Takaomi Taira

A Randomized Trial of Focused Ultrasound Thalamotomy for Essential Tremor

BACKGROUND Uncontrolled pilot studies have suggested the efficacy of focused ultrasound thalamotomy with magnetic resonance imaging (MRI) guidance for the treatment of essential tremor. METHODS We enrolled patients with moderate-to-severe essential tremor that had not responded to at least two trials of medical therapy and randomly assigned them in a 3:1 ratio to undergo unilateral focused ultrasound thalamotomy or a sham procedure. The Clinical Rating Scale for Tremor and the Quality of Life in Essential Tremor Questionnaire were administered at baseline and at 1, 3, 6, and 12 months. Tremor assessments were videotaped and rated by an independent group of neurologists who were unaware of the treatment assignments. The primary outcome was the between-group difference in the change from baseline to 3 months in hand tremor, rated on a 32-point scale (with higher scores indicating more severe tremor). After 3 months, patients in the sham-procedure group could cross over to active treatment (the open-label extension cohort). RESULTS Seventy-six patients were included in the analysis. Hand-tremor scores improved more after focused ultrasound thalamotomy (from 18.1 points at baseline to 9.6 at 3 months) than after the sham procedure (from 16.0 to 15.8 points); the between-group difference in the mean change was 8.3 points (95% confidence interval [CI], 5.9 to 10.7; P<0.001). The improvement in the thalamotomy group was maintained at 12 months (change from baseline, 7.2 points; 95% CI, 6.1 to 8.3). Secondary outcome measures assessing disability and quality of life also improved with active treatment (the blinded thalamotomy cohort)as compared with the sham procedure (P<0.001 for both comparisons). Adverse events in the thalamotomy group included gait disturbance in 36% of patients and paresthesias or numbness in 38%; these adverse events persisted at 12 months in 9% and 14% of patients, respectively. CONCLUSIONS MRI-guided focused ultrasound thalamotomy reduced hand tremor in patients with essential tremor. Side effects included sensory and gait disturbances. (Funded by InSightec and others; ClinicalTrials.gov number, NCT01827904.).

Consensus on guidelines for stereotactic neurosurgery for psychiatric disorders

Background For patients with psychiatric illnesses remaining refractory to ‘standard’ therapies, neurosurgical procedures may be considered. Guidelines for safe and ethical conduct of such procedures have previously and independently been proposed by various local and regional expert groups. Methods To expand on these earlier documents, representative members of continental and international psychiatric and neurosurgical societies, joined efforts to further elaborate and adopt a pragmatic worldwide set of guidelines. These are intended to address a broad range of neuropsychiatric disorders, brain targets and neurosurgical techniques, taking into account cultural and social heterogeneities of healthcare environments. Findings The proposed consensus document highlights that, while stereotactic ablative procedures such as cingulotomy and capsulotomy for depression and obsessive-compulsive disorder are considered ‘established’ in some countries, they still lack level I evidence. Further, it is noted that deep brain stimulation in any brain target hitherto tried, and for any psychiatric or behavioural disorder, still remains at an investigational stage. Researchers are encouraged to design randomised controlled trials, based on scientific and data-driven rationales for disease and brain target selection. Experienced multidisciplinary teams are a mandatory requirement for the safe and ethical conduct of any psychiatric neurosurgery, ensuring documented refractoriness of patients, proper consent procedures that respect patients capacity and autonomy, multifaceted preoperative as well as postoperative long-term follow-up evaluation, and reporting of effects and side effects for all patients. Interpretation This consensus document on ethical and scientific conduct of psychiatric surgery worldwide is designed to enhance patient safety.

A New Approach to Control Central Deafferentation Pain: Spinal Intrathecal Baclofen

We investigated the short-term effects of an intrathecal bolus injection of baclofen on central pain due to stroke or spinal cord injury. Pain relief was obtained in 64% of the patients. The effects developed 1-2 hours after the injection and continued for 10-24 hours. Both spinal segmental and supraspinal mechanisms may be involved in the production of baclofen-analgesia.

Stereotactic Ventrooralis Thalamotomy for Task-Specific Focal Hand Dystonia (Writer’s Cramp)

Background: Writer’s cramp is a type of focal dystonia due to dysfunction of the pallido-thalamo-cortical circuit. The symptom is refractory to most conservative treatment, though botulinum toxin injection is generally used for symptomatic relief. As a surgical treatment of dystonia, we performed stereotactic nucleus ventrooralis (Vo) thalamotomy for dystonic cramp of the hand. Methods: Twelve patients (5 men, 3 women; age 26–40 years, mean 32.1 years) with medically intractable task-specific focal dystonia of the hand underwent Vo thalamotomy. The stereotactic target was chosen at the junction of the anterior and posterior Vo nuclei. Results: The mean duration of the symptom ranged from 3 to 6 years (mean 4.5 years.) All patients had complained of difficulty in writing. Seven patients were professionals, such as a comic artist, guitarist and barber, and, because of the dystonic symptoms occurring during their work, they had stopped pursuing their profession. All patients showed immediate postoperative disappearance of dystonic symptoms, and the effect was sustained during the follow-up period (3–33 months, mean 13.1 months), except in one case. Two patients showed partial recurrence of the symptom and underwent second thalamotomy 5 months after the initial surgery with satisfactory results. The score on the writer’s cramp rating scale decreased significantly (p < 0.001) after Vo thalamotomy. There were no permanent operative complications. There was no mortality or permanent morbidity. Conclusion: Although a longer follow-up is needed, stereotactic Vo thalamotomy is a useful and safe therapeutic option for writer’s cramp.

Inclusion and exclusion criteria for DBS in dystonia.

When considering a patient with dystonia for deep brain stimulation (DBS) surgery several factors need to be considered. Level B evidence has shown that all motor features and associated pain in primary generalized and segmental dystonia are potentially responsive to globus pallidus internus (GPi) DBS. However, improvements in clinical series of ≥90% may reflect methods that need improvement, and larger prospective studies are needed to address these factors. Nevertheless, to date the selection criteria for DBS—specifically in terms of patient features (severity and nature of symptoms, age, time of evolution, or any other demographic or disease aspects)—have not been assessed in a systematic fashion. In general, dystonia patients are not considered for DBS unless medical therapies have been previously and extensively tested. The vast majority of reported patients have had DBS surgery when the disease was provoking important disability, with loss of independence and impaired quality of life. There does not appear to be an upper age limit or a minimum age limit, although there are no published data regarding the outcome of GPi DBS for dystonia in children younger than 7 years of age. There is currently no enough evidence to prove that subjects with primary‐generalized dystonia who undergo DBS at an early age and sooner rather than later after disease onset may gain more benefit from DBS than those undergoing DBS after the development of fixed skeletal deformities. There is no enough evidence to refuse or support consideration of DBS in patients with previous ablative procedures.

Intrathecal baclofen in the treatment of post-stroke central pain, dystonia, and persistent vegetative state

Intrathecal baclofen (ITB) administration is a fully established treatment for severe spasticity. However, it is not widely known that baclofen, an agonist of the GABA-B receptor, has additional beneficial effects in other conditions such as chronic pain, coma, dystonia, tetanus, and hyypothalamic storm. Sporadic cases of dramatic recovery from persistent vegetative state after intrathecal administration of baclofen have been reported. There have been also reports on the use of baclofen for control of dystonia due to cerebral palsy, neuropathic central pain syndrome or reflex sympathetic dystrophy. On the other hand, epidural spinal cord stimulation (SCS) has been used in the management not only of pain but also of spasticity, dystonia, and in order to improve deteriorated consciousness, but the effects so far have been modest and variable. Similarities between ITB and SCS are interesting as both involve the spinal GABAergic system. Based on a 15-year personal experience of intrathecal baclofen, I would stress the importance of this treatment not only for spasticity but also for other difficult neurological disorders.

CT-guided stereotactic surgery for evacuation of hypertensive intracerebral hematoma

During the last 3 years, 46 cases of hypertensive intracerebral hemorrhage were treated by CT-guided stereotactic surgery. Our present report is concerned with the evaluation of this procedure in the treatment of hypertensive intracerebral hematoma, in terms of the rate of aspirated hematoma and follow-up study of patients. It is difficult to draw any definite conclusion about the operative indications. CT-guided stereotactic aspiration, however, can be evaluated as a less invasive and more definitive treatment of intracerebral hematoma in the basal ganglia and thalamus.

Phrenic nerve stimulation for diaphragm pacing with a spinal cord stimulator: Technical note

BACKGROUND Diaphragm pacing with electrical stimulation of the phrenic nerve is an established treatment for central hypoventilation syndrome. The device, however, is not readily available, at least in Japan. We used the spinal cord stimulator for pain control for phrenic nerve stimulation. The purpose of this study is to evaluate the efficacy and feasibility of phrenic pacing with the compromise method. METHODS We implanted a stimulator for spinal cord stimulation (Itrel 3 or X-trel, Medtronic, MN) in 4 patients with chronic hypoventilation because of brainstem dysfunction of various origins. The stimulation electrode was placed along the right phrenic nerve in the neck, and the device was implanted in the anterior chest. We used the cyclic mode, and set the parameters at 1 second ramp up, 2 seconds on, 3 seconds off. The pulse width and the frequency were set at 150 microsec and 21 Hz, respectively. The amplitude of the output was adjusted to obtain sufficient tidal volume and to maintain PaCO(2) at around 40 mm Hg. RESULTS During the follow-up period from 6 to 19 months (mean 8.3 months), stable and sufficient ventilation were observed in all patients without complications. One patient with sleep apnea syndrome used the device only at night and became free from a respirator. Three patients who were completely respirator-dependent became ambulatory during the daytime. CONCLUSION Though longer follow-up is necessary, diaphragm pacing by stimulation of the phrenic nerve with the spinal cord stimulator is feasible for a treatment of central hypoventilation syndrome.

Long-term improvement of musician's dystonia after stereotactic ventro-oral thalamotomy.

Musicians dystonia is a task‐specific movement disorder that causes twisting or repetitive abnormal finger postures and movements, which tend to occur only while playing musical instruments. Such a movement disorder will probably lead to termination of the careers of affected professional musicians. Most of the currently available treatments have yet to provide consistent and satisfactory results. We present the long‐term follow‐up results of ventro‐oral thalamotomy for 15 patients with musicians dystonia.

The contemporary practice of psychiatric surgery: results from a survey of North American functional neurosurgeons.

Background: Deep brain stimulation (DBS) for psychiatric indications is becoming increasingly safe and effective. As a result, the treatment of these conditions by neurosurgeons is becoming more widespread and a larger part of the functional neurosurgeons’ practice. Given the troubled history of the field and its current renaissance, it is important to evaluate current practices, to serve as a baseline for future comparison, and to gauge changing cultural attitudes towards invasive neuromodulation. Objectives: The purpose of this study was to obtain a snapshot of the practice of the contemporary functional neurosurgeon engaged in psychiatric surgery. Current practices as well as attitudes towards the direction of the field and its future were also investigated. Methods: We designed an online survey and distributed it electronically to 299 functional neurosurgeons in North America identified by membership in the World Society for Stereotactic and Functional Neurosugery. Subsequent statistical and thematic analysis was performed on the data obtained. Results: Of 299 surveys sent out, 84 were completed (28%). Fifty percent of functional neurosurgeons are currently engaged in some form of psychiatric surgery, with DBS for obsessive-compulsive disorder and depression accounting for most cases. Most surgeons see psychiatric surgery as a growing field, with multidisciplinary teams and a greater engagement with psychiatry necessary for the expansion of the field. Opinions differed substantially on hypothetical scenarios dealing with surgical cognitive enhancement, with some in favour of it, citing patient autonomy and choice, and others drawing a clear distinction between pathologic and non-pathologic states. Conclusions: Surgery for psychiatric indications is a growing field in the contemporary functional neurosurgeon’s practice. Most neurosurgeons see the field continuing to grow and psychiatric surgery becoming a larger part of their daily practice, with the appropriate ethical and psychiatric oversight. Future editions of this survey and their results can be used to trace the development and growth of the field as technology and cultural attitudes continue to evolve.