Noninvasive Thalamotomy for Refractory Tremor by Frameless Radiosurgery.

PURPOSE: We sought to determine whether a more widely accessible, noninvasive, frameless approach to radiosurgical thalamotomy would improve objective measures of refractory essential or parkinsonian tremor without added toxicity compared with reports of frame-based radiosurgery. METHODS AND MATERIALS: We conducted a single-arm pilot observational prospective trial of adult patients with essential or parkinsonian tremor from 2013 to 2019 and report results at 1-year follow-up. Patients were treated with frameless unilateral radiosurgical ablation of the thalamic ventral intermediate nucleus to a maximum dose of 160 Gy. Treatment response was measured by the Fahn-Tolosa-Marin (FTM) tremor rating scale and the Quality of Life in Essential Tremor or Parkinson's Disease Questionnaire obtained before treatment and at 3, 6, 9, and 12 months. RESULTS: Thirty-three patients, including 23 with essential tremor and 10 with Parkinson's disease, were enrolled. Overall treatment response rate per FTM was 83% (15 of 18) at 6 months. There was a marked improvement in tremor, with an average total FTM reduction of 21% at 3 months (from 46 to 30 points; P = .003) and 41% at 6 months (from 46 to 24 points; P = .001). At 6 months, functional decline had regressed by 54% (from 15 to 7 points; P = .001). Quality of life improved by 57% (P = .001) at 6 months in patients with essential tremor, and patients with Parkinson's disease had unchanged quality of life. At 1-year follow-up, grade 2 neurologic adverse events were observed in 6% (2 of 33) of patients without any grade ≥ 3 events. CONCLUSION: Noninvasive, frameless radiosurgical thalamotomy may be a feasible treatment for patients with refractory tremor and demonstrates short-term safety at 1-year follow-up. This pilot study provides promising preliminary descriptions of efficacy, and definitive estimates of long-term safety and benefit require further study with longer follow-up.

Deep Brain Stimulation for Treatment of Tremor.

Deep brain stimulation is now the most common surgical treatment of tremor. Tremor can be classified as action or resting tremor and is one of the most common movement disorders. Initial treatment of tremor should focus on medical treatment but, if patients fail medical therapy, deep brain stimulation should be considered with likely success. The usual target is the ventral intermediate nucleus of the thalamus. Common side effects of treatment include paresthesias, dysarthria, and less often ataxia. Future directions of research and development, including directional leads and closed-loop stimulation, may eventually lead to additional improvement in patient outcomes.

Wilson's disease: A master of disguise.

Wilson's disease (WD), in contrast to many neurogenetic metabolic diseases, can be very effectively treated in acute and chronic stages of the disease. However, early recognition is paramount because delays in treatments have much higher risk of unfavorable clinical outcomes. Identification of WD remains challenging because it is a great imitator and requires a high index of suspicion for correct and timely diagnosis. Initial neurologic problems can be seen in approximately 40%-50% of patients and the rest has either hepatic or primarily psychiatric manifestations. Neurologic and neuropsychiatric problems in WD are quite nonspecific and we discuss the most common clinical problems associated with early and late stages of the disease. Many patients with neurologic symptoms do not have any obvious hepatic symptoms. Most common neurologic abnormalities include dysarthria, dystonia, tremor and Parkinsonism. In spite of its phenotypic heterogeneity, laboratory abnormalities, reflecting abnormal copper homeostasis, are very specific and the diagnosis of WD remains laboratory based. We review most important challenges and pitfalls in laboratory evaluation of WD, including emerging role of genetic testing. Pharmacologic treatments need to be life-long and are focused on restoration of negative copper balance without inducing iatrogenic copper deficiency. The gold standard of therapy is chelation of excessive copper. Chelators may induce further clinical deterioration in some treated patients. We also review most promising novel therapeutic approaches that appear to better control non-ceruloplasmin or free copper because elevation of free copper may be responsible for paradoxical neurologic worsening.

WTX101 - an investigational drug for the treatment of Wilson disease.

INTRODUCTION: Wilson disease (WD) is a genetic disorder in which excess toxic copper accumulates in the liver, brain, and other tissues leading to severe and life-threatening symptoms. Copper overload can be assessed as non-ceruloplasmin-bound copper non-ceruloplasmin-bound copper (NCC) in blood. Current therapies are limited by efficacy, safety concerns, and multiple-daily dosing. Areas covered: This article reviews the literature on WTX101 (bis-choline tetrathiomolybdate), an oral first-in-class copper-protein-binding agent in development for the treatment of WD. Expert opinion: In a proof-of-concept phase II trial, once-daily WTX101 over 24 weeks rapidly lowered NCC levels and this was accompanied by improved neurological status without apparent initial drug-induced paradoxical worsening, reduced disability, stable liver function, with a favorable safety profile. WTX101 directly removes excess copper from intracellular hepatic copper stores and also forms an inert tripartite complex with copper and albumin in the circulation and promotes biliary copper excretion. These mechanisms may explain the rapid biochemical and clinical improvements observed. A phase III trial of WTX101 is ongoing and results are eagerly awaited to confirm if WTX101 can improve the treatment of this devastating disease.

Confined stimulation using dual thalamic deep brain stimulation leads rescues refractory essential tremor: report of three cases.

BACKGROUND/AIMS: Deep brain stimulation (DBS) of the nucleus ventralis intermedius (VIM) provides a safe and effective therapy for medically refractory essential tremor (ET). However, as many as 9% of VIM DBS patients deteriorate after several years of good tremor control. For these patients, the high voltage needed to adequately control tremor also generates circumferential current spread causing intolerable adverse effects. METHODS: We report 3 ET patients where adding a second parallel thalamic lead anterior-medially to the original and connecting the 2 adjacent leads to a dual-channel pulse generator (Medtronic Synergy, model No. 7427) successfully recaptured tremor control with fewer adverse effects. RESULTS: This approach allowed us to direct the stimulation field away from nearby structures responsible for the adverse effects. Such confined stimulation can be achieved by connecting 2 adjacent DBS leads to a common voltage source, providing current flow between leads. CONCLUSION: This dual lead stimulation method can be used as a reversible rescue therapy in ET patients who require unacceptably high intensity stimulation.

Myelopolyneuropathy and pancytopenia due to copper deficiency and high zinc levels of unknown origin: further support for existence of a new zinc overload syndrome.

OBJECTIVE: To describe a patient with idiopathic zinc overload without an identifiable source and secondary copper deficiency causing myelopolyneuropathy and pancytopenia. DESIGN: Case report. PATIENT AND RESULTS: A 46-year-old man presented with severe bone marrow suppression and subsequently developed progressive myelopathy with sensory ataxia. No identifiable cause of myelopathy was detected, and his neuroimaging findings were unremarkable. Plasma analysis demonstrated a low copper level and an increased zinc level (<10 micro g/dL [<12.6-18.9 micro mol/L] and 184 micro g/dL [28.2 micro mol/L], respectively; normal range for both, 80-120 micro g/dL [12.6-18.9 micro mol/L and 12.3-18.4 micro mol/L, respectively) and a low level of ceruloplasmin. There was no evidence for an external source of zinc. Daily oral supplementation with 2 mg resulted in the prompt reversal of hematologic abnormalities, improved but still subnormal plasma copper levels, and normalization of ceruloplasmin values. The patient's neurologic condition deteriorated further, with worsening of myelopathy and development of polyneuropathy. Analyses of plasma copper and zinc levels demonstrated persisting hyperzincemia and subnormal copper levels during 4 years of follow-up. Increased copper supplementation to 8 mg/d partially reversed his neurologic signs. A clinical investigation of 6 siblings and 1 surviving parent did not identify family members with similar abnormalities. CONCLUSIONS: Persistent hyperzincemia without an identifiable external source appears to be a primary metabolic defect, while copper deficiency is a secondary phenomenon, causing hematologic and neurologic abnormalities. Two unrelated patients with similar idiopathic hyperzincemia and hypocupremia have been recently described. This suggests the existence of a new metabolic disorder with idiopathic zinc overload.