Genetic spectrum and clinical features in a cohort of Chinese patients with isolated dystonia.

Dystonia is a genetically and phenotypically heterogeneous disorder that occurs in isolation (isolated dystonia) or in combination with other movement disorders. To determine the genetic spectrum in isolated dystonia, we enrolled 88 patients with isolated dystonia for whole-exome sequencing (WES). Seventeen mutations, including nine novel ones, were identified in 19 of the 88 patients, providing a 21.59% positive molecular diagnostic rate. Eleven distinct genes were involved, of which TOR1A and THAP1 accounted for 47.37% (9/19) of the positive cases. A novel missense variant, p.S225R in TOR1A, was found in a patient with adolescence-onset generalized dystonia. Cellular experiments revealed that p.S255R results in the abnormal aggregation of Torsin-1A encoding by TOR1A. In addition, we reviewed the clinical and genetic features of the isolated dystonia patients carrying TOR1A, THAP1, ANO3, and GNAL mutations in the Chinese population. Our results expand the genetic spectrum and clinical profiles of patients with isolated dystonia and demonstrate WES as an effective strategy for the molecular diagnosis of isolated dystonia.

Pivotal role of obliquus capitis inferior in torticaput revealed by single-photon emission computed tomography.

Torticaput is the most common primary form of cervical dystonia (CD). Obliquus capitis inferior (OCI) plays a major role in ipsilateral rotation of the head. The present study aimed to use single-photon emission computed tomography (SPECT/CT) to determine the involvement of OCI in torticaput and in torticaput associated with no-no tremor. We retrospectively analyzed the SPECT/CT images of 60 patients with torticaput as the main abnormal posture and ranked the affected muscles. The affected muscles in patients with no-no tremor were also ranked. The correlation between the radioactivity of OCI and the thickness of OCI measured by ultrasonography was analyzed. The agreement between SPECT/CT and electromyography in detecting OCI was also analyzed. After sternocleidomastoid muscle (81.7%), OCI was the second most affected muscle (70.0%) in torticaput, followed by splenius capitis (63.3%). In 23 patients with no-no tremor, OCI (78.3%) and sternocleidomastoid muscle (78.3%) were the most frequently affected muscles, followed by splenius capitis (69.6%). Furthermore, bilateral muscle involvement was commonly seen in patients with no-no tremor, especially for OCI (12/23) and sternocleidomastoid muscle (11/23). A positive correlation was found between the radioactivity and thickness of OCI (r = 0.330, P < 0.001). The total agreement rate between SPECT/CT and electromyography in the diagnosis of OCI excitement was 94.0%, with kappa value = 0.866 (P < 0.001). OCI plays a critical role in torticaput and no-no tremor. SPECT/CT could be a practical tool to help clinicians detect abnormally excited OCI.

Brain connectivity abnormalities and treatment-induced restorations in patients with cervical dystonia.

BACKGROUND: The relationship between brain abnormalities and phenotypic characteristics in cervical dystonia (CD) patients has not been fully established, and little is known about the neuroplastic changes induced by botulinum toxin type A (BoNT-A) treatment. METHODS: Ninety-two CD patients presenting with rotational torticollis and 45 healthy controls from our database were retrospectively screened. After clinical assessment, the 92 patients underwent baseline magnetic resonance imaging (MRI) followed by a single-dose injection of BoNT-A. Four weeks later, 76 out of the 92 patients were re-evaluated with the Tsui scale for dystonia severity, and 33 out of 76 patients completed post-treatment MRI scanning. Data-driven global brain connectivity and regional homogeneity in tandem with seed-based connectivity analyses were used to examine the functional abnormalities in CD and longitudinal circuit alterations that scaled with clinical response to BoNT-A. Multiple regression models were employed for the prediction analysis of treatment efficacy. RESULTS: Cervical dystonia patients exhibited elevated baseline connectivity of the right postcentral gyrus with the left dorsomedial prefrontal cortex and right caudate nucleus, which was associated with their symptom severity. BoNT-A reduced excessive functional connectivity between the sensorimotor cortex and right superior frontal gyrus, which was significantly correlated with changes in Tsui score. Moreover, pre-treatment regional homogeneity of the left middle frontal gyrus was linearly related to varied response to treatment. CONCLUSIONS: Our findings unravel dissociable connectivity of the sensorimotor cortex underlying the pathology of CD and central effects of BoNT-A therapy. Furthermore, baseline regional homogeneity with the left middle frontal gyrus may represent a potential evidence-based marker of patient stratification for BoNT-A therapy in CD.

Facial asymmetry in patients with hemifacial spasm before and after botulinum toxin A treatment.

Botulinum toxin A (BoNT-A) injection is one of the most widely used methods for hemifacial spasm (HFS) with high efficacy in controlling spasm. However, it is still unknown if esthetic symmetry could be desired as the spasm was controlled by BoNT-A therapy. The purpose of this study is to clarify the facial asymmetric characteristics of HFS patients and if the asymmetry could be amended by BoNT-A injection in the abnormal side. In this prospective analysis, HFS patients were enrolled, who received hemifacial BoNT-A injection and completed follow-up at weeks 2-4. Self-reported improvement and negative influence of facial asymmetry in social life were documented. Facial asymmetry was assessed by the Sunnybrook facial grading system (SFGS) and a new scale created by our clinic-the Symmetry Scale for Hemifacial Spasm (SSHS). Thirty-eight patients were eligible for analysis. Among them, 34 patients (89 %) had marked improvement in spasm after BoNT-A injection. After BoNT-A injection, SFGS showed an improvement of synkinesis (p = 0.01). And SSHS showed an amelioration of resting symmetry in lower face after treatment (p < 0.05). However, SFGS showed a deterioration of voluntary movement in lower face after treatment (p < 0.01). In addition, a deterioration of voluntary movement in upper face and lower face was found in SSHS after treatment (p < 0.01). SSHS composite score showed a deterioration after BoNT-A injection (p = 0.01). In conclusions, BoNT-A was effective in controlling spasm and synkinesis of HFS and improved resting symmetry in lower face, but facial symmetry of voluntary movement deteriorated after hemifacial BoNT-A injection.

Polyclonal neural cell adhesion molecule antibody prolongs the effective duration time of botulinum toxin in decreasing muscle strength.

This study aimed to investigate if the effective duration time of botulinum toxin A (Btx-A) could be prolonged by polyclonal neural cell adhesion molecule antibody (P-NCAM-Ab). 175 male SD rats were randomly divided into three major groups: control group (n = 25), Btx-A group (n = 25), and P-NCAM-Ab groups. P-NCAM-Ab groups were composed of five sub-groups, with 25 rats each in the dose-response study. Muscle strength of rat lower limbs was determined using a survey system. The expressions of muscle-specific receptor tyrosine kinase (MuSK) and neural cell adhesion molecule (NCAM) were determined by real-time polymerase chain reactions (RT-PCR) and western blotting (WB). The muscle strength was significantly decreased by Btx-A in Btx-A/P-NCAM-Ab groups compared with normal control group. Besides, the muscle strength of P-NCAM-Ab group was significantly decreased compared with the Btx-A group. The recovery time of muscle strength in P-NCAM-Ab group was significantly longer compared with Btx-A group. RT-PCR and WB assay showed that PNCAM-Ab delayed the increase of MuSK and NCAM after Btx-A injection. P-NCAM-Ab prolongs the effective duration time of Btx-A in decreasing muscle strength, which could provide a novel enhancement in clinical application.

Treatment of Raynaud's phenomenon with botulinum toxin type A.

Raynaud's phenomenon (RP), an episodic vasospasm of the peripheral arteries, is quite common in general population. The current therapies of RP are limited by efficacy, side effects, and polypharmacy concerns. Botulinum toxin type A (BTX-A) local injections have been reported for the treatment of RP, but the injection sites, concentration and dose of BTX-A were different from each other in previous trials. In addition, so far, there have been no reports concerning local injection of BTX-A in Asian RP patients. Ten patients with RP in China were included in this retrospective study. All the patients had intractable pain and were non-responsive to conservative and/or medical therapy. A patterned BTX-A injection was performed in RP patients, guided by ultrasonography. BTX-A was injected as 20 u/ml devoid of preservatives. Outcomes were measured by ultrasonography, surface temperature, visual analog scale (VAS) for clinical symptoms (pain, numbness, stiffness and swelling), and changes in ulcers or gangrene. Overall, a great improvement in artery flow velocity (P < 0.01), surface temperature (P < 0.01), ulcer and VAS for clinical symptoms, was observed after BTX-A local injection. Complications were very rarely found, and no patients complained of hand weakness and bruise. BTX-A patterned injection guided by ultrasonography might be a useful therapeutic tool in the management of intractable RP.

Retroform Cervical Dystonia: Target Muscle Selection and Efficacy of Botulinum Toxin Injection.

Introduction: Retroform cervical dystonia (RCD), which includes retrocaput and retrocollis, is a rare form of cervical dystonia. Few reports have been published on RCD. The present study aimed to characterize the target muscles involved in RCD and the efficacy of botulinum toxin type A (BTX-A) injection. Methods: Patients with consecutive cervical dystonia with RCD as the most problematic feature were retrospectively analyzed over a 10-year period. Target muscles were screened and confirmed based on clinical evaluation, single-photon emission computed tomography, and electromyography. In addition, efficacy and adverse events following BTX-A injection in patients with RCD were evaluated. Results: A total of 34 patients with RCD were included, 18 of whom presented with retrocaput and 16 with retrocollis. The most frequently injected muscles in RCD were splenius capitis (SPCa, 97.1%) and semispinalis capitis (SSCa, 97.1%), followed by levator scapulae (LS, 50.0%), rectus capitis posterior major (RCPM, 47.1%), trapezius (TPZ, 41.2%), and sternocleidomastoid muscle (SCM, 41.2%). Besides cervical muscles, the erector spinae was also injected in 17.6% of patients. Most muscles were predominantly bilaterally injected. The injection schemes of retrocaput and retrocollis were similar, possibly because in patients with retrocollis, retrocaput was often combined. BTX-A injection achieved a satisfactory therapeutic effect in RCD, with an average symptom relief rate of 69.0 ± 16.7%. Mild dysphagia (17.6%) and posterior cervical muscle weakness (17.6%) were the most common adverse events. Conclusion: SPCa, SSCa, LS, RCPM, LS, and SCM were commonly and often bilaterally injected in RCD. Patients with RCD could achieve satisfactory symptom relief after BTX-A injection.

The expanding clinical and genetic spectrum of ANO3 dystonia.

INTRODUCTION: Dystonia is a movement disorder with high clinical and genetic heterogeneity. Mutations in Anoctamin-3 (ANO3) gene have been reported to cause dystonia 24 (DYT24). This study aims to clarify the spectrum and frequency of ANO3 rare variants in Chinese populations with primary dystonia and understand the clinical and genetic features of DYT24. METHODS: Sanger sequencing was used to screen all exons and exon-intron boundaries of ANO3 for rare variants in 115 primary dystonia patients. The clinical manifestations of patients with ANO3 variants in our study and previously reported literatures were further characterized. RESULTS: Four distinct variants of ANO3 (c.1127A > G, c.1235 T > A, c.1531-3T > C, c.-11G > T) were identified in six unrelated individuals. Combined with our work and literature review, a total of 35 different rare variants distributed in ANO3 were identified in 62 dystonia patients. The predominant phenotype is cranio-cervical dystonia and more than half of patients develop head/limb tremor. Most of patients presented with isolated dystonia whereas few of them showed combined dystonia. The age of onset ranged from 1 to 69 years and peaked in late adulthood, while for generalized dystonia it peaked in a young age. Half of patients with generalized dystonia experienced deep brain stimulation (DBS). And all of them showed improvement of dystonia by DBS. CONCLUSIONS: This study confirms a relatively high frequency of rare ANO3 variants in Chinese patients with dystonia and indicates that the late adulthood-onset, cranio-cervical dystonia seems to be an important feature of the ANO3 phenotype. Further functional studies are warranted to understand the role of ANO3 in dystonia.

Efficacy of single-photon emission computed tomography aided botulinum toxin injection in cervical dystonia: A double-blind, randomized study.

BACKGROUND: Although single-photon emission computed tomography (SPECT/CT) could help to predetermine dystonic muscles in patients with cervical dystonia (CD), its efficacy in aiding botulinum toxin injection is undetermined. This randomized, double-blinded study aimed to assess the efficacy of SPECT/CT aided botulinum toxin injection in CD. METHODS: Patients were randomized into study group (candidate muscles selected by SPECT/CT and clinical evaluation) or control group (clinical evaluation). Follow-ups were done at two weeks (T1), one (T2), three (T3) and six months (T4). The primary outcomes included symptom improvement assessed using Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) and Tsui score at T2. RESULTS: A total of 122 patients were enrolled and 108 patients accomplished the study. For primary outcomes, the study group had significantly better symptom improvement at T2 (TWSTRS: ß, -4.86 [95%CI -9.40 to -0.32; P = 0.036]; Tsui: ß, -1.65 [95%CI -2.77 to -0.54; P = 0.004]). For secondary outcomes, the study group also showed better outcomes at T1 (TWSTRS: ß, -6.33 [95%CI -10.17 to -2.49; P = 0.001]; Tsui: ß, -1.42 [95%CI -2.48 to -0.37; P = 0.008]) and T3 (TWSTRS: ß, -6.05 [95%CI -11.09 to -1.01; P = 0.019]; Tsui: ß, -1.24 [95%CI -2.40 to -0.08; P = 0.037]). The interval of re-injection was significantly longer in the study group than the control group (159.1 ± 28.6 versus 141.8 ± 51.0 days, P = 0.032). CONCLUSIONS: SPECT/CT could improve the efficacy of botulinum toxin in CD. It could become a useful tool to aid botulinum toxin injection.

Mutation screening of VPS16 gene in patients with isolated dystonia.

Mutations in VPS16 have been identified to be responsible for generalized dystonia. We screened VPS16 variants in 53 unrelated subjects with isolated dystonia via whole-exome sequencing. A novel pathogenic frameshift mutation p.R643fs* was found in a patient with early-onset multifocal dystonia with prominent oromandibular and bulbar involvement. Our findings expanded the spectrum of VPS16-related dystonia and suggested that mutations in VPS16 should be considered in patients with progressive early-onset dystonia.

Clinical and Molecular Features of POLG-Related Sensory Ataxic Neuropathy with Dysarthria and Ophthalmoparesis.

Sensory ataxic neuropathy, dysarthria, and ophthalmoparesis (SANDO) is a rare mitochondrial disorder associated with mutations in the POLG gene, which encodes the DNA polymerase gamma catalytic subunit. A few POLG-related SANDO cases have been reported, but the genotype-phenotype correlation remains unclear. Here, we report a patient with SANDO carrying two novel missense variants (c.2543G>C, p.G848A and c.452 T>C, p.L151P) in POLG. We also reviewed previously reported cases to systematically evaluate the clinical and genetic features of POLG-related SANDO. A total of 35 distinct variants in the coding region of POLG were identified in 63 patients with SANDO. The most frequent variant was the p.A467T variant, followed by the p.W748S variant. The clinical spectrum of SANDO is heterogeneous. No clear correlation has been observed between the mutation types and clinical phenotypes. Our findings expand the mutational spectrum of POLG and contribute to clinical management and genetic counseling for POLG-related SANDO.

Agrin Influences Botulinum Neurotoxin A-Induced Nerve Sprouting via miR-144-agrin-MuSK Signaling.

Botulinum neurotoxin (BoNT) has become a powerful therapeutic tool, and is extensively used in aesthetic medicine and in the treatment of neurological disorders. However, its duration of effect is limited, mainly owing to nerve sprouting. Inhibition of nerve sprouting to prolong the effective duration of BoNT is therefore of great clinical interest. However, appropriate interventional strategies to accomplish this are currently unavailable. In this study, we determined the role of the neurogenic regulator agrin in BoNT type A (BoNT/A)-induced nerve sprouting in a rat model. We then determined whether agrin could be used as an interventional target for prolonging the duration of effect of BoNT/A, and made a preliminary study of the upstream and downstream regulatory mechanisms by which agrin could influence the effective duration of BoNT/A. Our results showed that agrin was involved in the regulation of BoNT/A-induced nerve sprouting, and blocking of agrin function with anti-agrin antibody temporarily could delay muscle strength recovery and prolong the duration of BoNT/A effect. Moreover, agrin influenced the duration of BoNT/A effect by regulating downstream myogenic muscle-specific receptor tyrosine kinase (MuSK), and was simultaneously regulated by upstream miR-144. In conclusion, agrin could regulate BoNT/A-induced nerve sprouting through miR-144-agrin-MuSK signaling; it influences the effective duration of BoNT/A, and could find clinical application as an interventional target for prolonging the effect of BoNT/A.

The efficacy of single-photon emission computed tomography in identifying dystonic muscles in cervical dystonia.

INTRODUCTION: The key point for botulinum toxin type A injection in treating cervical dystonia is to accurately identify dystonic muscles. This study aimed to evaluate the efficacy of technetium-sestamibi single-photon emission computed tomography in identifying target muscles in cervical dystonia. METHODS: In the study group (n = 18), target muscles were selected according to clinical evaluation combined with technetium-sestamibi single-photon emission computed tomography, while in the control group (n = 18), target muscles were selected by clinical evaluation alone. All patients were followed-up at 2 weeks, 1, 3 and 6 months after botulinum toxin type A injection. The primary outcomes were the reduction rates in Toronto Western Spasmodic Torticollis Rating Scale and Tsui score at 1 month. RESULTS: Although the reduction rates in Toronto Western Spasmodic Torticollis Rating Scale and Tsui scores were not different between the two groups at 2 weeks and 1 month, the reduction rates in both scores were significantly higher in the study group at 3 and 6 months. The number of patients receiving re-injection within 6 months was significantly lower in the study group. Also, the re-injection interval was significantly longer in the study group. In the study group, more deep cervical muscles were injected, which concerns especially semispinalis capitis, longissimus capitis, and obliques capitis inferior muscles. CONCLUSION: technetium-sestamibi single-photon emission computed tomography is a useful method for screening target muscles in cervical dystonia. It helps clinicians draw a 'blueprint' for the distribution of dystonic muscles before botulinum toxin type A injection.

Synkinesis in primary and postparalytic hemifacial spasm: Clinical features and therapeutic outcomes of botulinum toxin A treatment.

Facial synkinesis can be present in both primary and postparalytic hemifacial spasm (HFS). The present retrospective study aimed to summarize the clinical features of synkinesis and explore an appropriate botulinum toxin A (BoNT-A) injection strategy to manage the synkinesis accompanying HFS. Video recordings of 234 patients with primary and postparalytic HFSs were analyzed. Improvements in the severity of spasm and synkinesis owing to BoNT-A treatment were monitored and compared among 36 primary and 12 postparalytic HFS patients with synkinesis and completed follow-up records. BoNT-A was injected into the voluntary facial region (VFR), the synkinetic facial region (SFR), or both VFR and SFR, and the efficacy of these strategies was evaluated and analyzed. Oral-ocular synkinesis in the primary group (32.8%) and ocular-oral synkinesis in the postparalytic group (81.0%) showed the highest incidence. Patients in both the primary and postparalytic groups exhibited a tremendous alleviation of spasm (97.2% vs. 91.7%, P > 0.05) following BoNT-A treatment. In both groups, coinjection and SFR injection were commonly used and effective in treatment of ocular and oral synkinesis, while VFR was frequently used but ineffective for frontal synkinesis. In addition, the improper muscle selection surrounding the mouth corner resulted in pattern change and treatment failure of oral synkinesis. Synkinesis mostly affected the ocular and oral regions. BoNT-A, via treatment of SFR, is effective against synkinesis accompanying HFS.

[99mTc]MIBI SPECT/CT for Identifying Dystonic Muscles in Patients with Primary Cervical Dystonia.

PURPOSE: This study aimed to evaluate the usefulness of [99mTc]sestamibi ([99mTc]MIBI) single photon emission computed tomography (SPECT)/X-ray computed tomography (CT) imaging for the identification of dystonic muscles in primary cervical dystonia (PCD) patients who underwent botulinum neurotoxin type A (BoNT-A) therapy. PROCEDURES: Thirty-six patients with PCD and 10 healthy subjects (control group) who underwent [99mTc]MIBI SPECT/CT were enrolled. The image characteristics of dystonic muscles and normal muscles were evaluated. Muscle/background ratio (MBR) of six representative muscles was calculated for dystonic muscles in PCD group and normal muscles in control group. In PCD patients, target muscles injected with BoNT-A were selected by clinical evaluations and the results of needle electromyography (EMG) were considered as the gold standard. The sensitivity, specificity, and diagnostic efficacy of SPECT/CT were obtained from the receiver operator characteristic (ROC) curve. RESULTS: Twenty-four PCD patients were included in our study eventually, because three PCD patients whose follow-up were lost and 9 PCD patients whose maximum reduction of Tsui scale scores was < 80 % were ruled out. Normal muscles of healthy subjects showed mild symmetrical radioactivity distribution, while in PCD patients, [99mTc]MIBI uptake in dystonic muscles abnormally increased. The mean MBRs of dystonic muscles were significantly higher than those of normal muscles. The sensitivity, specificity, and area under the curve (AUC) of SPECT/CT were 93.2 %, 88.5 %, and 0.908, respectively. CONCLUSIONS: Our study indicated that [99mTc]MIBI SPECT/CT may be a useful method for identifying dystonic muscles and a guide to BoNT-A therapy in PCD patients.

Botulinum toxin therapy of hemifacial spasm: bilateral injections can reduce facial asymmetry.

Botulinum toxin (BT) is the treatment of choice for hemifacial spasm (HFS). When BT is injected into the affected side, patients may experience increased facial asymmetry. We wanted to evaluate in a prospective, randomised, placebo-controlled study whether bilateral BT injections may reduce this facial asymmetry. For this, we treated 19 HFS patients with unilateral and 24 with bilateral BT therapy using CBTX-A (Lanzhou Biological Products Institute, Lanzhou, China). BT doses on the affected side were standard doses, on the non-affected side they were one-third of those. Facial asymmetry was studied with the Sunnybrook facial grading system (SFGS), the Facial Clinimetric Evaluation Scale (FaCE), the Symmetry Scale for Hemifacial Spasm (SSHS) and a self-assessment scale. As shown in SFGS and SSHS, bilateral BT therapy reduces facial asymmetry, whilst unilateral BT therapy increases it. Both effects are more pronounced during voluntary facial movements than at rest. BT effect delay, BT effect duration, adverse effect frequency and severity were not affected. FaCE total score, some of its subscores and the self-assessment scale did not show an effect. Bilateral BT therapy may improve the outcome of BT therapy for HFS without producing additional adverse effects. This strategy, however, raises drug costs (by about a third). Using even higher doses in the non-affected side may intensify the improvement even further. Future studies may also monitor the patient's quality of life and the naïve public's overall perception of the patient's facial expression.