Spasmodic torticollis

Overview

Spasmodic torticollis (ST), commonly known as cervical dystonia (CD). It is a kind of focal dystonia that affects adults. It is distinguished by abrupt and involuntary spasms of the muscles of the neck, head, and shoulders. These spasms are typically painful and cause the neck to twist to one side, resulting in an unnatural posture and hyperactivity symptoms. The disorder results from aberrant impulses in the central nerves. Several genes are considered to be involved in the development of cervical dystonia. Diseases itself is not life-threatening but the pain and irregular posture could affect the daily life routine .Some evidence suggests that ion channel dysfunction as the prognostic factor of dystonia.

Pathophysiology

It is unclear what causes ST, but some studies have made progress in defining the mechanism of CD.  Given disease is categorize as a neurological ailment, a variety of studies have shown that disruption of neuronal signaling may be a pathogenic feature. This idea is supported by research that links CD to major neurotransmitter receptors such as Dopamine D2 Receptor (DRD2), Dopamine Transporter (DAT), Serotonin Transporter (SERT), and GABA receptors(10). A research linked nine biological processes to cervical dystonia (CD), including pathways related to carbohydrate and lipid metabolism. In CD patients altered levels of dopaminergic and serotonergic compounds in plasma are found, indicating potential connections to motor and non-motor symptoms(11, 12).  MRI and voxel-based morphometry technique were utilized to uncover the structural and functional problems in non-task-specific dystonia(13-16). These abnormalities include white matter microstructural and grey matter changes in numerous areas of the brain, which are important in regulating movement and coordination. The damaged parts of the brain include the basal ganglia, thalamus, cerebellum, and cerebral cortex, all of which play essential roles in network models. According to the study, the brain stem, thalamus, corpus callosum, anterior limb/genu of the internal capsule, cerebellum, primary sensorimotor cortex, WM of the middle/inferior frontal gyrus, and inferior temporal gyrus are the locations where white and grey matter are altered(16-18). Furthermore, unusual connections have been identified between the pallidum and brain stem (19), the dentate-subthalamic tract, the thalamus, middle frontal gyrus, and the brain stem (20), as well as the globus pallidus, putamen, thalamus, and sensorimotor cortices(14). DTI investigations have revealed that the presence of anomalies in these locations suggests that CD may be characterized by widespread and substantial loss of WM integrity(21).

Etiology

The irregular lifestyle may be the reason for the ST including Desk work, working with corporations ST due to its long sitting and working hours, workload and irregular posture, rapid recitatives moment, poor gravitational alignment and another reason could be the caffeine consumption and stress can cause over activity of the pericranial and cervical muscles(23-28). Except these reasons some mutations are also involved in the pathogeny of CD patients. According to recent research, there are substantial links between the risk of getting CD and the genes COL8A1 (rs2219975, chromosome 3) and DENND1A. The study also found that a low-frequency variation (rs147331823) in GABBR2 was linked to an earlier start of CD. Patients with this variation generally develop symptoms at 16.4 ± 2.9 years old(29). In multiple ethnicities NALCN, the TOR1A gene is associated with dystonia(30, 31), In CD Neuronal signaling dysregulation is also the cause of the disease (32).

Epidemiology

ST is the most common type of dystonia with a prevalence of 20–38.1 cases per million in Asian countries however European countries and the US report high incidence  (44.3–183.1 cases per million and 89–4100 cases per million, respectively). This condition mostly affects women aged 50 and 60 years as reported in studies (44, 45).

Clinical presentation (6-9)

Symptoms can range from mild to moderate initially focal dystonia is characterized by various head postures including torticollis, laterocollis, anterocollis, and retrocollis

• ·       Neck pain (musculoskeletal pain)
• ·       Decrease neck mobility
• ·       Head stuck in cock- robin posture
• ·       Limited moment of the upper back part of the body
• ·       Tremor with abnormal head posture.
• ·       Occasional spasms and stiffness.
• ·       Swelling at stiff side
• ·       Tingling sensation and numbness
• ·       Disturb Speech
• ·       Cognitive impairment
• ·       Psychiatric disorder symptoms are not mostly manifest immediately after the onset of the problem and in some cases, patients recover without any medical treatment  

Diagnosis

The most prevalent form of dystonia seen in neurological clinics is ST. Despite its prevalence, there is no particular or standard diagnostic test that can be used in clinical follow-up(22), thus, diagnosis relies on clinical evaluation alongside electromyography (EMG) and X-rays. Clinical assessment of CD often involves employing tools such as the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS), Global Dystonia Rating Scale (GDS), and Cervical Dystonia Impact Profile-58 (CDIP-58). These assessment scales are widely utilized to gauge the severity, disability, and impact on quality of life associated with the condition(23).

Treatment and management

The manifestation is slow after the onset of the disease and sometimes patients are healed without any medical intervention(33). Curative treatment for ST is not available yet but fortunately, palliative treatment is available, because of its treatable potential it should be diagnosed. Treatment intervention is given to limit the damage caused by the disease (34) two types of treatment are offered to ST patients one is surgical and the second one is nonsurgical (including physical therapy, Oral medication, and botulinum toxin injections. Surgery is supposed to be the most common approach for the treatment because the non surgical intervention cannot provide long-term relief (35, 36) in 1641 German surgeon Isaac Minnius amputee the SCM for the first time to treat ST (37) and traditional Chinese medicine practitioners apply acupuncture method to treat the ST and shows the positive results by improving neck stiffness, and anxiety and help to improve neck mobility (38).

Botulinum toxin (BT)

Before the introduction of botulinum toxin type A (BTA) injections for cervical dystonia (CD), the main pharmacological treatment was trihexyphenidyl, an anticholinergic drug. BTA injections are now the preferred treatment as they have greatly improved patients' quality of life by relieving symptoms. However, some people may not respond well to BTA or develop resistance to it. As a result, botulinum toxin type B (BTB) injections have emerged as a viable alternative therapy. Ongoing research is still being conducted to determine the optimal doses for both BTA and BTB. The goal is to achieve the best combination of maximum clinical efficacy and minimal unwanted side effects(39).

Physical Interventions

Physical treatment options for cervical dystonia involve several approaches such as biofeedback, mechanical braces, and the geste antagonist technique. In addition, physical therapy has a crucial role in managing ST by providing stretching and strengthening exercises that help patients maintain proper head alignment with their body(40). Patients have ranked physical therapy as the second most effective treatment for cervical dystonia, right after botulinum toxin injections(41). Furthermore, patients have reported even greater improvements when physiotherapy is combined with botulinum toxin injections compared to injections alone(42). A study investigated a physiotherapy program for cervical dystonia, which included muscle stretching and relaxation, balance and coordination training, as well as exercises for muscle strengthening and endurance. The results showed a significant decrease in pain and severity of dystonia, along with improvements in postural awareness and overall quality of life. (43)

Others

Some lifestyle habits can help overcome diseases, including shoulder and upper back exercises, improving working and sitting posture, a balanced diet, and ceasing consumption of caffeine. (8)