What is deafness-dystonia-optic neuronopathy syndrome?
Deafness-dystonia-optic neuronopathy syndrome (DDON) is also known as Mohr-Tranebjaerg Syndrome. It is a genetic disease that includes hearing and vision impairment as well as neurological and psychiatric symptoms.
Males with DDON have hearing impairment in early childhood, usually beginning around 18 month of age. Symptoms include slowly progressive dystonia or ataxia in the teens, slowly progressive decreased vision beginning about age 20 years, and dementia beginning about age 40 years. Psychiatric symptoms such as personality change and paranoia may appear in childhood and progress. The hearing impairment appears to be constant in age of onset and progression, whereas the neurologic, visual, and neuropsychiatric signs vary in degree of severity and rate of progression. Females may have mild hearing impairment and focal dystonia.
Treatment is multifaceted and includes correcting, as much as possible, the hearing and vision symptoms, reducing dystonia and ataxia symptoms, and addressing psychiatric conditions.
What is the difference between facial tic and blepharospasm?
The term “facial tic” is often used to describe involuntary movements that involve the face, particularly those around the eyes and the corner of the mouth. These movements are usually brief and not sustained. They are usually not associated with the “squeezing” of the muscles around the eyes that typically accompanies blepharospasm.
The common facial tic includes the condition hemifacial spasm, a condition characterized by very rapid, abnormal contractions of one side of the face. Sometimes hemifacial spasm may follow Bell's palsy (Bell's palsy is a form of temporary facial paralysis resulting from damage or trauma to one of the two facial nerves.) or be associated with facial weakness. Often the movements are provoked by eating, talking, or whistling. Some patients experience symptoms in the upper areas of the face when they move the lower part of the face.
Another facial tic is the quick facial movements that occur in people who have chronic motor tics. Chronic motor tics may affect one or both sides of the face, and the movement is usually preceded by an urge to make the movements. After the movement is made, the urge is often relieved. The individual with chronic motor tics usually has the ability to suppress the movements if they concentrate on the movements. Chronic motor tics may involve any part of the body including the face, arms, legs, or trunk.
The manifestation of blepharospasm is an involuntary movement that involves the upper face, and may also involve the lower face, tongue, pharynx, jaw, neck, or other body segments. However, these movements are usually not suppressible, because they are involuntary and not under the direct control of the person with them.
There is some overlap among how blepharospasm and tics appear, so that even experts may disagree on whether a patient has chronic motor tics or blepharospasm. Most of the disagreement will occur when the symptoms are subtle, and they present with similar findings on examination. Taking a history will sometimes clarify the cause. Hemifacial spasm and blepharospasm are known to have an excellent response to botulinum toxin treatment. Facial tics may respond, too.
What is the difference between essential tremor and dystonia tremor?
Essential tremor is one of the most common movement disorders. It is usually inherited. The tremor is not present when someone is relaxed but becomes evident when a body part assumes a posture or undertakes a specific action. The tremor is generally rhythmic and can vary from being only subtle to very severe and debilitating. The tremor affects the hands and arms and may affect the head and the voice.
Dystonic tremors are quite variable in their presentation and on some occasions can look like essential tremor. They are, however, seldom seen in isolation and usually are associated with dystonic body postures. The tremors are also sometimes somewhat more irregular than what is seen with essential tremor. Because essential tremor and dystonia tremor may look the same and both can be genetic, researchers have investigated whether patients with essential tremor might carry an abnormality in the DYT1 gene that is associated with early onset genetic dystonia. This has been found not to be the case although the actual gene for essential tremor has not been identified.
What is the difference between a Parkinson's disease patient with dystonia and a dystonia patient with Parkinson's symptoms?
Parkinson’s disease is a neurological movement disorder with a wide array of symptoms that includes slowness of movement, rigidity of muscles, tremor, loss of balance, memory impairment, personality changes, and others. The “movement” symptoms of Parkinson’s disease (slowness of movement, rigidity, tremor, loss of balance) may be called parkinsonism. Parkinsonism is one aspect of Parkinson’s disease.
Symptoms of dystonia and parkinsonism can occur in the same patient because both of these movement disorders seem to arise from involvement of the basal ganglia in the brain. Both parkinsonism and dystonia can each be caused by a great many disorders, and some of these disorders includes features of both parkinsonism and dystonia.
For example, there are the disorders known as dopa-responsive dystonia (DRD) and x-linked dystonia-parkinsonism (XDP). DRD commonly begins in children as a dystonia predominately affecting the feet and being first manifested by an abnormal gait. In these children, features of parkinsonism tend to develop such as slowness of movement and also decreased muscle tone.
When DRD begins in adults, it usually appears first as parkinsonism and can be mistaken for Parkinson's disease. XDP can also first develop as either dystonia or parkinsonism, and the symptoms of other disorder may occur.
In the parkinsonian disorder known as Parkinson's disease, certain features of the disease can be thought of as a form of dystonia. These features include postural changes in the hands and feet and also in the neck. These partial changes are so common that most physicians consider them as part of Parkinson's disease and do not consider them to be a form of dystonia that has developed on top of parkinsonism. In parkinsonian syndromes such as progressive supranuclear palsy, certain features of dystonia may appear (such as dystonia of the facial muscles or the neck muscles).
In primary dystonia, by definition, the patient presents only pure dystonia without any features of parkinsonism. If parkinsonism were to develop in such a patient, it could be considered that this patient happens to have two different disorders. For example, a patient may have adult-onset cervical dystonia in which the neck is twisted and, after several years, develop features of parkinsonism. It is generally believed that cervical dystonia and Parkinson's disease are two separate entities occurring in the same patient.
Some medications might be helpful for both parkinsonism and dystonia symptoms. For example, levodopa is the most effective drug to reverse parkinson symptoms, and it is also very effective in treating DRD and in some patients with other forms of dystonia. Anticholinergic drugs, such as Artane®, are often used to treat dystonia, but they can also help some of the symptoms of parkinsonism. Essentially all the drugs currently in use to treat dystonia were first utilized in the treatment of Parkinson's disease.
Is tremor a symptom of dystonia?
Tremor is not a main symptom of dystonia. Dystonia is primarily characterized by an involuntary sustained twisting or cramping posture. If someone began having a tremor, a physician would not necessarily expect dystonic postures as well. Having said that, tremor can sometimes be seen as a secondary symptom. For instance, many patients with cervical dystonia will also have an associated head tremor and some patients with writer's cramp will have an associated writing tremor of the hand. Researchers continue to learn about the relationship between tremor and dystonia.
My child developed torticollis at age two. Is this similar to adult-onset spasmodic torticollis/cervical dystonia?
Although the term spasmodic torticollis is used to describe cervical dystonia, the word torticollis actually refers to any abnormal twisting of the neck. The words “torticollis” does not necessarily mean “dystonia.”
Torticollis that occurs very early in life (usually within the first few weeks) is not a true dystonia. This condition is called infant torticollis, and there are many different reasons why a baby may have torticollis. The most common form of torticollis in infants is congenital torticollis. Congenital torticollis usually improves with physical therapy; however, surgery may be needed.
A toddler who develops torticollis or an irregular neck posture may be affected by a host of conditions including hiatal hernia (with vomiting, feeding problems, and posturing of neck during feeding), double vision (producing head tilt), lack of oxygen or high bilirubin counts during the perinatal period (producing cerebral palsy), severe brain infection (encephalitis), head or neck trauma, toxin exposure, brain or spinal tumors or vascular malformations, specific kinds of brain cysts, and certain chemical disorders, such as Leigh's disease. These conditions may generally be assessed with brain and neck imaging and blood and urine analysis.
Cervical dystonia that affects adults usually occurs after age 30. Children who develop true dystonia rarely begin with symptoms in the neck.
Is TMJ a form of dystonia?
Temporomandibular joint (TMJ) disease is an arthritic condition, not a dystonia. Oromandibular dystonia may be misdiagnosed as TMJ.