Showing posts with label Neurology. Show all posts
Showing posts with label Neurology. Show all posts
Wednesday, 22 June 2011
Stroke
Definition
Ø Stroke (WHO definition)
§ Rapidly developing clinical signs of focal/global cerebral dysfunction
§ Lasting >24hours or leading to death
§ With no apparent cause other than of vascular origin
ü ischaemia (85%) /haemorrhage (15%)
Ø Transient ischaemic attack (TIA)
§ Sudden onset of transient focal neurological deficit
§ lasting < 24h (however, usually lasting < 24 hours)
Classification
1. Pathogenesis
a. Ischaemia (thrombosis, embolism, hypoperfusion)
b. Hemorrhage (ICH, SAH)
2. Arterial vs Venous vs Watershed
(Boundary zone infarcts)
3. Arterial Territory
a. Anterior Circulation (ACA, MCA)
b. Posterior Circulation (VBA, PCA)
ACA – Gold
MCA – Pink
PCA – blue
a. Children
b. Young adult
c. Older adult
Classification of ischaemic stroke by TOAST classification (Trial of Org 10172 in Acute Stroke Treatment)
Atherosclerosis – thrombosis or embolism | Lacunar - Occlusion of small blood vessel | Cardiogenic embolism | Other determined causes | Cryptogenic |
20% | 25% | 20% | 5% | 30% |
§ Large artery, >50% occlusion § Size of infarct >1.5cm | § a/w diabetes and hypertension § infarct < 1.5cm | § AF § valve disease § Ventricular thrombi § cardiomyopathy | § Arteritis § Thrombophilia § Arterial dissection § drugs |
Haemorrhagic classification
1. Intracerebral
a. RF - hpt, bleeding into tumor
2. Subarachnoid – crescentric
a. RF – berry aneurysm, AV malform, coagulopathy, drugs
DDx of stroke
1. Post-ictal Todd’s paralysis
2. Subdural haematoma
3. Brain abscess
4. Brain tumor
5. Hypoglycaemia
RF for stroke
Ø Non-Modifiable
1. Age
2. Gender
3. Race
4. Hereditary
Ø Modifiable
1. DM
2. Dyslipidaemia
3. HTN
4. Smoking
5. Alcohol
6. Obesity
Additional risks in young patient with stroke
1. Cardioembolic
a. Atrial fibrillation
b. Prostatic valve
c. Patent foramen ovale
2. Carotid/vertebral dissection
3. Anti-phospholipid syndrome, thrombophilia
4. Drugs – OCP, MAO inhibitor, mainliner
5. Vasculitis
Warning signs of stroke
1. Sudden onset of numbness / weakness of face, leg, arm
2. Difficult to speak
3. Visual field loss
4. Loss of balance
How to diagnose?
· History – sudden focal neurological sign + RF
· Neurological evidence of infarction / haemorrhage
Neurologic Diagnostic Formulation
1. Summarise deficit
2. Localise lesion
3. Postulate pathogenesis /aetiology.
Where is the lesion?
Anterior circulation | Posterior circulation |
ACA/MCA territory | Brainstem/cerebellar |
Transient monocular blindness Hemisensory loss Hemiparesis/hemiplegia Speech disorder Spatial neglect (sensory inattention, visual field defect) | Diplopia Vertigo Dysphagia Dysarthria Ataxia Cross paralysis Altered consciousness |
Localisation of lesion and CF
L gaze preference with R hemiparesis | L cortical infarct |
R gaze preferecene with R hemiparesis | L pons lesion |
Weakness : R arm > R leg Aphasia Hemisensory loss L gaze preference Homonymous hemianopia | L MCA territory |
Weakness: R leg > R arm | L ACA territory |
Acalculia Agraphia Left right disorientation Finger agnosia | Gerstmann’s syndrome Dominant Parietal lobe lesion |
R hemiplegia + R facial nerve palsy | L internal capsule, basal ganglia (lacunar stroke, intracerebral haemorrhage) |
R hemiplegia + L facial nerve palsy | L pontine lesion |
NB:-
1. Corticospinal tract decussates at lower medulla
2. Corticobulbar tract decussates at midbrain
3. Gaze preference towards lesion in cortical infarct
Oxfordshire Community Stroke Project Classification (OCSP)
Routine I(x)
1. FBC Anaemia, thrombocytosis, thrombocytopenia
2. RFT Hydration status, electrolyte imbalance
3. PT/APTT Baseline (if thrombolysis indicated)
4. FBS Hypo/hyperglycaemia
5. Lipid profile Athrosclerosis
6. ECG A. fib, IHD
7. CXR Baseline, enlarged in HTN patient
8. CT Ischaemia vs. haemorrhage, site of lesion, extent of lesion
9. MRI DWI (diffusion weighted), T2W
I(x) in young stroke
1. Echo Cardioembolism, assess cardiac function
2. ANA, Anti-dsDNA Auto-immune
3. Thrombophilia screen, APS
4. Droppler US KIV if anterior circulation involvement
5. CTA/MRA If planned for thrombolysis
Acute management
Quick history and exam
Call for help
Urgent CT scan
Monitoring esp ECG
IV line
Baseline I(x) – FBC, U&E, LFT, coag profile, RBS, lipid profile
Ø Ischaemic stroke
1. Thrombolysis if <3h – if no contra-indication – start on alteplase
a. Rule out CI
b. Suitability for thrombolysis
i. NIHSS – National Institute of Health Stroke Scale
iii. BP<185/110
iv. No contraindication for thrombolytic
v. Normal/ischaemic CT scan
2. T. aspirin 300mg if CI or
3. T. statin
Ø Haemorrhagic stroke
Monitor
Refer to neurosurgeon
Stroke rehab unit
Long term – multi disciplinary
– OT, physiotherapy, speech therapy, dietician, physician
Life style changes
Tackle morbidity – DM, Hpt, dyslipidaemia
High dose statin
Study shows ischaemic stroke improvement if on statin
ALGORITHM OF MANAGEMENT OF STROKE
 |
Source: CPG MOH, Management of Stroke, Jun 2006 MOH/P/PAK/113.06(GU) |
What happen to a person after having stroke?
1. Initial phase of cerebral shock (1st 2 weeks)
a. Immediately after cerebral infarct
b. Muscle tone is flaccid (hypotonic)
2. Recovery phase (2nd -6th week)
a. Persistence of hypotonicity (flaccid stage)
i. Motor loss is usually accompanied by severe sensory loss
ii. Most disabling stage
b. Evolution towards normal tone (recovery stage)
i. Movements start in the limp, distil first
ii. UL first
iii. Slight disability usually remain
c. Evolution towards hypertonicity (spastic stage)
i. Most frequent occurrence
ii. Initial recovery of proximal movement (hip & shoulder)
iii. Earlier in lower limp, typical spasm for hypertonicityàspacticity
iv. Spasticity > at anti-gravity muscle
v. UL: flexor>extensor
vi. LL: extensor>flexor
Complications of stroke
Acute | Chonic |
Aspiration pneumonia DVT Bedsore UTI Septicaemia Depression Death | Seizure Physical disability Dependance Contracture, disuse atrophy Psychological |
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