Stroke Pathology and Clinical Assessment Flashcards
Stroke
Neurological deficit of sudden onset and vascular origin that lasts more than 24 hours
Transient ischaemic attack
Same as stroke but lasts less than 24 hours
Stroke symptoms include loss of
Power, sensation, speech, vision, coordination
Neurological history/examination findings
Motor and sensory weakness Dysarthria/dysphasia Neglect/visuospatial problems Vision loss in one eye or hemianopia Gaze palsy Ataxia/vertigo/incoordination/nystagmus
Causes of stroke
Thrombus/embolism causing blockage of a blood vessel
Haemorrhage from rupture of blood vessel
Disease of vessel wall
Disturbance of normal properties of blood
What brain arteries make up the Circle of Willis
Posterior, middle and anterior cerebral arteries
Internal carotid artery
Posterior and anterior communicating arteries
Anterior cerebral artery supplies
Front of brain
Posterior cerebral artery supplies
Back of brain
The carotid system supplies
Most of the hemispheres and cortical deep white matter
The vertebro-basilar system supples
Brain stem, cerebellum and occipital lobes
Carotid system contains which arteries
Internal carotid, common carotid, anterior and middle cerebral
Vertebro-basilar system contain which artieres
Posterior cerebral. basilar, vertebral, cerebellar
Lobes of the brain
Temporal, frontal, parietal, occipital
Brain stem function
Swallowing, breathing, heartbeat, wakefulness centre, other involuntary functions
Cerebellum function
Coordination
Anterior brain functions
Speech, smell, judgement, foresight, voluntary movement
Middle brain functions
Movement, intellectual and emotional functions, pain, heat and other sensations, hearing
Posterior brain functions
Comprehension of language, visual, speech comprehension
Why will small stroke in internal capsule or brain stem result in a major deficit
Fibres packed closely together
What percentage of stroke are caused by haemorrhage
15%
What percentage of stroke are caused by infarction
85%
Commonest cause of cardioembolic stroke
Atrial fibrillation
Lacunar stroke
Stroke in small vessels of brain - deep white matter
Lacunar stoke is caused by
Ischaemia
Conditions that can lead to lacunar stroke
Hypertension
Diabetes
Rarer cause of stroke
Carotid dissection
Carotid dissection can be caused by
Idiopathic
Trauma
Locked-in syndrome
Patient is aware but cannot move or communicate verbally due to complete paralysis of nearly all voluntary muscles in body apart from vertical eye movement and blinking
Ischaemic stroke causes
Large artery atherosclerosis Cardioembolic Small artery occlusion Undetermined/cryptogenic Atrial dissection Venous sinus thrombosis
Haemorrhagic stroke causes
Primary intracerebral haemorrhage
Secondary haemorrhage - subarachnoid or arteriovenous malformation
Cortical stroke
Stroke involving the cortex
Advantages of localisation of stroke
Confrims diagnosis
Selection of imaging
Indicates cause and prognosis
Most common imaging method for stroke
MRI scan
TACS
Total anterior circulation stroke
PACS
Partial anterior circulation stroke
LACS
Lacunar stroke
POCS
Posterior circulation stroke
Usual visual defect in stroke
Homonymous hemianopia
TACS makes up what percentage of strokes
20%
Cause of TACS
Occlusion of proximal middle cerebral artery or internal carotid artery
Symptoms of TACS
Weakness
Sensory deficit
Homonymous hemianopia
Higher cerebral dysfunction - dysphasia/dyspraxia
PACS makes up what percentage of strokes
35%
PACS affects
One side of the brain
Symptoms of PACS
Partial motor and sensory deficit in one side, 2/3 body areas
Higher cerebral dysfunction - dysphasia, visuospatial disturbances
Homonymous hemianopia
LACS makes up what percentage of strokes
20%
Different types of LACS
Pure motor
Pure sensory
Sensorimotor
Pure motor LACS
Complete or incomplete weakness of 1 side, 2/3 body areas
LACS are under diagnosed because
They are often silent
POCS makes up what percentage of strokes
25%
POCS affect
Brainstem, cerebella or occipital lobes
POCS symptoms
Bilateral motor/sensory deficit Disordered conjugate eye movement Coma Vertigo Disordered breathing Homonymous hemianopia Nerve palsy Tinnitus Horner's syndrome
Risk factors for stroke
Hypertension Atrial fibrillation Age Race Family history