Deep brain stimulation electrode position impact on parkinsonian non-motor symptoms.

BACKGROUND: In this study we evaluated the impact of location of deep brain stimulation electrode active contact in different parts of the subthalamic nucleus on improvement of non-motor symptoms in patients with Parkinson's disease. METHODS: The subthalamic nucleus was divided into two (dorsolateral/ventromedial) and three (dorsolateral, medial, ventromedial) parts. 37 deep brain stimulation electrodes were divided according to their active contact location. Correlation between change in non-motor symptoms before and one and four months after deep brain stimulation electrode implantation and the location of active contact was made. RESULTS: In dividing the subthalamic nucleus into three parts, no electrode active contact was placed ventromedially, 28 active contacts were located in the medial part and 9 contacts were placed dorsolaterally. After one and four months, no significant difference was found between medial and dorsolateral positions. In the division of the subthalamic nucleus into two parts, 13 contacts were located in the ventromedial part and 24 contacts were placed in the dorsolateral part. After one month, significantly greater improvement in the Non-motor Symptoms Scale for Parkinson's disease (P=0.045) was found on dorsolateral left-sided stimulation, but no significant differences between the ventromedial and dorsolateral positions were found on the right side. CONCLUSION: This study demonstrated the relationship between improvement of non-motor symptoms and the side (hemisphere, left/right) of the deep brain stimulation electrode active contact, rather than its precise location within specific parts of the subthalamic nucleus in patients treated for advanced Parkinson's disease.

Botulinum toxin injection changes resting state cerebellar connectivity in cervical dystonia.

In cervical dystonia, functional MRI (fMRI) evidence indicates changes in several resting state networks, which revert in part following the botulinum neurotoxin A (BoNT) therapy. Recently, the involvement of the cerebellum in dystonia has gained attention. The aim of our study was to compare connectivity between cerebellar subdivisions and the rest of the brain before and after BoNT treatment. Seventeen patients with cervical dystonia indicated for treatment with BoNT were enrolled (14 female, aged 50.2 ± 8.5 years, range 38-63 years). Clinical and fMRI examinations were carried out before and 4 weeks after BoNT injection. Clinical severity was evaluated using TWSTRS. Functional MRI data were acquired on a 1.5 T scanner during 8 min rest. Seed-based functional connectivity analysis was performed using data extracted from atlas-defined cerebellar areas in both datasets. Clinical scores demonstrated satisfactory BoNT effect. After treatment, connectivity decreased between the vermis lobule VIIIa and the left dorsal mesial frontal cortex. Positive correlations between the connectivity differences and the clinical improvement were detected for the right lobule VI, right crus II, vermis VIIIb and the right lobule IX. Our data provide evidence for modulation of cerebello-cortical connectivity resulting from successful treatment by botulinum neurotoxin.

Contemporary clinical neurophysiology applications in dystonia.

The complex phenomenological understanding of dystonia has transcended from the clinics to genetics, imaging and neurophysiology. One way in which electrophysiology will impact into the clinics are cases wherein a dystonic clinical presentation may not be typical or a "forme fruste" of the disorder. Indeed, the physiological imprints of dystonia are present regardless of its clinical manifestation. Underpinnings in the understanding of dystonia span from the peripheral, segmental and suprasegmental levels to the cortex, and various electrophysiological tests have been applied in the course of time to elucidate the origin of dystonia pathophysiology. While loss of inhibition remains to be the key finding in this regard, intricacies and variabilities exist, thus leading to a notion that perhaps dystonia should best be gleaned as network disorder. Interestingly, the complex process has now spanned towards the understanding in terms of networks related to the cerebellar circuitry and the neuroplasticity. What is evolving towards a better and cohesive view will be neurophysiology attributes combined with structural dynamic imaging. Such a sound approach will significantly lead to better therapeutic modalities in the future.

The Prevalence of Dystonic Tremor and Tremor Associated with Dystonia in Patients with Cervical Dystonia.

The link between dystonia and tremor has been known for decades, but the question of whether they are two separate illnesses or just different manifestations of one disease with the same pathophysiological background remains unanswered. We distinguish two types of tremor in dystonia: dystonic tremor (DT), which appears on the body part affected by dystonia, and tremor associated with dystonia (TAWD), which appears in locations where the dystonia does not occur. In this study, the frequency of occurrence of different forms of tremor was determined by clinical examination in a group of adult-onset isolated cervical dystonia (CD) patients treated with regular local injections of botulinum toxin A in our department. In total, 120 patients were included in the study, of which 70 (58.3%) had DT of the head. TAWD was, in all 14 cases (11.7%), observed on the upper limbs, in the form of static or intentional tremor. The aim of this study was to point out the presence of TAWD as one of the clinical signs of CD. DT occurred in more than half of the patients and appears to be a relatively common part of the clinical picture in patients with CD.

Bilateral subthalamic deep brain stimulation initial impact on nonmotor and motor symptoms in Parkinson's disease: An open prospective single institution study.

Numerous studies document significant improvement in motor symptoms in patients with Parkinson's disease (PD) after deep brain stimulation of the subthalamic nucleus (STN-DBS). However, little is known about the initial effects of STN-DBS on nonmotor domains.Our objective was to elucidate the initial effects of STN-DBS on non-motor and motor symptoms in PD patients in a 4-month follow-up.This open prospective study followed 24 patients with PD who underwent STN-DBS. The patients were examined using dedicated rating scales preoperatively and at 1 and 4 months following STN-DBS to determine initial changes in motor and nonmotor symptoms. Patients at month 1 after STN-DBS had significantly reduced the Parkinson's disease Questionnaire scores (P = .018) and Scales for Outcomes in Parkinson's disease - Autonomic scores (P = .002); these scores had increased at Month 4 after DBS-STN. Nonmotor Symptoms Scale for Parkinson's Disease had improved significantly at Month 1 (P < .001); at Month 4, it remained significantly lower than before stimulation (P = .036). There was no significant difference in The Parkinson's Disease Sleep Scaleat Month 1 and significant improvement at Month 4 (P = .026). There were no significant changes in The Female Sexual Function Index or International Index of Erectile Function. Movement Disorder Society Unified Parkinson's Disease Rating Scale, Part III scores show significant improvements at Month 1 (P < .001) and at Month 4 (P < .001).STN-DBS in patients with advanced PD clearly improves not only motor symptoms, but also several domains of nonmotor functions, namely sleep, autonomic functions and quality of life quickly following the start of stimulation.