What are the implications of a right internal capsule infarct (intracerebral infarction)?

From the Guidelines

A right internal capsule infarct should be managed with immediate medical attention, including thrombolytic therapy if the patient presents within the appropriate time window, and long-term management with antiplatelet medications, blood pressure control, and rehabilitation therapies to improve morbidity, mortality, and quality of life. The internal capsule is a critical area of the brain containing important nerve fibers that control motor function, and an infarct in this region can result in significant disability. Patients with a right internal capsule infarct typically present with left-sided weakness or paralysis (hemiparesis or hemiplegia) affecting the face, arm, and leg due to the crossing of motor pathways in the brain [ 1 ]. Other symptoms may include sensory deficits on the left side, speech difficulties if language areas are affected, and occasionally visual field defects. According to the guidelines for the early management of adults with ischemic stroke, brain swelling is a potential complication of ischemic stroke, and its management should focus on preventing further deterioration from tissue displacement and brain stem shift [ 1 ]. Key aspects of management include:

• Restriction of free water to avoid hypo-osmolar fluid that may worsen edema
• Correction of factors that could exacerbate swelling such as hypoxemia, hypercarbia, and hyperthermia
• Elevation of the head of the bed at 20° to 30° to help venous drainage
• Avoidance of antihypertensive agents that include cerebral vasodilatation
• Consideration of decompressive surgery in cases of severe brain swelling. Long-term management of a right internal capsule infarct should also include antiplatelet medications (such as aspirin 81-325mg daily, clopidogrel 75mg daily, or combination therapy), blood pressure control, cholesterol management with statins, and diabetes control if applicable [ 1 ]. Physical, occupational, and speech therapy are crucial for rehabilitation and improving functional outcomes. Prevention of future strokes involves lifestyle modifications including smoking cessation, limited alcohol consumption, regular exercise, and a heart-healthy diet. The prognosis varies depending on the size of the infarct, timing of treatment, and the patient's overall health status, but many patients can achieve significant functional recovery with appropriate rehabilitation [ 1 ].

From the Research

Right Internal Capsule Infarct

• A right internal capsule infarct can cause left motor neglect, as seen in a case report where a 69-year-old hypertensive man had left motor neglect following an infarct of the anterior limb of the right internal capsule 2.
• The patient also had left auditory extinction on verbal dichotic listening and a slight constructional apraxia, and regional cerebral blood flow (CBF) was measured at rest with Xenon 133 inhalation and was found to be slightly decreased in a diffuse fashion 2.
• Motor activation of the right hand resulted in an increase of CBF in the contralateral superior rolandic area, whereas no such increase was found during motor activation of the left hand, indicating a failure of some corticosubcortical connexions involved in motor arousal 2.

Treatment of Acute Ischemic Stroke

• Systemic thrombolysis with alteplase is the only approved medical treatment for patients with acute ischemic stroke, and thrombectomy is also increasingly used to treat proximal occlusions of the cerebral arteries 3.
• Antithrombotic medication is a cornerstone of acute ischemic stroke treatment and secondary prevention, and the efficacy of thrombolysis with alteplase in acute stroke has been demonstrated in several clinical trials 4.
• Early antiplatelet therapy after intravenous thrombolysis for acute ischemic stroke has been shown to be safe and effective, with a positive effect on excellent functional recovery, but further large-scale RCTs are warranted 5.

Thrombolytic Therapy

• Thrombolytic therapy with alteplase in acute ischemic stroke is currently established within 3 h from symptom onset in carefully selected patients, and expansion of the time window is being assessed in trials with alteplase and desmoteplase 6.
• A better understanding of the coagulation and fibrinolytic systems may provide insight into drug development, interactions, complications, and may ultimately improve patient triage and treatment regimens 6.