Session Information
Date: Wednesday, June 7, 2017
Session Title: Ataxia
Session Time: 1:15pm-2:45pm
Location: Exhibit Hall C
Objective:
To investigate the effects of deep brain stimulation (DBS) or lesions of the ventral intermediate nucleus (Vim) of the thalamus for spinocerebellar ataxia (SCA) and characterize the neuronal mechanism of the cerebellothalamic projection underlying ataxia.
Background:
The efficacy of Vim DBS on action tremor in SCA has not been fully assessed, and little is known about the changes in Vim neuronal activity underlying cerebellar ataxia.
Methods:
Five patients with SCA with cortical atrophy (ages 60-69 years; 2 sporadic and 3 familial SCA) and 5 patients with essential tremor (ET) (ages 57-71 years) were treated with Vim DBS. Intra-operatively, we recorded neuronal activity from single neurons in the Vim thalamus while patients were at rest and compared the physiological properties in those neurons collected from patients with SCA to those with ET.
Results: The mean score for the Fahn-Tolosa-Marin Tremor Scale was improved from 78 (before surgery) to 44 (after surgery, DBS on) in SCA patients and from 54 to 21 in ET patients, (Wilcoxon signed-rank test, P = 0.043 in SCD and P = 0.041 in ET). Vim DBS did not improve ataxia in our patients with SCA. The best location for stimulation or coagulation was in the posterior and ventral half of the Vim in all patients, but stronger stimulation was necessary to attain the best outcome in SCA as compared with stimulation intensity in ET. We analyzed 68 Vim neurons in 5 SCA patients and 60 Vim neurons in 5 ET patients. Mean discharge rates, burst characteristics and oscillatory activity were similar in SCA and ET patients, however, we did observe that the ratio of cells responding to passive manipulation was significantly smaller (P = 0.0001) in SCA (22 %) than in ET (71 %).
Conclusions:
Abolishment of tremor by thalamic surgery led to a significant improvement in tremor in both SCA patient as well as in ET patients. One potential mechanism underlying ataxia in SCA may be disruption of cerebellar sensory feedback, which modulates motor commands in the cerebellar thalamo-cortical network.
To cite this abstract in AMA style:
T. Hashimoto, A. Muralidharan, K. Yoshida, T. Goto, T. Yako, K. Baker, J. Vitek. Comparison of the effect of thalamic DBS/coagulation on tremor and thalamic neuronal activity in spinocerebellar ataxia and essential tremor [abstract]. Mov Disord. 2017; 32 (suppl 2). https://www.mdsabstracts.org/abstract/comparison-of-the-effect-of-thalamic-dbscoagulation-on-tremor-and-thalamic-neuronal-activity-in-spinocerebellar-ataxia-and-essential-tremor/. Accessed November 22, 2024.« Back to 2017 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/comparison-of-the-effect-of-thalamic-dbscoagulation-on-tremor-and-thalamic-neuronal-activity-in-spinocerebellar-ataxia-and-essential-tremor/