Roopa Rajan (India)
All India Institute of Medical Sciences NeurologyAuthor Of 1 Presentation
DENTATO-RUBRO-THALAMIC TRACT (DRTT) DYSFUNCTION IN THE EMERGENCE OF TREMOR IN SPINOCEREBELLAR ATAXIA TYPE -12 (SCA-12)
- Achal Kumar Srivastava (India)
Abstract
Background and Aims:
Spinocerebellar ataxia type 12 begins with action tremor of hand followed by gait ataxia. The tremor matches with ET and PD in early illness which has shown impairment of DRTT. We aimed to determine the white matter changes in regions of the DRT tract using Diffusion tensor imaging (DTI) in SCA-12 patients.
Methods:
Twenty-six genetically confirmed SCA12 patients and 13 healthy controls were enrolled. Clinical and electrophysiological evaluation of tremors was done in SCA12 patients. DTI was performed on a 3T scanner, with b=800 s/mm2 and 32 directions. Fractional anisotropic (FA) values were measured for regions in the DRRT.
Results:
Electrophysiology of tremor showed a synchronous pattern of muscle activation, with an average frequency of 4-5 Hz and varying amplitude in SCA12 patients. DTI in SCA12 patients showed significant reduction in the FA values for the left dentate nucleus (0.30± 0.01in controls versus 0.28 ± 0.04 in SCA12 patients, p=0.0256), left red nucleus (0.11±0.01 in controls versus 0.08 ± 0.02 in SCA12 patients, p=0.007), thalamus (0.10 ± 0.02 in controls, 0.07 ± 0.01in SCA12 patients, p=0.000), and VL nucleus of thalamus (0.39 ± 0.03 in controls, 0.35 ± 0.03 in SCA12 patients, p=0.007). The FTM tremor rating scale and FA value in the red nucleus showed a significant negative correlation (r=-0.5128-, p=0.0074).
Conclusions:
Microstructural white matter changes were found in specific regions (Dentate nucleus, red nucleus, thalamus, and VL nucleus) of DRTT in SCA12 patients. Dysfunction of DRRT may be implicated in the emergence of tremors in SCA12 patients.