Open AccessAltered Activation in Cerebellum Contralateral to Unilateral Thalamotomy May Mediate Tremor Suppression in Parkinson’s Disease: A Short-Term Regional Homogeneity fMRI Study
Author(s) -
Zhi Wen,
Jie Zhang,
Jielan Li,
Jiankun Dai,
Fuchun Lin,
Guangyao Wu
Publication year - 2016
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0157562
Subject(s) - thalamotomy , thalamus , cerebellum , medicine , basal ganglia , parkinson's disease , essential tremor , resting state fmri , neuroscience , psychology , physical medicine and rehabilitation , central nervous system , deep brain stimulation , disease , radiology
Background Ventral intermediate nucleus thalamotomy is an effective treatment for Parkinson’s disease tremor. However, its mechanism is still unclear. Purpose We used resting-state fMRI to investigate short-term ReHo changes after unilateral thalamotomy in tremor-dominant PD, and to speculate about its possible mechanism on tremor suppression. Methods 26 patients and 31 healthy subjects (HS) were recruited. Patients were divided into two groups according to right- (rPD) and left-side (lPD) thalamotomy. Tremor was assessed using the 7-item scale from the Unified Parkinson’s disease rating scale motor score (mUPDRS). Patients were scanned using resting state fMRI after 12h withdrawal of medication, both preoperatively (PD pre ) and 7- day postoperatively (PD post ), whereas healthy subjects were scanned once. The regions associated with tremor and altered ReHo due to thalamic ablation were examined. Results The impact of unilateral VIM thalamotomy was characterized in the frontal, parietal, temporal regions, basal ganglia, thalamus, and cerebellum. Compared with PD pre , significantly reduced ReHo was found in the left cerebellum in patients with rPD post , and slightly decreased ReHo in the cerebellum vermis in patients with lPD post , which was significantly higher than HS. We demonstrated a positive correlation between the ReHo values in the cerebellum (in rPD, peak coordinate [-12, -54, -21], R = 0.64, P = 0.0025, and peak coordinate [-9, -54, -18], R = 0.71, P = 0.0025; in lPD, peak coordinate [3, -45, -15], R = 0.71, P = 0.004) in the pre-surgical condition, changes of ReHo induced by thalamotomy (in rPD, R = 0.63, P = 0.021, R = 0.6, P = 0.009; in lPD, R = 0.58, P = 0.028) and tremor scores contralateral to the surgical side, respectively. Conclusion The specific area that may be associated with PD tremor and altered ReHo due to thalamic ablation is the cerebellum. The neural basis underlying thalamotomy is complex; cerebellum involvement is far beyond cerebello-thalamic tract breakage.