Symptomatic paroxysmal hemidystonia due to a demyelinating subthalamic lesion

Abstract

We present a case of paroxysmal hemidystonia in a patient with an isolated demyelinating lesion in the subthalamic region, involving the posterior arm of the internal capsule and extending to the subthalamic nucleus and mesencephalon, possibly due to multiple sclerosis. Compared with similar reports in the literature, in our case there was a paucity of lesions, permitting a more direct clinico-anatomical correlation. The role of the subthalamic region and basal ganglia circuitry in the genesis of symptomatic dystonia is discussed.

Clinical Features and Treatment in the Spectrum of Paroxysmal Dyskinesias: An Observational Study in South-West Castilla y Leon, Spain

“…The response to treatment is difficult to interpret, especially for PNKD. In the patients with multiple sclerosis (MS) and cerebral haemorrhage was observed an improvement with anticonvulsants and benzodiazepines, respectively, outcomes consistent with other cases published [16–18]. However, in two cases with encephalitis (one in a patient with HIV stage C3), neither benzodiazepines nor anticonvulsants were beneficial, not confirming the effective response to benzodiazepines observed in some patients with HIV from the literature [19].…”

Paroxysmal dystonia and pathological laughter as a first manifestation of multiple sclerosis

“…The pathophysiology might involve different phenomena: hypersensitivity of axons to minor insults, inflammatory irritation of axons, reduction of ionized calcium after hyperventilation, alterations of potassium channels and demyelination of afferent inhibitory pathways [5][6][7][8]. Osterman and Westenberg [1] have suggested that tonic spasms could be caused by the transversely spreading ephaphtic activation of axons in a partially demyelinated lesion within fibre tracts at a particular area of the central nervous system.…”

“…Attacks tend to cease spontaneously over months, probably with evolutionary change of the causative plaque. Treatment with carbamazepine has shown the greatest efficacy in suppressing tonic spasms [2][3][4][5][6][7][8].…”

“…Paroxysmal dystonia, also called tonic spasms or tonic seizures, is a well-established feature of multiple sclerosis (MS), which, while uncommon, is the most frequent movement disorder described in MS [1][2][3][4][5][6][7][8]. Attacks, which are sometimes preceded by a sensory area in either the affected or the contralateral limbs, are brief lasting between 30 s and 2 min, frequent, sometimes occurring up to 60 times a day, stereotyped and often painful [2].…”

“…These events may be precipitated by voluntary movement, tactile stimulation, startling noise and hyperventilation. Attacks can occur in established MS and may even occasionally be the initial symptom of this disorder [2][3][4][5][6][7][8].…”