Unilateral caudal zona incerta deep brain stimulation for Parkinsonian tremor.
BACKGROUND
The subthalamic nucleus is currently the target of choice in deep brain stimulation (DBS) for Parkinson's disease (PD), while thalamic DBS is used in some cases of tremor-dominant PD. Recently, a number of studies have presented promising results from DBS in the posterior subthalamic area, including the caudal zona incerta (cZi). The aim of the current study was to evaluate cZi DBS in tremor-dominant Parkinson's disease.


METHODS
14 patients with predominately unilateral tremor-dominant PD and insufficient relief from pharmacologic therapy were included and evaluated according to the motor part of the Unified Parkinson Disease Rating Scale (UPDRS). The mean age was 65 ± 6.1 years and the disease duration 7 ± 5.7 years. Thirteen patients were operated on with unilateral cZi DBS and 1 patient with a bilateral staged procedure. Five patients had non-L-dopa responsive symptoms. The patients were evaluated on/off medication before surgery and on/off medication and stimulation after a minimum of 12 months after surgery.


RESULTS
At the follow-up after a mean of 18.1 months stimulation in the off-medication state improved the contralateral UPDRS III score by 47.7%. Contralateral tremor, rigidity, and bradykinesia were improved by 82.2%, 34.3%, and 26.7%, respectively. Stimulation alone abolished tremor at rest in 10 (66.7%) and action tremor in 8 (53.3%) of the patients.


CONCLUSIONS
Unilateral cZi DBS seems to be safe and effective for patients with severe Parkinsonian tremor. The effects on rigidity and bradykinesia were, however, not as profound as in previous reports of DBS in this area.
Department of Pharmacology and Clinical Neuroscience, Division of Neurosurgery, Umeå University, Umeå, Sweden. patric.blomstedt@neuro.umu.se
Patric
P
Blomstedt
Anders
A
Fytagoridis
Mattias
M
Åström
Jan
J
Linder
Lars
L
Forsgren
Marwan I
MI
Hariz
D000368:Aged; D000978:Antiparkinson Agents / Q000627:therapeutic use; D046690:Deep Brain Stimulation / Q000379:methods*; D004351:Drug Resistance; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality; D006801:Humans; D018476:Hypokinesia / Q000188:drug therapy / Q000601:surgery / Q000628:therapy; D007980:Levodopa / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000188:drug therapy / Q000601:surgery / Q000628:therapy*; D020531:Subthalamic Nucleus / Q000033:anatomy & histology / Q000502:physiology / Q000601:surgery; D020530:Subthalamus / Q000033:anatomy & histology / Q000502:physiology* / Q000601:surgery; D016896:Treatment Outcome; D014202:Tremor / Q000188:drug therapy / Q000601:surgery / Q000628:therapy*
D000978:Antiparkinson Agents; D007980:Levodopa