Paralysis agitans is an outdated medical term once used to refer to the condition now known as Parkinson's disease. It can be encountered in old medical texts and sometimes shows up when people are conducting historical research of a medical nature. The name change reflects the research conducted by James Parkinson in the 1800s. He contributed a detailed description and, as is common in medicine, the disease was named after him to honor his contribution to understanding of the disease.
This term literally means “shaky palsy,” a reference to the hallmark symptom of paralysis agitans. This condition, classified as a movement disorder, usually starts to manifest with tremors in the hands, proceeding to a bent, shuffling gait. Over time, the patient can start to experience a cognitive decline, along with the tremors, and may find it increasingly difficult to complete basic tasks. Patients may need assistance from an aide with tasks of daily living and can be at risk of slips and falls, potentially posing a danger for people with brittle bones that may fracture when stressed.
Paralysis agitans involves damage to the midbrain, the area of the brain responsible for regulating movement. In healthy individuals, the brain controls movements to limit shaking, firing neurons to help muscles work in opposition to each other to stabilize motions. Especially with the hands, precision movements require very exact control. In people with this condition, the brain does not function properly and the body starts to shake due to the lack of muscle control.
It is not possible to cure paralysis agitans, but the condition can be managed. Medications are available to replace missing neurotransmitters and increase muscle control. Physical therapy helps some patients. Adaptations such as using devices designed to help people with shaky hands when it comes to gripping and manipulating objects are also available. All of these treatment options can be adjusted over time as the patient's condition evolves.
There are numerous potential reasons for hand tremors, and people who start to notice poor muscle control should not assume it is the result of paralysis agitans. A thorough evaluation by a neurologist, including imaging studies of the brain, is necessary to determine why the patient is having problems. The tremors may be related to a curable condition, or could be caused by an issue that needs to be managed differently than this common disease of aging. Especially if tremors appear when someone is young, they may be caused by something entirely different.