Combined focal myoclonus and dystonia secondary to a cerebellar hemorrhage: a case report

Abstract

BackgroundMyoclonus is a clinical sign characterized by sudden, brief jerky, shock-like involuntary movements of a muscle or group of muscles. Dystonia is defined as a syndrome of sustained muscle contractions, frequently causing twisting and repetitive movements or abnormal postures. Cases of myoclonus or dystonia secondary to a structural lesion in the cerebellum have been reported. However, there has never been a reported case of combined myoclonus and dystonia secondary to a cerebellar lesion.Case presentationHerein, we report a 22-year-old female patient with sudden-onset myoclonic jerks, dystonic posture and mild ataxia in the right upper extremity. At age 19, she experienced sudden headache with vomiting. The neurological examination showed ataxia, myoclonus and dystonia in the right upper extremity. Brain images demonstrated a hemorrhage in the right cerebellar hemisphere secondary to a cavernous malformation. After resection of the hemorrhagic mass, headache with vomiting disappeared and ataxia improved, but myoclonus and dystonia persisted.ConclusionsIt is the first report of combined focal myoclonus and dystonia secondary to a cerebellar lesion.Electronic supplementary materialThe online version of this article (doi:10.1186/s12883-016-0745-6) contains supplementary material, which is available to authorized users.

The Cortico-Basal Ganglia-Cerebellar Network: Past, Present and Future Perspectives

“…Anomalies in the cerebellum and basal ganglia have been widely investigated in both animal and human studies of dystonia (Filip et al, 2013; Tewari et al, 2017). Different cases of secondary dystonia emerging from cerebellar lesions are described in humans (Alarcón et al, 2001; LeDoux and Brand, 2003; Shen et al, 2016). In a murine model of cerebellar-induced dystonia, a cerebellar outflow interruption has been causally linked to burst firing activity in basal ganglia, which is a prominent feature of dystonia (Chen et al, 2014).…”

Case report: Unilateral GPi DBS in secondary myoclonus-dystonia syndrome after acute disseminated encephalomyelitis

“…Our results indicate an alleviation of both symptoms upon modulation of basal ganglia circuits with fibre tracts intersecting the DRT and projecting to the SFG. The interpretation of a complex multinetwork model seems to be corroborated by findings indicating a synchronicity of pallidal oscillations and myoclonic jerks (31), whereas secondary myoclonus may also result from lesions in the cerebellum (32). While DBS targeting the posterior of the ventrolateral thalamic nucleus (VLp) can effectively address myoclonus (33,34), in our patient, right-sided dystonic features were the predominant symptom, causing significant difficulties with activities of daily-living and severely affecting the patient's quality of life.…”

“…Our results indicate an alleviation of both symptoms upon modulation of basal ganglia circuits with fibre tracts intersecting the DRT and projecting to the SFG. The interpretation of a complex multinetwork model seems to be corroborated by findings indicating a synchronicity of pallidal oscillations and myoclonic jerks ( 31 ), whereas secondary myoclonus may also result from lesions in the cerebellum ( 32 ).…”

Cerebellum in Neurological Disorders: A Review on the Role of Inter-Connected Neural Circuits

“…Though there have been extensive reports of dystonia associated with cerebellar lesions, the pathophysiology is not clear. However the structural and functional interactions between the cerebellum and basal ganglia circuits plays a major role [53,54] In this movement disorder dystonic, movement disorder has been associated to both basal ganglia and cerebellar circuits, which forms multi synaptic loops with cerebral cortex [55].…”

“…Absence seizures are kinds of epileptic seizures which lasts for few seconds and characterized by unconsciousness or absent state and appear to be initiated in a putative control initiation site with expression of 5-9Hz due to decreased GABAA receptor function [45]. Absence seizures have been associated to abnormal electric activity in reciprocally connected thalamo-cortical areas [52][53][54][55][56].…”