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Motor complications in Parkinson's disease (PD) result from the short half-life and irregular plasma fluctuations of oral levodopa. When strategies of providing more continuous dopaminergic stimulation by adjusting oral medication fail, patients may be candidates for one of three device-aided therapies: deep brain stimulation (DBS), continuous subcutaneous apomorphine infusion, or continuous duodenal/jejunal levodopa/carbidopa pump infusion (DLI). These therapies differ in their invasiveness, side-effect profile, and the need for nursing care. So far, very few comparative studies have evaluated the efficacy of the three device-aided therapies for specific motor problems in advanced PD. As a result, neurologists currently lack guidance as to which therapy could be most appropriate for a particular PD patient. A group of experts knowledgeable in all three therapies reviewed the currently available literature for each treatment and identified variables of clinical relevance for choosing one of the three options such as type of motor problems, age, and cognitive and psychiatric status. For each scenario, pragmatic and (if available) evidence-based recommendations are provided as to which patients could be candidates for either DBS, DLI, or subcutaneous apomorphine. [ABSTRACT FROM AUTHOR]

Synchronization of neuronal activity evident in the local field potential (LFP) recorded in the subthalamic region of patients with Parkinson's disease occurs at low frequencies (< 30 Hz) and, in some patients following treatment with levodopa, at high frequencies between 65 and 85 Hz. Here we investigate the functional relationship between these different activities by determining whether spontaneous fluctuations in their strength are correlated across time. To this end, we analysed recordings of LFPs from macroelectrodes inserted in the subthalamic area of 16 patients with Parkinson's disease, after treatment with anti-parkinsonian medication. Time-evolving autospectra of LFPs with significant 65–85 Hz peaks (from 21 sides) were computed and correlations between frequency components determined over time. LFP activity in the 5–32 Hz band was significantly negatively correlated with that in the 65–85 Hz band in data averaged across all 21 sides, as well as in 15 (71%) of the individual records. Negative correlations were relatively selective for interactions between these frequency bands and occurred over time epochs of as little as 40 s. They occurred about 50 min after levodopa and were recorded concurrently with contralateral levodopa-induced dyskinesias in all but four cases. Positive correlations were not seen between activities in the 5–32 Hz and 65–85 Hz bands. The spontaneous negative correlations suggest a reciprocal relationship between population synchrony in the high- and low-frequency ranges, and raise the possibility that spontaneous fluctuations in the balance between these activities may contribute to levodopa-induced dyskinesias. [ABSTRACT FROM AUTHOR]

Averaging techniques have demonstrated that movement preparatory cues and movement itself are associated with marked reductions in the oscillatory synchrony of local neuronal populations in the area of the human parkinsonian subthalamic nucleus (STN), as indexed by 8–30 Hz local field potential (LFP) activity. In order to examine the detailed nature and strength of the relationship between reductions in oscillatory activity and movement we examined single-trial LFP activity recorded from the STN area of parkinsonian subjects engaged in a choice reaction task. In this task an initial warning cue was either fully predictive or non-predictive of the hand required to make a later motor response. This motor response was elicited by a second go cue to which data were aligned. We observed a significant linear relationship between the onset time of oscillation reduction after go cues and subsequent motor response time across single trials within subjects. Consistent with this observation we also found a positive correlation of power with response time following go cues. In addition, we observed shorter durations of suppression in fully predictive trials where selection of the response could precede go cue presentation. The results are consistent with the hypothesis that reductions in 8–30 Hz population synchrony in the STN area are related to the processing required for motor preparation, particularly response selection. [ABSTRACT FROM AUTHOR]

Postural instability and gait disability (PIGD) are disabling signs of Parkinson's disease. Stereotactic surgery aimed at the internal globus pallidus (GPi) or subthalamic nucleus (STN) might improve PIGD, but the precise effects remain unclear. We performed a systematic review of studies that examined the effects of GPi or STN surgery on PIGD. Most studies examined the effects of bilateral GPi stimulation, bilateral STN stimulation, and unilateral pallidotomy; we, therefore, only performed a meta-analysis on these studies. Bilateral GPi stimulation, bilateral STN stimulation, and to a lesser extent, unilateral pallidotomy significantly improved PIGD, and more so during the ON phase than during the OFF phase. © 2004 Movement Disorder Society [ABSTRACT FROM AUTHOR]

Assesses the incidence of AIDS dementia complex after introduction of zidovudine treatment in the Netherlands. Decline in the incidence of AIDS dementia; Effects of AIDS dementia complexes on nervous systems; Detection of HIV p24 antigen in the cerebrospinal fluid.