:
HTN
atherosclerotic disease
AF
symptoms: LOCKED IN SYNDROME - middle and proximal consciousness preserved but paralysis globally eye movement preserved bulbar involvment
mortalty
85%
thrombolysis
35% restore reasonable QOL
Ramsay Hunt Syndome
Definition:
Hearing loss / hyperacusis / ptosis
see herpetic lesions on TM
VII palsy resulting from HERPES ZOSTER INFECTION of GENICULATE GANGLION
viii MAY ALSO BE AFFECTED = SENSORINEURA HEARING LOSS AND VERTIGO
IX:
schirmer test strip swab of pinna and viral pcr
vesicular blisters over tympanic membrane - NOT PAINFUL as bullous myringitis - mycoplasma pneumonia
Mx:
pred
aciclovir
Autonomic myopathy
Definition:
Group of conditions affects SNS / PNS or both
presentation: postural drops hypotension tachycardia - loss of vagal tone anhydryasis impotence nocturia impotence urgency horners sign - ptosis with constricted pupil and decreased sweating on side affected
Primary: DM amyloidosis GBS - poly motorneuropathy infections - HIV / chagas metabolic - uraemic neuropathy / hepatic related / alcohol immune - RA /
RX: dependent on cause
1. raise bed at night to increase renin production and raise baseline bp
2. slow standing exercises to reduce falls risk
3. increase salt intake
4. fludricortisone
5. eat little and often to reduce post prandial syncope
6.diabetic control
etc
Holmes - Adie Syndrome
Definition:
inherited polyneuropathy - degeneration of cilia ganglion and post synaptic ganglionic fibres
signs:
purely motor
ipsilateral ptosis
blurred vision
Rx:
0.1% pilocarpine to constrict pupil
CADASIL
cerebral autosomal dominant arteriopathy with subcortical infarcts
Arteriopathy - media thickening and stenosis with loss of smc
Definition:
syndrome of multiple early onset TIAs / stroke like episodes and complete strokes with significant periventricular white mater changes on MRI T” weighted imaging
early onset dementia
FMH migraine
Definitive Ix:
NOTCH-3 gene testing
lyme disease
definition:
Tick borne parasitic infection characerrised by meningitis / motor or sensory radiculopathy / cranial neuropathy
botulism
Definition:
bilateral cranial nerve neuropathy with descending weakness caused by botulinum toxin release from clostridium botulinum
diplopia
opthalmoplegia / blurred vision - CN involvement
desending weakness
neurotoxin blocks acetylcholine at NMJ
i.e. FLACCID PARALYSIS
Therefore EMG shows incremental increase in response to repeated stimulation as more AcH enters NMJ
PURE MOTOR - no sensory / remains responsive
signs: symmetrical descending paralysis CN: diplopia / ptosis / dysarthria / dysphagia / facial weakness RESP: diaphragmatic paralysis IC muscle weakness AUTONOMIC: Diarrhea / abdo pain / fixed or dilated pupils / tachycardia / urinary symptoms
macular sparing homonomymous hemianopia
definition in stroke:
macular sparred single sided hemianopia affecting both sets of optic radiaotin therefore must originate in cerebellum
macular sparred as supplied by distant branch of MCA
location of occulusion
posterior cerebellar artery
inferior quadrantinopia
definition in stroke
homonymous hemianopia knocking out parietal optic radiations supplying information from the inferior quadrants of the visual fields
associated:
same sided neglect or inattention
superior quadrantinopia
defintion in stroke:
homonymous hemianopia knocking out temporal optic radiations supplying information from the superior quadrants of the visual fields
associated:
AV hallucinations / dysphasia
Juvenile monoclonic epilepsy
Definition
Early onset periodic a)GTCS b)myoclonic jerking of one or more limbs c)absence seizures
strong genetic component - 50% have another affected relative
most common of all generalised epilepsies
Presentation:
On waking typically
Precipitant:
exacerbated by a)sleep deprivation b) alcohol c)anxiety
Mx:
lamotrigine - non teratogenic
avoid precipitants
AVOID CARBAMAZEPINE - WORSENS SEIZURES
AVOID PHENOBARBITONE
EEG: BURST WAVES / POLYSPIKE COMBINATIONSFDIVE
Myaesthenia Gravis
Definition
A progressive autoimmune myopathy resulting from antbodies directed against the AcH receptor on the on post synaptic termini (ant acHR) or against a post synaptic protein muscle specific kinase (anti-MUSK) in 40% where ach abs are negative
thymectomy may be required.
late in disease there is thymic atrophy
Mx: pyridostigmine 30mg qds increasing incremental steroid o alternate days IV Ig FVC monitoring +/- ITU
5 causes of extensor plantar and absent knee and ankle jerks
extensor plantars = UMN - babinksi sign
absent reflexes = LMN
5 causes
- subacute combined degeneration of the cord
- Hereditary Cerebellar Ataxia - Friedreichs / spinocerebellar ataxia (heterogenous group of inherited ataxia -
- MND
- Combined pathology neuropathy and myelopathy- DM to give sensory loss of reflexes and Cervical spondlylolithiasis / trauma / syrinogmyellia causing compression to give UMN
- Syphillis taboparesis
- Conus medullaris
What is Webers Syndrome
IPSILATERAL COMPLETE CN 3 PALSY
CONTRALATERAL HEMIPARESIS
MIDBRAIN STROKE POST CEREBRAL ARTERY
substantia nigra gives contralateral PD
Stroke Investigations
CT HEAD / CTA WITH CONTRAST CREAT AND INR THROMBOLYSIS WITHIN 4 HR THROMBECTOMY WITHIN 6 HR 24 HR TAPE ECHO DOPPLER STUDIES THROMBOPHILIA SCREEN MRI HEAD TO CONFIRM
Stroke Differentials
Tia SOL CVA Meningitis Todds paresis Functional MS
