[A case of generalized dystonia DYT28 with a novel de novo mutation in the KMT2B gene]

The patient exhibited plantarflexion during walking at the age of five. He then developed writer's cramp at the age of six, dysphonia at 15 years, and action-induced dystonia with left knee elevation and trunk swinging when walking at 16 years, which subsequently spread to the right leg at 19 years. Levodopa therapy was ineffective for dystonia. Brain MRI showed no abnormalities. He was diagnosed with DYT28 after detecting a novel heterozygous mutation (c.433C>T, p.Arg145*) in the KMT2B gene using whole-exome sequencing at age 39. Furthermore, the patient's parents exhibited normal alleles, confirming the de novo status of KMT2B gene mutation. We should consider DYT28 in addition to DYT1 and DYT5 in patients who developed leg dystonia in childhood.

Cortical and Subcortical Structural Abnormalities in Patients With Idiopathic Cervical and Generalized Dystonia

OBJECTIVES

In this study, we sought to investigate structural imaging alterations of patients with idiopathic dystonia at the cortical and subcortical levels. The common and specific changes in two subtypes of dystonia, cervical dystonia (CD) and generalized dystonia (GD), were intended to be explored. Additionally, we sought to identify the morphometric measurements which might be related to patients' clinical characteristics, thus providing more clues of specific brain regions involved in the mechanism of idiopathic dystonia.

METHODS

3D T1-weighted MRI scans were acquired from 56 patients with idiopathic dystonia and 30 healthy controls (HC). Patients were classified as CD or GD, according to the distinct symptom distributions. Cortical thickness (CT) of 30 CD and 26 GD were estimated and compared to HCs using Computational Anatomy Toolbox (CAT12), while volumes of subcortical structures and their shape alterations (29 CD, 25 GD, and 27 HCs) were analyzed via FSL software. Further, we applied correlation analyses between the above imaging measurements with significant differences and patients' clinical characteristics.

RESULTS

The results of comparisons between the two patient groups and HCs were highly consistent, demonstrating increased CT of bilateral postcentral, superiorparietal, superiorfrontal/rostralmiddlefrontal, occipital gyrus, etc., and decreased CT of bilateral cingulate, insula, entorhinal, and fusiform gyrus (PFWE < 0.005 at the cluster level). In CD, trends of negative correlations were found between disease severity and CT alterations mostly located in pre/postcentral, rostralmiddlefrontal, superiorparietal, and supramarginal regions. Besides, volumes of bilateral putamen, caudate, and thalamus were significantly reduced in both patient groups, while pallidum volume reduction was also presented in GD compared to HCs. Caudate volume reduction had a trend of correlation to increasing disease severity in GD. Last, shape analysis directly demonstrated regional surface alterations in bilateral thalamus and caudate, where the atrophy located in the head of caudate had a trend of correlation to earlier ages of onset in GD.

CONCLUSIONS

Our study demonstrates wide-spread morphometric changes of CT, subcortical volumes, and shapes in idiopathic dystonia. CD and GD presented similar patterns of morphometric abnormalities, indicating shared underlying mechanisms in two different disease forms. Especially, the clinical associations of CT of multiple brain regions with disease severity, and altered volume/shape of caudate with disease severity/age of onset separately in CD and GD might serve as potential biomarkers for further disease exploration.

A description of novel variants and review of phenotypic spectrum in UBA5-related early epileptic encephalopathy

Early infantile epileptic encephalopathy-44 (EIEE44, MIM: 617132) is a previously described condition resulting from biallelic variants in UBA5, a gene involved in a ubiquitin-like post-translational modification system called UFMylation. Here we report five children from four families with biallelic pathogenic variants in UBA5 All five children presented with global developmental delay, epilepsy, axial hypotonia, appendicular hypertonia, and a movement disorder, including dystonia in four. Affected individuals in all four families have compound heterozygous pathogenic variants in UBA5 All have the recurrent mild c.1111G > A (p.Ala371Thr) variant in trans with a second UBA5 variant. One patient has the previously described c.562C > T (p. Arg188*) variant, two other unrelated patients have a novel missense variant, c.907T > C (p.Cys303Arg), and the two siblings have a novel missense variant, c.761T > C (p.Leu254Pro). Functional analyses demonstrate that both the p.Cys303Arg variant and the p.Leu254Pro variants result in a significant decrease in protein function. We also review the phenotypes and genotypes of all 15 previously reported families with biallelic UBA5 variants, of which two families have presented with distinct phenotypes, and we describe evidence for some limited genotype-phenotype correlation. The overlap of motor and developmental phenotypes noted in our cohort and literature review adds to the increasing understanding of genetic syndromes with movement disorders-epilepsy.

Non-motor Symptoms in Chinese Patients With Isolated Generalized Dystonia: A Case-Control Study

Background: Previous studies have indicated that non-motor symptoms are primary problems in focal dystonia, but limited data are available about non-motor problems and their correlation with motor severity in generalized dystonia (GD).

Methods: In the present study, we performed a case-control study and enrolled isolated inherited or idiopathic GD patients and age- and sex-matched healthy controls (HC). Clinical characteristics, motor symptoms, non-motor problems, including psychiatric co-morbidity, sleep problems, fatigue, and quality of life (QoL) were assessed in both groups using various rating scales and assessments.

Results: Thirty-three patients with GD and 33 controls were enrolled. Significant higher scores on depression and anxiety (p < 0.001) were shown in GD compared with HC, whereas the frequency of obsessive-compulsive disorders approached that of HC (p = 0.238). Patients with GD also had significantly higher Pittsburg Sleep Quality Index (PSQI) and fatigue scores than HC, whereas no difference was observed in excessive daytime somnolence. In GD, QoL was more impaired, with statistically lower scores in both physical and mental components. Psychiatric rating scales did not correlate to motor severity or disease duration but might influence quality of sleep. Subgroup analysis suggests non-motor manifestations differ with different etiologies in GD.

Conclusion: This study suggests that non-motor symptoms in GD, such as psychiatric problems, are likely to be primary determinants not correlated to motor severity, which may also affect quality of sleep and fatigue.

Staged pallidotomy: MRI and clinical follow-up in status dystonicus

PURPOSE

We report on a patient affected by Status Distonicus who was treated with Deep Brain Stimulation electrodes implanted in the Globus Pallidus internus (Gpi) and used for serial radiofrequency lesions.

MATERIALS AND METHODS

The evolution of radiofrequency lesions was monitored by post-operative and late Magnetic Resonance Imaging (MRI). After the first lesion the patient did improve, though not in a significant fashion. Therefore, three further radiofrequency lesions were delivered 2, 4 and 6 days respectively after surgery with subsequent improvement of dystonic movements.

RESULTS

MRI scans performed at 8 days, 3 months, and 6 months after surgery showed a diffuse T2-hyperintense and T1-hypointense GPi signal alteration which progressively decreased over time.

CONCLUSION

We confirm that the possibility to stage pallidotomies over time using a couple of new contacts is a safe and efficacious procedure in treating SD patients where the lesions themselves are limited by the appearance of side effects, or in patients showing a poor response to a single lesion. As far as we know, this is the first description of MRI evolution and monitoring of a staged pallidotomy.

Efficacy of zolpidem for dystonia: a study among different subtypes

Although there are some newly developed options to treat dystonia, its medical treatment is not always satisfactory. Zolpidem, an imidazopyridine agonist with a high affinity on benzodiazepine subtype receptor BZ1 (ω1), was found to improve clinical symptoms of dystonia in a limited number of case reports. To investigate what subtype of dystonia is responsive to the therapy, we conducted an open label study to assess the efficacy of zolpidem (5–20 mg) in 34 patients suffering from miscellaneous types of dystonia using the Burke–Fahn–Marsden Dystonia Rating Scale (BFMDRS). Patients were entered into the study if they had been refractory to other medications as evaluated by BFMDRS (no change in the previous two successive visits). After zolpidem therapy, the scores in the patients as a whole were decreased from 7.2 ± 7.9 to 5.5 ± 5.0 (P = 0.042). Patients with generalized dystonia, Meige syndrome/blepharospasm, and hand dystonia improved in the scale by 27.8, 17.8, and 31.0%, respectively, whereas no improvement was found in cervical dystonia patients. Overall response rate among patients were comparable to that of trihexyphenidyl. Zolpidem may be a therapeutic option for generalized dystonia, Meige syndrome, and hand dystonia including musician’s. Drowsiness was the dose-limiting factor.