Daniela Muñoz Chesta’s research while affiliated with University of Santiago Chile and other places

Childhood presentations of ataxia can often be challenging to diagnose. Recognising ataxia is especially difficult in young children, the most frequent reason for consultation is walking instability and loss of balance. Clinical presentations tend to be heterogeneous; key considerations may vary based on the age of onset, time course, and associated manifestations. Ataxias can be acute, intermittent, chronic non-progressive, or chronic progressive conditions. Acute ataxias are mostly acquired conditions (post-infectious or immune-mediated). Intermittent ataxias may be secondary to genetic channelopathies or metabolic diseases. Non-progressive chronic ataxias are mostly related to cerebellar malformations and progressive chronic ataxias are usually secondary to genetic variants, which in children are usually autosomal recessive conditions. A complete medical history and a detailed physical examination are essential for an adequate approach. Treatment of a child with ataxia depends on the aetiology. One of the most important challenges is to identify the treatable causes.

Objective: The aim of this study is to quantify DBS treatment outcome in patient with chilhood onset dystonia between the years 2014-2020. Background: Deep brain stimulation (DBS) in the internal pale globe (Gpi) has been proposed as an effective treatment of patients with refractory dystonia. Although DBS is an accepted treatment for childhood dystonia, there is significant heterogeneity in treatment response and few data are available to identify the best surgical candidates. Methods: Prospective analytical interventional cohort study. Dystonia severity was quantified using Burke-Fahn-Mardsen Dystonia Scale (BFMDRS), applying its 2 subscales: motor and disability. Dystonia severity was measured pre-DBS and 1, 3, and 6 months after DBS. All patients have video registration of each control. Results: 14 patients were analyzed. All of them with bilateral Gpi DBS. 8 men, 6 women. Average age dystonia onset was 8.2 years. Etiologies: genetic primary dystonia 7 patients (1 DYT1, 1 DYT 5, 2 DYT 24, 1 DYT25, 1 DTDS, 1 mutation KMT2B gene); idiopathic primary dystonia 2 patients and secondary dystonia (2 PKAN, 1 Kernicterus, 2 late dystonia). Each patient was evaluated with BFMDRS scale pre-DBS and in controls of 1, 3 and 6 months. The average pre-DBS BFMDRS score was 71.5/21.42pts on motor/disability scales respectively. The average score in controls of 1, 3 and 6 months was 37.03/15.35pts, 30.75/12.41 and 29.45/11.7 respectively. The average improvement percentage was 66.89% on motor scales and 58.19% on disability scales. When we analyzed each group, the percentages of improvement were 72.68%/66.6% genetic primary dystonia, 69.68%/63.18% idiopathic primary dystonia and 59.94%/47.74% secondary dystonia. The median (p25-p75) of the motor BFMDRS score and disability at 6 months of control was significantly better than the median score obtained preDBS (p value <0.05). The group of genetic dystonia presented a statistically significant improvement at the control of 6 months in both subscales. The secondary dystonia group showed significant improvement in disability subscale. One patient (PKAN) received this therapy as a dystonic status treatment with good response. Conclusions: Our study confirms the effectiveness of this therapy, especially in patients with primary genetic dystonia.