Volume 18, Issue 2 p. 163-170
Research Article

Long-term efficacy of thalamic deep brain stimulation for tremor: Double-blind assessments

Stig Rehncrona MD, PhD

Corresponding Author

Stig Rehncrona MD, PhD

The Department of Clinical Neuroscience, Division of Neurosurgery, University in Lund, Sweden

Department of Neurosurgery, University Hospital, S-221 85 Lund, SwedenSearch for more papers by this author
Bo Johnels MD, PhD

Bo Johnels MD, PhD

The Department of Neurology, Göteborg University, Sweden

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Håkan Widner MD, PhD

Håkan Widner MD, PhD

The Department of Clinical Neuroscience, Division of Neurology, University in Lund, Sweden

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Anna-Lena Törnqvist RN

Anna-Lena Törnqvist RN

The Department of Clinical Neuroscience, Division of Neurosurgery, University in Lund, Sweden

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Marwan Hariz MD, PhD

Marwan Hariz MD, PhD

The Department of Neurosurgery, University Hospital, Umeå, Sweden

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Olof Sydow MD, PhD

Olof Sydow MD, PhD

The Department of Neurology, Karolinska Hospital, Stockholm, Sweden

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First published: 21 October 2002
Citations: 257

Abstract

Thalamic deep brain stimulation (DBS) is proven to suppress tremor in Parkinson's disease (PD) and essential tremor (ET). However, there are few reports on its long-term efficacy. We studied the efficacy of DBS at 2 years and 6–7 years after electrode implantations in the ventrointermediate nucleus of the thalamus in 39 patients (20 PD, 19 ET) with severe tremor. Twenty-five of the patients completed the study. Evaluations were done in a double-blind manner with the Unified Parkinson's Disease Rating Scale (UPDRS) and Essential Tremor Rating Scale (ETRS). DBS decreased tremor sum scores in PD (P < 0.025) compared to the preoperative baseline (median, 7; Q25–75, 6–9) both at 2 years (median, 2; Q25–75, 2–3.5; n = 16) and at 6 to 7 years (median, 2.5; Q25–75, 0.5–3; n = 12). Stimulation on improved tremor sum as well as sub scores (P < 0.025) compared to stimulation off conditions. In ET, thalamic stimulation improved (P < 0.025) kinetic and positional tremor at both follow-up periods (n = 18 and n = 13, respectively) with significant improvements (P < 0.025) in hand-function tests. PD but not ET patients showed a general disease progression. Stimulation parameters were remarkably stable over time. We conclude that high-frequency electric thalamic stimulation can efficiently suppress severe tremor in PD and ET more than 6 years after permanent implantation of brain electrodes. © 2002 Movement Disorder Society