Quality of sleep in primary focal dystonia: a case–control study

Background: Sleep disturbances are common in patients with movement disorders. Evaluating quality of sleep is of primary importance because of the effect that nocturnal and daytime sleep abnormalities exert on general health status. However, quality of sleep has never been addressed in detail in patients with dystonia. The aim of this case–control study was to analyse quality of sleep in patients with the two most common forms of primary focal dystonia, blepharospasm (BSP) and cervical dystonia (CD). Methods: We evaluated quality of sleep (Pittsburgh Sleep Quality Index, PSQI) and excessive daytime sleepiness (Epworth Sleepiness Scale, ESS) in 98 patients with focal adult‐onset dystonia (52 with BSP; 46 with CD) and in a group of 56 age‐and gender‐matched healthy subjects. The Beck Depression Inventory (BDI) was used for the evaluation of depressive symptomatology. Results: Quality of sleep was impaired (significantly higher PSQI scores) in both groups of patients. However, differences in PSQI scores between patients with CD and control subjects were partly confounded by BDI scores, whereas differences in PSQI scores between patients with BSP and control subjects were not influenced by BDI. Excessive daytime sleepiness was not significantly more frequent than in control subjects in either patients with BSP or patients with CD. Conclusions: This study suggests that the assessment and treatment of insomnia‐related complaints should be considered in global management plans of patients with focal dystonia, particularly in those affected by BSP.     

DYT6 dystonia: Mutation screening,phenotype, and response to deep brain stimulation

Mutations in THAP1, a gene encoding a nuclear pro‐apoptotic protein, have been associated with DYT6 dystonia. First reports on the phenotype of DYT6 dystonia show an early onset dystonia with predominant cranio‐cervical and laryngeal involvement. Here we assessed the frequency and phenotype of THAP1 mutation carriers in a large Dutch cohort of adult‐onset (≥26 years) dystonia (n = 388) and early‐onset dystonia (n = 67) patients. We describe the phenotype of DYT6 dystonia patients and their response on GPi DBS. Overall, 3 nonsynonymous heterozygous mutations were detected in the early‐onset group (4.5%). Two DYT6 families were identified, showing a heterozygous phenotype. All patients had segmental or generalized dystonia, often associated with profound oromandibular and laryngeal involvement. No nonsynonymous mutations were found in patients with adult‐onset focal dystonia. Rare synonymous variants were identified in conserved regions of THAP1, two in the adult‐onset cervical dystonia group and one in the control group. Four DYT6 dystonia patients were treated with GPi DBS with moderate to good response on motor function but marginal benefit on speech. © 2010 Movement Disorder Society     

Increased basal-ganglia activation performing a non-dystonia-related task in focal dystonia

Background and purpose:  We tried to determine whether altered sensorimotor cortex and basal-ganglia activation in blepharospasm (BSP) and cervical dystonia (CD) are restricted to areas directly responsible for the innervation of dystonic muscles, or whether impairment in focal dystonia reaches beyond these direct associations supporting a more global disturbance of sensory and motor control in focal dystonia.
Methods:  Twenty patients with focal dystonia (11 BSP, 9 CD) and 14 healthy controls were investigated with functional magnetic resonance imaging (fMRI) performing a simple grip force forearm contraction task.
Results:  BSP and CD patients and healthy controls showed similar activation in the pre-motor, primary motor and primary sensory cortex, whilst basal-ganglia activation was increased in BSP and CD with related activation patterns compared with controls. BSP patients had increased activation in the thalamus, caudate nucleus, putamen and lateral globus pallidus, whilst CD patients showed increased activation in the caudate nucleus, putamen and thalamus. No differences in applied grip force were detected between groups.
Conclusions:  In both, BSP and CD, increased basal-ganglia activation could be demonstrated in a task not primarily involving the dystonic musculature affected by these disorders. Comparable activation changes may also indicate a common pathway in the pathophysiology in BSP and CD.     

Assessment of D216H DYT1 polymorphism in a Chinese primary dystonia patient cohort

Background: The D216H single‐nucleotide polymorphism (SNP) (rs1801968) in DYT1 exon 4 has been suggested to be a genetic modifier in primary dystonia. Methods: To further explore this question, we assessed rs1801968 variations in a cohort of 210 Chinese patients with primary dystonia devoid of DYT1 mutations. Results: We found that focal dystonia, specifically cervical dystonia, was the most common form of dystonia, with 8.1% of all the patients having a positive family history of dystonia. No association of the D216H SNP with primary dystonia was identified. In a subsequent subgroup analysis, the 216H allele was found to occur more frequently in patients with writer’s cramp, but no correlation was found between the allele and other forms of dystonia or age of onset. Conclusions: Our findings do not confirm that the allele contributes to the risk of D216H SNP primary dystonia.     

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.     

Lower limb involvement in adult‐onset primary dystonia: frequency and clinical features

Background and purpose: Despite the growing number of reports describing adult‐onset primary lower limb dystonia (LLD) this entity has never been systematically evaluated in the general population of patients with primary adult‐onset dystonia. Methods: From outpatients with adult‐onset primary dystonia attending nine Italian University centres for movement disorders we consecutively recruited 579 patients to undergo a standardized clinical evaluation. Results: Of the 579 patients assessed, 11 (1.9%) (8 women, 3 men) had LLD, either alone (n = 4, 0.7%) or as part of a segmental/multifocal dystonia (n = 7, 1.2%). The age at onset of LLD (47.9 ± 17 years) was significantly lower than the age at onset of cranial dystonias (57.9 ± 10.7 years for blepharospasm, and 58.9 ± 11.8 years for oromandibular dystonia) but similar to that of all the other adult‐onset primary dystonias. The lower limb was either the site of dystonia onset (36.4%) or the site of dystonia spread (63.6%). In patients in whom LLD was a site of spread, dystonia seemed to spread following a somatotopic distribution. Only one patient reported a recent trauma involving the lower limb whereas 36.4% of the patients reported pain at the site of LLD. Only 64% of our patients needed treatment for LLD, and similarly to previously reported cases, the most frequently tried treatments was botulinum toxin and trihexyphenidyl. Conclusion: The lower limb is an uncommon but possible topographical site of dystonia in adulthood that should be kept in consideration during clinical evaluation.     

Psychiatric disorders in adult‐onset focal dystonia: A case‐control study

In a single‐center, case–control study, we investigated the frequency and types of psychiatric disturbances in 89 consecutive patients with various primary focal dystonias (34 had cervical dystonia (CD), 28 blepharospasm (BPS), 16 laryngeal dystonia (LD), and 11 arm dystonia), 62 healthy control subjects and as controls for BPS, 26 patients with hemifacial spasm (HFS). Patients and controls underwent a full psychiatric evaluation. Diagnosis was based on the structured clinical interview for DSM‐IV, obsessive‐compulsive disorder (OCD) was assessed with the Yale‐Brown Obsessive‐Compulsive scale, anxiety with the Hamilton Rating Scale for Anxiety, the severity of depression with the Beck Depression Inventory. Of the 89 patients with focal dystonias studied, 51 patients (57.3%) had a diagnosis of psychiatric disorders compared with only 15 of 62 healthy subjects (24.1%) and 9 of the patients with HFS (34.6%). Depressive disorders were more frequent in the CD and BPS groups than in healthy controls, whereas the frequency of anxiety disorders, OCDs or adjustment disorders approached that of healthy subjects. No difference was found in the frequency of any specific psychiatric disorder in patients with LD and arm dystonia and healthy controls. In 35 of 51 patients who had psychiatric disorders, these started before and in 16 patients after the onset of dystonia. No differences were found in age, dystonia severity, and duration of botulinum toxin treatment between patients with and without psychiatric disturbances. The most common psychiatric features in patients with CD and BPS are depressive disorders. © 2010 Movement Disorder Society     

Arm swing is reduced in idiopathic cervical dystonia

Arm swing is typically reduced in people with Parkinsonism, and also in those with pyramidal dysfunction. We have previously observed that patients with focal arm dystonia can also have reduced arm swing. However, arm swing has not been formally studied in adult‐onset primary cervical dystonia (AOPCD). We assessed arm swing in 100 consecutive patients diagnosed with AOPCD and 50 healthy controls. Reduced arm swing was more common in patients with AOPCD compared with healthy controls (55% vs. 6%, P < 0.001) and was more often abnormal on the same side as the direction of head turning (P < 0.05). Women with AOPCD had more often reduced arm swing compared with men (P = 0.002). Reduced arm swing is common in AOPCD. It may indicate segmental spread of subtle motor dysfunction or it may be a feature of dystonia per se. © 2008 Movement Disorder Society     

The TOR1A polymorphism rs1182 and the risk of spread in primary blepharospasm

We studied the influence of the rs1182 polymorphism of the TOR1A gene on the risk of dystonia spread in two representative cohorts of patients presenting with primary blepharospasm (BSP), one from Italy and the other from the United States of America. The relationship between rs1182 polymorphism and spread was estimated by Kaplan‐Meier survival curves and Cox proportional hazard regression models adjusted by age and sex, age of BSP onset. In both series, patients carrying the T allele (G/T or T/T) in the rs1182 polymorphism were more likely to have dystonia spread as compared with the homozygous carriers of the common G allele. The comparable findings obtained in two independent cohorts support a genetic contribution to BSP spread. © 2009 Movement Disorder Society     

Auditory startle reaction in primary blepharospasm.

Primary dystonia is associated with abnormal brainstem function, as shown by abnormalities of the blink reflex in blepharospasm (BSP) and of the auditory startle reaction in cervical dystonia. We examined the auditory startle reaction--a brainstem reflex elicited by an unexpected loud stimulus--in patients with primary BSP to expand knowledge on brainstem pathophysiology in primary focal dystonia. Thirteen patients with primary BSP were included and 13 age- and sex-matched healthy volunteers served as controls. Auditory startle responses (ASRs) were elicited by binaural high-intensity auditory stimuli, and reflex electromyographic activity was recorded simultaneously with surface electrodes bilaterally from masseter, orbicularis oculi, sternocleidomastoid, and biceps brachii muscles. Patients with BSP showed higher ASR probabilities (masseter, sternocleidomastoid, biceps brachii), shorter ASR onset latencies (masseter, orbicularis oculi, sternocleidomastoid), and larger ASR area-under-the-curve (masseter, sternocleidomastoid) as compared with normal controls. Habituation of ASRs did not differ significantly between patients and controls. These results corroborate previous findings of increased brainstem excitability in primary BSP but point to a different pattern of brainstem dysfunction compared to cervical dystonia, indicating that different pathophysiological mechanisms are involved in the two types of focal dystonia.     

A family study on primary blepharospasm

BACKGROUND: Previous family studies provided evidence that blepharospasm (BSP) can aggregate in families but did not give accurate and reliable information on the characteristics and degree of familial clustering. AIM: To evaluate the proportion of familial and non-familial BSP cases, the clinical expression of dystonia within families, the inheritance pattern, and the extent of penetrance. METHODS: The study was based on the examination of the first degree relatives of 56 probands with primary BSP. RESULTS: The 56 families produced a potential population of 436 first degree relatives of whom 296 were alive and 233 were examined. The proportion of index patients with at least one first degree relative affected by BSP, or adult onset dystonia other than BSP, was 27%. There was a remarkable degree of phenotypic variability of dystonia within families. Similar segregation ratios were calculated for probands' siblings and children. Under the assumption of autosomal dominant transmission of adult onset dystonia, penetrance was about 20%. CONCLUSIONS: The findings of this family study are relevant for accurately counselling the families of patients with BSP and may help identify the most appropriate study design to explore genetic susceptibility in BSP.     

Impaired sleep quality and restless legs syndrome in idiopathic focal dystonia: a controlled study

While sleep disorders are common in Parkinson’s disease and other basal ganglia disorders, information on sleep disturbances in dystonia is limited to generalized forms or Segawa disease. Although many patients with idiopathic cervical dystonia (CD) and blepharospasm (BL) report poor sleep, there are no data on frequency or interactions with well known symptoms like depression and pain. Standardized interviews and assessment instruments, clinical examinations, and self rating forms were applied in 221 patients with CD and BL, and in 93 neurologically healthy controls. Impaired sleep quality was found in 44% of CD patients, 46% of BL patients, and 20% of controls. In dystonia, it was associated with symptoms of depression (frequency of 26%; p < 0.001) and restless legs syndrome (RLS) (frequency of 19%; p < 0.01). Bruxism (in CD; p < 0.05), and female sex (in BL; p < 0.001) were identified as further risk factors, but not severity of dystonic symptoms. Excessive daytime sleepiness was rare in CD and BL (6%). With a frequency of 45%, impairment of sleep quality is common in focal dystonia and associated with symptoms of depression, bruxism, and RLS. Results in CD and BL patients are similar, pointing to an intrinsic mechanism of sleep disturbances rather than a direct effect of dystonic muscle activity. Further studies on sleep in focal dystonia, including polysomnographic recordings, are warranted.     

The phenotypic spectrum of DYT24 due to ANO3 mutations

Genes causing primary dystonia are rare. Recently, pathogenic mutations in the anoctamin 3 gene (ANO3) have been identified to cause autosomal dominant craniocervical dystonia and have been assigned to the dystonia locus dystonia‐24 (DYT24). Here, we expand on the phenotypic spectrum of DYT24 and provide demonstrative videos. Moreover, tremor recordings were performed, and back‐averaged electroencephalography, sensory evoked potentials, and C‐reflex studies were carried out in two individuals who carried two different mutations in ANO3. Ten patients from three families are described. The age at onset ranged from early childhood to the forties. Cervical dystonia was the most common site of onset followed by laryngeal dystonia. The characteristic feature in all affected individuals was the presence of tremor, which contrasts DYT24 from the typical DYT6 phenotype. Tremor was the sole initial manifestation in some individuals with ANO3 mutations, leading to misdiagnosis as essential tremor. Electrophysiology in two patients with two different mutations showed co‐contraction of antagonist muscles, confirming dystonia, and a 6‐Hz arm tremor at rest, which increased in amplitude during action. In one of the studied patients, clinically superimposed myoclonus was observed. The duration of the myoclonus was in the range of 250 msec at about 3 Hz, which is more consistent with subcortical myoclonus. In summary, ANO3 causes a varied phenotype of young‐onset or adult‐onset craniocervical dystonia with tremor and/or myoclonic jerks. Patients with familial cervical dystonia who also have myoclonus‐dystonia as well as patients with prominent tremor and mild dystonia should be tested for ANO3 mutations. © 2014 The Authors. Movement Disorders published by International Parkinson and Movement Disorder Society     

Mutation screening of GNAL gene in patients with primary dystonia from Northeast China

BackgroundMutations in GNAL have recently been identified as responsible for primary dystonia, however, GNAL mutations in Chinese patients with primary dystonia are not well characterized.Patients and methodsFifty-nine unrelated patients with cervical onset or cervical involved primary dystonia and 120 neurologically normal controls from Northeast China without mutations of TOR1A and THAP1 were all screened for mutation of GNAL gene.ResultsOne subject with adult-onset generalized dystonia was found have a novel nonsense GNAL mutation (c.284C>T, p.Ser95X). Another subject with adult-onset cervical dystonia was found harbor the c.932-7T>G tentative splice site mutation. Although another seventeen sequence variants were identified in both patients and controls, no disease association was found among these sequence variants.ConclusionsMutations in GNAL gene can cause adult-onset primary dystonia in Chinese patients, and the mutation frequency is 3.4% in cervical onset or cervical involved primary dystonia. This paper identifies the first case of GNAL dystonia in the Chinese population.     

Association of the Val66Met polymorphism of the BDNF gene with primary cranial–cervical dystonia patients from South-west China

BackgroundThe etiology of primary dystonia remains unclear. Recent genetic studies suggest that the Val66Met polymorphism of the BDNF gene is a genetic modifier in cranial–cervical dystonia in Caucasians. However, the finding is not consistent.Patients and MethodsA total of 193 patients with primary cranial–cervical dystonia from the Department of Neurology, West China Hospital of Sichuan University was included. From the same region, 216 healthy individuals were recruited as a control group. The Val66Met SNP was identified by polymerase chain reaction-restriction fragment length polymorphism.ResultsIn the present study, cervical dystonia (59.59%) was the most common type of primary cranial–cervical dystonia. No significant difference was found in the genotype and minor allele frequencies between all patients and controls, between cervical dystonia patients and controls, and between craniocervical dystonia patients and controls. However, significant differences were found in the genotype and minor allele frequencies of Val66Met SNP between blepharospasm (BSP) patients and controls (P = 0.0080 and P = 0.0042, respectively), and between BSP patients and patients with craniocervical derived from BSP (P = 0.0010 and P = 0.0002, respectively).ConclusionMinor allele “A” of BDNF Val66Met SNP may increase the risk for developing BSP and may be a protective factor for preventing BSP progressing to craniocervical dystonia. More association studies involving a larger number of participants are needed to confirm the present findings.     

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.     

Cervical dystonia: clinical and therapeutic features in 85 patients

We studied patients with cervical dystonia (CD) to determine clinical features and response to botulinum toxin A (BoNT/A). Patients were submitted to clinical, laboratory and neuroimaging evaluation. BoNT/A was injected locally in 81 patients using electromyographic guidance. Four patients who had had previous treatment were considered to be in remission. The average ages at onset of focal dystonia and segmental dystonia were greater than for generalized dystonia (p<0.0003). The severity of the abnormal head-neck movements were more severe among the patients with generalized dystonia (p<0.001). Pain in the cervical area was noted in 59 patients. It was not possible to determine the etiology of the disease in 62.3% of patients. Tardive dystonia was the most common secondary etiology. A major improvement in the motor symptoms of CD and pain was observed in patients following treatment with BoNT/A. The tardive dystonia subgroup did not respond to the treatment. Dysphagia was observed in 2.35% of the patients.     

The impact of blepharospasm and cervical dystonia on health-related quality of life and depression

The aim of the study was to evaluate and compare health-related quality of life (HR-QoL) and depression in essential blepharospasm (BSP) and idiopathic cervical dystonia (CD), to identify the clinical and demographic factors associated with poor HR-QoL in both disorders and to analyse the effect of Botulinum Toxin A (BtxA) therapy. Two hundred-twenty consecutive patients with BSP (N = 89, 62 % women, mean age 64 years, mean disease duration 7 years) and CD (N = 131, 64 % women, mean age 53 years, mean disease duration 8 years) recruited from routine referrals to eight Austrian dystonia clinics were included. HR-QoL was measured by the Short Form 36 (SF-36) and depression by the Beck Depression Inventory (BDI). At baseline, patients with CD and BSP scored significantly worse in all eight SF-36 domains compared with an age-matched community sample. In addition, 47 % of patients with CD and 37 % of those with BSP were depressed. Women with BSP scored significantly lower in all SF-36 domains and were more depressed than male patients. In contrast, there was no significant effect of gender on HR-QoL and depression in CD. Neck pain had a significant impact on all SF-36 domains and represented the main determinant of depression in CD. Although BtxA therapy resulted in a significant improvement of clinical symptoms in BSP and CD, HR-QoL did not improve in BSP and only two of the eight SF-36 domains improved significantly in patients with CD. The present study for the first time demonstrated that BSP has a substantial impact on health status emphasizing the need for psychological support with interventions aimed at treating depression in these patients. Our results provide further evidence for the profound impact of CD on HR-QoL and indicate the importance of an adequate management of neck pain in addition to reducing the severity of dystonia in CD. The mismatch between objective BtxA derived improvement of dystonia and lack of change of HR-QoL as determined by the SF-36 illustrates the need for optimized disease specific quality of life rating scales in patients with craniocervical dystonia.     

EFNS guidelines on diagnosis and treatment of primary dystonias

Objectives: To provide a revised version of earlier guidelines published in 2006. Background: Primary dystonias are chronic and often disabling conditions with a widespread spectrum mainly in young people. Diagnosis: Primary dystonias are classified as pure dystonia, dystonia plus or paroxysmal dystonia syndromes. Assessment should be performed using a validated rating scale for dystonia. Genetic testing may be performed after establishing the clinical diagnosis. DYT1 testing is recommended for patients with primary dystonia with limb onset before age 30, and in those with an affected relative with early‐onset dystonia. DYT6 testing is recommended in early‐onset or familial cases with cranio‐cervical dystonia or after exclusion of DYT1. Individuals with early‐onset myoclonus should be tested for mutations in the DYT11 gene. If direct sequencing of the DYT11 gene is negative, additional gene dosage is required to improve the proportion of mutations detected. A levodopa trial is warranted in every patient with early‐onset primary dystonia without an alternative diagnosis. In patients with idiopathic dystonia, neurophysiological tests can help with describing the pathophysiological mechanisms underlying the disorder. Treatment: Botulinum toxin (BoNT) type A is the first‐line treatment for primary cranial (excluding oromandibular) or cervical dystonia; it is also effective on writing dystonia. BoNT/B is not inferior to BoNT/A in cervical dystonia. Pallidal deep brain stimulation (DBS) is considered a good option, particularly for primary generalized or cervical dystonia, after medication or BoNT have failed. DBS is less effective in secondary dystonia. This treatment requires a specialized expertise and a multidisciplinary team.