Blepharospasm-oromandibular dystonia syndrome is a rare, neurological condition characterized by blepharospasm (abnormal movement of the eyelids); oromandibular dystonia (spasms in the jaw and tongue); and sometimes, cervical dystonia. Symptoms and severity can vary. The exact cause of blepharospasm-oromandibular dystonia syndrome is unknown.

The specific symptoms, severity and progression of blepharospasm-oromandibular dystonia syndrome can vary from person to person. It most often affects middle-aged people and usually is characterized by a combination of blepharospasm and oromandibular dystonia.

Blepharospasm is characterized by abnormal, forced blinking and spasms of the eyelids. Eye irritation often occurs in response to various stimuli such as bright lights, wind or fatigue. As the frequency of muscle spasms and contractions increases, it may become progressively harder for affected people to keep their eyes open.

Oromandibular dystonia is characterized by involuntary and often forceful contractions of the jaw and tongue, which can make it hard to open or close the mouth. Some people may have clenching of the teeth, displacement of the jaw, grimacing, chin thrusting, or repeated pursing of the lips. Eyelid and facial muscle tone may gradually decline.

People with blepharospasm-oromandibular dystonia syndrome may also have spasms of the tongue and throat, which can result in the tongue protruding from the mouth and difficulty swallowing. In some cases, muscles in the neck, arms, legs or other areas of the body may become affected.

The long-term outlook (prognosis) for people with blepharospasm-oromandibular dystonia syndrome is hard to predict because the specific symptoms, severity and progression of the condition vary from person to person. The prognosis likely depends on several factors, such as age of onset; rate of progression; muscles affected; how early treatment is started; and how a person responds to treatment. Some affected people improve over time.

The first symptoms of blepharospasm-oromandibular dystonia syndrome may occur anywhere from about 30 to 70 years of age, but they most often occur in the sixth decade of life. Blepharospasm (dystonia of the eyelids) is the most frequent initial complaint of affected people.

In most cases, dystonia begins focally. Over time, it may spread to other muscles of the body. When dystonia spreads, it most commonly spreads to areas immediately next to affected muscles. For example, blepharospasm typically spreads to the lower face and jaw muscles. Rarely, dystonia can spread to more distant muscles in the arms and legs. The chance for dystonia to spread is thought to be highest within the first 3 years after onset. However, it can spread more than a decade later. Overall, people with initial onset of blepharospasm have at least a 50% lifetime risk of dystonia spreading.

One study found that on average, affected people show gradual worsening of involuntary movements for a little over 2 years, followed by movements slowly improving. The authors of this study suggested that factors that may contribute to a better prognosis include younger age of onset; shorter time between initial onset and progression to the worst symptoms; mild involuntary movements when the symptoms were the worst; and shorter time between onset and starting treatment.