Dystonia is a neurological disorder characterized by involuntary muscle contractions. These muscle contractions manifest in uncomfortable movements, including abnormal positioning of a body part and spasms. For example, the neck may turn involuntarily. A foot may tend to drag or flex. Speech may be restricted and breathy.
In some cases, dystonia affects all or most of the body. Dystonia can also be localized to a specific section of the body, two or more body parts, adjacent parts of the body, or one side of the body. Certain dystonias are linked to tasks like handwriting or playing a musical instrument.
Dystonia is often painful and obstructive. Most of the time, symptoms appear in middle age. In the rare cases when it occurs in infancy, dystonia can stem from a birth injury.
Cervical dystonia, also called spasmodic torticollis, is a form of dystonia limited to the head, neck, and shoulders. The word “cervical” means related to the neck and has nothing to do with the cervix. About 60,000 people suffer from cervical dystonia in the United States, not including undiagnosed cases1. An infant with cervical dystonia may display the following involuntary movements:
The head might remain stuck in an abnormal position in some individuals. In others, movements may be jerky spasms or resemble tremor. In either case, involuntary muscle contractions are painful and uncomfortable, affecting quality of life and ability to perform everyday tasks. As many as 75% of people experience pain as a result of cervical dystonia1.
The basic symptoms of cervical dystonia, involuntary movement and pain, can cause additional symptoms. Headaches and fatigue are common. Participants in a study of the disorder reported broken teeth, impaired peripheral vision, tongue and mouth injuries, falls and fractures, and dislodged discs2. Nerve damage, arthritis, and damage to the spinal cord can occur.
Symptoms can be brought on or worsened by stress or excitement. Certain postures and positions of the body can also trigger symptoms.
According to the National Institute of Neurological Disorders and Stroke, the causes for most incidences of dystonia are unknown, with symptoms developing spontaneously. Cases without an underlying cause or relation to another condition are referred to as idiopathic dystonia. Damage from a past trauma to the basal ganglia or other brain regions that control movement is believed to be a factor. Abnormalities in the brain may be present that are not visible to MRI or other imaging technologies.
Some forms of dystonia are genetic, passed as a dominant trait from parents to children. However, symptoms of dystonia are not always developed even when the gene is inherited. And, if symptoms do arise, they do not necessarily match those of the parent.
Finally, dystonia can be acquired as a result of environmental factors, brain damage, reaction to a medication, and as a symptom of another condition. Acquired dystonia, or secondary dystonia, typically has an identifiable cause or is related to another condition.
Cervical dystonia can be idiopathic, genetic, or acquired due to physical trauma or reaction to antipsychotic drugs.
When an infant has cervical dystonia, it is probable that physical trauma occurred during pregnancy or birth. Hypoxia, or oxygen deprivation, can lead to brain damage. Shoulder dystocia, when the infant’s shoulder becomes stuck behind the mother’s pelvic bone during delivery, can lead a doctor to apply excessive force to the infant’s head and neck. Injury to the brachial plexus, a group of nerves in the spinal cord, neck, and arms, during rough labor and delivery is also associated with cervical dystonia.
People with the neurological movement disorder cerebral palsy, which in some cases results from a birth injury, can develop secondary cervical dystonia symptoms.
Diagnosis of cervical dystonia is based on a patient’s health history and observation of their symptoms. Early signs of the disorder are involuntarily twisting or turning of the head, headaches, neck and shoulder pain, and enlarged neck muscles.
Since some dystonia is genetic, knowing a patient’s family history can determine if they are at risk for the disorder. Testing can rule out other conditions, but there is no laboratory or imaging test for dystonia. A neurologist well versed in movement disorders diagnoses cervical dystonia.
Abnormal posturing of the neck in an infant or toddler may not be cervical dystonia, as cervical dystonia usually develops later in life. Other conditions that cause dystonia symptoms can typically be cured or resolve on their own once diagnosed.
Dystonia-like postures may be “benign idiopathic dystonia of infancy,” which resolves on its own. If accompanied by vomiting, the infant may have “benign paroxysmal torticollis,” which improves as the child gets older. “Congenital muscular torticollis” is a shortening of a neck muscle that is corrected with rehabilitation and sometimes surgery. “Paroxysmal tonic upgaze,” in which the eyes look up and the chin points down for sustained periods, can also resemble cervical dystonia.
When an infant is diagnosed with true cervical dystonia, a healthcare provider should consider possible secondary causes, such as a birth injury or a related condition.
Unfortunately, there is no cure for cervical dystonia, and symptoms usually last a lifetime. Symptoms usually start slowly before worsening and eventually stabilizing. The dystonia may progress from the head, neck, and shoulders to other muscles in the body. Some people experience spontaneous remission, though the remission is almost never permanent.
Researchers are working to better understand cervical dystonia. The good news is that treatment for cervical dystonia does exist. Standard medication for cervical dystonia is an injection of botulinum toxin every 3 to 4 months. Botulinum toxin promotes a shift towards normal brain function by blocking the neurotransmitter acetylcholine, which causes muscles to contract.
A minority of children benefit from the muscle relaxers Baclofen and Tizanidine, which otherwise have limiting side effects for adults. Some oral medications that act on neurotransmitters have been successful for small groups of patients. Anti-convulsant medications, like those used to treat epilepsy, are also employed.
Deep brain stimulation, the surgical implantation of electrodes into the brain, is an option in more severe situations. Just as a pacemaker uses electricity to control heart rhythm, electrical pulses can regulate brain signaling. Another surgical option is selective denervation, cutting nerves and muscles where the dystonia occurs.
Patients can also take advantage of a technique called a “sensory trick” to relieve symptoms: gently touching the chin, face, or back of the head can cause temporary improvement. Pain relievers and neck braces are useful as well.
It is important to note that depression and anxiety can result from the experience of cervical dystonia. Support groups are available to help children with dystonia better live with and understand their condition.
“Cervical Dystonia” by Moon Suk Bang MD, Ph.D. and Shi-Uk Lee MD, Ph.D. in Essentials of Physical Medicine and Rehabilitation, 4th Edition. Elsevier, 2020.
“Application of botulinum toxin in pregnancy and its impacts on female reproductive health” by Wu Li and Min Tang, Expert Opinion on Drug Safety, Oct 10 2019.
“Early Botulinum Toxin Injections in Infants With Musculoskeletal Disorders: A Systematic Review of Safety and Effectiveness” by Jean-Sebastien Bourseul, MD, MSc et al, Archives of Physical Medicine and Rehabilitation, 27 Dec 2017.
“Botulinum Toxin Type A Injection for Cervical Dystonia in Adults with Dyskinetic Cerebral Palsy” by You Gyoung Yi et al, Toxins, May 16 2018.
“Striving for more good days: patient perspectives on botulinum toxin for the treatment of cervical dystonia” by Michele Poliziani et al, Patient Preference and Adherence, Aug 22 2016.
“Sensory Tricks Are Associated with Higher Sleep-Related Quality of Life in Cervical Dystonia” by Casey Benadof et al, Tremor and Other Hyperkinetic Movements, Jun 17 2019.