On the problem of the pathology of spasmodic torticollis in man

Pathologic changes in the brain in cervical dystonia pre- and post-mortem - a commentary with a special focus on the cerebellum

In a recent issue of Experimental Neurology, Prudente et al. (2012) investigated the neuropathology of cervical dystonia in six patients. Their most important finding was a patchy loss of cerebellar Purkinje cells in the cerebellum. In this article we discuss their findings in the context of a review including primary and secondary cervical dystonia. An update is given of the current knowledge on structural and functional brain abnormalities in idiopathic cervical dystonia with a special focus on the cerebellum.

Neuropathology of cervical dystonia

The aim of this study was to search for neuropathological changes in postmortem brain tissue of individuals with cervical dystonia (CD). Multiple regions of formalin-preserved brains were collected from patients with CD and controls and examined with an extensive battery of histopathological stains in a two-stage study design. In stage one, 4 CD brains underwent a broad screening neuropathological examination. In stage two, these 4 CD brains were combined with 2 additional CD brains, and the subjective findings were quantified and compared to 16 age-matched controls. The initial subjective neuropathological assessment revealed only two regions with relatively consistent changes. The substantia nigra had frequent ubiquitin-positive intranuclear inclusions known as Marinesco bodies. Additionally, the cerebellum showed patchy loss of Purkinje cells, areas of focal gliosis and torpedo bodies. Other brain regions showed minor or inconsistent changes. In the second stage of the analysis, quantitative studies failed to reveal significant differences in the numbers of Marinesco bodies in CD versus controls, but confirmed a significantly lower Purkinje cell density in CD. Molecular investigations revealed 4 of the CD cases and 2 controls to harbor sequence variants in non-coding regions of THAP1, and these cases had lower Purkinje cell densities regardless of whether they had CD. The findings suggest that subtle neuropathological changes such as lower Purkinje cell density may be found in primary CD when relevant brain regions are investigated with appropriate methods.

Update on the pathology of dystonia

Dystonia is a clinical syndrome with sustained muscle contraction, twisting, and abnormal postures. A number of different genetic forms have been defined, but most cases are sporadic in nature and of uncertain cause. Relatively few cases of dystonia have been studied pathologically. In primary dystonias, where dystonia is the main symptom, most reports describe little or no detectable neuropathology, although changes in brainstem neurons have been described in some cases. Secondary dystonias are associated with degenerative or destructive diseases of the nervous system; the pathology may be located in the basal ganglia, but in some cases the primary pathological changes are found in the cerebellum or cerebellar outflow pathways, suggesting that both regions may be involved in the pathogenesis of dystonic symptoms. Overall the number of well-documented pathological cases available for study is few, and there is an urgent need for additional postmortem studies. This article is part of a Special Issue entitled "Advances in dystonia".

Adult-onset dystonia

Dystonia is defined as involuntary sustained muscle contractions producing twisting or squeezing movements and abnormal postures. The movements can be stereotyped and repetitive and they may vary in speed from rapid to slow; sustained contractions can result in fixed postures. Dystonic disorders are classified into primary and secondary forms. Several types of adult-onset primary dystonia have been identified but all share the characteristic that dystonia (including tremor) is the sole neurologic feature. The forms most commonly seen in neurological practice include cranial dystonia (blepharospasm, oromandibular and lingual dystonia and spasmodic dysphonia), cervical dystonia (also known as spasmodic torticollis) and writer's cramp. These are the disorders that benefit most from botulinum toxin injections. A general characteristic of dystonia is that the movements or postures may occur in relation to specific voluntary actions by the involved muscle groups (such as in writer's cramp). Dystonic contractions may occur in one body segment with movement of another (overflow dystonia). With progression, dystonia often becomes present at rest. Dystonic movements typically worsen with anxiety, heightened emotions, and fatigue, decrease with relaxation, and disappear during sleep. There may be diurnal fluctuations in the dystonia, which manifest as little or no involuntary movement in the morning followed by severe disabling dystonia in the afternoon and evening. Morning improvement (or honeymoon) is seen with several types of dystonia. Patients often discover maneuvers that reduce the dystonia and which involve sensory stimuli such as touching the chin lightly in cervical dystonia. These maneuvers are known as sensory tricks, or gestes antagonistes. This chapter focuses on adult-onset focal dystonias including cranial dystonia, cervical dystonia, and writer's cramp. The chapter begins with a review of the epidemiology of focal dystonias, followed by discussions of each major type of focal dystonia, covering clinical phenomenology, differential genetics, and diagnosis. The chapter concludes with discussions of the pathophysiology, the few pathological cases published of adult-onset focal dystonia and management options, and a a brief look at the future.

Severe generalized dystonia due to primary putaminal degeneration: case report and review of the literature

Putaminal lesions of a variety of etiologies may cause secondary dystonia. We report on a case of primary putaminal degeneration as a cause of severe childhood-onset generalized dystonia and review the literature of the pathology of dystonia. A 44-year-old patient with severe generalized childhood-onset dystonia and macrocephaly underwent neurological evaluation and neuropathological examination. Neurological examination was normal apart from dystonia and signs referable to prior cryothalamotomy. Workup for metabolic and genetic causes of dystonia was negative. Neuroimaging showed severe bilateral putaminal degeneration, which subsequently correlated with the neuropathological findings of gliosis, spongiform degeneration, and cavitation. The substantia nigra pars compacta contained a normal number of neurons but decreased tyrosine hydroxylase immunoreactivity. There were no histopathological markers of other metabolic or degenerative diseases.

1H magnetic resonance spectroscopy of the lentiform nucleus in primary focal hand dystonia

Several radiologic findings point toward the lentiform nucleus as a possible site of lesion in primary dystonia. Histologic examinations, however, have shown inconsistent results. 1H-magnetic resonance spectroscopy (MRS) has proved helpful to assess neuronal degeneration in a variety of basal ganglia disorders. MRS data of dystonia patients are, however, lacking so far. 1H-MRS centered on the lentiform nuclei was performed in 14 patients with primary focal hand dystonia and in 12 healthy control subjects using a 1.5-T MR imager. No statistically significant differences of N-acetylaspartate/creatine and lactate/creatine ratios were found between patients and control subjects. Based on these data, the authors found no evidence that primary focal dystonia was associated with a conspicuous loss of lentiform nucleus neurons or a marked disturbance of the aerobic metabolism, although minor abnormalities cannot be excluded because of the possibly limited sensitivity of the method.

Mosaic pattern of gliosis in the neostriatum of a North American man with craniocervical dystonia and parkinsonism

We present the case of a 51-year-old patient with a 31-year history of psychiatric symptoms, craniocervical dystonia, bulbar dysfunction, and parkinsonism. His dystonic movements included blepharospasm, jaw opening and lingual dystonia, and spasmodic retrocollis. Psychiatric symptoms included psychosis and depression, with onset years before the movement disorder. After his death by aspiration, examination of his brain revealed abnormalities limited to the neostriatum. Staining of brain sections, including Holzer, glial fibrillary acidic protein, and immunohistochemical stain for calbindin D28k, revealed the presence of a mosaic pattern of gliosis with neuronal loss (sparing large neurons) within this region. The islands of tissue between stands of gliosis had a normal appearance. This patient represents only the fourth case (and first North American born) with a mosaic pattern of gliosis in the neostriatum. The clinical and pathologic features were similar in all four cases except that our patient was the first with prominent psychiatric symptoms and a more stable, less progressive course. Mosaicism has been described in the X-linked Filipino disorder Lubag. Occurrence in non-Filipino patients, such as ours, suggest that either Lubag can develop in non-Filipino families or that mosaicism is a nonspecific pathologic finding in some patients with idiopathic dystonia. Finally, our case reports the notion that craniocervical dystonia may result from neostriatal dysfunction.

Cerebral glucose metabolism in patients with spasmodic torticollis

The pathophysiology of spasmodic torticollis is not clear. Basal ganglia dysfunction has been suggested to underlie this clinical syndrome. We studied resting cerebral glucose metabolism in 10 spasmodic torticollis patients and 10 healthy controls by using positron-emission tomography and [18F]2-fluoro-2-deoxy-D-glucose. Statistical parametric mapping (SPM95) was used to compare both groups on a pixel-by-pixel basis. Torticollis patients showed a significantly higher glucose metabolism bilaterally in the lentiform nucleus (p < 0.005). Analyses performed using normalization of regional to global glucose metabolism confirmed this finding (controls, 1.26 +/- 0.06, and patients, 1.35 +/- 0.06; p < 0.01). The torticollis score did not correlate with glucose metabolism, nor did disease duration or side of chin direction. Our results indicate that the lentiform nucleus plays a predominant role in the pathophysiology of idiopathic spasmodic torticollis.

Perception of spatial orientation in spasmodic torticollis. Part I: The postural vertical

Estimates of points of entering and exiting from upright posture were obtained from 25 seated, restrained patients with idiopathic spasmodic torticollis (ST) and matched normal subjects exposed to cycles of 1.5 degrees/s tilts in a flight simulator. Estimates were obtained for displacements in roll and pitch about upright and for yaw tilts about a rostrocaudal, "barbecue," axis with the subjects supinated. For both pitch and roll, normal subjects estimated entering upright when they were still approximately 1 degree from machine upright and perceived themselves to be upright through a mean arc of 6 degrees. In barbecue tilt, entering upright was estimated at 0.2 degree for an arc of 6 degrees. Patients estimated entering upright at 2.8 degrees in roll and 3 degrees in pitch but estimated exiting upright at the same tilt as normal subjects; that is, they were less specific in detecting verticality. Patients were normal in barbecue tilt. No relationship between tilt estimates and head deviation was found. There were no differences between normal subjects when tested with their head in normal posture and with an assumed tilt of 20 degrees. Normal subjects probably based their estimates on combined vestibular-somatosensory signals, whereas torticollis patients appeared to derive more from a vestibular signal. However, patients referred the vestibular signals to the trunk long axis when asked to indicate the whole-body vertical. The findings suggest disruption of the normal combined vestibuloproprioceptive mechanism for detecting body uprightness in ST.

Cervical dystonia associated with tumors of the posterior fossa

Cervical dystonia was associated with posterior fossa tumors in three patients. The onset of dystonia paralleled the appearance of other focal neurologic signs. All patients had extraaxial tumors located in the cerebellopontine angle that were removed via suboccipital approaches. The tumors were identified as schwannomas arising from the glossopharyngeal nerve and from the vagus/accessory nerves; and a meningioma. Postoperatively, the cervical dystonia improved markedly during a period of 8 years in one patient, and it remitted completely within 1 year in another patient. In the third patient, cervical dystonia persisted. The combination of the clinical findings and the temporal relationship of their appearance suggest a causal association between the posterior fossa tumors and cervical dystonia in three cases. Possible pathogenic mechanisms are reviewed.

Cervical dystonia due to spinal cord ependymoma: involvement of cervical cord segments in the pathogenesis of dystonia

We report a patient with a progressive motor disorder dominated by pyramidal signs in all four extremities and cervical dystonia in the form of torticollis, who had imaging features of cervical cord tumor on magnetic resonance imaging (MRI) scanning. Ependymoma was the final diagnosis by histology. Cervical dystonia presenting as a manifestation of an identified focal central nervous system (CNS) lesion is infrequent. We believe our patient to be the first adult example of cervical cord tumor giving rise to cervical dystonia. Adding this entity to the list of differential diagnosis of torticollis is considered, and its mechanisms are discussed.

Microvascular decompression for spasmodic torticollis

Twenty patients with spasmodic torticollis (ST) were treated by microvascular decompression (MVD) of the spinal accessory nerves, the upper cervical nerve roots and the brainstem. Thirteen were female and seven male. Median age was 47 years (range 39 to 70 years). Median duration of symptoms was 5 years (range 4 months to 17 years). Ten had right horizontal; nine, left horizontal; and one, retrocollis ST. Twenty-two operations were performed on twenty patients, suboccipital craniectomy and C1 laminectomy in 18 and retromastoid craniectomy in 4 operations. The most common compressing blood vessels were the vertebral artery and/or the posterior inferior cerebellar artery. No nerve section was performed. Three patients died of unrelated conditions, 3, 5 1/2, and 6 years postoperatively, respectively. Minimum follow-up period in the rest of the cases is 5 years (range 5 to 10 years). Thirteen (65%) were cured, four (20%) improved with minimal spasm, one (5%) improved with moderate spasm, and two (10%) improved minimally or unchanged. In most cases the cure or improvement was noticed gradually over 6 months to two years following the operation. There was no operative mortality. Postoperative morbidities included transient cerebrospinal fluid leakage through the surgical incision in one case and an apparent multiple small vessel stroke involving periventricular white matter in one reoperation case with full recovery. MVD for ST is a nondestructive benign procedure with high probability of cure or significant improvement.

Neuropathology of lubag (x-linked dystonia parkinsonism)

Lubag is an x-linked recessive dystonia parkinsonism that affects Filipino men originating principally from the Panay Island. Linkage analysis has confirmed the mode of inheritance and localized the disease gene to the proximal long arm of the x-chromosome. We studied the brain of a 34 year old Filipino man affected with lubag. He developed truncal dystonia at age 30, which subsequently generalized. With disease progression, he also presented with parkinsonism including, rigidity, bradykinesia, and impaired balance. His symptoms were largely unaffected by medication and, at age 34, he underwent a right cryothalamotomy. He died suddenly 2 days after the procedure. The principal neuropathological findings were neuronal loss and a multifocal mosaic pattern of astrocytosis restricted to the caudate and lateral putamen. Similar findings have been reported in two other men with dystonia--one Filipino and the other non-Filipino. The similar pathology of the two Filipino men suggests that this is the pathology of lubag. Recognition of this pathology in a non-Filipino man suggests that the mutation causing lubag may not be restricted to the Filipino population.

CT-scanning and magnetic resonance imaging in idiopathic spasmodic torticollis

Twenty-five consecutive patients with idiopathic spasmodic torticollis (IST) were investigated with computerized tomography (CT) or magnetic resonance imaging (MRI) of the brain. In only six patients (24%) did CT or MRI reveal brain pathology (focal cortical atrophy and lacunary infarcts). No consistent pathological pattern was detected. Consequently, CT and MRI of the brain provides little diagnostic information in this disorder.

Severe generalised dystonia associated with a mosaic pattern of striatal gliosis

A mosaic pattern of striatal pathology is described in a male who developed severe generalised dystonia from the age of 10 years, and died at the age of 18 years. There was no family history of dystonia, and extensive investigations during his life failed to identify a cause for the dystonia. The caudate nucleus and putamen showed a network of cell loss and gliosis surrounding islands of preserved striatum. Dorsal parts showed confluent gliosis, and ventral parts were spared. The pattern suggested a correlation with patch-matrix organisation, but there was no correlation with the distribution of calbindin immunoreactive cells, which are present in the matrix of the classical striosome-matrix organisation. The pathological findings were unlike those in status marmoratus, perinatal hypoxia-ischaemia, Huntington's disease, and neuroacanthocytosis, but similar to those reported in a 44-year-old man with predominantly cranial dystonia.

Spasmodic torticollis--review of 220 patients

220 patients with isolated and idiopathic spasmodic torticollis were followed and treated over a 14 year period. Each patient was given a short questionnaire leading to the present retrospective data analysis. In most areas, including female preponderance and frequency of postural tremor, the findings confirmed previous studies and highlighted particular points: importance of psychopathological antecedents and association with stressful life-events. The discussion deals with some of the conflicting debates surrounding this unusual disorder. What is the role of psychopathological factors? What is the therapeutic prognosis? The best therapeutic results were obtained by combining anticholinergic drugs, local injections and rehabilitation.

[Spasmodic torticollis and frontal meningioma]

A 57 year-old man developed a spasmodic torticollis with involuntary deviation of the head to the right-side. He had a left paramedian frontal meningioma. The association of spasmodic torticollis and other movement disorders has been reported with contralateral lesions in the basal ganglia. Its occurrence in association to a frontal lesion appears to be much less frequent suggesting a possible disorder of frontostriatal connections.

Spasmodic torticollis due to a midbrain lesion in a case of multiple sclerosis

A case of multiple sclerosis is described in which spasmodic torticollis occurred abruptly and abated after 1 year. Magnetic resonance imaging (MRI) demonstrated a lesion in the mesencephalon. Other symptoms and physical signs that developed at the same time as the spasmodic torticollis were compatible with the lesion that had not been present on MRI 18 months previously. There are very few reports of spasmodic torticollis due to an identified focal lesion; there is evidence from experimental work on animals that midbrain lesions may cause spasmodic torticollis but there has been no previous human example.

Vestibulo-ocular abnormalities in spasmodic torticollis before and after botulinum toxin injections

In order to establish whether vestibular abnormalities often found in spasmodic torticollis are secondary to the abnormal head posture, the vestibulo-ocular reflex (VOR) was studied in eight patients before and after correction of head posture with botulinum toxin. Eye movements were recorded in the dark during sinusoidal and velocity step rotation. Four patients showed a significantly asymmetric response, with the slow phase of the VOR more active ipsilateral to the torticollis (chin). Despite significant improvement of the head posture in all patients for up to 10 weeks following treatment, no correction of the vestibular asymmetry occurred. This suggests that the VOR abnormalities are not caused by the head posture itself. We interpret the findings as evidence of primary involvement of the vestibular system in torticollis and we postulate a widespread derangement of the sensory-motor mechanisms controlling head posture in this disease.

Pathological report of four patients presenting with cranial dystonias

Secondary dystonias and experimental models of dystonia suggest that mechanisms responsible for primary dystonias may lie in the basal ganglia or brainstem. A histological study has been done in three patients with cranial dystonia (blepharospasm with oromandibular dystonia in two, blepharospasm alone in one), and one patient with craniocervical dystonia (oromandibular dystonia with retrocollis). In the patient with blepharospasm alone, an angioma, 0.5 mm in diameter, was found in the dorsal pons at the site of the central tegmental tract, confirming that some patients presenting with primary dystonias may have longstanding lesions in the brainstem. In the three other cases, the striatum, pallidum, thalamus, and brainstem were examined and cell populations in the putamen, substantia nigra, and inferior olives were compared with age-matched controls, but no significant abnormality was found.

Spasmodic torticollis: the problem of pathophysiology and assessment

In 17 patients with idiopathic spasmodic torticollis (ST) quantitative indices for both signs (extent and direction of the head deflexions) and complaints (of deflexion, shaking and pain) were collected. In the literature deflexion in the horizontal plane is most frequently considered, but analysis of the data shows that deflexion in the coronal and sagittal planes is also important. Furthermore, it is found that especially the deflexions in the coronal and sagittal plane covariate with the patients' complaints, but not with horizontal deflexion. On the basis of these and related data, it is suggested that we are dealing with at least two subtypes of ST. Finally, the patient's neuroticism and depression scale values are within the normal range and do not show significant correlations with ST duration. The present study provides no evidence that ST is a psychogenic disorder. ST should be regarded as a central nervous system disorder of unknown aetiology.

Torticollis following radiation therapy

A patient with adenocarcinoma in the apical portion of the lung producing a Pancoast's syndrome developed torticollis a few months after receiving a course of radiation therapy (5,040 rad) to his upper chest and neck. We describe this case, in which local radiation fibrosis of the neck muscles and perhaps segmental demyelination of the 11th cranial nerve resulted in peripheral nervous system lesion causing torticollis.

Lymphocyte subset abnormalities in patients with spasmodic torticollis

The aetiology of spasmodic torticollis is unknown but the patients form a heterogeneous group among which are cases apparently precipitated by a viral illness and others associated with autoimmune disease. We therefore decided to investigate the immunoregulatory lymphocyte subsets in our 11 cases. A significant decrease of both helper and suppressor lymphocytes was identified in the group, together with in vitro evidence of depressed suppressor cell function. Disturbance of the immune response may play a role in this puzzling disorder.

A study of multimodality evoked responses in idiopathic spasmodic torticollis

A wide variety of anatomical sites have been implicated in the pathogenesis of torticollis, based primarily on animal studies. These include lesions in the mesencephalic tegmentum, third ventricle, diencephalon, pre-tectal area, prestitial nucleus of the mid-brain, cervical cord, atlanto-axial junction and motor cortex, amongst others. This study describes the use of multimodality evoked potentials including visual, auditory, bilateral median and peroneal somatosensory evoked responses, undertaken in patients with idiopathic spasmodic torticollis. An attempt was made to non-invasively identify any physiological disruption along these major pathways which could help locate a causative lesion. Normal evoked responses were obtained both ipsilateral and contralateral to the affected side in all patients. It is concluded that the lesion in idiopathic spasmodic torticollis does not discernibly involve the visual, auditory or motor somatosensory pathways.

Electrophoresis and immunoblot of cerebrospinal fluid proteins in spasmodic torticollis

Protein patterns of cerebrospinal fluid (CSF) from patients with spasmodic torticollis (ST) were investigated to determine whether abnormalities previously reported could be detected and further identified. CSF was collected from 12 patients with ST and 6 normal controls. The CSF proteins were analyzed using sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis and silver staining. In 11 of the 12 patients with ST, a CSF protein pattern was observed which differed from that in the controls. The identity of the abnormal proteins was ascertained by blotting and immunostaining with specific antisera to IgG and ceruloplasmin (Cp). CSF from 2 of 12 patients had distinct bands staining for IgG and 7 had abnormal immunostaining for Cp.

Spasmodic torticollis: a behavioral perspective

The literature on spasmodic torticollis is critically reviewed. The currently most popular etiological hypothesis characterizes torticollis as an extrapyramidal disorder, the symptoms of which are aggravated by stress, but there is no unequivocal evidence available to support this view. Psychological mechanisms have been suggested but not elaborated or tested in any detail. A wide range of treatments has been advocated but controlled studies have not been reported, and the problems of assessing outcome have never been tackled adequately. Behavioral treatments have been evaluated more rigorously than other approaches (particularly EMG feedback training), and the literature suggests that they benefit some patients. It is argued that psychologists have the potential for making a very significant contribution to the understanding and management of torticollis. In discussing outcome measures, the more promising techniques that have been used are summarized and a list is presented of the factors which must be considered when assessing torticollis symptoms. Directions for future research are outlined and priorities suggested.

Postural laterality in torticollis and torsion dystonia

Tests of postural rotational laterality were carried out in 63 patients suffering from torticollis (53) or torsion dystonia with torticollis (10) and in 33 normal subjects. There was a correlation between the predominant direction of postural functions and the direction of the rotatory component of torticollis. Torticollis and torsion dystonia may be due to the release of a postural rotational laterality in pre-disposed subjects and not to a presumed asymmetric lesion of the brain-stem.

Pathophysiology and pharmacotherapy of spasmodic torticollis: a review

The few existing neuropathological, neurochemical, and neuropharmacological studies have shed little light on the pathophysiology of spasmodic torticollis (ST). The relevance of experimental ST in animals and drug-induced ST in man to idiopathic ST is unclear. Most pharmacotherapeutic endeavors have focused on drugs affecting basal ganglia function. Unfortunately, problems of sample size, clinical heterogeneity of patient population, research design, objective evaluation of response, documentation of key data, and adequacy of duration of follow-up make interpretation of published results difficult. Because of the heterogeneity of ST, investigations aimed at establishing a neurotransmitter profile for each patient by observing the acute response to a test dose of drugs affecting cholinergic, dopaminergic, serotonergic, and gamma-aminobutyric acid systems may provide a more rational basis to the selection of treatment.

Torticollis caused by an infratentorial tumour: three cases

Three cases with torticollis caused by an infratentorial tumour are presented. A father and his son both had a Lindau tumour, and another patient had an ependymoma. It is stressed that torticollis may be the predominant or only sign of an infratentorial tumour, and that torticollis should always be suspected to have an organic origin.

Spasmodic torticollis: a combined clinical study

The prognosis in 30 patients with spasmodic torticollis proved to be unexpectedly bad, only one patient making a full and sustained recovery. Investigation did not confirm previously reported reflex influences on the degree of spasm. Detailed otological investigation did not suggest that spasmodic torticollis originates in vestibular dysfunction. Psychological assessment of the patients showed no deviation from normal in premorbid personality but confirmed the severe adverse effects of the condition.

Extrapyramidal dysfunction with cerebral arteriovenous malformations

Arteriovenous malformations have only rarely been implicated as a cause of basal ganglia dysfunction. In four instances where such a lesion was uncovered, abnormal involuntary movements were present. In two, tremor involving the contralateral limbs occurred, while in others the head and neck were involved in dystonic movements and posture. The clinical and angiographic characteristics of these four patients have been assessed and are presented in detail in this report. The possible mechanism by which arteriovenous malformations may disturb the internal circuitry of the basal ganglia and induce symptoms are discussed.

Spasmodic torticollis

Spasmodic torticollis is a distressing condition, characterised by involuntary and intermittent spasm of neck muscles, which in time become hypertrophied. It should be distinguished from a tic. Its incidence has been estimated at 1 in 1200 psychiatric referrals. Its relative rarity is a possible reason for the sparseness of the literature, which in turn helps to explain the confusion surrounding its aetiology. This is still unknown, but there is sufficient evidence to suggest that spasmodic torticollis is of interest as a model of “psychosomatic” illness, in that the convergence of a number of organic, personality, and situational factors may be necessary for its production.