Pallidal and thalamic deep brain stimulation in myoclonus‐dystonia

Abstract

Deep brain stimulation (DBS) of the internal globus pallidus (GPi) and ventral intermediate thalamic nucleus (VIM) are established treatment options in primary dystonia and tremor syndromes and have been reported anecdotally to be efficacious in myoclonus-dystonia (MD). We investigated short- and long-term effects on motor function, cognition, affective state, and quality of life (QoL) of GPi- and VIM-DBS in MD. Ten MD-patients (nine epsilon-sarcoglycan-mutation-positive) were evaluated pre- and post-surgically following continuous bilateral GPi- and VIM-DBS at four time points: presurgical, 6, 12, and as a last follow-up at a mean of 62.3 months postsurgically, and in OFF-, GPi-, VIM-, and GPi-VIM-DBS conditions by validated motor [unified myoclonus rating scale (UMRS), TSUI Score, Burke-Fahn-Marsden dystonia rating scale (BFMDRS)], cognitive, affective, and QoL-scores. MD-symptoms significantly improved at 6 months post-surgery (UMRS: 61.5%, TSUI Score: 36.5%, BFMDRS: 47.3%). Beneficial effects were sustained at long-term evaluation post-surgery (UMRS: 65.5%, TSUI Score: 35.1%, BFMDRS: 48.2%). QoL was significantly ameliorated; affective status and cognition remained unchanged postsurgically irrespective of the stimulation conditions. No serious long-lasting stimulation-related adverse events (AEs) were observed. Both GPi- and VIM-DBS offer equally effective and safe treatment options for MD. With respect to fewer adverse, stimulation-induced events of GPi-DBS in comparison with VIM-DBS, GPi-DBS seems to be preferable. Combined GPi-VIM-DBS can be useful in cases of incapaciting myoclonus, refractory to GPi-DBS alone.

Long-term outcome of deep brain stimulation in generalised dystonia: a series of 60 cases

“…Indeed one of the three (with DYT11) showed an 81% improvement in BFM-S; the patients with DYT6 showed 23% and 52% improvements. The patient with DYT11 (myoclonus dystonia) also saw an improvement in myoclonic symptoms, although this was not quantified, The literature concerning the response to DBS in patients with mutations at loci other than DYT1 is sparse, however in the small numbers with DYT627 28 and DYT1129 that have been reported, the results have been encouraging. It is clear at least that individual cases with DYT6 or DYT11 mutations have the potential to respond as well to treatment as the typical patient with DYT1 does.…”

Deep Brain Stimulation for Movement Disorders of Basal Ganglia Origin: Restoring Function or Functionality?

“…The stimulation parameters are typically the same as for PD, although some patients may also respond to lower frequencies. There is growing evidence supporting the use of GPi DBS for the treatment of tardive dystonia or myoclonus dystonia [244][245][246][247][248][249][250][251][252][253][254]. Lesser and inconsistent benefit is seen in dystonia secondary to structural brain damage [255].…”

Clinical Reasoning: A 13-year-old boy presenting with dystonia, myoclonus, and anxiety

“…8,9 Diagnostic criteria for definite myoclonus dystonia have been proposed and include early onset (Ͻ20 years), myoclonus predominating in the upper body either isolated or associated with dystonia, positive family history with paternal transmission when due to SGCE mutation or deletion, exclusion of additional neurologic findings such as cerebellar ataxia, spasticity, and dementia, and a normal brain MRI. 5,10 Myoclonus dystonia is a rare cause of dystonia in childhood but must be considered in the setting of early onset dystonia when myoclonus is present, especially in cases with potential paternal inheritance. Our patient meets the suggested criteria for the diagnosis of myoclonus dystonia as described above.…”