Session Information
Date: Sunday, October 7, 2018
Session Title: Ataxia
Session Time: 1:45pm-3:15pm
Location: Hall 3FG
Objective: The aim of the study was to describe electrophysiological features of tremor in SCA12 patients and to compare it with that in ET patients.
Background: SCA12 and ET are neurodegenerative disorders with hand tremor as their initial manifestation. Hand tremors occur in 94% of ET and 91% of SCA12. ET starts with a postural/kinetic tremor later evolves to develop rest tremor and intention tremor with late subtle cerebellar dysfunction. Both have bilateral hand tremor but may begin in unilateral manner.
Methods: ET and SCA12 patients were enrolled from the Ataxia clinic, Department of Neurology, AIIMS, New Delhi. A bipolar surface EMG and accelerometer were used to evaluate tremor frequency, type, symmetry and pattern of muscle activation in these patients. Diagnosis of SCA 12 was based on clinical evaluation followed by genetic confirmation. Diagnosis of ET was based on consensus statement of the Movement Disorder Society (MDS) on Tremor in 1998.
Results: A total of 20 patients with SCA12 (n=10) and ET (n=10) were included in the study. SCA12 patients had a mean age of 49.7 years + 10.1 (range 34 – 66). ET patients had a mean age of 48.8 years + 10.7 (range 29 – 55). The age at disease onset ranged from 28-53 years in SCA12 patients and 27-58 years in ET patients. These patients had postural, rest and intention tremor of hands with tremor frequency ranging 3.1-8 Hz (SCA12) and 2.5-8.1 Hz (ET). Most of the SCA12 patients (8/10) and all of the ET patients (10/10) showed asymmetric tremor and synchronous muscle activation pattern.
Conclusions: This study sheds light on characteristics of tremor in SCA12 and ET patients. Our preliminary data indicates that the tremor in SCA12 and ET have almost similar characteristics in terms of frequency range and synchronicity of muscle activation. It may be difficult to differentiate between the two diseases in the early stage of illness. Similarity in the tremor electrophysiology may indicate a similar response to drug and/or neuromodulation therapies.
To cite this abstract in AMA style:
A. Srivastava, M. Narang, R. Rajan, G. Shukla, F. Mohammad, A. Pandit, D. Vibha, M. Singh, M. Srivastava, K. Prasad. Electrophysiological characteristics of tremor in spinocerebellar ataxia type12 (SCA-12) and essential tremor (ET) [abstract]. Mov Disord. 2018; 33 (suppl 2). https://www.mdsabstracts.org/abstract/electrophysiological-characteristics-of-tremor-in-spinocerebellar-ataxia-type12-sca-12-and-essential-tremor-et/. Accessed June 14, 2025.« Back to 2018 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/electrophysiological-characteristics-of-tremor-in-spinocerebellar-ataxia-type12-sca-12-and-essential-tremor-et/