Gamma Knife Radiosurgery for Tremor Movement Disorder: A Systematic Review

Abstract

AIM: The goal of this systematic review is to know how outcome of GKRS for tremor movement disorder. METHODS: Literature searching was conducted in database online that is PubMed, Science Direct, Cochrane Library, Google Scholar and hand searching with keyword “gamma knife,” “parkinson,” “tremor,” “success rate,” “good outcome,” and “free tremor.” Articles included were full-text and observational study and written in Bahasa or English. RESULTS: This systematic review used only six articles, which five of them examined ET and the other PD. Majority of studies used Fahn-Tolosa-Marin clinical tremor rating scale (TRS) for evaluation pre- and post-GKRS. However, the duration of follow-up is varies from <1 year until 76 months. The doses are also varies from 110 until 150 Gy (Median 120–130 Gy). A study report that 1 year after GKRS, ET patients could have 58% improvement in writing and 51% in drawing. Other study, which of median follow-up was 36 months, had 69% of samples showed improvement in both action tremor and writing scores. Ohye et al. in 2008 reported that since 1992, they have 80% successful in GK thalamotomy for tremor, either ET or PD. Similar author has been done multivariate study in six Japanese institution which of result was GKRS thalamotomy could be alternative treatment for intractable tremor, either ET or PD until 24 months. All of the study about ET have improvement results with GKRS in ventralis intermedius (VIM) of the thalamus. However, one study about PD evaluated GKRS in subthalamic nucleus (STN) of thalamus and got neurological complication with higher-risk of GKRS hyper response. CONCLUSION: GKRS, especially VIM thalamotomy, offers effective and safe alternative for ET and PD. We need more studies with approved method to answer this clinical question accurately. However, the study comparing GKRS and open surgical is still needed.