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The aim of the present study was to examine impairment of implicit learning in Parkinson's disease (PD) by means of a meta-analysis of studies that used the serial reaction time (SRT) task. The authors performed a systematic review and meta-analysis of published journal articles (1987-2005) that used the SRT task with patients with PD. The principal outcome measures used to compare studies were (a) the difference in reaction time between the last block of ordered sequence trials and the randomized block for PD and control participants and (b) fixed and random effects pooled estimates by the inverse weighting method. Six studies, including 67 patients with PD, met the inclusion criteria. The meta-analysis showed that implicit learning was impaired in PD, relative to healthy controls, with a standardized mean difference of 0.73 (95% confidence interval = 0.38, 1.07). Implicit sequence learning appears to be impaired in patients with PD. Some common methodological weaknesses and limitations in the reporting of statistical data are discussed.

ObjectivesWe have undertaken a clinic-based survey of neuromyelitis optica spectrum disorders (NMOSD) in Australia and New Zealand in order to establish incidence and prevalence across the region and in populations of differing ancestry.Background NMOSD is a recently defined demyelinating disease of the central nervous system. The incidence and prevalence of NMOSD in Australia and New Zealand has not been established. European ancestry. We found NMOSD to be more common in the population with Asian ancestry. Methods

This study confirms the presence of a robust latitudinal gradient of MS prevalence in New Zealand. This gradient is largely driven by European females with the RRMS/SPMS phenotype. These results indicate that the environmental factors that underlie the latitudinal gradient act differentially by gender, ethnicity and MS phenotype. A better understanding of these factors may allow more targeted MS therapies aimed at modifiable environmental triggers at the population level.

Multiple sclerosis (MS) is an immune-driven, demyelinating disease of the central nervous system (CNS). Although many types of immune cells are involved in disease progression, activated monocytes are believed to be one of the first to arrive to the brain and initiate inflammation. However, little is known about how the two main monocyte subsets, CD14(++)CD16(-) and CD14(+)CD16(+), are involved in MS. To understand how the phenotype and responses of these monocyte subsets are altered during MS, total monocytes and the purified monocyte subsets from healthy subjects (n=29) and MS patients (n=20) were characterized ex vivo and stimulated in vitro with lipopolysaccharide (LPS). The ex vivo analyses showed that total monocytes from MS patients had significantly elevated levels of CD40, CD86, HLA-DR, CD64 and C-C motif chemokine receptor 2 (CCR2), and this elevation was most marked on CD16(+) monocytes. In vitro stimulation with LPS led to an increase in CD86, HLA-DR, CD64 and IL-6 production by monocytes from MS patients. Furthermore, in purified cultures, CD14(+) monocytes were found to be the main producers of IL-10 while CD16(+) monocytes produced more IL-12. In monocytes from MS patients, both subsets produced substantially more IL-6, and the production of IL-10 by the CD16(+) subset was also significantly elevated compared with healthy monocytes. Together these findings highlight the important contribution of the CD16(+) monocyte subset in driving inflammatory responses during MS.