Modulation of specific components of sleep disturbances by simultaneous subthalamic and nigral stimulation in Parkinson's disease.

OBJECTIVE: To compare the effect of simultaneous deep brain stimulation of the subthalamic nucleus and substantia nigra pars reticulata (STN+SNr-DBS) to conventional subthalamic stimulation (STN-DBS) on sleep quality in Parkinson's disease (PD) patients. METHODS: The study was a single-center, randomized, double-blind, cross-over clinical trial to compare the effect of STN-DBS vs. combined STN+SNr-DBS on subjective measures of sleep quality. Fifteen PD patients (2 female, age 62.5 ± 6.7 years) suffering from moderate idiopathic PD (disease duration: 12.0 ± 5.0 years, Hoehn & Yahr stage: 2.2 ± 0.4 in the MED-ON & STN-DBS-ON condition, Hoehn & Yahr stage: 2.6 ± 0.8 in the MED-OFF condition preoperatively) participated in the study. Sleep quality was evaluated in both stimulation conditions using the PDSS-2 score as a self-rating questionnaire covering several aspects of sleep disturbances. RESULTS: PD patients showed mild-moderate sleep disturbances (STN-DBS: PDSS-2 score 17.0 ± 11.0; STN+SNr-DBS: 14.7 ± 9.5) with slight but not significant differences between both stimulation conditions. Considering the different subitems of the PDSS-2, combined STN+SNr stimulation was superior to conventional STN stimulation in improving restless legs symptoms (RLS) at night (STN-DBS = 1.9 ± 2.7 STN+SNr-DBS = 1.0 ± 1.8; W = -2.06, p = 0.039) and immobility at night (STN-DBS = 1.5 ± 1.4 STN+SNr-DBS = 0.6 ± 0.8; W = -2.041, p = 0.041). CONCLUSION: This study demonstrates the safety of STN+SNr-DBS compared to conventional STN-DBS on sleep in general with potential beneficial input on RLS symptoms and akinesia at night.

Evidence of rapid ongoing brain development beyond 2 years of age detected by fiber tracking.

BACKGROUND AND PURPOSE: Development of callosal fibers is important for psychomotor and cognitive functions. We hypothesized that brain maturation changes are detectable beyond 2 years of age by using diffusion tensor imaging (DTI) of the corpus callosum (CC). MATERIALS AND METHODS: T2 and fractional anisotropy (FA) maps of the brain of 55 healthy subjects between 0.2 and 39 years of age were obtained. Quantitative T2 and FA values were measured at the genu and splenium of the CC (gCC and sCC). Fiber tracking, volumetric determination, and the fiber density calculations of the CC were related to age. A paired t test was used for significant differences between the values at the gCC and sCC. RESULTS: T2 relaxation times at gCC and sCC decrease fast in the first months of life and very little after 2 years of age. The FAgCC increases until 5 years of age and remains nearly constant thereafter; it showed a significant increase from 0 to 2 years versus 2-5 years, whereas there was no difference in the other age groups. FAsCC values showed no significant changes after 2 years of age. The fiber density of the CC shows a tendency of inverse age dependence from childhood to adulthood. CONCLUSION: Rapid ongoing changes in brain maturation (increase in FAgCC) are detectable until 5 years of age. DTI reveals more information about brain maturation than T2 relaxometry.