Determining the Forms of Dystonia

There are several forms of dystonia, and dystonia may be a symptom of many diseases and conditions. If you are new to dystonia, it can be a challenging disorder to understand. The words used to describe your specific diagnosis may be confusing. To accurately describe the “form” of dystonia that an individual has, at least four specific pieces of information must be accounted for:

• The age at which the symptoms started
• How the body is affected
• What is known about the cause
• If the dystonia occurs with symptoms of additional neurological disorders

All of the above is needed to set the best course for treatment, but for the sake of routine conversation, most people use the terms that describe the most prominent feature of the dystonia (for example, cervical dystonia for dystonia that affects the neck and shoulders; dopa-responsive dystonia for the form of childhood-onset dystonia that has characteristics that resemble parkinsonism.).

 Age of Onset
 

The age at which symptoms begin is referred to as age of onset. If an individual develops symptoms prior to approximately age 30, it may be referred to as early-onset or childhood-onset. (If the dystonia occurs during the teen years, the term adolescent-onset may be used.)
If symptoms develop after the age of 30, it is called late-onset or adult-onset.

These forms of dystonia are typically early-onset:

• DYT1 generalized dystonia
Non-DYT1 generalized dystonia
Paroxysmal dystonia & dyskinesias
• Dopa-responsive dystonia
• Myoclonic dystonia
• X-linked dystonia-parkinsonism

These forms of dystonia are typically adult-onset:
• Blepharospasm
• Cervical dystonia
• Embouchure dystonia
• Oromandibular dystonia
• Laryngeal dystonia (spasmodic dysphonia)
• Hand dystonia (writer’s cramp)

Secondary dystonia may be early- or adult-onset, depending on the underlying cause.
 

How the Body is Affected
 

When dystonia affects only one part of the body, it is called focal dystonia.

Segmental dystonia affects two or more connected body areas (for example the neck, shoulder, and arm). If two or more areas in different parts of the body are affected, the dystonia is termed multifocal(for example the eyes and vocal cords).

Generalized dystonia refers to dystonia that may affect the limbs, trunk, and other major body areas simultaneously. The term axial dystonia describes dystonia that specifically affects the torso.

When dystonia only affects muscles on one side of the body, it is called hemidystonia

Certain dystonias are labeled task-specific which means that the symptoms occur only when the person is performing a specific task or movement. These forms often involve the fingers and hands or the mouth.

If symptoms only occur in “episodes” that last for minutes or hours, the terms paroxysmal dystonia and dyskinesias are used.

The word torsion is sometimes used, usually in reference to generalized, axial, or segmental dystonia. Torsion refers to the twisting element of dystonia. It describes muscles contracting against each other.
 

Additional Disorders and Conditions
 

Dystonia can be associated with approximately 50 diseases and conditions. These include specific vascular conditions, infections, brain tumors, metabolic conditions, neurodenegerative disorders, demylianating disorders, and structural conditions:

Cerebrovascular or ischemic injury (stroke)
Arteriovenous malformation
Perinatal cerebral injury
Viral encephalitis
Subacute sclerosing panencephalitis
AIDS
Creutzfeldt-Jakob disease
Kernicterus
Huntington’s disease
Parkinson’s disease
Spinocerebellar ataxias
HARP syndrome (Hypobetalipoproteinemia, acanthocytosis, retinitis pigmentosa, pallidal degeneration)
Familial frontotemporal dementias
Familial basal ganglia calcifications
Wilson’s disease
Juvenile parkinsonism
Neurodegeneration with brain iron accumulation type 1
Ataxia-telangiectasia
Triosephosphate isomerase deficiency
Vitamin E deficiency
Biopterin deficiency
Sphingolipidoses
Niemann-Pick disease type C and D
Ceroid lipofuscinosis
Homocystinuria
Hartnup disease
Methylmalonic aciduria
Tyrosinaemia
Lesch-Nyhan syndrome
Rett’s syndrome
Pelizaeus-Merzbacher disease
Dystonia-deafness syndrome
MERRF (myoclonus epilepsy associated with ragged-red fibers)
MELAS (myopathy, mitochondrial-encephalopathy-lactic acidosis-stroke)
Leber’s disease
Leigh’s syndrome
Neuroacanthocytosis
Neuronal intranuclear inclusion disease
Haemochromatosis
Progressive supranuclear palsy
Multiple system atrophy
Corticobasal ganglionic degeneration
Dentatorubropalidoluysian atrophy
Glutaric academia
Methylmalonic academia
Homocystinuria
Metachromatic leukodystrophy
Neuronal ceroid lipofuscinosis
Primary antiphospholipid antobidy syndrome
Gangliosidoses
Hallervorden-Spatz disease
Multiple sclerosis
Atlantoaxial sublaxation
Syringomyelia
Arnold-Chiari malformation
Congenital Klippel-Feil syndrome