Ten patients with severe cervical dystonia (CD) unresponsive to medical treatment underwent bilateral globus pallidus internus (GPi) deep brain stimulation (DBS) and were followed for 31.9 +/- 20.9 months. At last follow-up, the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) severity score improved by 54.8%, the TWSTRS disability score improved by 59.1%, and the TWSTRS pain score improved by 50.4%. Bilateral GPi DBS is an effective long-term therapy in patients with CD.

Subthalamic nucleus deep brain stimulation (STN-DBS) is effective in advanced Parkinson's disease (PD), but its effects on the levodopa response are unclear. We studied the levodopa response after long-term STN-DBS, STN-DBS efficacy and predictive value of preoperative levodopa response to long-term DBS benefit in 33 PD patients with bilateral STN-DBS. Patients were assessed using the Unified Parkinson's Disease Rating Scale preoperatively (with and without medications) and postoperatively (without medications or stimulation, with only medications or stimulation, and with both medications and stimulation). Levodopa response significantly decreased postoperatively by 31.1% at 3 years and 32.3% at 5 years, possibly related to the reduction in medication requirement, direct STN stimulation effect or PD progression. STN-DBS alone significantly improved motor scores (37.2% at 3 years and 35.1% at 5 years) and activities of daily living scores (27.1% at 3 years and 19.2% at 5 years). Anti-PD drugs were significantly reduced by 47.9% at 3 years and 39.8% at 5 years. However, the magnitude of the preoperative response to levodopa did not predict DBS benefit at 3 and 5 years.

Orthostatic tremor (OT) is a condition described as high-frequency tremors predominantly in the legs and trunk, which are present not only in the standing position but also during isometric contraction of the limb muscles. This report is one of the largest OT series describing clinical and neurophysiologic findings in 26 subjects with OT. The main findings included 13.0 to 18.6 Hz leg tremors while standing with varied patterns of phase relationships between the antagonists of the ipsilateral leg and between the homologous muscles of the contralateral leg, short latency tremor onset upon standing with abrupt cessation after sitting, coexistence of tremors in the cranial structures and the arms, and sense of unsteadiness without actual falls. Although the oscillator of OT is most likely located in the brainstem, cerebral cortex, basal ganglia, and cerebellum may also be involved in its pathogenesis.

Aim: We sought to identify markers of motor and nonmotor function in Parkinson's disease (PD) using advanced neuroimaging techniques in subjects with PD. Methods: We enrolled 26 nondemented PD subjects and 12 control subjects. All subjects underwent [¹⁸F]fluorodeoxyglucose positron emission computed tomography (FDG-PET) and magnetic resonance imaging, and a complete neuropsychological battery. Results: FDG-PET of subjects with PD revealed significant metabolic elevations in the bilateral posterior lentiform nucleus, posterior cingulate, and parahippocampus, and metabolic reductions in the bilateral temporoparietal association cortex and occipital lobe versus controls. PD subjects had significant reductions in executive/attention function, memory/verbal learning, and speed of thinking, and significantly increased depression, anxiety and apathy scores compared with controls. Motor dysfunction correlated with increased metabolism in the posterior lentiform nucleus, pons, and cerebellum, and decreased metabolism in the temporoparietal lobe. Cognitive dysfunction correlated with increased posterior cingulate metabolism and decreased temporoparietal lobe metabolism. Depressive symptoms correlated with increased amygdala metabolism; anxiety scores correlated with decreased caudate metabolism, and apathy scores correlated with increased metabolism in the anterior cingulate and orbitofrontal lobe and decreased metabolism in the temporoparietal association cortex. Conclusions: Our findings showed that motor, cognitive, and emotional dysfunction in PD are associated with distinct patterns of cerebral metabolic changes.

Frequency and amplitude appear to be the most important factors in the acute anti-dystonic effects in GPi-DBS patients with CD.

Variability in pull test (PT) performance can lead to inadequate evaluation of postural instability in patients with Parkinson's disease (PD). Assessing 66 PTs by 25 examiners, at least two of four raters agreed that specific items were performed incorrectly for stance in 27.3%, for strength and briskness of the pull in 84.9%, for examiner's response in 36.4%, and for technique issues in 9.1%. Examiners were consistent in their errors, and only 9% of examinations were error-free.

Transcranial magnetic stimulation (TMS) findings, particularly TMS amplitude, can objectively discriminate corticospinal tract involvement in amyotrophic lateral sclerosis (ALS) from controls and assess the progression of ALS. While central motor conduction time and response threshold worsen by less than 2% per month, TMS amplitude decrease averages 8% per month, and may be a useful objective marker of disease progression.

Epidural motor cortex stimulation has been reported to be effective in treating some movement disorders. Nevertheless, clinical results have been variable and no double-blinded evaluations have been reported. The aim of this study was to investigate efficacy and safety of unilateral subdural motor cortex stimulation in patients with essential tremor and Parkinson's disease. Six patients with essential tremor and five parkinsonian patients were selected. Craniotomy was performed under local anaesthesia with conscious sedation. A four contact electrode (Resume II model 3587, Medtronic, Inc) was positioned on the motor cortex, after identification of the area with direct monopolar cortical stimulation. Soon after surgery, a variety of different settings of stimulation were assessed using standard rating scales to select the optimal stimulation parameters. The effects of chronic stimulation were evaluated in both groups of patients after 3 months (double-blinded fashion) and 1 year (open fashion). In essential tremor, contralateral hand tremor scores significantly improved (P = 0.04) with stimulation during the double-blinded study, whereas in Parkinson's disease, there were no changes in the OFF medication/on stimulation motor scores compared with off stimulation. At 1 year, tremor was improved by stimulation in two out of three patients with essential tremor available at follow-up, whereas no improvement was observed in the five parkinsonian patients. One parkinsonian patient had a cortical venous infarct. Three other patients had self-limiting seizures with aggressive trials of stimulation in the period of dosage selection. These findings suggest that unilateral subdural motor cortex stimulation may be useful for contralateral hand tremor in selected patients with essential tremor but was not effective in improving parkinsonian signs in our series.