What Is Dyskinesia? Symptoms, Causes and Treatment

If you’ve watched TV lately, you’ve seen a wave of ads about dyskinesia. But the bounty of ads doesn’t mean the condition is more common, only that a new class of medications to treat it has entered the market. In fact, most people had never heard of the term until that campaign aired

What is dyskinesia?

Dyskinesia is a broad medical term for involuntary movements that can affect the entire body or just one part or limb. The severity can range from mild to severe. Many confuse it with Parkinson’s (or other tremor-related movement disorders), but there are many differences between the two.

Parkinson’s disease (PD) “is characterized by rhythmic, shaking movement (tremors) that has a predictable pattern,” says Matthew Feldman, M.D., a neurologist at the University of Miami Health System who specializes in movement disorders. “In dyskinesia the writhing and fidgeting are unpredictable and there’s a different quality to it. It’s like the flight of a bird in the cage. You know the bird is going to fly, but you can’t predict where it’s going.”

Yet, Parkinson’s and dyskinesia are inextricably tied. The most common form of dyskinesia is a result of medications taken by PD patients to treat the neurodegenerative disease. In other words, tremors result from Parkinson’s itself, while dyskinesia arises from the medications used to treat it.

Dyskinesia has been historically underdiagnosed because it is either overlooked or misattributed to Parkinson’s, Dr. Feldman explains. It usually takes a specialist to thread out the difference between treatment side effects and the disease symptoms themselves. Also, there are no reliable incidence statistics for dyskinesia, primarily because it isn’t a disease but a collection of movement symptoms with multiple causes.

That said, Dr. Feldman is seeing more cases. He attributes this to increased awareness by both patients and referring physicians, usually general practitioners. “More are arriving in my office already knowing what they have and what causes it,” he adds.

There are two major dyskinesia types, grouped by what causes the movements:

Levodopa-induced dyskinesia (LID) is the most common type of dyskinesia.

It develops as a side effect of levodopa, a common medication prescribed to manage Parkinson’s, and it occurs in 30% to 40% of PD patients who have been taking levodopa for more than four years. Risk tends to rise the longer the patient has PD. Those most at risk of developing LID are early-onset PD patients (younger than 50 years of age) and those on higher daily doses of levodopa. 

Even the symptoms of Parkinson’s dyskinesia — and time of occurrence — can vary depending on the level of levodopa in the blood. For example, symptoms can develop one to two hours after taking the medication because that’s when levels of levodopa are highest. But they can also occur when levodopa levels are falling before the next dose.

One study found that levodopa causes “maladaptive plasticity.” meaning that repeated levodopa doses actually reshape the movement circuits of the brain which, in turn, produce involuntary movements.

Treatment seeks to “smooth out” the medication levels, Dr. Feldman explains. This can mean a change of dosage or a change of dose frequency. In addition, he sometimes recommends adding anti‑dyskinesia medication to the treatment protocol.

Stopping levodopa altogether is not an option because the drug acts like dopamine in the brain, alleviating symptoms of Parkinson’s caused by dopamine deficiency. Also, “there are studies demonstrating that the most common PD medication does not accelerate the onset of dyskinesias, and provides many other benefits in the meantime.”

Tardive dyskinesia (TD) is a side effect of taking psychiatric and anti-nausea medications.

As many as 30% of patients on antipsychotic medicines develop TD, according to an article in Psychiatric Times. About 500,000 people in the U.S. have TD, but most cases (70%) are mild. Patients most at risk are those being treated for schizophrenia, schizoaffective disorder, or bipolar disorder.

TD may improve when the medication is stopped, though in many patients—especially older adults—it can persist or become irreversible. It’s typically treated by switching medications and/or adding a drug that inhibits dopamine levels in the brain.

More recently, according to the NIH, TD management emphasizes minimizing exposure to dopamine‑blocking medications, using the lowest effective dose, and considering temporary medication breaks when clinically appropriate.

In addition to these two major types, dyskinesia can also be caused by genetic, metabolic, and autoimmune conditions. The neurodegenerative diseases of Huntington’s and Wilson’s, for instance, can cause uncontrollable movements. Dyskinesia can also develop after strokes, a traumatic brain injury or a bout of encephalitis.

Dr. Feldman encourages his patients with dyskinesia to be proactive. “Think of dyskinesia with empowerment instead of fear,” he says. “We can work together to manage it. It’s very treatable.”

Written by Ana Veciana-Suarez. Reviewed by Matthew Feldman, M.D.

Tags: dyskinesia causes, dyskinesia symptoms, dyskinesia treatment, dyskinesia vs. tremor, involuntary movements, levodopa-induced dyskinesia, Parkinson’s dyskinesia, tardive dyskinesia