Status dystonicus in children: Treat the precipitating factors

Status dystonicus (SD) is a life-threatening movement disorder associated with significant morbidity and requires immediate and urgent intervention. It usually develops from both primary and secondary dystonias and rarely can be a complication of symptomatic insults such as infections, brain insults, or drugs. Compared to adults, it is seen more commonly in children due to the risk of many trigger factors and vulnerability of the developmental brain. Due to the delay in the identification and prevention of the triggering factors, nowadays most children require intensive care. Here, we report a 1-year-old boy, who was a known case of dyskinetic cerebral palsy, presented with increased twisting movements after an episode of febrile illness. The SD partially resolved after midazolam infusion, however, after treating the triggering factors (constipation and pneumonia), the SD resolved completely.

Status Dystonicus in Children with Secondary Dystonia: Reporting 3 Cases of Cerebral Palsy, Leigh Disease and Molybodynum Co Factor Deficiency

Objective: Patients with primary and secondary dystonic syndromes occasionally develop severe episodes of generalized dystonia and rigidity which is known as status dystonicus (SD) or dystonic storm. This is a frightening hyperkinetic movement disorder and it is an emergency. Marked, rapid exacerbation of dystonia requires prompt intervention and admission in the hospital. It is critical to recognize early and differentiate dystonic storm from other hyperkinetic movement disorder as it may lead to metabolic complications such as rhabdomyolysis, leading to acute renal failure. This paper has been written to describe three cases of SD, all having secondary dystonia with different etiologies to highlight the mode of presentation, diagnosis, treatment and outcome. Methodology: We report 3 cases of severe secondary dystonia culminating in SD necessitating management in hospital setting. All the three cases were admitted in a tertiary care hospital and evaluated. Results: One patient was treated in intensive care unit. In brief 1st case was a 5 year boy with dyskinetic CP who was treated with trihexiphenidyl (THP), baclofen and midazolam infusion. Second case was a 15 month old boy, diagnosed case of mitochondrial encephalopathy (Leigh disease) who was treated with THP, baclofen, haloperidol, clonazepam and infusion midazolam. The third case was a 13 month old boy, diagnosed case of Molybdenum Cofactor deficiency who was treated with THP, tizanidine but they refused to take midazolam. Conclusion: In this case series, three cases with SD with different etiology have been described with clinical features, modalities of treatment and outcome.

KMT2B-related disorders: expansion of the phenotypic spectrum and long-term efficacy of deep brain stimulation

Heterozygous mutations in KMT2B are associated with an early-onset, progressive and often complex dystonia (DYT28). Key characteristics of typical disease include focal motor features at disease presentation, evolving through a caudocranial pattern into generalized dystonia, with prominent oromandibular, laryngeal and cervical involvement. Although KMT2B-related disease is emerging as one of the most common causes of early-onset genetic dystonia, much remains to be understood about the full spectrum of the disease. We describe a cohort of 53 patients with KMT2B mutations, with detailed delineation of their clinical phenotype and molecular genetic features. We report new disease presentations, including atypical patterns of dystonia evolution and a subgroup of patients with a non-dystonic neurodevelopmental phenotype. In addition to the previously reported systemic features, our study has identified co-morbidities, including the risk of status dystonicus, intrauterine growth retardation, and endocrinopathies. Analysis of this study cohort (n = 53) in tandem with published cases (n = 80) revealed that patients with chromosomal deletions and protein truncating variants had a significantly higher burden of systemic disease (with earlier onset of dystonia) than those with missense variants. Eighteen individuals had detailed longitudinal data available after insertion of deep brain stimulation for medically refractory dystonia. Median age at deep brain stimulation was 11.5 years (range: 4.5–37.0 years). Follow-up after deep brain stimulation ranged from 0.25 to 22 years. Significant improvement of motor function and disability (as assessed by the Burke Fahn Marsden’s Dystonia Rating Scales, BFMDRS-M and BFMDRS-D) was evident at 6 months, 1 year and last follow-up (motor, P = 0.001, P = 0.004, and P = 0.012; disability, P = 0.009, P = 0.002 and P = 0.012). At 1 year post-deep brain stimulation, >50% of subjects showed BFMDRS-M and BFMDRS-D improvements of >30%. In the long-term deep brain stimulation cohort (deep brain stimulation inserted for >5 years, n = 8), improvement of >30% was maintained in 5/8 and 3/8 subjects for the BFMDRS-M and BFMDRS-D, respectively. The greatest BFMDRS-M improvements were observed for trunk (53.2%) and cervical (50.5%) dystonia, with less clinical impact on laryngeal dystonia. Improvements in gait dystonia decreased from 20.9% at 1 year to 16.2% at last assessment; no patient maintained a fully independent gait. Reduction of BFMDRS-D was maintained for swallowing (52.9%). Five patients developed mild parkinsonism following deep brain stimulation. KMT2B-related disease comprises an expanding continuum from infancy to adulthood, with early evidence of genotype-phenotype correlations. Except for laryngeal dysphonia, deep brain stimulation provides a significant improvement in quality of life and function with sustained clinical benefit depending on symptoms distribution.