Exploration of potential immune mechanisms in cervical dystonia

BACKGROUND

Although there are many possible causes for cervical dystonia (CD), a specific etiology cannot be identified in most cases. Prior studies have suggested a relationship between autoimmune disease and some cases of CD, pointing to possible immunological mechanisms.

OBJECTIVE

The goal was to explore the potential role of multiple different immunological mechanisms in CD.

METHODS

First, a broad screening test compared neuronal antibodies in controls and CD. Second, unbiased blood plasma proteomics provided a broad screen for potential biologic differences between controls and CD. Third, a multiplex immunoassay compared 37 markers associated with immunological processes in controls and CD. Fourth, relative immune cell frequencies were investigated in blood samples of controls and CD. Finally, sequencing studies investigated the association of HLA DQB1 and DRB1 alleles in controls versus CD.

RESULTS

Screens for anti-neuronal antibodies did not reveal any obvious abnormalities. Plasma proteomics pointed towards certain abnormalities of immune mechanisms, and the multiplex assay pointed more specifically towards abnormalities in T lymphocytes. Abnormal immune cell frequencies were identified for some CD cases, and these cases clustered together as a potential subgroup. Studies of HLA alleles indicated a possible association between CD and DRB1*15:03, which is reported to mediate the penetrance of autoimmune disorders.

CONCLUSIONS

Altogether, the association of CD with multiple different blood-based immune measures point to abnormalities in cell-mediated immunity that may play a pathogenic role for a subgroup of individuals with CD.

Polymorphic variability in the exon 19 of the RB1 gene and its flanking intronic sequences in HPV16-associated precancerous lesions in the Greek population

PURPOSE

The tumour suppressor protein RB plays a decisive role in negative control of the cell cycle, inhibiting tumour development. The present analysis investigated the prevalence of the nucleotide polymorphism A153104G, which is located at intron 18 of the RB1 gene, and investigated the impact of the polymorphic variability in the exon 19 and its flanking intronic sequences on the severity of cervical disease in HPV16-positive Greek women.

METHODOLOGY

The nucleotide polymorphism A153104G was detected by PCR-RFLP assay, while the amplicons were further subjected to cloning and sequencing. Moreover, molecular evolutionary analysis was performed using the maximum-likelihood (ML) and empirical Bayesian (EB) methods in order to evaluate the selective pressure acting on exon 19 of the RB1 gene.Results/Key findings. The A153104G nucleotide polymorphism was only detected in one control case. Moreover, sequence analysis of the amplicons revealed that the polymorphic variability in the RB1 gene increased with the severity of the cervical dysplasia. The link between the observed polymorphic variability and the progress of cervical disease was reflected in the molecular evolutionary analysis that was performed on the exon 19 of the RB1 gene, since negative selective pressure was acting upon exon 19 in the control and low-grade squamous intraepithelial lesion (LSIL) cervical samples, while positive selective pressure was acting upon exon 19 in the high-grade squamous intraepithelial lesion (HSIL) specimens.

CONCLUSIONS

The A153104G nucleotide polymorphism did not emerge as a potential biomarker for the development of precancerous lesions in the Greek patients, while the accumulation of sequence variations in RB1 gene might influence patients' susceptibility towards the progression of cervical neoplasia.

Functional Genomic Analyses of Mendelian and Sporadic Disease Identify Impaired eIF2α Signaling as a Generalizable Mechanism for Dystonia

Dystonia is a brain disorder causing involuntary, often painful movements. Apart from a role for dopamine deficiency in some forms, the cellular mechanisms underlying most dystonias are currently unknown. Here, we discover a role for deficient eIF2α signaling in DYT1 dystonia, a rare inherited generalized form, through a genome-wide RNAi screen. Subsequent experiments including patient-derived cells and a mouse model support both a pathogenic role and therapeutic potential for eIF2α pathway perturbations. We further find genetic and functional evidence supporting similar pathway impairment in patients with sporadic cervical dystonia, due to rare coding variation in the eIF2α effector ATF4. Considering also that another dystonia, DYT16, involves a gene upstream of the eIF2α pathway, these results mechanistically link multiple forms of dystonia and put forth a new overall cellular mechanism for dystonia pathogenesis, impairment of eIF2α signaling, a pathway known for its roles in cellular stress responses and synaptic plasticity.

Duplication of 8q12 encompassing CHD7 is associated with a distinct phenotype but without duane anomaly

Interstitial duplications of 8q12 encompassing CHD7 have recently been described as a new microduplication syndrome. Three 8q12 duplications have been reported with shared recognizable phenotype: Duane anomaly, developmental delay and dysmorphic facial features. We identified a 2.7 Mb duplication on chromosome 8q12 with SNP-array in a patient with growth delay, congenital heart defects, ear anomalies and torticollis. To our knowledge, this is the smallest duplication reported to date. Our findings support the notion that increased copy number of CHD7 may underlie the phenotype of the 8q12 duplication. Our study together with previous studies suggest that the 8q12 duplication could be defined as a novel syndrome.

Molecular immune recognition of botulinum neurotoxin B. The light chain regions that bind human blocking antibodies from toxin-treated cervical dystonia patients. Antigenic structure of the entire BoNT/B molecule

We recently mapped the regions on the heavy (H) chain of botulinum neurotoxin, type B (BoNT/B) recognized by blocking antibodies (Abs) from cervical dystonia (CD) patients who develop immunoresistance during toxin treatment. Since blocking could also be effected by Abs directed against regions on the light (L) chain, we have mapped here the L chain, using the same 30 CD antisera. We synthesized, purified and characterized 32 19-residue L chain peptides that overlapped successively by 5 residues (peptide L32 overlapped with peptide N1 of the H chain by 12 residues). In a given patient, Abs against the L chain seemed less intense than those against H chain. Most sera recognized a limited set of L chain peptides. The levels of Abs against a given region varied with the patient, consistent with immune responses to each epitope being under separate MHC control. The peptides most frequently recognized were: L13, by 30 of 30 antisera (100%); L22, by 23 of 30 (76.67%); L19, by 15 of 30 (50.00%); L26, by 11 of 30 (36.70%); and L14, by 12 of 30 (40.00%). The activity of L14 probably derives from its overlap with L13. The levels of Ab binding decreased in the following order: L13 (residues 169-187), L22 (295-313), L19 (253-271), and L26 (351-369). Peptides L12 (155-173), L18 (239-257), L15 (197-215), L1 (1-19) and L23 (309-327) exhibited very low Ab binding. The remaining peptides had little or no Ab-binding activity. The antigenic regions are analyzed in terms of their three-dimensional locations and the enzyme active site. With the previous localization of the antigenic regions on the BoNT/B H chain, the human Ab recognition of the entire BoNT/B molecule is presented and compared to the recognition of BoNT/A by human blocking Abs.

Increased prevalence of val(66)met BDNF genotype among subjects with cervical dystonia

Abnormalities of cortical representational maps and their plasticity have been described in dystonia. A common polymorphism for BDNF has been associated with abnormal cortical plasticity, and thus might contribute to pathogenesis of dystonia in some subjects. As a first step towards this suggestion, the current study examined the prevalence of this polymorphism. BDNF genotype was examined in 34 subjects with cervical dystonia, 54 age-matched healthy controls, and 53 subjects with a different movement disorder, Parkinson's disease. ApoE genotype, known to influence neurological outcome in some conditions, was also examined as a control. In subjects with cervical dystonia, the val(66)met polymorphism was approximately twice as prevalent when compared to either control group. This was not true of ApoE genotype, which was similarly distributed across subject groups. The current findings suggest that the BDNF val(66)met polymorphism might play a role in the pathogenesis of cervical dystonia in some subjects.

Non-DYT1 early-onset primary torsion dystonia: comparison with DYT1 phenotype and review of the literature

To investigate the clinical features of early-onset primary torsion dystonia (EO-PTD), 57 consecutive genetically characterized patients with onset before 21 years were studied. Sex, ethnic origin, family history of dystonia, age at onset, disease duration, site of dystonia onset and distribution at latest examination, dystonia progression, time to generalization, and motor disability were noted. The 14 patients (25%) with GAG deletion (904_906/907_909delGAG) in the DYT1 gene were compared with the remaining non-DYT1 patients. Cranial involvement was present in 49% of non-DYT1 cases, but only 14% of DYT1 cases; non-DYT1 patients were younger at time of generalization. DYT1 cases had features similar to sporadic non-DYT1 cases but differed markedly from familial non-DYT1 cases, the latter having later age at onset, less common limb onset, more frequent cervical involvement, and slower progression than DYT1 PTD. These findings indicate that non-DYT1 forms of EO-PTD differ clinically from those of DYT1 forms. Cranial involvement before 21 years of age is the strongest predictor of non-DYT1 status. Positive family history and cervical involvement are associated with less severe progression in non-DYT1 forms.

Are nongenetic triggers for dystonia type-specific? A study exploring scoliosis in blepharospasm

We previously observed that diseases of the anterior ocular segment predispose to primary blepharospasm, but not to other focal dystonias. In this multicenter study, we tested whether prior scoliosis, which increases the risk of developing cervical dystonia, is also a predisposing factor to blepharospasm. The frequency of scoliosis did not differ between blepharospasm patients and controls. This finding supports the hypothesis that environmental risk factors may be specific for a single form of adult-onset dystonia.

Mutations in the gene encoding peroxisomal sterol carrier protein X (SCPx) cause leukencephalopathy with dystonia and motor neuropathy

In this report, we describe the first known patient with a deficiency of sterol carrier protein X (SCPx), a peroxisomal enzyme with thiolase activity, which is required for the breakdown of branched-chain fatty acids. The patient presented with torticollis and dystonic head tremor as well as slight cerebellar signs with intention tremor, nystagmus, hyposmia, and azoospermia. Magnetic resonance imaging showed leukencephalopathy and involvement of the thalamus and pons. Metabolite analyses of plasma revealed an accumulation of the branched-chain fatty acid pristanic acid, and abnormal bile alcohol glucuronides were excreted in urine. In cultured skin fibroblasts, the thiolytic activity of SCPx was deficient, and no SCPx protein could be detected by western blotting. Mutation analysis revealed a homozygous 1-nucleotide insertion, 545_546insA, leading to a frameshift and premature stop codon (I184fsX7).

Familial dopa-responsive cervical dystonia

The authors present four cases from two unrelated families with young-onset predominant cervical dystonia with a dramatic sustained response to levodopa. Onset age was 12 years (range 9 to 15). Additional symptoms included postural hand tremor and laryngeal dystonia. Genetic testing for GTP cyclohydrolase I, tyrosine hydroxylase, and sepiapterin reductase was negative. These cases may represent new forms of dopa-responsive dystonia. Levodopa is advisable in all patients with young-onset cervical dystonia.

Animal models of focal dystonia

Animal models indicate that the abnormal movements of focal dystonia result from disordered sensorimotor integration. Sensorimotor integration involves a comparison of sensory information resulting from a movement with the sensory information expected from the movement. Unanticipated sensory signals identified by sensorimotor processing serve as signals to modify the ongoing movement or the planning for subsequent movements. Normally, this process is an effective mechanism to modify neural commands for ongoing movement or for movement planning. Animal models of the focal dystonias spasmodic torticollis, writer's cramp, and benign essential blepharospasm reveal different dysfunctions of sensorimotor integration through which dystonia can arise. Animal models of spasmodic torticollis demonstrate that modifications in a variety of regions are capable of creating abnormal head postures. These data indicate that disruption of neural signals in one structure may mutate the activity pattern of other elements of the neural circuits for movement. The animal model of writer's cramp demonstrates the importance of abnormal sensory processing in generating dystonic movements. Animal models of blepharospasm illustrate how disrupting motor adaptation can produce dystonia. Together, these models show mechanisms by which disruptions in sensorimotor integration can create dystonic movements.

[Arthrogryposis associated with facial scoliosis and torticollis in German Holstein calves]

In 13 German Holstein calves from two different dairy farms arthrogryposis of the front legs, facial scoliosis and torticollis were observed. Obvious environmental reasons could not be found. Chromosomal anomalies in two affected calves were not detectable. A striking feature was the high frequency of affected calves among the offspring of one natural service sire. A plausible explanation of the congenital anomalies observed is a dominantly inherited mutation restricted to germ cells.

Familial adolescent-onset scoliosis and later segmental dystonia in an Irish family

Adolescent-onset scoliosis occurs more frequently than expected in primary adult-onset cervical dystonia and a genetic association between the conditions has been postulated. The authors report a family in which four members have adult-onset cervical and/or brachial dystonia, two of whom have coexistent scoliosis. Four other individuals have isolated childhood- or adolescent-onset scoliosis. Adolescent-onset scoliosis may represent part of the dystonia phenotype in this family.

Focal dystonia as a presenting sign of spinocerebellar ataxia 17

We report on the clinical manifestation of spinocerebellar ataxia 17 (SCA17) in 3 members of a German family, in whom the pathological repeat expansion in the TATA-binding protein gene ranged from 53 to 55 repeats (normal: 29-42). The main clinical features were focal dystonia as presenting sign, followed by cerebellar ataxia, and, in the later course of one case, dementia and marked spasticity with signs of cerebellar and cerebral atrophy on brain computed tomography (CT) scan. In conclusion, SCA17 mutations should be considered in the differential diagnosis of focal dystonia.

Clinical and genetic features of myoclonus-dystonia in 3 cases: A video presentation

Many cases of myoclonus-dystonia (M-D) are caused by mutations in the epsilon-sarcoglycan (SGCE) gene. We describe 3 children with a similar clinical picture of autosomal dominant M-D and an SGCE mutation in only one of them, suggesting that M-D is genetically heterogeneous.

Frequency of familial aggregation in primary adult-onset cranial cervical dystonia

Family history of definite/probable dystonia was studied in 36 probands with primary adult-onset cranial/cervical dystonia. Of the 157 relatives who were examined, 8 from 7 families and 11 from 10 families were diagnosed as having definite or probable dystonia, respectively. The frequency of familial occurrence of definite dystonia was 19.4%, 33% when considering both definite and probable dystonia. There was a tendency for relatives affected by either definite or probable dystonia to have the same type of dystonia as the index patient. Similar segregation ratios were found for parents, siblings, and children with either definite or probable dystonia. These observations raise the possibility that probable dystonia represents formes frustes/mild phenotypes of dystonia rather than another movement disorder.

Familial restrictive cardiomyopathy with skeletal abnormalities

A family is described in which 5 of 9 living children were found to have restrictive cardiomyopathy associated with skeletal muscle and orthopedic abnormalities. In the absence of another identifiable etiology, a genetic cause for restrictive cardiomyopathy in this family is probable. Consistent with the poor prognosis encountered for children with restrictive cardiomyopathy, 2 children in this family died, whereas a third was symptomatic by age 3 years.

[Molecular cytogenetic detection of partial chromosome 13q trisomy and its relation with the clinical features of tortilcollis]

OBJECTIVE

To search for the possible relation between tortilcollis and partial chromosome 13q trisomy.

METHODS

Fluorescence in situ hybridization (FISH) technique combined with chromosome banding was performed to determine the karyotype of two patients with typical clinical features of partial 13q trisomy syndrome, then their manifestations were compared with those of the literatures published previously.

RESULTS

The two cases were partial trisomy of 13q14--> ter with a different second derivative chromosome, in spite of this difference, both of them had tortilcollis.

CONCLUSION

It is suggested that a potential site for tortilcollis may locate on the long arm of chromosome 13. With reference to a report previously published, the more precise candidate related region may be 13q32--> qter.

Role of the dopamine D5 receptor (DRD5) as a susceptibility gene for cervical dystonia

Cervical dystonia (CD) is one of the most common forms of primary dystonia. The pathogenesis of the disease is still unknown, although evidence suggests a role for genetic factors. Recently, a polymorphism in the dopamine D5 receptor (DRD5) gene has been associated with the disease in a British population, suggesting that DRD5 is a susceptibility gene for CD. To confirm these data, we performed a case-control study of the microsatellite (CT/GT/GA)(n) at the DRD5 locus in 104 Italian CD patients and 104 healthy controls. The frequency of allele 4 was higher in the CD patients compared to the controls. This resulted in a twofold increased risk of developing the disease. These results provide further evidence of an association between DRD5 and cervical dystonia, supporting the involvement of the dopamine pathway in the pathogenesis of CD.

Benign paroxysmal torticollis of infancy: four new cases and linkage to CACNA1A mutation

Benign paroxysmal torticollis of infancy (BPTI) is a disorder characterized by recurrent episodes of head tilt secondary to cervical dystonia. Attacks are often accompanied by vomiting, pallor, and ataxia, settling spontaneously within hours or days. Episodes begin within the first 12 months of life and resolve by 5 years. We report four patients with BPTI. Symptoms started from 3 months of age, with head tilting lasting between 10 minutes and 2 months; the shorter episodes were followed by vomiting, apathy, and unsteadiness. Head tilt became less prominent after infancy, replaced by vertigo and eventually by migraine headaches. Two patients came from a kindred with familial hemiplegic migraine linked to CACNA1A mutation. BPTI may be regarded as a migraine aura equivalent. The syndrome poses interesting questions regarding varying phenotypic expression of calcium channelopathies at different stages of development.

Novel Italian family supports clinical and genetic heterogeneity of primary adult-onset torsion dystonia

We report on an Italian kindred with adult-onset primary torsion dystonia (PTD). A detailed clinical examination of the six definitely affected family members revealed a mild, purely focal phenotype. The disease involved only one body part (eyes, neck, or arm). PTD in this family was not linked to the known disease loci (DYT1, DYT6, DYT7, and DYT13), and the 3-bp deletion in the DYT1 gene was also excluded. These findings support genetic heterogeneity of PTD and indicate that a novel unassigned gene is responsible for focal dystonia in this family.

Familial torticollis with polydactyly: manifestation in three generations

Familial transmission of congenital muscular torticollis (CMT) has been reported in the literature, and postaxial polydactyly has been frequently reported in familial cases, but, to our knowledge, familial CMT with postaxial polydactyly has not been described. In this article, we report a rare case of CMT with postaxial polydactyly in 3 generations of a family and suggest an autosomal-dominant pattern of inheritance in these cases.

Cervical dystonia in monozygotic twins: case report and review of the literature

We report on monozygotic male twins of German origin with early onset cervical dystonia. No other family members were affected. Although identical in age of onset and clinical course, there were phenotypic variations. While the second-born, more affected twin suffered from a symmetric retrocollis, the twin brother mainly presented with a spasmodic torticollis to the left. Dystonia remained focal in both siblings. A DYT1 gene deletion was excluded. Including our patients, hitherto only four twin pairs with idiopathic dystonia have been reported. Although dystonia in twins can be remarkably uniform in some cases, major differences in terms of disease progression, remissions, and disability may be found. These observations underline the role of inheritance in the pathogenesis of idiopathic dystonia but also indicate that some other factors contribute to the clinical presentation of dystonia.

A Yorkshire family with adult-onset cranio-cervical primary torsion dystonia

Although a family history is described in approximately 20% of patients, large families with adult-onset craniocervical primary (idiopathic) torsion dystonia (PTD) are rare. We report a new British family with cranio-cervical dystonia. Seventeen members of the family were examined. Five cases were diagnosed as definite PTD and one as probable PTD. Mean age at onset was 29 years (range, 19-40 yrs). The phenotype was characterized by adult-onset cranio-cervical dystonia in all affected cases. A few cases had additional voice tremor and/or postural arm tremor. The GAG deletion in the DYT1 gene was excluded in the index case. Linkage analysis was performed between the disease and several marker loci spanning DYT6 and DYT7 regions, and haplotypes were reconstructed in all subjects. Although linkage analysis was not completely informative, reconstructed haplotypes excluded linkage between the disease and either DYT6 or DYT7. This report confirms that familial cranio-cervical dystonia is genetically heterogeneous, and further studies of other PTD families with similar clinical features are needed to identify other new genes.

Childhood head tremor

We report here four children (three girls, one boy) with head tremor followed longitudinally, ages 15 months to 11 years, with follow-up over 1 to 8 years. Each demonstrated onset of head tremor between the ages of 5 and 10 months. In each case head tremor was characterized by a predominant "yes-yes" or "no-no" movement of the head. In two of the children the movement was slightly skewed with chin movement toward the shoulder. Oscillations were at a frequency of about 1 to 2 Hz. They were accentuated when sitting upright without head support, increased at times of movement, and dissipated while lying flat or sleeping. The children were unable to voluntarily suppress the action and did not experience any sensation of movement. Three of the children had shuddering spells prior to onset of head tremor. Two children have developed mild dystonic posturing of the legs when intently concentrating. Their general and neurologic examinations were normal. Normal investigations included brain magnetic resonance imaging and computed tomography, urine amino acids and organic acids screening, serum lactate, erythrocyte sedimentation rate, antinuclear antibodies, and ceruloplasmin and copper levels. A family history of tremor was present in two children, maternal epilepsy in one child, and infantile shuddering occurred in the father of one child. Therapy included trials of selective and nonselective beta-adrenergic blockers, alpha-adrenergic agonists, anticholinergics, anticonvulsants, and amantadine. One child responded well to both timolol and trihexyphenidyl. A second child responded moderately to primidone. Two have not been treated. Two have had head tremor spontaneously remit. We conclude from this small series of children with head tremor that it can evolve from a prior history of shuddering spells, occurs in the context of a positive family history of tremor, and can be accompanied by the development of a mild dystonia. Therapeutic response is variable to multiple agents. Spontaneous remission occurs, suggesting a benign course.

Search for a founder mutation in idiopathic focal dystonia from Northern Germany

Both the discovery of the DYT1 gene on chromosome 9q34 in autosomal dominant early-onset torsion dystonia and the detection of linkage for one form of adult-onset focal dystonia to chromosome 18p (DYT7) in a family from northern Germany provide the opportunity to further investigate genetic factors in the focal dystonias. Additionally, reports of linkage disequilibrium between several chromosome 18 markers and focal dystonia, both in sporadic patients from northern Germany and in members of affected families from central Europe suggest the existence of a founder mutation underlying focal dystonia in this population. To evaluate the role of these loci in focal dystonia, we tested 85 patients from northern Germany who had primary focal dystonia, both for the GAG deletion in the DYT1 gene on chromosome 9q34 and for linkage disequilibrium at the chromosome 18p markers D18S1105, D18S1098, D18S481, and D18S54. None of these patients had the GAG deletion in the DYT1 gene. Furthermore, Hardy-Weinberg analysis of markers on 18p in our patient population and in 85 control subjects from the same region did not support linkage disequilibrium. Taken together, these results suggest that most cases of focal dystonia in patients of northern German or central European origin are due neither to the GAG deletion in DYT1 nor to a proposed founder mutation on chromosome 18p but must be caused by other genetic or environmental factors.

[Psychosomatic aspects of idiopathic spasmodic torticollis. Results of a multicenter study]

Idiopathic spasmodic torticollis (IST) is one of the most frequent dystonic movement disorders. Its classification as a focal dystonia, as well as its treatment with botulinum toxin resulted in groups of patients being regularly seen by neurologic specialists. In a multicentre study, we investigated psychosocial changes, coping and psychopathology, and their interrelations with signs, symptoms and course. 256 patients were included in the study (59.3% women, 40.7% men). The mean age was 49.1 years. Rotating torticollis occurred more often than latero-retrocollis and antero-retrocollis. A family history of IST was seen in 3.1% of the total sample. 34% of the patients had additional dystonic symptoms. Most frequently, these affected the upper extremities (13%), less often the legs. 19.1% of the patients had experienced a period of complete remission. The General Symptom Index of the SCL 90-R in 27% of the patients ranged above the double standard deviation of the normal controls, indicating a clinically significant psychopathology.

Evidence for DYT7 being a common cause of cervical dystonia (torticollis) in Central Europe

Adult-onset focal idiopathic torsion dystonias (AFITD), such as torticollis, have a prevalence similar to that of multiple sclerosis and usually seem sporadic. Only recently has one large AFITD pedigree "K" with autosomal dominant inheritance and reduced penetrance from Northwest Germany provided the opportunity to identify a gene locus on chromosome 18p. We have now tested the relevance of this DYT7 gene locus in a collective of 18 nuclear AFITD families from Central Europe who were genotyped with chromosome 18p microsatellites. In three families, the affected relatives did not share a chromosome 18p haplotype, suggesting locus heterogeneity in AFITD. In the remaining 15 families, significant allelic association was observed for marker D18S1098. This result suggests that DYT7 is a common cause for AFITD at least in Central Europe, that many patients are descended from a common ancestor, and that the DYT7 gene is mapped in a 4.4 centimorgan subregion of chromosome 18p.

Congenital muscular torticollis: is heredity a possible factor in a family with five torticollis patients in three generations?

Although the clinical features of congenital muscular torticollis are well known, the cause of this disorder still remains hypothetical. The role of heredity is not well established, because there have been only a few studies on it. We presented a family in which five members suffer from CMT in three generations, two of whom were operated on. According to the pattern in the pedigree, probably an autosomal dominant condition could be considered.

Exclusion of the DYT1 locus in familial torticollis

Clinical-genetic studies of idiopathic torsion dystonia (ITD) indicate that the DYT1 gene on chromosome 9q34 is responsible for most childhood limb-onset disease. The genetic basis of adult-onset ITD is less well studied. In most multiplex adult-onset ITD families, dystonia is limited to the cervical, cranial, or brachial muscles; in a few rare families, dystonia also involves the legs and trunk. Previous linkage studies have excluded the DYT1 locus in these atypical families. We studied two large non-Jewish families with adult-onset ITD limited to the cervical and brachial muscles and excluded the DYT1-containing region. This study further restricts the role of DYT1 to childhood limb-onset ITD and suggests that other genes are responsible for focal adult-onset ITD.

Cervical dystonia (spasmodic torticollis). Some aspects of the natural history

A literature survey was done to outline the natural history of cervical dystonia (spasmodic torticollis). The disorder starts between 25 and 60 years with head deviation or neck pain. Sometimes, there are personal or familial extrapyramidal antecedents (tremor, dystonia). The role of a preceding neck or head trauma is unsettled. Often, there is a delay in diagnosis of more than one year. The majority of patients show steady progression of their focal dystonia and reach maximal disability after five years; neck pain occurring in 70-80% contributes significantly to disability. In a third of the cases, there is a progression to segmental dystonia. In about 20% of the patients a spontaneous, sustained or unsustained remission of the torticollis can be observed; this occurs particularly in cases with earlier age of onset. Cervical dystonia has important psychosocial consequences: many patients have to withdraw from their job or from social activities.

A genetic study of idiopathic focal dystonias

The inheritance of focal dystonias was investigated in 43 families containing 43 index cases with torticollis (n = 21), blepharospasm (n = 18) and writer's cramp (n = 4). They generated a potential population of 235 first-degree relatives, and 168 out of 179 living first-degree relatives were examined. Ten relatives with dystonia were identified in ten families. Another two parents from two of the same group of ten families were affected according to the family history. The majority of the secondary cases (six patients, five siblings, and one child) were not aware of any dystonia. The tendency for affected relatives to have the same type of dystonia as index patients was observed only for torticollis. Overall, 23% of index patients had relatives with dystonia. Segregation analysis suggested the presence of an autosomal dominant gene or genes with reduced penetrance underlying focal dystonia.

A family with hereditary juvenile dystonia-parkinsonism

We report a family with autosomal dominant type hereditary juvenile dystonia-parkinsonism in which eight members in three generations exhibited parkinsonism, sleep benefit, marked efficacy of levodopa, wearing-off phenomenon, and dopa-induced choreic dyskinesia. However, one case showed mainly dystonic movement that worsened after administration of levodopa. The patients in this family showed neck dystonia, such as torticollis and retrocollis, in addition to foot dystonia and other dystonic movement, such as frequently lifting the thigh. From the family history and clinical findings, these patients are considered to have a specific form of hereditary dystonia-parkinsonism.

Respiratory chain and mitochondrial deoxyribonucleic acid in blood cells from patients with focal and generalized dystonia

An increasing number of neurodegenerative diseases seem to be associated with or even due to disturbances of cerebral energy metabolism. One generally accepted example is complex I deficiency in substantia nigra from patients with Parkinson's disease. Reports on a complex I defect in platelets from patients with dystonia led us to check for disturbances of the respiratory chain or of the mitochondrial genome in isolated mitochondria from patients with focal or generalized dystonia. We could not confirm the idea of mitochondrial disturbance in platelets from patients with dystonia because we did not find abnormal enzyme activities or any deletions of the mitochondrial genome. Thus, we do not think that blood cells such as platelets can serve as markers for neurodegenerative disorders such as dystonia.

Benign paroxysmal torticollis in infancy

Benign paroxysmal torticollis in infancy is characterized by periods of torticollic posturing of the head. The onset of the episodes usually occurs during the first month of life and may recur at varying intervals until the age of 1-5 years. This appears to be a self-limited disorder. The follow-up of 7 patients with benign paroxysmal torticollis is presented.

Genetic contribution to idiopathic adult-onset blepharospasm and cranial-cervical dystonia

A family study in 29 patients with idiopathic adult-onset blepharospasm (n = 16) and cranial-cervical dystonia (n = 13) was undertaken by examining 189 first-degree relatives. Six relatives with dystonia were identified in 6 families. A further 3 affected relatives, now deceased, were from 2 other families. All the secondary cases were parents or siblings. There was a tendency for affected relatives to have the same type of dystonia of index patients. To assess the significance of secondary cases we compare the incidence of affected siblings between probands and their spouses. Dystonia was found in 5 out of 120 proband siblings whereas none of the 142 spouse siblings was affected (p < 0.05). Segregation analysis suggested an autosomal-dominant transmission and reduced penetrance or, alternatively, polygenic inheritance.