Palsy

Palsy is a term used in medicine to describe a partial or complete loss of motor function in a part of the body due to nerve, muscle, or tract damage. It is not a disease itself but a symptom cluster that may arise from diverse conditions. When the impairment arises from the brain or spinal cord, it is termed central palsy; when from peripheral nerves or muscles, it is peripheral palsy. Common examples include cerebral palsy, a non-progressive motor impairment caused by brain injury or development before or during birth; facial palsy, which affects facial muscles due to dysfunction of the facial nerve; and specific nerve palsies such as Erb-Duchenne palsy of the arm.

Causes include stroke, head trauma, infections, inflammatory or autoimmune diseases, toxins, metabolic disorders, and congenital conditions. Symptoms depend on the site and size of the lesion and may include weakness or paralysis of a limb, facial drooping, difficulty speaking or swallowing, abnormal muscle tone, and impaired coordination.

Diagnosis relies on clinical examination and is supplemented by imaging (MRI or CT) and sometimes nerve conduction studies or electromyography to identify the affected nerves. Treatment targets the underlying cause and the resulting disability. For example, facial palsy may be treated with corticosteroids and protective measures for the eye; physical therapy can help maintain movement. Cerebral palsy management is multidisciplinary, including physical and occupational therapy, speech therapy, medications to reduce spasticity, and sometimes surgical procedures.

Prognosis varies widely. Bell's palsy (idiopathic facial palsy) often improves over weeks to months, while cerebral palsy is typically lifelong but non-progressive, with ongoing therapies enhancing function.