Gamma Knife Thalamotomy for Parkinson Disease and Essential Tremor

A Prospective Multicenter Study

Ohye, Chihiro MD, DMSc; Higuchi, Yoshinori MD, PhD^‡; Shibazaki, Toru MD^*; Hashimoto, Takao MD, PhD^§; Koyama, Toru MD^§; Hirai, Tatsuo MD, DMSc^‖; Matsuda, Shinji MD^¶; Serizawa, Toru MD, PhD^¶; Hori, Tomokatsu MD, DMSc^#; Hayashi, Motohiro MD, DMSc^#; Ochiai, Taku MD, DMSc^#; Samura, Hirofumi MD^**; Yamashiro, Katsumi MD, DMSc^**

Author Information

^*Functional and Gamma Knife Surgery Center, Hidaka Hospital, Takasaki, Japan

^‡Department of Neurological Surgery, Chiba University Graduate School of Medicine, Chiba, Japan

^§Center for Neurological Diseases, Aizawa Hospital, Matsumoto, Japan

^‖Gamma Knife Center, Heisei Memorial Hospital, Fujieda, Japan

^¶Gamma Knife House, Chiba Cardiovascular Center, Ichihara, Japan

^#Department of Neurosurgery, Tokyo Women's Medical University, Tokyo, Japan

^**Department of Neurosurgery, Okinawa Central Hospital, Naha, Japan

Correspondence: Yoshinori Higuchi, MD, PhD, Department of Neurological Surgery, Chiba University Graduate School of Medicine, Inohana 1-8-1, Chuo-ku, Chiba City, Chiba 260-8670, Japan. E-mail:[email protected]

† Deceased

Received January 4, 2010

Accepted August 17, 2011

Neurosurgery70(3):p 526-536, March 2012. |DOI:10.1227/NEU.0b013e3182350893

Abstract

BACKGROUND:

No prospective study of gamma knife thalamotomy for intractable tremor has previously been reported.

OBJECTIVE:

To clarify the safety and optimally effective conditions for performing unilateral gamma knife (GK) thalamotomy for tremors of Parkinson disease (PD) and essential tremor (ET), a systematic postirradiation 24-month follow-up study was conducted at 6 institutions. We present the results of this multicenter collaborative trial.

METHODS:

In total, 72 patients (PD characterized by tremor, n = 59; ET, n = 13) were registered at 6 Japanese institutions. Following our selective thalamotomy procedure, the lateral part of the ventralis intermedius nucleus, 45% of the thalamic length from the anterior tip, was selected as the GK isocenter. A single 130-Gy shot was applied using a 4-mm collimator. Evaluation included neurological examination, magnetic resonance imaging and/or computerized tomography, the unified Parkinson's disease rating scale (UPDRS), electromyography, medication change, and video observations.

RESULTS:

Final clinical effects were favorable. Of 53 patients who completed 24 months of follow-up, 43 were evaluated as having excellent or good results (81.1%). UPDRS scores showed tremor improvement (parts II and III). Thalamic lesion size fluctuated but converged to either an almost spherical shape (65.6%), a sphere with streaking (23.4%), or an extended high-signal zone (10.9%). No permanent clinical complications were observed.