Spasmodic torticollis is an extremely painful chronic

neurological Neurology (from , "string, nerve" and the suffix -logia, "study of") is the branch of medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the nervous system, which comprises the brain, the s ...

movement disorder Movement disorders are clinical syndromes with either an excess of movement or a paucity of voluntary and involuntary movements, unrelated to weakness or spasticity. Movement disorders present with extrapyramidal symptoms and are caused by basa ...

causing the neck to involuntarily turn to the left, right, upwards, and/or downwards. The condition is also referred to as "cervical

dystonia Dystonia is a neurology, neurological Hyperkinesia, hyperkinetic Movement disorders, movement disorder in which sustained or repetitive muscle contractions occur involuntarily, resulting in twisting and repetitive movements or abnormal fixed po ...

". Both agonist and antagonist muscles contract simultaneously during dystonic movement. Causes of the disorder are predominantly

idiopathic An idiopathic disease is any disease with an unknown cause or mechanism of apparent spontaneous origin. For some medical conditions, one or more causes are somewhat understood, but in a certain percentage of people with the condition, the cause ...

. A small number of patients develop the disorder as a result of another disorder or disease. Most patients first experience symptoms midlife. The most common treatment for spasmodic torticollis is the use of

botulinum toxin Botulinum toxin, or botulinum neurotoxin (commonly called botox), is a neurotoxic protein produced by the bacterium ''Clostridium botulinum'' and related species. It prevents the release of the neurotransmitter acetylcholine from axon en ...

type A.

Signs and symptoms

Initial symptoms of spasmodic torticollis are usually mild. Some feel an invisible tremor of their head for a few months at onset. Then the head may turn, pull or tilt in jerky movements, or sustain a prolonged position involuntarily. Over time, the involuntary spasm of the neck muscles will increase in frequency and strength until it reaches a plateau. Symptoms can also worsen while the patient is walking or during periods of increased stress. Other symptoms include muscle

hypertrophy Hypertrophy is the increase in the volume of an organ or tissue due to the enlargement of its component cells. It is distinguished from hyperplasia, in which the cells remain approximately the same size but increase in number. Although hypertro ...

, neck pain,

dysarthria Dysarthria is a speech sound disorder resulting from neurological injury of the motor component of the motor–speech system and is characterized by poor articulation of phonemes. It is a condition in which problems effectively occur with the ...

and tremor. Studies have shown that over 75% of patients report neck pain, and 33% to 40% experience tremor of the head.

Pathophysiology

The pathophysiology of spasmodic torticollis is still relatively unknown. Spasmodic torticollis is considered neurochemical in nature, and does not result in structural neurodegenerative changes. Although no lesions are present in the

basal ganglia The basal ganglia (BG) or basal nuclei are a group of subcortical Nucleus (neuroanatomy), nuclei found in the brains of vertebrates. In humans and other primates, differences exist, primarily in the division of the globus pallidus into externa ...

in primary spasmodic torticollis,

fMRI Functional magnetic resonance imaging or functional MRI (fMRI) measures brain activity by detecting changes associated with blood flow. This technique relies on the fact that cerebral blood flow and neuronal activation are coupled. When an area o ...

and

PET A pet, or companion animal, is an animal kept primarily for a person's company or entertainment rather than as a working animal, livestock, or a laboratory animal. Popular pets are often considered to have attractive/ cute appearances, inte ...

studies have shown abnormalities of the

and hyper activation of the cortical areas. Studies have suggested that there is a functional imbalance in the striatal control of the

globus pallidus The globus pallidus (GP), also known as paleostriatum or dorsal pallidum, is a major component of the Cerebral cortex, subcortical basal ganglia in the brain. It consists of two adjacent segments, one external (or lateral), known in rodents simpl ...

, specifically the

substantia nigra The substantia nigra (SN) is a basal ganglia structure located in the midbrain that plays an important role in reward and movement. ''Substantia nigra'' is Latin for "black substance", reflecting the fact that parts of the substantia nigra a ...

pars reticulata. The studies hypothesize the hyper activation of the cortical areas is due to reduced pallidal inhibition of the

thalamus The thalamus (: thalami; from Greek language, Greek Wikt:θάλαμος, θάλαμος, "chamber") is a large mass of gray matter on the lateral wall of the third ventricle forming the wikt:dorsal, dorsal part of the diencephalon (a division of ...

, leading to over activity of the medial and prefrontal cortical areas and under activity of the primary

motor cortex The motor cortex is the region of the cerebral cortex involved in the planning, motor control, control, and execution of voluntary movements. The motor cortex is an area of the frontal lobe located in the posterior precentral gyrus immediately ...

during movement. It has also been suggested that the functional imbalance is due to an imbalance of neurotransmitters such as

dopamine Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. It is an amine synthesized ...

acetylcholine Acetylcholine (ACh) is an organic compound that functions in the brain and body of many types of animals (including humans) as a neurotransmitter. Its name is derived from its chemical structure: it is an ester of acetic acid and choline. Par ...

, and

gamma-aminobutyric acid GABA (gamma-aminobutyric acid, γ-aminobutyric acid) is the chief inhibitory neurotransmitter in the developmentally mature mammalian central nervous system. Its principal role is reducing neuronal excitability throughout the nervous system. GA ...

. These neurotransmitters are secreted from the basal ganglia, traveling to muscle groups in the neck. An increase in neurotransmitters causes spasms to occur in the neck, resulting in spasmodic torticollis. Studies of local field potentials have also shown an increase of 4–10 Hz oscillatory activity in the globus pallidus internus during myoclonic episodes and an increase of 5–7 Hz activity in dystonic muscles when compared to other primary dystonias. This indicates that oscillatory activity in these frequency bands may be involved in the pathophysiology of spasmodic torticollis.

Diagnosis

The most commonly used scale to rate the severity of spasmodic torticollis is the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS). It has been shown that this rating system has widespread acceptance for use in clinical trials, and has been shown to have “good interobserver reliability.” There are three scales in the TWSTRS: torticollis severity scale, disability scale, and pain scale. These scales are used to represent the severity, the pain, and the general lifestyle of spasmodic torticollis.

Classification

Spasmodic torticollis is a form of focal

, a neuromuscular disorder that consists of sustained muscle contractions causing repetitive and twisting movements and abnormal postures in a single body region. There are two main ways to categorize spasmodic torticollis: age of onset, and cause. The disorder is categorized as early onset if the patient is diagnosed before the age of 27, and late onset thereafter. The causes are categorized as either primary (

) or secondary (

symptomatic Signs and symptoms are diagnostic indications of an illness, injury, or condition. Signs are objective and externally observable; symptoms are a person's reported subjective experiences. A sign for example may be a higher or lower temperature ...

). Spasmodic torticollis can be further categorized by the direction and rotation of head movement.

Primary

Primary spasmodic torticollis is defined as having no other abnormality other than dystonic movement and occasional tremor in the neck. This type of spasmodic torticollis is usually inherited. Studies have shown that the DYT7 locus on

chromosome 18 Chromosome 18 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 18 spans about 80 million base pairs (the building material of DNA) and represents about 2.5 percent of the total DNA in ...

p in a German family and the DYT13 locus on

chromosome 1 Chromosome 1 is the designation for the largest human chromosome. Humans have two copies of chromosome 1, as they do with all of the autosomes, which are the non-sex chromosomes. Chromosome 1 spans about 249 million nucleotide base pairs, which a ...

p36 in an Italian family is associated with spasmodic torticollis. The inheritance for both loci is

autosomal An autosome is any chromosome that is not a sex chromosome. The members of an autosome pair in a diploid cell have the same morphology, unlike those in allosomal (sex chromosome) pairs, which may have different structures. The DNA in autosome ...

dominant. These loci are all

autosomal dominant In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the Phenotype, effect of a different variant of the same gene on Homologous chromosome, the other copy of the chromosome. The firs ...

ly inherited with reduced

penetrance Penetrance in genetics is the proportion of individuals carrying a particular variant (or allele) of a gene (genotype) that also expresses an associated trait (phenotype). In medical genetics, the penetrance of a disease-causing mutation is the pr ...

. Although these loci have been found, it is still not clear the extent of influence the loci have on spasmodic torticollis.

Secondary

When other conditions lead to spasmodic torticollis, it is said that the spasmodic torticollis is secondary. A variety of conditions can cause brain injury, from external factors to diseases. These conditions are listed below: *

Central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity o ...

tumor * Central pontine myelinolysis * Cerebrovascular diseases * Drug induced * Infectious or post infectious

encephalopathies Encephalopathy (; ) means any disorder or disease of the brain, especially chronic degenerative conditions. In modern usage, encephalopathy does not refer to a single disease, but rather to a syndrome of overall brain dysfunction; this syndrome ...

Kernicterus Kernicterus is a bilirubin-induced brain dysfunction. The term was coined in 1904 by Christian Georg Schmorl. Bilirubin is a naturally occurring substance in the body of humans and many other animals, but it is neurotoxic when its concentration ...

* Metabolic * Paraneoplastic syndromes *

Perinatal Prenatal development () involves the development of the embryo and of the fetus during a viviparous animal's gestation. Prenatal development starts with fertilization, in the germinal stage of embryonic development, and continues in fetal deve ...

(during birth) cerebral injury *

Peripheral A peripheral device, or simply peripheral, is an auxiliary hardware device that a computer uses to transfer information externally. A peripheral is a hardware component that is accessible to and controlled by a computer but is not a core compo ...

or central trauma * Toxins Secondary spasmodic torticollis is diagnosed when any of the following are present: history of

exogenous In a variety of contexts, exogeny or exogeneity () is the fact of an action or object originating externally. It is the opposite of endogeneity or endogeny, the fact of being influenced from within a system. Economics In an economic model, an ...

insult or exposure, neurological abnormalities other than dystonia, abnormalities on brain imaging, particularly in the

Head positions

To further classify spasmodic torticollis, one can note the position of the head. * Torticollis is the horizontal turning (rotational collis) of the head, and uses the

ipsilateral Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

splenius The splenius muscles are: *Splenius capitis muscle *Splenius cervicis muscle Their origins are in the upper thoracic and lower cervical spinous process Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bo ...

, and

contralateral Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

sternocleidomastoid The sternocleidomastoid muscle is one of the largest and most superficial cervical muscles. The primary actions of the muscle are rotation of the head to the opposite side and flexion of the neck. The sternocleidomastoid is innervated by the acces ...

muscles. This is the "chin-to-shoulder" version. * Laterocollis is the tilting of the head from side to side. This is the "ear-to-shoulder" version. This involves many more muscles: ipsilateral sternocleidomastoid, ipsilateral splenius, ipsilateral scalene complex, ipsilateral

levator scapulae The levator scapulae is a slender skeletal muscle situated at the back and side of the neck. It originates from the transverse processes of the four uppermost cervical vertebrae; it inserts onto the upper portion of the medial border of the scapu ...

, and ipsilateral posterior paravertebrals. * The flexion of the neck (head tilts forwards) is anterocollis. This is the "chin-to-chest" version and is the most difficult version to address. This movement utilizes the bilateral sternocleidomastoid, bilateral scalene complex, bilateral submental complex. * Retrocollis is the extension of the neck (head tilts back) and uses the following muscles for movement: bilateral splenius, bilateral upper

trapezius The trapezius is a large paired trapezoid-shaped surface muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae of the human spine, spine and laterally to the spine of the scapula. It moves the scapula and ...

, bilateral deep posterior paravertebrals. This is the "chin-in-the-air" version. A combination of these head positions is common; many patients experience turning and tilting actions of the head.

Treatment

There are several treatments for spasmodic torticollis, the most commonly used being botulinum toxin injections in the dystonic muscle of the neck. Other treatments include sensory trick for a mild occasional twinge, oral medications, and deep brain stimulation. Combinations of these treatments have been used to control spasmodic torticollis. In addition, selective surgical denervation of nerves triggering muscle contractions may offer relief from spasms and pain, and limit damage to the spine as a result of torqued posture. Spinal fibrosis (i.e., locking of spinal facets due to muscular contortion resulting in fused vertebrae) may occur rapidly. This suggests that the desynchronization of the frequency range is movement related. Obtaining relief via a "sensory trick", also known as a ''geste antagoniste'', is a common characteristic present in focal dystonias, most prevalently in cervical

; however, it has also been seen in patients with

blepharospasm Blepharospasm is a neurological disorder characterized by intermittent, involuntary spasms and contractions of the orbicularis oculi muscle, orbicularis oculi (eyelid) muscles around both eyes. These result in abnormal twitching or blinking, an ...

. Sensory tricks offer only temporary and often partial relief of spasmodic torticollis. 74% of patients report only partial relief of spasmodic torticollis compared to 26% reporting complete relief. The sensory trick must also be applied by the patient themselves. When the sensory trick is applied by an examiner, only 32% of patients report relief comparable to relief during self-application. Since the root of the problem is neurological, doctors have explored sensorimotor retraining activities to enable the brain to "rewire" itself and eliminate dystonic movements.

Oral medications

In the past,

blocking agents have been used in the treatment of spasmodic torticollis. Treatment was based on the theory that there is an imbalance of the neurotransmitter dopamine in the basal ganglia. These drugs have fallen out of fashion due to various serious side effects: sedation,

parkinsonism Parkinsonism is a clinical syndrome characterized by tremor, bradykinesia (slowed movements), Rigidity (neurology), rigidity, and balance disorder, postural instability. Both hypokinetic features (bradykinesia and akinesia) and hyperkinetic f ...

, and

tardive dyskinesia Tardive dyskinesia (TD) is an iatrogenic disorder that results in involuntary repetitive body movements, which may include grimacing, sticking out the tongue or smacking the lips, which occurs following treatment with medication. Additional mo ...

. Other oral medications can be used in low doses to treat early stages of spasmodic torticollis. Relief from spasmodic torticollis is higher in those patients who take anticholinergic agents when compared to other oral medications. Many have reported complete management with

gabapentin Gabapentin, sold under the brand name Neurontin among others, is an anticonvulsant medication primarily used to treat neuropathic pain and also for partial seizures of epilepsy. It is a commonly used medication for the treatment of neuropath ...

alone or in combination with another drug such as clonazepam. 50% of patients who use anticholinergic agents report relief, 21% of patients report relief from

clonazepam Clonazepam, sold under the brand name Klonopin among others, is a benzodiazepine medication used to prevent and treat anxiety disorders, seizures, bipolar mania, agitation associated with psychosis, obsessive–compulsive disorder (OCD), and ...

, 11% of patients report relief from

baclofen Baclofen, sold under the brand name Lioresal among others, is a medication used to treat muscle spasticity, such as from a spinal cord injury or multiple sclerosis. It may also be used for hiccups and muscle spasms near the end of life, and ...

, and 13% from other

benzodiazepines Benzodiazepines (BZD, BDZ, BZs), colloquially known as "benzos", are a class of central nervous system (CNS) depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed to treat co ...

. Higher doses of these medications can be used for later stages of spasmodic torticollis; however, the frequency and severity of side effects associated with the medications are usually not tolerated. Side effects include dry mouth, cognitive disturbance, drowsiness, diplopia, glaucoma and urinary retention.

Botulinum toxin

] The most commonly used treatment for spasmodic torticollis is the use of botulinum toxin injection in the dystonic musculature. Botulinum toxin type A is most often used; it prevents the release of

from the

presynaptic In the nervous system, a synapse is a structure that allows a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or a target effector cell. Synapses can be classified as either chemical or electrical, depending o ...

axon An axon (from Greek ἄξων ''áxōn'', axis) or nerve fiber (or nerve fibre: see American and British English spelling differences#-re, -er, spelling differences) is a long, slender cellular extensions, projection of a nerve cell, or neuron, ...

of the motor end plate, paralyzing the dystonic muscle. By disabling the movement of the antagonist muscle, the agonist muscle is allowed to move freely. With botulinum toxin injections, patients experience relief from spasmodic torticollis for approximately 12 to 16 weeks. There are several type A preparations available worldwide and in the United States. Some patients experience or develop immunoresistance to botulinum toxin type A and must use botulinum toxin type B. Approximately 4% to 17% of patients develop botulinum toxin type A antibodies. The only botulinum toxin type B accessible in the United States is Myobloc. Treatment using botulinum toxin type B is comparable to type A, with an increased frequency of the side effect dry mouth. Common side effects include pain at the injection site (up to 28%),

dysphagia Dysphagia is difficulty in swallowing. Although classified under " symptoms and signs" in ICD-10, in some contexts it is classified as a condition in its own right. It may be a sensation that suggests difficulty in the passage of solids or l ...

due to the spread to adjacent muscles (11% to 40%), dry mouth (up to 33%), fatigue (up to 17%), and weakness of the injected or adjacent muscle (up to 56%). A

Cochrane review Cochrane is a British international charitable organisation formed to synthesize medical research findings to facilitate evidence-based choices about health interventions involving health professionals, patients and policy makers. It includes ...

published in 2016 reported moderate-quality evidence that a single Botulinum toxin-B treatment session could improve cervical dystonia symptoms by 10% to 20%, although with an increased risk of dry mouth and swallowing difficulties. Another Cochrane review published in 2020 for Botulinum toxin-A found similar results.

Deep brain stimulation

Deep brain stimulation Deep brain stimulation (DBS) is a type of neurostimulation therapy in which an implantable pulse generator is stereotactic surgery, surgically implanted subcutaneous tissue, below the skin of the chest and connected by Lead (electronics), leads ...

to the basal ganglia and

has recently been used as a successful treatment for tremors of patients with

Parkinson's disease Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become ...

. This technique is currently, as of 2007, being trialed in patients with spasmodic torticollis. Patients are subjected to stimulation of the

internus, or the subthalamic nucleus. The device is analogous to a

pacemaker A pacemaker, also known as an artificial cardiac pacemaker, is an implanted medical device that generates electrical pulses delivered by electrodes to one or more of the chambers of the heart. Each pulse causes the targeted chamber(s) to co ...

: an external battery is placed subcutaneously, with wires under the skin which enter the skull and a region of the brain. To stimulate the globus pallidus internus, microelectrodes are placed into the globus pallidus internus bilaterally. After the surgery is performed, multiple visits are required to program the settings for the stimulator. The stimulation of the globus pallidus internus disrupts the abnormal discharge pattern in the globus pallidus internus, resulting in inhibition of hyperactive cortical activity. Globus pallidus internus deep brain stimulation is the preferred surgical procedure, due to the lower frequency of side effects. Advantages of deep brain stimulation include the reversibility of the procedure, and the ability to adjust the settings of the stimulation. In one study, patients who had developed immunoresistance to botulinum toxin underwent globus pallidus internus deep brain stimulation, showing improvement by 54.4% after three to six months. There is a low rate of side effects for those who undergo deep brain stimulation. The most common side effect is headache, occurring in 15% of patients, followed by infection (4.4%) and cognitive dysfunction (4%). Serious side effects are seizure (1.2%), intracerebral hemorrhage (0.6%), intraventricular

hemorrhage Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, ...

(0.6%), and large

subdural hematoma A subdural hematoma (SDH) is a type of bleeding in which a collection of blood—usually but not always associated with a traumatic brain injury—gathers between the inner layer of the dura mater and the arachnoid mater of the meninges surrou ...

(0.3%).

Physical Interventions

Physical treatment options for cervical dystonia include biofeedback, mechanical braces as well as patients self-performing a geste antagoniste.

Physical therapy Physical therapy (PT), also known as physiotherapy, is a healthcare profession, as well as the care provided by physical therapists who promote, maintain, or restore health through patient education, physical intervention, disease preventio ...

also has an important role in managing spasmodic torticollis by providing stretching and strengthening exercises to aid the patient in keeping their head in proper alignment with their body. Patients with cervical dystonia ranked physical therapy intervention second to botulinum toxin injections in overall effectiveness in reducing symptoms and patients receiving physiotherapy in conjunction with botulinum toxin injections reported enhanced effects of treatment compared to the injections alone. One study examined patients with cervical dystonia who were treated with a physiotherapy program that included muscle stretching and relaxation, balance and coordination training, and exercises for muscle strengthening and endurance. A significant reduction in pain and severity of dystonia as well as increased postural awareness and quality of life was found.

Epidemiology

Spasmodic torticollis is one of the most common forms of dystonia seen in neurology clinics, occurring in approximately 0.390% of the United States population in 2007 (390 per 100,000). Worldwide, it has been reported that the incidence rate of spasmodic torticollis is at least 1.2 per 100,000 person years, and a prevalence rate of 57 per 1 million. The exact prevalence of the disorder is not known; several family and population studies show that as many as 25% of cervical dystonia patients have relatives that are undiagnosed. Studies have shown that spasmodic torticollis is not diagnosed immediately; many patients are diagnosed well after a year of seeking medical attention. A survey of 59 patients diagnosed with spasmodic torticollis show that 43% of the patients visited at least four physicians before the diagnosis was made. There is a higher prevalence of spasmodic torticollis in females; females are 1.5 times more likely to develop spasmodic torticollis than males. The prevalence rate of spasmodic torticollis also increases with age, most patients show symptoms from ages 50–69. The average onset age of spasmodic torticollis is 41.

References

Dystonia Medical Research Foundation: Cervical Dystonia

External links

Neck Pain Treatment
{{Diseases of the nervous system Extrapyramidal and movement disorders Neurological disorders pl:Kręcz szyi