Diffusion tensor imaging: tract based spatial statistics study in essential tremor.
BACKGROUND
Essential tremor (ET) is a common movement disorder with motor and non-motor symptoms. We aimed to investigate the neurodegenerative changes in the brain white matter of patients with ET using Diffusion Tensor Imaging (DTI).


METHODS
Clinical and MRI data from 20 patients (5 women and 15 men; age-38.2 ± 16.5 yrs) with ET and 17 controls (3 women and 14 men; age-40.7 ± 16.5 yrs) were collected prospectively. The DTI data were analyzed using tract based spatial statistics (TBSS) software for tract wise analysis. Further region of interest (ROI) analysis was carried out in the genu of corpus callosum, anterior limb of internal capsule (ALIC), corticospinal tract (CS), and cerebellar peduncles. Effect of tremor severity, disease duration and age of onset on DTI metrics was also studied.


RESULTS
Patients with ET in comparison to controls showed significant (P(corrected) < 0.05) increase of mean diffusivity and radial diffusivity in right frontoparietal white matter. Axial diffusivity increase was seen in bilateral cerebral hemispheres, thalamus, brainstem and cerebellar hemisphere white matter. No significant change in fractional anisotropy of the white matter was seen. ROI analysis also revealed abnormalities in the ALIC and cerebellar peduncles. There was no correlation between the severity of white matter changes and clinical tremor severity score as well as disease duration.


CONCLUSIONS
This study provides in vivo evidence for axonal disintegration of the cerebral and cerebellar white matter fibres in patients with ET.
Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health & Neurosciences, Hosur Road, Bangalore-560029, Karnataka, India.
Jitender
J
Saini
Bhavani Shankara
BS
Bagepally
Maya Dattatraya
MD
Bhatt
Vijay
V
Chandran
Rose Dawn
RD
Bharath
Chandrajit
C
Prasad
Ravi
R
Yadav
Pramod Kumar
PK
Pal
D000328:Adult; D000367:Age Factors; D017668:Age of Onset; D001931:Brain Mapping; D003627:Data Interpretation, Statistical; D056324:Diffusion Tensor Imaging; D020329:Essential Tremor / Q000473:pathology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D055815:Young Adult