What is Spasmodic Torticollis?
Table Of Content:
- What is Spasmodic Torticollis?
- Spasmodic Torticollis Epidemiology
- Spasmodic Torticollis Classification
- Spasmodic Torticollis Causes
- Spasmodic Torticollis Pathophysiology
- Spasmodic Torticollis Symptoms
- Spasmodic Torticollis Diagnosis
- Spasmodic Torticollis Differential Diagnosis
- Spasmodic Torticollis Treatment
- Spasmodic Torticollis Complications
- Spasmodic Torticollis Prognosis
- Spasmodic Torticollis Support Groups
- Spasmodic Torticollis Pictures
Spasmodic Torticollis (ST) is a chronic neurologic movement disorder that causes involuntary turning of the neck towards right, left, downwards and/or upwards. It is also accompanied by extremely painful sensations. During a dystonic movement, both the agonist as well as the antagonist musculature contracts simultaneously. The factors responsible for the disorder are mainly idiopathic. A small percentage of patients develop this condition due to some other disease or disorder. Most patients experience the initial surge of symptoms during their midlife, although it may even occur at infancy.
The disorder is also known as Cervical dystonia.
Spasmodic Torticollis Epidemiology
ST is considered to be among the most common types of dystonia observed in neurology clinics, affecting nearly 0.390% of United States population in the year 2007. The worldwide incidence rate of this disorder is close to 1.2 per 100000 person years, with the rate of prevalence nearing 57 individuals per million. There are also numerous cases that are undiagnosed (at least 25%). Studies have revealed that this disorder is not immediately diagnosed, and many individuals are diagnosed more than a year later from the time of seeking initial medical attention. Females are nearly 1.5 times more prone to this disorder than males. The risks of developing this disorder also increase with age; most patients show initial symptoms from the ages 50 to 69. The average age of onset for ST symptoms is 41.
Spasmodic Torticollis Classification
ST develops as a type of focal dystonia in which sustained muscle contractions cause repetitive, twisting movements, thereby leading to abnormal bodily postures in one single region. ST can be classified primarily in 2 main ways: by the age of onset and by cause. The disorder can be categorized as an early onset if a patient is diagnosed with it prior to 27 years of age, and then late onset thereafter. Causes responsible for the disorder can be either idiopathic (primary) or symptomatic (secondary). It can also be further classified according to the direction as well as the rotation of the head movement.
Classification according to head positions
According to the head positions, ST can be categorized into the following types:
- Torticollis – The horizontal turning or rotational collis of head is termed torticollis and uses the ipsilateral splenius, as well as the contralateral sternocleidomastoid muscles. It is essentially the “chin-to-shoulder” version.
- Laterocollis – It involves tilting of head from one side to another. This is essentially the “ear-to-shoulder” version. It incorporates many more muscles, such as ipsilateral sternocleidomastoid, ipsilateral scalene complex, ipsilateral splenius, ipsilateral posterior paravertebrals and ipsilateral levator scapulae.
- Anterocollis – The flexion of neck or the forward head tilt is known as Anterocollis. It is essentially the “chin-to-chest” version. It is also the most complex version to address. The movement makes use of the bilateral sternocleidomastoid, bilateral submental complex and the bilateral scalene complex.
- Retrocollis – The extension of neck towards back is referred to as retrocollis. The following muscles are used for its movement: bilateral upper trapezius, bilateral splenius and bilateral deep posterior paravertebrals. It is mainly the “chin-in-the-air” version.
Spasmodic Torticollis Causes
The primary form of ST is generally inherited. Research has shown that DYT13 locus on the chromosome 1p36 in one Italian family and DYT7 locus on the chromosome 18p of a German family is linked with this disorder. The inheritance pattern for both forms of loci is autosomal dominant. These autosomal dominant loci are inherited with a reduced penetrance. Even though these specific loci responsible for the disorder have been identified, it is yet unclear how much influence the loci exert on spasmodic torticollis.
Secondary ST occurs when other factors lead to the development of the disorder. A number of conditions, both environmental and internal diseases, can be held responsible for the causation of this disease. These factors are listed below:
- Metabolic reactions
- Perinatal cerebral injury
- Drug induced conditions
- Cerebrovascular diseases
- Paraneoplastic syndromes
- Central or peripheral trauma
- Central pontine myelinolysis
- Central nervous system tumor
- Infectious or post infectious encephalopathies
A patient is diagnosed with secondary ST when one of the following factors are present:
- A history of an exogenous exposure
- Neurological abnormalities apart from dystonia
- Abnormalities on the brain imaging, especially in basal ganglia
Spasmodic Torticollis Pathophysiology
The pathophysiology of this disorder is still more or less unknown. Researchers are of the opinion that ST is primarily a neurochemical condition and does not lead to structural neurodegenerative changes. Even though no lesions can be seen in the basal ganglia in the primary form of spasmodic torticollis, PET studies and fMRI have revealed abnormalities of basal ganglia as well as hyper-activation of cortical areas. It has been indicated that there is a functional imbalance within striatal control of globus pallidus, especially the substantia nigra pars reticulate. These studies hypothesize that the hyper-activation of cortical areas is caused by the reduced pallidal inhibition of thalamus, which leads to surplus activity of the prefrontal cortical and the medial areas as well as under activity of primary motor cortex at the time of the movement. Experts have also suggested that this functional imbalance is caused by an imbalance of various neurotransmitters such as acetylcholine, dopamine, and gamma-aminobutyric acid. The neurotransmitters are actually secreted from the basal ganglia which then travel to the muscle groups that are present in the neck. Increase in the neurotransmitters result in spasms within the neck which leads to spasmodic torticollis. Research based on local field potentials have also demonstrated an increase of 4 to 10 Hz oscillatory activity in globus pallidus internus at the time of the myoclonic episodes as well as an increase of 5 to 7 Hz activity in the dystonic muscles compared to the other primary dystonias. It indicates that the oscillatory activity in all these frequency bands might be associated with the pathophysiology of this disorder.
Spasmodic Torticollis Symptoms
Cervical dystonia is characterized by involuntary contractions of the neck muscles. If the contractions continue for a prolonged period of time, they might cause abnormal postures of the neck and head. If the spasms occur periodically or in a patterned way, they can give rise to jerky head movements. The severity of the symptoms might vary from being mild to severely critical. Other symptoms include:
- Neck pain
- Muscle hypertrophy
The movements are often somewhat relieved by sensory tricks referred to as geste antagoniste. These include touching the chin, the back portion of the head or other parts of the face gently. The symptoms of cervical dystonia might go away while sleeping and then return again after waking up.
ST or cervical dystonia might begin around the neck and then spread into shoulders. However, the symptoms generally plateau and stay stable within 5 years of onset. Such a type of focal dystonia is quite unlikely to spread outside the shoulders and neck region and become generalized dystonia. On certain occasions, individuals having cervical dystonia might also develop other types of focal dystonias.
Spasmodic Torticollis Diagnosis
While determining the diagnosis for ST, a doctor is likely to first conduct a thorough physical checkup and go through the medical history of a patient. The various parts of the body, especially the neck region, the shoulders and the head will be inspected to see if there are any abnormal movements or changes. The doctor may also want to evaluate the performance of the brain and nervous system. The patient will also be asked questions on how he or she is feeling and how strong the muscles are.
A number of diagnostic tests may require the use of special dyes to study the structures and organs better. Special care should be taken for patients who are allergic to shellfish or iodine as they may be allergic to these dyes. The following tests might be conducted to see if a person is having this disorder:
- Urine tests
- Blood tests
- C-spine x-rays
- Magnetic resonance imaging (MRI scans)
- Computerized tomography scans (CT scans)
The scale that is most commonly used to study the severity of this disorder is known as the Toronto Western Spasmodic Torticollis Rating Scale or TWSTRS. This state-of-the-art rating system has a widespread acceptance for being used in the clinical trials, and is known to have a good inter-observer reliability. There are 3 scales in TWSTRS, namely:
- The torticollis severity scale
- The disability scale
- The pain scale
The scales are employed to represent severity, pain, as well as the general lifestyle associated with ST.
Spasmodic Torticollis Differential Diagnosis
A number of disorders are manifested by signs and symptoms similar to that of ST. Hence, while determining the diagnosis of this condition, it is necessary to differentiate it from these similar disorders in order to come up with the optimum treatment plan. The differential diagnoses of ST include telling its symptoms apart from those of other health disorders such as:
- Cerebral Palsy
- Wilson Disease
- Spinal deformity
- Essential Tremor
- Multiple Sclerosis
- Spinal Hematoma
- Parkinson Disease
- Myasthenia Gravis
- Tardive Dyskinesia
- C1 and C2 fractures
- Peritonsillar Abscess
- Anterior horn disease
- Neuroleptic Agent Toxicity
- Juvenile-onset Wilson disease
- Retropharyngeal Abscess (RPA)
- Acquired dystonias of childhood
- Juvenile-onset Huntington disease
- Juvenile cerebral palsy with cervical dystonia
- Gastroesophageal reflux or Sandifer syndrome
- Phenothiazine-induced acute dystonic reactions of childhood
- Movement disorders in people having developmental disabilities
Spasmodic Torticollis Treatment
There are a number of treatment methods that are commonly in use to manage the symptoms of ST. These include usage of botulinum toxin injections administered in dystonic muscle of the neck, oral medications, sensory trick, deep brain stimulation, surgery and physical therapy. A combination of these various forms of intervention has been employed to manage this disorder. Selective surgical denervation of the nerves that trigger the muscle contractions can offer relief from pain, spasms, and limit the damage to spine caused by torqued posture. As there is a high chance of rapid spinal fibrosis, it is important to quickly assess the option of a surgical denervation.
This points to the fact that desynchronization of frequency range is related to movement. A sensory trick referred to as geste antagoniste, is frequently present in the focal dystonias, especially in ST. However, patients with blepharospasm have also been known to have this feature. Sensory tricks can offer mostly partial and temporary relief from ST. Sensory trick should also be administered by the patients themselves. Only 32% of all patients experience relief when sensory trick is given by a healthcare professional.
Dopamine blocking agents were used in the past to treat this condition, as there was a belief that an imbalance of neurotransmitter dopamine in basal ganglia is its root cause. Nowadays these drugs are not in use due to a variety of side effects such as sedation, tardive dyskinesia and Parkinsonism. Other oral medications are now employed in lower doses to manage early stages of cervical dystonia. Patients who are treated with anticholinergic agents seem to fare better than people taking other oral drugs. Some of the notable drugs used for this purpose include:
These medications can be administered in higher doses for managing the later stages of cervical dystonia.
Botulinum toxin injections administered in the dystonic muscles is the most common form of treatment for this disorder. The most frequently used variant is the Botulinum toxin type A as it prevents release of the acetylcholine from presynaptic axon of motor end plate, which paralyzes the dystonic muscle. The agonist muscle is rendered free by disabling the movements of the antagonist muscles. With the Botulinum toxin injections, the patients can experience relief from this disorder for nearly 12-16 weeks. Although numerous type A preparations that are available worldwide, Dysport and BOTOX are the only ones approved by U.S. Food and Drug Administration (FDA) to be used clinically in United States.
Botulinum toxin type B should be used for those patients who develop or experience immunoresistance to the type A. nearly 4-17% of all patients develop the botulinum toxin type A antibodies. Botulinum toxin type B is available in United States as Myobloc.
Deep Brain Stimulation
Deep brain stimulation to basal ganglia and the thalamus has been used recently as a successful mode of treatment for the tremors experienced by patients having Parkinson’s disease. It is also currently being used for patients of ST in the clinical trials. Stimulation is administered to the subthalamic nucleus or the globus pallidus internus. The device is comparable to a pacemaker, where one external battery is put subcutaneously with wires moving through skin and then entering the skull to a portion of the brain. Microelectrodes are put bilaterally into globus pallidus internus to stimulate it. Once the surgery is over, multiple trips are needed to program all the settings of the stimulator. Stimulation of globus pallidus internus disturbs the anomalous discharge pattern characteristic of globus pallidus internus, thereby resulting in the inhibition of the hyperactive cortical activity. Deep brain stimulation of globus pallidus internus is the most preferred surgical procedure as it promises lower side effects. The advantages of this procedure include reversibility as well as the option to adjust the settings of stimulation. Patients who have shown resistance to treatment by botulinum toxin have shown considerable improvement when treated with deep brain stimulation of the globus pallidus internus within 3 to 6 months.
Patients of ST can be treated with physical interventions such as biofeedback, mechanical braces and self-performance of geste antagoniste. Stretching as well as strengthening exercises have also been helpful in aiding patients to keep their head properly aligned with their bodies. Patients receiving physiotherapy along with Botulinum toxin injections have shown marked improvement.
Sufferers are advised to reduce stress and get as much rest as possible. Sensory tricks or heat packs can help to minimize pain and stiffness of muscles.
Spasmodic Torticollis Complications
Patients may experience side effects from a number of medications and other treatment methods, which might include the following:
- Dry mouth
- Urinary retention
- Intracerebral hemorrhage
- Large subdural hematoma
- Pain at the site of injection
- Intraventricular hemorrhage
- Cognitive disturbance or dysfunctions
- Weakness of injected or the adjacent muscle
- Dysphagia caused by spreading of the pain to the adjacent muscles
Spasmodic Torticollis Prognosis
Sufferers have been reported to attain spontaneous recovery in almost 10% of cases. The symptoms normally reach a plateau within 5 years of onset. Sometimes, patients might also experience focal dystonia of face, eyelids, and hands. There might also be some tremors in around 20% of all cases. No neurological deficits are noticed other than that.
Spasmodic Torticollis Support Groups
A number of support groups provide aid to ST-affected individuals and their families as well as raise awareness of the condition. One of the most important organizations dedicated to this cause is the National Spasmodic Torticollis Association.
Spasmodic Torticollis Pictures
These images give a clearer idea of how the neck, shoulders and head can get affected by this disorder.
Picture 1 – Spasmodic Torticollis
Picture 2 – Spasmodic Torticollis Image