From the Research
Focal weakness is a loss of muscle strength that affects a specific area or part of the body, typically resulting from damage to the nervous system, and prompt medical attention is crucial as it may indicate a serious condition requiring immediate treatment. The causes of focal weakness can vary, including stroke, multiple sclerosis, nerve compression, traumatic injuries, and infections or inflammatory conditions 1. According to the most recent evidence, stroke is a leading cause of focal weakness, with approximately 85% of strokes being ischemic, predominantly caused by small vessel arteriolosclerosis, cardioembolism, and large artery athero-thromboembolism 1. Some key points to consider in the diagnosis and management of focal weakness include:
- The importance of neuroimaging, including non-contrast computed tomography (CT) and magnetic resonance imaging (MRI), in differentiating ischemic stroke and intracerebral hemorrhage 2
- The use of advanced imaging such as MRI or perfusion imaging to assist in making a diagnosis of ischemic stroke versus mimics such as migraine, Todd's paresis, or functional disorders 2
- The identification of medium-large vessel occlusions with CT or MR angiography to trigger consideration of endovascular thrombectomy (EVT) 2
- The role of perfusion imaging in identifying salvageable brain tissue in patients who are likely to benefit from reperfusion therapies, particularly in the ≥6 h window 2 Treatment should be guided by the underlying cause of the focal weakness, and may include medication, physical therapy, or surgery. For example, in patients with acute ischemic stroke, treatment may involve thrombolysis within 4.5 hours and mechanical thrombectomy within 24 hours after symptom onset to improve functional outcomes 3. In patients with high-risk transient ischemic attack (TIA) or minor stroke, dual antiplatelet therapy initiated within 24 hours of symptom onset and continued for 3 weeks may reduce stroke risk 3. Overall, the management of focal weakness requires a comprehensive approach that takes into account the underlying cause, the severity of symptoms, and the individual patient's needs and circumstances.