Understanding Stroke: Causes, Impact, and Management

STROKE • Define what a stroke is and outline the three major causes ‘a clinical syndrome, of presumed vascular origin, typified by rapidly developing signs of focal or global disturbance of cerebral functions lasting more than 24 hours or leading to death' “Transient” = recovery within 24 hrs = TIA “Completed” deficit persists but is stable “Evolving” deficit persists & worsens after 6 hrs Can be Infarction (80%) or Haemorrhage (20%) o INFARCT § risk factors – HT, DM, Smoking, AF, High Cholesterol, Clotting disorders, infective endocarditis, alcohol, IVDU o HAEMORRHAGE § can be intracranial haemorrhage (10%) or sub-arachnoid haemorrhage (10%) § Both present as strokes, but are managed differently to infarcts. • Describe the importance of stroke o Single biggest cause of severe disability o one of the leading causes of mortality and morbidity in the UK o It affects over 130,000 individuals annually. o 174 - 216 /100,000 o NB: not only affect the elderly – 8% under 55, 1% under 30 o Huge impact on individuals and families; It can dramatically change an individual's function, role and lifestyle from one day to the next. à require carer / care home o Stroke is associated with high levels of anxiety and depression. o STROKE IS PREVENTABLE – Control of risk factors reduces incidence • Outline the major factors that predispose to stroke disease Non-Modifiable o Increasing age o Male o FH o PMH of stroke / embolism o Heart disease (HF, AF, endocarditis) Modifiable o High BP - promote health lifestyle, diet etc, medicate aim for < 140/90, <130/85 if renal impairement, <130/80 if DM o Heart disease – reduce risk factors, anticoagulate if required o Atrial Fibrillation – verify, convert to sinus if poss, warfarin (INR 2-3) or aspirin if warfarin contraindicated or <65yrs o Carotid stenois – antiplatelet, endarterectomy o Smoking – support for quitting o Poor diet – advise o Obesity – advise BMI 18-25 o Excess alcohol – avoid exess / binge o Hyperlipidaemia – statin / diet o DM – aim for HbA1C < 7% o Others - Polycythaemia, Oral contraceptive • Describe the morphology and pathological consequences of haemorrhagic and ischaemic stroke. Ischaemic Occlusion of cerebral artery Anastomosis required to maintain perfusion Other mechanisms help to maintain homeostasis Failure of these mechanisms à ischaemia à neurones fail Temporary period where recovery is possible if flow is restored If flow is not restored à cell death Can take several hours for cell damage to complete & full effects to be seen Haemorrhagic Rupture of blood vessels à Immediate cessation of function due to structural disruption (damage to white cell tracts) If severe can à increased ICP à coning à instant death Can occur into previous infracted / TIA regions due to endothelial damage • Outline the suggested involvement of EAA receptors in neurodegeneration following stroke • Describe the Classification of Strokes and the features of each type Bamford stroke classification TACS – Total Anterior Circulation Syndrome Blockage of proximal stem of Middle cerebral artert (by thrombus/embolus) Often associated with internal carotid occlusion ALL patients present with Hemiplegia and/or Sensory loss on contralateral side Hemianopia opposite side to lesion Disturbance of higher cerebral function (speech, neglect, inattention, reading, writing) PACS – Partial Anterior Circulatory Syndrome Restricted infarcts of upper or lower divisions of middle cerebral artery Same symptoms of PACS but fewer LACS – Lacunar Syndrome Single vessel damage, deep within the brain (e.g. internal capsule) = Maximal damage from a single vascular event Partial motor / sensory loss Can be ataxic if in BG or pons NO higher function impairment NO visual field deficit No sign if brainstem disturbance POCS – Posterior Circulatory Syndrome Infarcts of the brain stem, cerebellum or occipital lobes Isolated hemianopia / cortical blindness CN palsy same side, with contralateral motor/sensor loss Cerebellar Ataxia Disorders of eye movement (Diplopia, Nystagmus) • State the differentials for stroke (stroke syndromes) and how to recognise them o Subdural Haematoma – may be more gradual onset, S&S fluctuate, drowsiness. Consider if Hx of fall/trauma/aspirin/warfarin, Diagnose by CT o Epilepsy – post icteral weakness = Todds Paresis. Obtain collateral history, recovery <24hrs o Hypoglycaemia – poorly controlled DM, ALWAYS CHECK BM o Brain Tumour – more insidious onset (days-weeks), stuttering / slow progressive course, vomiting & headache, seen on CT o Migraine – transient weakness, rapidly improves, Hx of headache o Encephalitis – uncommon, features of infection, fits common, CT/MRI may help, EE most use o Cerebral Abscess – uncommon, important to diagnose as surgery required, signs of infection, long prodrome, headache, reduced conciousness, CT scan diagnostic • Elicit relevant clinical signs in a patient presenting with a stroke including atrial fibrillation, valvular heart disease and carotid/vertebral bruits. • Describe the initial investigations for a patient presenting with a stroke including the indications for performing a CT/MRI scan. o FBC, CRP, Glucose, Renal function, LFT, Cardiac Enzymes, cholesterol, TFTs, ECG, CXR, Cardiac Echo, 24hr tape o Head CT (for most) § Indications – suspicion of SOL / SAH / Meningitis / need to distinguish between haemorrhage & infarct, possible cerebellar haematoma § Contraindications – so likely to die that result unlikely to help • Describe the initial and long-term management of a patient with an established stroke including rehabilitation and measures for secondary prevention in appropriate cases. Initial Management o Thrombolysis / drainage if appropriate o Aspirin / anticoagulant / TEDs o Good hydration + O2 (reduces ischaemic damage) o Check blood glucose – avoid lactic acid buildup à avoids further damage 2o complication of stroke o Aspiration pneumonia Involve SALT team o Malnutrition Check SALT, involve dietician if required o Pressure sores Move position regularly, mobilise early o Depression Set realistic goals, medicate if required o Incontinence Catheterise? Can à decreased bladder size o Joint damage o Shoulder pain o Neurological pain o Contractures / spacsiticy Good physiotherapy & botox / baclofen o DVT from immobility Exclude haemorrhagic stroke and anticoagulate SPEECH DISTURBANCES DYSPHASIA= Impairment of language due to brain damage & divided into: • Receptive - Unable to understand language - lesion in Wernicke's area o Speech may be fluid & confident but not make sense, patient doesn’t recognise errors • Expressive - Unable to express via speech - lesion in Broca's area o Understanding is preserved o Speech often hesitant & stuttering, non fluent - patient recognises that their speech is incorrect o Use of neologisms – e.g. “short” instead of “stroke”, “wash” instead of “watch” o Poverty of speech – vocabulary is limited NB: Often a combination of the 2 as the areas are anatomically close together APHASIA = complete inability to express thoughts as language DYSARTHRIA • Motor disturbance of speech • due to weakness to the tongue or facial muscles (facial nerve palsy) • Understanding & expression usually in tact but cant get words out • If complete can be difficult to distinguish from aphasia (check comprehension) ASSESSING SPEECH & LANGUAGE TEST UNDERSTANDING • Name • Address • 3 stage command (lift right arm, touch nose, touch left ear) TEST EXPRESSION • Ask to name simple objects (pen, book, comb, watch) • Ask to describe a picture (magazine cover) TEST DYSARTHRIA • Baby Hippopotamus • West Register Street • British Constitution • P–P–P • C–C–C • T–T–T SENSORY DISTURBANCE SENSORY NEGLECT / INATTENTION • Test sensation unilaterally (check each side individually) • Then bilaterally (both sides together). • If only feel on one side = neglect • Then test “visual fields with confrontation” in same way • Full neglect would show in vision and touch NB: left / right sensory disorientation is very common post stroke AGNOSIA = Inability to recognise familiar objects • Check sensation is in tact & no sensory neglect • Trace numbers onto hand = dysgraphesthesia if unable to recognise (Astereognosis) • Give 2p and £1 ask to identify by touch alone = inability is consistent with agnosia HEMISENSORY LOSS Loss of light touch sensation down one side Can be confused with sensory neglect (always check unilateral sensation first) VISUAL DISTURBANCE HOMONYMOUS HEMIANOPIA • Hemianopia = loss of one-half of a visual field • Quandrantopia = loss of one quarter of visual field • Homonymous = loss of the same side visual field (knocks out nerve/brain dealing with C/D) • Cant see stimulus presented in that field • NB: different to neglect (see on own but not when bilateral) • NB: If hemianopia is present, NOT possible to comment on visual neglect. Left Visual Field Right Visual Field A B A B C D MOTOR LOSS E • • • C C – loss of all information from the Right Visual Field D D – loss of all information from the Left Visual Field E E – loss of all information from the outer edges = BITEMPORAL Hemianopia Hemiparesis = weakness down one side of the body - Upper motor neurone deficit Hemiplegia = complete paresis (MRC grade 0 power) Weakness graded using the Medical Research Council scale MOTOR & SENSORY ASSESSMENT • Tone A/B – loss of all sensation from an eye à loss of that eye’s visual field • • • • • • Power – graded 0-5 o typically extensors weak in stroke o pyramidal weakness – hold out arms, palms up, close eyes, look for drift Peripheral reflexes Co-ordination – eyes closed, touch a finger & ask to touch nose Sensation - Light Touch (unilateral to check intact, bilateral to assess neglect) Visual field & confrontation testing Cranial nerves – esp eye movements & swallowing NB: partial III palsy = eye movements normal, but dilated pupil & partial ptosis. DYSPRAXIA Inability to perform tasks, despite having the necessary strength and sensation e.g., unable to dress in the absence of a hemiparesis (‘dressing apraxia'). It is a problem with processing information. BRAINSTEM Can be difficult to classify accuratley Include CN palsies, cerebellar signs (ataxia) & locked in syndrome CN lesions • Due to brain stem stroke • Signs based on section affected E.g. DYSPHAGIA • Motor abnormality of swallowing • Common in stroke (30-50% initially) • Can à aspiration pneumonia. • It does not affect language, but can coexist with dysphasia Cerebellar signs • Dysarthria • Nystagmus • Intention tremor • Past pointing • Broad based staggering gait (drunken sailor) Locked in syndrome • Patient unable to move or speak • May be able to make limited communication by eye gestures • May be mistaken for a coma •