Stroke

What is a stroke:

• Loss of function that occurs when brain cells are killed by a loss of their blood supply

• The characteristic diagnostic features are:

• Sudden onset of symptoms

• Interruption of blood flow in the brain with symptoms lasting 24 hours or lomger

• Can lead to death

Causes and risk factors:

• Cerebrovascular disorder

• Stroke strikes every 5 mins in the UK

• Risk factors include:

• Hypertension, CVD, diet, high cholesterol and smoking

• More than 400 childhood strokes a year in the UK

• The brain needs high levels of oxygen via red blood cells

• Neurons mostly respire areobically

• Need oxygen to provide energy to neurons

• A deprivation of oxygen means you are unable to survive for more than a few mins

Type of stroke:

• Haemorrhagic:

• Where a weakened blood vessel supplying the brain bursts

• Usually occurs due to cardiovascular anomaly or a long history of hypertension

• Weakened blood vessels:

• Arteriovenous malformations, (AVMs), abnormal development of blood vessels in brain since birth

• Aneurysms:

• Usually develop at branching points of arteries

• Enlarges ‘ballooning’ of the blood vessels which can lead to ruptures

• Subarachnoid haemorrhage leads to bleeding into space around the brain

• Haemorrhagic steoke leads to bleeding in the brain which increases pressure

• Ischaemic:

• Where the blood supply is obstructed due to a clot

• Atherosclerosis is a build up of fatty deposits inside the arteries which blocks blood flow

• Two types of obstructions:

• Cerebral thrombosis, blood clot develops at the fatty plaque within the blood vessel (narrowing)

• Cerebral embolism, part of blood clot breaks loose and enters bloodstream of the brain and vessels are too small to let it pass

• Transient Ischaemic attack:

• (Mini stroke)

• Lasts for a short amount of time, usually a few mins but less thsn 24 hours

• A sign that there is a problem and at high risk of having a stroke

• Temporary blockage cuts off the blood supply to part of the brain however this either dissolves on its own or moves away

• Returns normal blood supply and stroke symptoms dissapear

Symptoms:

• Facial dropping on 1 side, corner of lip or eye may droop

• Might not be able to lift 1 or both arms up due to weakness

• Speech is slurred or jumbled

• Neuronal death of posterior frontal, temporal amd parietal areas usually involve MCA

• If veretebra-basilar arteries are involved then infarct in brain stem, inferior temporal lobe (hippocampus) and occipital lobes

F.A.S.T:

• Face, facial weakness

• Arm, can they raise both arms or hold their arms up

• Speech, can they talk, is it slurred

• Time, time to call for an ambulance or to have intervention

Circle of Willis:

• 3 branches coming off aorta

• A structure in the brain that may protect against stroke

• A complete circle of Willis allows blood to flow from one side of the brain to the other, even when blockages or thinning vessels occur.

What symptoms would you expect to find with damage to the following regions:

• Left, speech and language disorders are common

• Right, perceptual and visuo-spatial deficits

• Anterior- executive, personality

• Posterior- visual

• Neuronal death of posterior frontal, temporal and parietal areas usually involves MCA (most common)

• If Vertebra basilar is involved then infarct in brain stem, inferior temporal lobe (hippocampus) and occipital lobes

Symptoms you would expect to find after MCA stroke:

• Left frontal lobe (somatosensory)

• Right face and arm weakness

• Non fluent aphasia (language production)

• Deficits may also include visuospatial abilities

• Hemiplegia (one sided paralysis)

• Somatosensory

• Basilar artery, movement, sensation and consciousness

• Ruptured anterior communicating artery aneurysm

• Frontal lobe syndromes (apathy, childishness, indifference and memory disorder)

• Damage tends to be more widespread, does not follow anatomical pattern

Neuropsychological assessment:

• Visual neglect:

• Right hemisphere stroke, will continuously fail visuo spatial tests if they have neglect

• Minimizes problem by using remediation and compensation

• Limits presentation to ‘good’ right visual field

• Aphasia:

• Comprehension problems, non verbal gesturing

• Expressive problems, multiple choice and yes/no

• Hemiparesis:

• Weakness in one side of the body

• Physical impact on mental function testing

• Paretic limb, weakness in a limb, most common is the arm

• Occurs in 80% of stroke survivors

• Severity of motor impairment relates to level of recovery

• 30-50% of all stroke survivors have a severely impaired affected arm 6 months after stroke

• 70-80% of occurrence due to anterior circulation infarctions

Emotional disruption:

• Acute presentation:

• Left, depression, catastrophic

• Right, indifference, apathy

• Depression is common, 40% regardless of site of lesion over long term

• Poor insight (anosognosia), right parietal can differ

• Depression associated with restrictions in activity and social life

Assessment measures:

• Mood:

• Stroke aphasic depression questionnaire hospital version (10 item)

• Depression intensity scale with circle

• General health questionnaire, 12 item

• Hospital anxiety and depression scale

• Cognitive:

• Addenbrooks cognitive examination, revised

• Montreal cognitive assessment

• Repeatable battery for the assessment of neuropsychological status

• Rivermead perceptual assessment battery

• Behavioral assessment of dysexecutive syndrome

Rehabilitation/ treatment considerations:

• Treatment of emotional behaviors:

• Psychotherapy

• Behavioral techniques eg CBT

• Medication, monitor neurovegetative signs

• Rehabilitation:

• Visuo- perceptual deficits, right hemisphere stroke, inattention, neglect

• Speech and language therapy

• Memory deficits

• Executive function deficits

• Mirror therapy:

• Utilize mirror neuron theory

• Reduces pain

• Improves movement of affected paretic limb

• rTMS:

• Repetitive TMS is used to help improve movement of affected limbs

• Also has been found to improve mood

o