Stroke

Understanding strokes involves recognizing their localization in the brain and correlating this with functional impairments in occupational performance.
The key question by the end of the lecture is: "How does the location of a stroke relate to the functional symptoms a client experiences?"
Different brain functions are localized in distinct areas, leading to common symptom presentations based on stroke location.
Occupational therapists must be cautious not to overgeneralize based on stroke location and should perform comprehensive evaluations to tailor interventions.
The size and severity of strokes vary significantly, resulting in diverse presentations among clients who may have similar stroke locations.

The middle cerebral artery (MCA) is a branch of the internal carotid artery; it accounts for approximately 70% of first-time strokes.
Location and Functionality:
- The MCA supplies blood to the lateral aspect of the cortex, impacting motor and sensory areas, including language processing regions.
- The upper extremity and facial areas of the motor and sensory homunculus are especially vulnerable, often leading to greater impairment in these areas compared to the lower extremities.
Typical Symptoms of MCA Stroke:
- Left MCA Stroke:
- Loss of motor function and sensation on the right side (contralateral).
- Language deficits localized to the left brain (e.g., dysarthria).
- Decreased right visual field (homonymous hemianopsia).
- Possible memory impairment.
- Right MCA Stroke:
- Loss of motor function and sensation on the left side (contralateral).
- Spatial and perceptual deficits including left inattention or neglect.
- Potential for dressing apraxia, anosognosia, and decreased left visual field.
- Behavioral changes leading to impulsivity and impaired judgment.

The anterior cerebral artery runs more centrally from the front to the back of the brain.
It is somewhat protected by the Circle of Willis, which may help maintain blood supply despite blockages.
Typical Symptoms of ACA Stroke:
- Peripheral implications include contralateral lower extremity paralysis (often more affected than the upper extremity).
- Loss of voluntary control of bowel and bladder function.
- Decreased balance, and potential changes in emotion and personality due to injury in the frontal lobe.
- Memory impairments may also be observed.

The posterior cerebral artery supplies the occipital lobe and represents about 20% of ischemic strokes.
Typical Symptoms of PCA Stroke:
- Homonymous hemianopsia (loss of vision in half of the visual field).
- Visual agnosia (difficulty recognizing objects).
- Memory deficits and contralateral motor/sensory loss.
- Right hemisphere strokes are associated with cortical blindness, visuospatial deficits, and impaired left-right discrimination.
- Left hemisphere strokes may lead to anomia, agraphia, acalculia, alexia, and dyslexia.

Represents about 20% of ischemic strokes, often occurring in older individuals due to natural wear and tear.
Typical Symptoms of Vertebrobasilar Artery Stroke:
- Visual impairments, vertigo, and dizziness.
- Coordination impairments, including ataxia (balance disturbances) and dysmetria (difficulty with precise limb movements).
- Potential for dysphasia (difficulty with chewing and swallowing).
- Memory decrease and focal sensory loss may also be evident.

Represents about 25% of all ischemic strokes, occurring in deep brain structures (e.g., basal ganglia, thalamus).
Typical Symptoms of Lacunar Stroke:
- Generally results in more mild and localized symptoms; often initially undetected.

Can occur at various levels and generally results in severe symptoms due to the brainstem’s role in vital functions.
Common Features:
- Cranial nerves are particularly susceptible to brainstem strokes.
Notable Stroke Syndromes:
- Wallenberg Syndrome: Contralateral sensory loss of pain and temperature, Ipsilateral Horner syndrome, and ataxia-associated sensory loss in the face.
- Locked-In Syndrome: Results in complete paralysis except for movements in the eyes. Communication is possible only through eye movement; this indicates severe impairment.

A transient ischemic attack refers to a temporary blockage of blood flow that resolves within 24 hours.
While TIAs do not cause permanent damage, they serve as a warning for potential future strokes; approximately 15% of stroke patients experienced a prior TIA.
Symptoms for TIA may mimic stroke but without definitive permanent damage, making it critical for immediate medical attention as response time is essential (time lost is brain lost).

The American Stroke Association uses the acronym BE FAST to help identify signs of stroke:
- Balance: Sudden loss of balance.
- Eyes: Vision change in one or both eyes.
- Face: Facial drooping.
- Arm: Weakness or numbness in one arm.
- Speech: Difficulty speaking or understanding speech.
- Time: Call 911 immediately if any symptoms occur.
It is critical for both the public and healthcare professionals to recognize stroke symptoms and respond rapidly to enhance chances of recovery.

A comprehensive understanding of the functional presentations of strokes in the MCA, ACA, PCA, vertebrobasilar, and brainstem locations, as well as TIAs as critical warning signals.
Occupational therapists must be knowledgeable in identifying stroke symptoms and educating clients accordingly, prioritizing swift action to ensure the best outcomes for affected individuals.