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.

Developmental trends for auditory selective attention: dependence on central-incidental word relations.

Using the central-incidental learning task, we examined central task scores and numbers of correctly recognized incidental words for 48 children each from the first, fourth, and seventh grades, and for 48 adults. Differences in developmental trends were observed for subjects who heard related pairs of central and incidental words (compound words), unrelated word pairs, and central words only (control condition). In experiment 2, when incidental words were rhymes or synonyms of central words, fourth graders performed as well as did adults in the central phase of the task. Also, fourth graders were as likely to recognize incidental words which had rhymed as those that had been synonyms of central words; adults recognized more synonyms than rhymes. The results of both experiments confirmed that researchers must assess the nature of the task demands, as well as differentiate between valiables affecting central versus incidental learning scores, in deriving estimates of selectivity.