Focused Ultrasound Thalamotomy for Refractory Essential Tremor: A Japanese Multicenter Single-Arm Study.

BACKGROUND: Several feasibility studies and a randomized, controlled, multicenter trial have demonstrated the safety and efficacy of unilateral transcranial magnetic resonance-guided focused ultrasound (FUS) lesioning of the ventral intermediate thalamic nucleus in treating essential tremor. OBJECTIVE: To evaluate the safety and efficacy of FUS thalamotomy in a Japanese patient cohort through a prospective, multicenter, single-arm confirmatory trial. METHODS: A total of 35 patients with disabling refractory essential tremor underwent unilateral FUS thalamotomy and were followed up for 12 post-treatment months. Safety was measured as the incidence and severity of treatment-related adverse events. Efficacy was measured as the tremor severity and quality of life improvements using the Clinical Rating Scale for Tremor and Questionnaire for Essential Tremor. RESULTS: The mean skull density ratio (SDR) was 0.47. There was a significant decrease in the mean postural tremor score of the treated hand from baseline to 12 mo by 56.4% (95% CI: 46.7%-66.1%; P < .001), which was maintained at last follow-up. Quality of life improved by 46.3% (mean overall Questionnaire for Essential Tremor score of 17.4 [95% CI: 12.1-22.7]) and there were no severe adverse events. The most frequent adverse event was gait disturbance and all events resolved. CONCLUSION: Unilateral FUS thalamotomy allowed significant and sustained tremor relief and improved the quality of life with an outstanding safety profile. The observed safety and efficacy of FUS thalamotomy were comparable to those reported in a previous multicenter study with a low SDR, and inclusion of the low SDR group did not affect effectiveness.

Predictors of Outcomes After Focused Ultrasound Thalamotomy.

BACKGROUND: Magnetic resonance-guided focused ultrasound thalamotomy (FUS-T) is an emerging treatment for essential tremor (ET). OBJECTIVE: To determine the predictors of outcomes after FUS-T. METHODS: Two treatment groups were analyzed: 75 ET patients enrolled in the pivotal trial, between 2013 and 2015; and 114 patients enrolled in the postpivotal trials, between 2015 and 2016. All patients had medication-refractory, disabling ET, and underwent unilateral FUS-T. The primary outcome (hand tremor score, 32-point scale with higher scores indicating worse tremor) and the secondary outcome variables (Clinical Rating Scale for Tremor Part C score: 32-point scale with higher scores indicating more disability) were assessed at baseline and 1, 3, 6, and 12 mo. The operative outcome variables (ie, peak temperature, number of sonications) were analyzed. The results between the 2 treatment groups, pivotal and postpivotal, were compared with repeated measures analysis of variance and adjusted for confounding variables. RESULTS: A total of 179 patients completed the 12-mo evaluation. The significant predictors of tremor outcomes were patient age, disease duration, peak temperature, and number of sonications. A greater improvement in hand tremor scores was observed in the postpivotal group at all time points, including 12 mo (61.9% ± 24.9% vs 52.1% ± 24.9%, P = .009). In the postpivotal group, higher energy was used, resulting in higher peak temperatures (56.7 ± 2.5 vs 55.6 ± 2.8°C, P = .004). After adjusting for age, years of disease, number of sonications, and maximum temperature, the treatment group was a significant predictor of outcomes (F = 7.9 [1,165], P = .005). CONCLUSION: We observed an improvement in outcomes in the postpivotal group compared to the pivotal group potentially reflecting a learning curve with FUS-T. The other associations of tremor outcomes included patient age, disease duration, peak temperature, and number of sonications.

Neurological adverse event profile of magnetic resonance imaging-guided focused ultrasound thalamotomy for essential tremor.

BACKGROUND: Magnetic resonance imaging-guided focused ultrasound thalamotomy is approved by the U.S. Food and Drug Administration for treatment of essential tremor. Although this incisionless technology creates an ablative lesion, it potentially avoids serious complications of open stereotactic surgery. OBJECTIVE: To determine the safety profile of magnetic resonance imaging-guided focused ultrasound unilateral thalamotomy for essential tremor, including frequency, and severity of adverse events, including serious adverse events. METHODS: Analysis of safety data for magnetic resonance imaging-guided focused ultrasound thalamotomy (186 patients, five studies). RESULTS: Procedure-related serious adverse events were very infrequent (1.6%), without intracerebral hemorrhages or infections. Adverse events were usually transient and were commonly rated as mild (79%) and rarely severe (1%). As previously reported, abnormalities in sensation and balance were the commonest thalamotomy-related adverse events. CONCLUSION: The overall safety profile of magnetic resonance imaging-guided focused ultrasound thalamotomy supports its role as a new option for patients with medically refractory essential tremor. © 2018 International Parkinson and Movement Disorder Society.

Clinical significance of polyglutamylation in primary central nervous system lymphoma.

The therapeutic response to high-dose methotrexate (HD-MTX) therapy for primary central nervous system lymphoma (PCNSL) varies. Polyglutamylation is a reversible protein modification with a high occurrence rate in tumor cells. MTX incorporated into cells is polyglutamylated and strongly binds to dihydrofolate reductase without competitive inhibition by leucovorin (LV). Tumor cells with high polyglutamylation levels are selectively killed, whereas normal cells with lower polyglutamylation are rescued by LV. We hypothesized that the extent of polyglutamylation in tumor cells determines treatment resistance. Here, we investigated the therapeutic response of PCNSL to HD-MTX therapy with LV rescue based on polyglutamylation status. Among 113 consecutive PCNSL patients who underwent HD-MTX therapy in our department between 2001 and 2014, polyglutamylation was evaluated by immunostaining in 82 cases, with relationships between polyglutamylation and therapeutic response retrospectively examined. Human malignant lymphoma lines were used for in vitro experiments, and folpolyglutamate synthetase (FPGS), which induces polyglutamylation, was knocked down with short-hairpin RNA, and a stable cell line with a low rate of polyglutamylation was established. Cell viability after MTX treatment with LV rescue was evaluated using sodium butyrate (NaBu), a histone-deacetylase inhibitor that induces polyglutamylation by elevating FPGS expression. The complete response rate was significantly higher in the group with polyglutamylation than in the non-polyglutamylation group [58.1% (25/43) and 33.3% (13/39), respectively] (p < 0.05), and progression-free survival was also significantly increased in the group with polyglutamylation (p < 0.01). In vitro, the relief effect of LV after MTX administration was significantly enhanced after FPGS knockdown in al cell lines, whereas enhancement of FPGS expression by NaBu treatment significantly reduced this relief effect. These findings suggested that polyglutamylation could be a predictor of therapeutic response to HD-MTX therapy with LV rescue in PCNSL. Combination therapy with HD-MTX and polyglutamylation-inducing agents might represent a promising strategy for PCNSL treatment.

Thalamic stimulation alleviates levodopa-resistant rigidity in a patient with non-Parkinson's disease parkinsonian syndrome.

Deep brain stimulation (DBS) to the thalamic ventrointermediate nucleus (Vim) is a useful treatment in patients with tremor-dominant Parkinson's disease (PD). Efficacy to alleviate rigidity remains controversial. We report a 65-year-old right-handed man with persistent severe rigidity and bradykinesia on the right side despite daily administration of levodopa/carbidopa (600/60mg). His right-hand tremor was continuous at rest and present at action. His antiparkinsonian medications appeared ineffective and he reported difficulties with writing and eating. Repeated (123)I-meta-iodobenzylguanidine myocardial scintigraphy studies demonstrated a non-PD pattern. He underwent the stereotactic implantation of a DBS electrode into the left Vim. Using contacts 1 and 2 we started continuous unipolar stimulation with a pulse generator implanted in a subclavian pocket. This improved the tremor and the rigidity and bradykinesia of his right hand. Postoperative image analysis revealed the likelihood of simultaneous stimulation of the Vim and the nucleus ventralis oralis posterior. Our findings suggest thalamic stimulation as a therapeutic option for drug-resistant rigidity (and tremor) in patients with parkinsonian syndromes ineligible for DBS targeted at the globus pallidus internus or subthalamic nucleus.

Hemidystonia secondary to thalamic hemorrhage treated with GPi stimulation.

There have been few reports on the surgical treatment of secondary hemidystonias, most of which are due to basal ganglia stroke or trauma. We present 2 patients with hemidystonia secondary to thalamic hemorrhage whom we successfully treated with unilateral globus pallidus internus (GPi) stimulation. Case 1 is a 56-year-old man with abnormal posturing and intolerable muscle contraction pain in the left arm. Case 2 is a 73-year-old woman who developed severe abnormal posturing in the right arm and gait disturbance due to hyperextension of the right leg. The dystonic symptoms of both patients were refractory to medication. Three months after the inception of high frequency GPi stimulation, the motor scores on the Burke-Fahn-Marsden Dystonia Rating Scale were improved by 49.2% and 34.3% in Cases 1 and 2, respectively. We suggest GPi stimulation as a possible alternative to treat secondary hemidystonia.

Secondary cervical dystonia following stereotactic radiosurgery in a patient with thalamic glioma.

BACKGROUND: Cervical dystonia associated with structural lesion is uncommon. We report the first patient with secondary CD after stereotactic radiosurgery for thalamic glioma. Possible network abnormalities relevant to manifestation of CD were discussed. CASE DESCRIPTION: A 27-year-old woman complaining of headache and left motor weakness was found to have a thalamic tumor on the right side. The lesion was totally removed using transventricular approach. Histopathologically, tumor samples manifested features of anaplastic astrocytoma. She underwent stereotactic radiosurgery in addition to the conventional radiation and chemotherapy. Afterward, she returned to her usual life without any neurological deficits. Sixteen months postoperatively, the patient developed forced head tilting to the left side combined with chin lift. On the TWSTRS, she registered 15 for torticollis severity. The abnormal head posturing was alleviated by the sensory trick of touching her face with her right hand. Irregular-shaped lesion involving the thalamus, lenticular nuclei, midbrain, pons, and cerebellum was presented on magnetic resonance images. Steroid therapy effectively diminished the lesion size, and her abnormal head posturing was gradually ameliorated (TWSTRS severity scale = 3). CONCLUSION: The clinical-neuroradiological course of the present case strongly suggested that the lesion detected long after the surgery was due to radiation necrosis. The present study may provide a critical information in understanding pathophysiological mechanisms of CD that may involve substantial interactions between olivocerebellar and basal ganglia-thalamocortical circuits.

Complete suppression of paroxysmal nonkinesigenic dyskinesia by globus pallidus internus pallidal stimulation.

Stereotactic functional surgery is being explored as potential therapies for medically intractable paroxysmal dyskinesias (PxD). We report on a 59-year-old man in whom stimulation of globus pallidus internus produced immediate and sustained relief of paroxysmal non-kinesigenic dyskinesia secondary to a rotator cuff tears on the left shoulder. Our finding strongly suggests that altered function of neuronal circuits of the basal ganglia underlies the manifestation of PxD.

Bilateral subthalamic nucleus stimulation results in reversal of alopecia in Parkinson's disease.

Alopecia is a rare but important side effect of anti-parkinsonian medications. Our patient was a 72-year-old man with advanced Parkinson's disease (PD) who received levodopa and anti-cholinergic drugs and whose head had become almost completely bald. As bilateral subthalamic nucleus (STN) stimulation produced improvement in his motor symptoms, his drug dosages were reduced postoperatively. At 8 months after surgery, hair again covered his entire head. Our study presents a new aspect of the benefit of STN stimulation with regard to drug-induced non-motor symptoms in patient with PD.