Stereotactic radiosurgery for movement disorders

Abstract

Initially designed for the treatment of functional brain targets, stereotactic radiosurgery (SRS) has achieved an important role in the management of a wide range of neurosurgical pathologies. The interest in the application of the technique for the treatment of pain, and psychiatric and movement disorders has returned in the beginning of the 1990s, stimulated by the advances in neuroimaging, computerized dosimetry, treatment planning software systems, and the outstanding results of radiosurgery in other brain diseases. Since SRS is a neuroimaging-guided procedure, without the possibility of neurophysiological confirmation of the target, deep brain stimulation (DBS) and radiofrequency procedures are considered the best treatment options for movement-related disorders. Therefore, SRS is an option for patients who are not suitable for an open neurosurgical procedure. SRS thalamotomy provided results in tremor control, comparable to radiofrequency and DBS. The occurrence of unpredictable larger lesions than expected with permanent neurological deficits is a limitation of the procedure. Improvements in SRS technique with dose reduction, use of a single isocenter, and smaller collimators were made to reduce the incidence of this serious complication. Pallidotomies performed with radiosurgery did not achieve the same good results. Even though the development of DBS has supplanted lesioning as the first alternative in movement disorder surgery; SRS might still be the only treatment option for selected patients.

Magnetic resonance–guided focused ultrasound thalamotomy for tremor: a report of 30 Parkinson's disease and essential tremor cases

“…While as stated above, our patients experienced only mild and transient adverse events, the adverse events reported after invasive RF included intracerebral or extracerebral hemorrhage, seizures, infection, brain displacement, tension pneumocephalus, and direct injury from probe placement. 10 Gamma Knife thalamotomy is reported to achieve approximately 90% tremor relief as well, 3,31 but as opposed to the other procedures mentioned above in which tremor relief is noted immediately or a short time after the procedure, with Gamma Knife thalamotomy there is a long lag to the beginning of tremor relief that appears only approximately 1 year following radiation. 31 A recent review indicated that the most common adverse events after Gamma Knife thalamotomy include motor complications ranging from mild transient weakness to permanent hemiparesis and dysphagia.…”

“…Unilateral thalamotomy using RF has been reported effective in 73%-93% of patients but is accompanied by permanent complications in 9%-23%. 10 Bilateral thalamotomy using RF carries an even a higher risk of complications including anarthria and dysphagia, and therefore it is rarely performed today. 26 Thalamotomy using the Gamma Knife is effective but the beneficial clinical effects are delayed and prevent accurate localization and size determination of the planned lesion.…”

Willingness-to-Accept Gamma Knife Radiosurgery for Tinnitus Among Career San Francisco Firefighters

“…In contrast to DBS, SRS is not an open procedure and carries no risk of intracranial hemorrhage or postoperative infection. On the other hand, SRS may have more uncertainty in target identification as there is no intraoperative confirmation (11). Whereas Duma et al showed that functional SRS was effective and safe with no neurologic complication in 34 patients at 1 center (12), others have reported occasional serious complications such as visual field defects, new movement disorders, hemiparesis, and even death due to dysphagia and aspiration (13,14).…”

“…Whereas Duma et al showed that functional SRS was effective and safe with no neurologic complication in 34 patients at 1 center (12), others have reported occasional serious complications such as visual field defects, new movement disorders, hemiparesis, and even death due to dysphagia and aspiration (13,14). Complications are thought to be results of unexpectedly larger lesions that impair neighboring structures (11). Overall, complications are rare.…”

Expected Fate of Radiofrequency Lesioning: A Silent Death or a Cold-Blooded Murder

“…Gross [7] has strongly commented that bilateral pallidotomy is similar to internal segment globus pallidus DBS in effectiveness and safety for dystonia, and that pallidotomy was not rejected because of lack of effectiveness or safety. Various leading radiosurgical experience groups have also published guidelines for radiosurgical lesioning [8, 9]. There is now enough level of evidence in support of MR-guided focused ultrasound for thalamotomies in patients with essential tremor.…”