Radiofrequency Lesioning for Movement and Psychiatric Disorders-Experience of 107 Cases

Abstract

BackgroundRadiofrequency lesioning (RFL) though used since the 1950s, had been replaced by DBS in the 1990s. The availability of magnetic resonance-guided focused ultrasound for lesioning has renewed the interest in RFL.ObjectiveThis paper analysis RFL in contemporary Functional Neurosurgery for various indications and its outcome. Complication rates of RFL are compared with the same author’s experience of DBS.MethodsOne hundred and seven patients underwent RFL between 1998 and 2019. Indications included Parkinson’s Disease (PD), tremors, dystonia, and obsessive-compulsive disorders (OCD). The surgeries performed include thalamotomy (29), pallidotomy (49), subthalamotomy (23), and anterior capsulotomy/nucleus accumbens lesioning (6). Appropriate rating scales were used for preoperative and postoperative evaluations.ResultsThere was a 25% recurrence rate of tremors for PD after thalamotomy. Writer’s cramp rating scale improved from a mean of 10.54–1.6 in task specific dystonia (TSD) patients, after thalamotomy. In PD patients, after pallidotomy, contralateral motor Unified Parkinson’s Disease Rating Scale (UPDRS) and dyskinesia scores, improved by 41 and 57%, respectively, at 1-year. Burke-Fahn-Marsden Dystonia Rating Scale in hemidystonia patients improved from 18.04 to 6.91, at 1-year. There was 32 and 31% improvement in total and motor UPDRS, respectively, in the subthalamotomy patients, at 2-year. All patients of OCD were in remission. There were three deaths in the pallidotomy group. Postoperative, dysarthria, confusion, hemiparesis, dyskinesia, and paraesthesia occurred in 12 patients, of which, 7 were transient.ConclusionRFL is a useful option in a select group of patients with tremors and dystonia. It is our preferred treatment option for TSD and OCD.

Tremor in Parkinson’s Disease: From Pathophysiology to Advanced Therapies

“…Unlike MRgFUS and GK treatments, RF ablation is performed through a frontal burr hole of the skull and requires brain penetration with a special electrode [156,157]. The electrode can be heated to sub-ablative thermal temperatures to produce a "test lesion."…”

“…The modality seems to achieve the highest tremor control in PD when targeting the thalamus, with improvements reaching up to 74%. In most cases, the use is limited to one side, as bilateral RF thalamotomy is typically associated with a high rate of adverse effects [156,157]. Complications are usually transient and result from local edema produced after ablation, which ultimately recover as the edema resolves [139].…”

Surgical Therapies for Parkinson Disease

“…During this procedure, multiple beams of radiation converge onto the target, delivering a dose of radiation that can vary from 120 Gy to 200 Gy depending on the institution 24 . There is also a concern for latent radiation effects and potential risk for secondary neoplasia 15,25 . Niranjan and colleagues 26 discussed using bilateral gamma knife thalamotomy for bilateral tremor; however, this therapy is generally applied unilaterally in clinical practice 24 …”

“…24 There is also a concern for latent radiation effects and potential risk for secondary neoplasia. 15,25 Niranjan and colleagues 26 discussed using bilateral…”

Effective Subthalamic Nucleus Deep Brain Stimulation Following MRgFUS for Tremor Dominant Parkinson's Disease

“…MRI guided Focused Ultrasound (MRgFUS) is an effective treatment option for tremor in PD, 5 however there are reports of tremor recurrence following MRgFUS VIM thalamotomy 6 . The reported rates of tremor recurrence following methods of single target ablative therapy are variable 7,8 and rescue DBS has been shown to be effective in treating tremor recurrence following non‐MRgFUS thalamotomy 9 . The dualism of tremor propagation has been noted with dual site DBS, targeting both the VIM and STN, shown to be efficacious in cases of tremor dominant PD unresponsive to VIM stimulation alone 10 .…”