Neurology Flashcards
Extrapyramidal triad of Parkinsonism
- Tremor: worse at rest, ‘pill-rolling’
- Hypertonia: rigidity + tremor, ‘cogwheel rigidity’
- Bradykinesia: decrease blink rate, micrographia, decrease arm swing, expressionless face
Pathology of Parkinson’s disease
Loss of dopaminergic neurons in substantia nigra in the basal ganglia
Bamford stroke classification***
> TACS
All three:
- Unilateral weakness (and/or sensory deficit) of the face, arm and leg
- Homonymous hemianopia
- Higher cerebral dysfunction (dysphasia, visuospatial disorder)
> PACS
Two of following:
(Same as TACS)
> Lacunar syndrome One of following: - Pure sensory stroke - Pure motor stroke - Sensori-motor stroke - Ataxic hemiparesis
> POCS
One of following:
- CN palsy and contralateral motor/ sensory deficit
- Bilateral motor/ sensory deficit
- Conjugated eye movement disorder (eg: gaze palsy)
- Cerebellar dysfunction (eg: ataxia, nystagmus, vertigo)
- Isolated homonymous hemianopia or cortical blindness
NIH Stroke Scale
- Objective quantify severity of stroke
- 11 components, all related to symptoms of stroke
- Ranged from no stroke symptoms to severe stroke symptoms
Contraindication for thrombolysis
> History - Unclear time/ wake up stroke - Within 3 months (prior ischemia stroke, recent head trauma, intracranial/ spine surgery) - Recent birth, surgery, trauma - Intracranial pathology > Investigation - BP >220/130 - Major infarct or hemorrhage on CT - Coagulopathy (platelets <100 x 10*9/L, INR >1.7, aPTT >40s, PT >15s)
Monitoring of stroke
- Admit stroke unit
- BP and neurological examination
- Every 15 min during and 2 hours after IV alteplase, then
- Every 30 min for 6 hours, then
- Hourly until the 24th hour
- Maintain BP <180/105mmHg
History taking for stroke*
- Onset (Important for management)
- Visual disturbance
- Speech disturbance
- Headache
- Sign of meningism (might indicate SAH)
- Risk factor of stroke
Expected physical sign for stroke***
○ Cerebral infarct - 50%
- Contralateral sensory loss or hemiplegia
- Initially flaccid, becoming spastic
- Dysphagia
- Homonymous hemianopia
○ Brainstem - 25%
- Quadriplegia
- Disturbance of gaze and vision
- Locked-in syndrome
○ Lacunar infarct - 25%
- Ataxic hemiparesis
- Pure motor
- Pure sensory
- Sensorimotor
- Dysarthria/ clumsy hand
Investigation for stroke**
> ETD
- CT brain: exclude ICH
- Random blood glucose: hypoglycemia cause focal neurologic deficit mimicking stroke; hyperglycemia associate with worse outcome
> Work-up
- FBC: exclude anemia, polycythemia, thrombocytosis, thrombocytopenia
- Urea and electrolyte: hydration status, exclude electrolyte imbalance
- Coagulopathy: as baseline if thrombolysis considered
- CT angiogram
- Echocardiogram: mural thrombus, hypokinetic segment, valvular lesion
- 12- lead ECG, 24-hr hotler: AF
- CXR: enlarged left atrium
- Carotid doppler: carotid artery stenosis
Immediate management for stroke***
- Non-contrast CT brain
- Monitor vital signs
- Supportive treatment (O2, airway support, correct hypovolemia, maintain normothermia)
- Monitor blood glucose (aim 6-10 mmol/L), NIHSS score, GCS
Definitive treatment for stroke***
- Mechanical thrombectomy
- Thrombolysis using tPa (eg: IV alteplase)
Post-thrombosis:
- CT 24h post-lysis to identify bleed before initiating antiplatelet
Stroke unit care management**
- Supplement O2, airway support
- Swallowing test
- DVT prophylaxis (DO NOT use compression stocking)
- Monitoring and treatment of acute complication: cerebral edema, seizure, infection (eg: pneumonia, UTI)
Pathogenesis for Gullain Barre Syndrome*
- “Molecular mimicry”
- Typically Campylobacter jejuni, crosses react with ganglioside GM1 in the myelin
- Other: CMV, EBV
Types of GBS
○ Acute inflammatory demyelinating polyneuropathy (AIDP)
- Acute variant of GBS
○ Chronic inflammatory demyelinating polyneuropathy (CIDP)
- Chronic variant of GBS
○ Miller-Fisher syndrome
- With cranial nerve involvement
○ Multifocal motor neuropathy
- Only affect motor neurons
Clinical features of GBS***
- Lower motor neuron signs (areflexia is highly suggestive, wasting and weakness at distal muscles of hands and feet)
- Shortness of breath (due to bulbar palsy and phrenic nerve involvement)
- Distal numbness
Investigation of GBS**
○ DIAGNOSED CLINICALLY (No specific test)
○ Lumbar puncture: Albumin-cytologic dissociation - Hallmark of GBS (increase protein with normal WCC)
○ Nerve conduction studies: Demyelinating pattern, slow conduction
○ Forced vital capacity: Respiratory muscle may be compromised
Management for GBS**
- First line: IVIG
- Mechanical ventilation if respiratory muscle are involved
- Chest physiotherapy
Triad of Miller-Fisher syndrome
- Ophthalmoplegia
- Ataxia
- Areflexia
Features in CT brain of ischemic stroke
- Loss of insular ribbon
- Hypoattenuation of brain tissue
- Loss of sulcus and grey-white differentiation
- Dense MCA
- Obscuration of lentiform nucleus
Causes of postural instability
- Weakness and spasticity: central lesion or spinal cord disease
- Foot drop: lumbar spinal stenosis
- Apraxic gait: normal pressure hydrocephalus, neurodegenerative dementia
- Narrow based gait: Parkinson’s disease
- Vestibular gait: sensorineural vestibular disease
Causes of stroke
- Atherothrombosis
- Embolism (eg: AF, infective endocarditis)
- CNS bleed (eg: hypertension, trauma, aneurysm rupture, anticoagulant)
Target INR for AF stroke prevention
2 to 3
Risk factor for stroke***
> Non-modifiable
- Age
- Sex: Male
- Family history
> Modifiable
- Hypertension, DM
- Smoking
- Hypercholesterolemia
- Peripheral vascular disease
- Atrial fibrillation
Management of hemorrhagic stroke
- Severe hypertension should be lowered
□ IV beta blocker, nicardipine, hydralazine, nitroglycerine - Reversal of anticoagulation
□ Administration of fresh frozen plasma and vitamin K
□ Antiplatelet and anticoagulation are contraindicated - Prevention of venous thromboembolism
□ Intermittent pneumatic compression - If significant mass effect
□ Surgical evacuation: >20ml in volume or a midline shift on CT scan
Causes of young stroke
- Atrial fibrillation
- Arterial dissection
- Thrombophilic disorders: protein C/ S deficiency, antiphospholipid syndrome
- Acquired thrombophilic state: hormonal contraception, nephrotic syndrome
Quick, early recognition of stroke
“FAST”
- Facial dropping
- Arm weakness
- Speech difficulty
- Time to call for ambulance!
What to do if suspicious for subarachnoid hemorrhage but CT is normal
- Arrange lumbar puncture after 12 hours
- Look for xanthochromia (presence of bilirubin in CSF due to break down of blood)
Management of dementia
- Cholinesterase inhibitors (eg: donepezil): reduce symptoms through increase cholinergic transmission by inhibiting cholinesterase at the synaptic cleft
- NMDA receptor antagonist (eg: memantine): block pathologic stimulation of NMDA receptor against further damage in patient with vascular dementia
