 |
OROMANDIBULAR DYSTONIA
Oromandibular
dystonia (OMD) is a form of focal dystonia that affects varying areas of the
head and neck including the lower face, jaw, tongue and larynx.
The spasms may cause the mouth to pull open, shut tight, or move
repetitively. Speech and swallowing
may be distorted. It is often
associated with dystonia of the cervical muscles (Spasmodic Torticollis),
eyelids (Blepharospasm), or larynx (Spasmodic
Dysphonia).
The combination of upper and lower dystonia is sometimes called
cranial-cervical dystonia. When OMD
is combined with Blepharospasm, it may be referred to as Meige’s Syndrome
named after Henry Meige, the French neurologist who first described the symptoms
in detail in 1910.The symptoms usually begin between the ages of 40 and 70 years
old and appear to be more common in women than in men.
The
cause of OMD is unknown. Some examples of familial (inherited) cranial dystonia
have been reported, usually in conjunction with Idiopathic Torsion Dystonia.
Persons may have a family history of other forms of dystonia. Some people
with OMD have facial tics (or possibly misdiagnosed, Cranial dystonia),
increased blinking rate, of Parkinsonism and Essential
Tremor.
OMD can be an acute or delayed (tardive) adverse reaction to the
administration of neuroleptics. The disorder may include the muscles involved in
chewing and facial expression as well as the tongue and the palate. The dystonic
movements include jaw opening or clenching, even sustained jaw closure and
grinding of the teeth, lip pursing/tightening, or retractions, nasal flaring,
contractions of the soft palate and muscles of the floor of the mouth, or tongue
protrusion. These spasms may last up to half a minute or more.
In addition to these usually prolonged spasms, more clonic, brief,
sometimes rhythmical movements can occur. Grunting,
throat clearing, and inspiratory noises (which are occasionally features of
cranial dystonia) may accompany these symptoms. The movements of OMD can be task
specific, appearing only during activities, such as talking or chewing, which
use the involved muscles, but it can progress to the point where the spasms are
continuous.
What
is the Prognosis of Oromandibular Dystonia?
OMD has a variable nature, therefore making it difficult to predict the prognosis of
the disorder. The movements of OMD can cause damage to
the teeth through the clenching action or may interfere with the use of
dentures.
Temporo-mandibular pain is common, and some people complain of
tension-type headaches. In OMD, the muscles around the mouth which are used
in articulating speech sounds may be affected by the dystonic movements.
This can lead to the distortion of vowels and consonants, resulting in
speech which is slower and more difficult to understand. People with OMD
may have difficulty chewing and swallowing, because of the movements of the
tongue and jaw. Eating, slowly,
taking only small amounts of food, and drinking small amounts of fluid between
mouthfuls are just a few suggestions to help maintain good nutrition.
What
are the Current Forms of Therapy for OMD?
Unfortunately
at this time, there is no cure for dystonia, but treatments are available.
Treatment is designed to help the symptoms of spasms, pain and disturbed
posture and function. The goal of any treatment, including that of OMD, is
to achieve the greatest benefits while incurring the fewest risks.
It involves beginning with the least risky treatment.
Establishing a satisfactory treatment scheme requires patience on the
part of both the physician and the patient.
Conservative
Therapies
Conservative
therapies include “tricks” used by people to improve their symptoms.
Many people with OMD put their fingers on their lips, teeth, or hard
palate to aid mouth opening. Jaw
closure may be facilitated by touching the fingers to the chin.
During intense spasms, people may forcefully attempt to pull the jaw open
or push it closed with their hands. Speech
and swallowing therapy may lessen spasms, improve range of motion, teach
“tricks” to lessen the dystonia, strengthen unaffected muscles, and
facilitate speech and swallowing.
Medications
Medications
such as anticholinergics (trihexphenidyl and benztropine) baclofen,
benzodiazepines (diazepam, clonazepam, and lorazepam), and treatrabenzine may
help some people with OMD.
Botulinum
Toxin Injections
Botulinum
toxin, a complex protein produced by the Bacterium Clostridium Botulinum,
weakens a muscle sufficiently to reduce a spasm but not enough to cause
paralysis. It is a nerve “blocker,” binding to nerve endings and preventing
the release of chemical transmitters that activate muscles.
The chemicals carry the “message” from the brain that causes a muscle
to contract. If the message is
blocked, the muscle doesn’t spasm. The injections are done with a small needle,
and there is usually only temporary discomfort at the site of injections.
Effects are not usually noticed for 5 to 10 days and benefits last three
to four months with minimal side effects. About 70 percent of people with
OMD experience some reduction of spasm and improvement of chewing and speech
after injection of Botox into the masseter temporalis, and lateral pterygoid
muscles.
Side effects such as swallowing difficulties, slurred
speech, and excess weakness in injected muscles may occur, but these side
effects are usually transient and well tolerated.
Surgical
Treatment
Since
oromandibular dystonia involves muscles of chewing, swallowing and talking,
local surgeries to destroy the nerves or muscles are not typically considered.
Supportive
Forms of Treatment
Although
stress clearly does not cause OMD, many people have reported that in a stressful
situation, symptoms may worsen. Unfortunately,
it is not possible to get rid of all stress, but a course of stress management
or relaxation techniques is beneficial. By educating yourself with information,
you have taken the first step in dealing with dystonia.
Reassurance from family friends, and others who have OMD is beneficial. Support
groups offer encouragement, camaraderie, and information about new treatments
and medical advances.
This
article was originally printed by the Dystonia Medical Research Foundation in
the U.S.A.
Wemove.org
|
