ABOUT THE DISEASE

Dystonia is an abnormal involuntary muscle contraction, which forces body parts to abnormal postures (sometimes painful). It is thought to occur due to disorganization in certain areas of brain (e.g. Basal ganglia) that is responsible for normal body movements. In this disorder, abnormal signals are sent from the brain to the muscles, which cause simultaneous contractions of several muscles. When this happens it leads to abnormal and sometimes painful posturing of body parts.

SYMPTOMS

It may present as:
Involuntary muscle contractions that cause repetitive movements or distorted postures, that begin in a single area, such as foot, hand or neck. It may worsen with stress, fatigue or anxiety.

Areas of the body affected may include:
Eyelids (blepharospasm), neck (Cervical dystonia), Face & head and neck (craniofacial dystonia), vocal cords (spasmodic dysphonia), Hand and forearm.

CAUSES

Some forms of dystonia are genetic but the cause for the majority of cases is not known. Secondary dystonia is where dystonia occurs as a symptom of an underlying condition or injury. Common causes include stroke, brain injury, encephalitis (infection of the brain) and Parkinson`s disease.

DIAGNOSIS

Dystonia is a clinical diagnosis, i.e. it is diagnosed based on clinical examination. The workup of dystonia is directed towards the probably etiology and underlying pathophysiology. Commonest forms of dystonia are genetic forms. The routine work up for dystonia may include:

1. Neuroimaging ( MRI/CT)
2. Blood work:- Liver function tests, Serum ceruloplasmin, Renal function tests, Basic metabolic pane, Complete blood count with manual differential and smear, Antinuclear antibody test, Erythrocyte sedimentation rate, Rapid plasma reagin and fluorescent treponemal antibody.
3. Urinalysis:- 24-hour urine copper

TREATMENT METHODS

Therapeutic options include medical and surgical options.

Medical line of treatment include dopaminergic medications (levodopa), Dopamine depleting medications (tetrabenzine), anticholinergic, and muscle relaxants. Currently for most of the focal and segmental dystonia botulinum toxin injections is the preferred first line of therapy due to its very good effects and limited side effects profile in relation to other medications.

In patients who do not respond to medications or have severe debilitating symptoms surgical therapies are considered.

Surgical therapies include lesioning of the brain and Deep brain stimulation. Deep brain stimulation or DBS is the current state of the art and preferred line of surgical therapy due to its adjustable character of stimulation and technically being labeled `reversible surgery`.

Contributed by:
Dr. Prashanth LK
DM (Neurology) Fellowship in Movement Disorders (Toronto))
Consultant Neurologist.
Specialist : Parkinson`s Disease & Other Movement Disorders

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