Clinical and Structural Findings in Patients With Lesion-Induced Dystonia

Abstract

Background and Objectives:Brain lesions are a well-recognized etiology of dystonia. These cases are especially valuable as they offer causal insight into the neuroanatomical substrates of dystonia. To date, knowledge of lesion-induced dystonia comes mainly from isolated case reports or small case series, restricting broader description and analysis.Methods:Cases of lesions-induced dystonia were first identified from a systematic review of published literature. Latent class analysis then investigated whether patients could be classified into subgroups based on lesion location and body regions affected by dystonia. Regression analyses subsequently investigated whether subgroup membership predicted clinical characteristics of dystonia.Results:359 published cases were included. Lesions causing dystonia occurred in heterogeneous locations, most commonly in the basal ganglia (46.2%), followed by the thalamus (28.6%), brainstem (22.6%), and white matter (21.2%). The most common form of lesion-induced dystonia was focal dystonia (53.2%), with the hand (49.9%) and arm (44.3%) most commonly affected. Of all cases, 86.6% reported co-occurring neurological manifestations, and 26.1% reported other movement disorders. Latent class analysis identified three distinct subgroups of patients: those with predominantly limb dystonias, which were associated with basal ganglia lesions; those with predominantly cervical dystonia, associated with brainstem and cerebellar lesions; and those with predominantly hand dystonia, associated with thalamic lesions. Regression demonstrated significant differences between these subgroups on a range of dystonia symptoms, including dystonic tremor, symptom latency, other movement disorders, and dystonia variability.Discussion:While dystonia can be induced by lesions to numerous brain regions, there are distinct relationships between lesion locations and dystonic body parts. This suggests that the affected brain networks are different between types of dystonia.

WITHDRAWN: Infratentorial Morphometry and Deep Brain Stimulation Outcome in Cervical Dystonia

“…Intersection of the cerebellum and pallidum verifies lesion sites identified in patients with secondary cervical dystonia. (9)(10)(11) Posteroventral GPi intersection supports the brainstems involvement in mediating therapeutic networks, given that this area of the pallidum is widely regarded as the DBS hotspot for cervical dystonia, and occupies somatotopic cervical territory. (15,73,74) The observed cortical motor fibre intersection corroborates the somatotopic head and neck areas, as the terminus of white matter tracts associated with optimal clinical motor symptom reduction, in cervical dystonia.…”

“…(7,8) Lesion-identification studies have identified spinal cord, basal ganglia, brainstem, cerebellum, and thalamic regions as most affected in patients with cervical dystonia, (9,10) with the brainstem and cerebellum as the most commonly affected regions in a recent study. (11) All lesion sites have been classified to ascertain connectivity with the cerebellum, (10) and surmounting evidence supports cerebellar involvement in dystonic sensorimotor pathophysiology. (7,8,(12)(13)(14) Brain-based imaging markers offer a potential avenue to explore variability in patients with cervical dystonia, in relation to therapeutic DBS outcomes.…”

Proprioceptive Modulation of Pallidal Physiology in Cervical Dystonia

“…18,19 Lesion network mapping studies associate focal CD with cerebellar and brainstem lesions, whereas limb dystonia is linked to basal ganglia lesions. 20,21 Contemporary dystonia theories highlight the significance of an abnormal neural network connecting the cerebellum, brainstem, basal ganglia, and cerebral cortex. Dysregulation in any part of this network can manifest as dystonia symptoms through a common pathway.…”

“…Modern theories propose involvement of the cerebellum and brainstem, 11‐17 and CD patients with head tremors may also exhibit cerebellar ataxia 18,19 . Lesion network mapping studies associate focal CD with cerebellar and brainstem lesions, whereas limb dystonia is linked to basal ganglia lesions 20,21 …”

Lesion-Induced Dystonia

“…Although cases of lesion-induced dystonia are rarer than those of isolated dystonia, they offer a unique opportunity to explore causal inferences between neuroanatomical structures and dystonia. In this issue of Neurology ®, Corp et al 5 identified 359 published cases of lesion-induced dystonia in a systematic review of published cases. By investigating the relationship between lesion location and phenotypic features of the dystonia, they ascertained that only half of the lesions were located in the basal ganglia, with other lesions commonly located in the cerebellum, brainstem, and white matter.…”