Clostridium perfringens type B, an epsilon toxin-secreting bacillus, may trigger multiple sclerosis (MS), according to research published October 16 in PLOS One. After detecting C. perfringens type B in a woman with MS, investigators tested blood and CSF from patients with MS and controls for antibody reactivity to the epsilon toxin. Levels of epsilon toxin antibodies were 10 times higher in patients with MS, compared with controls. After examining stool samples, the study authors found the human commensal C. perfringens type A in approximately 50% of healthy controls, compared with 23% of patients with MS. C. perfringens epsilon toxin fits mechanistically with nascent MS lesion formation because these lesions are characterized by blood–brain barrier permeability and oligodendrocyte cell death in the absence of an adaptive immune infiltrate, said the researchers.
Chronic cerebrospinal venous insufficiency (CCSVI), which has been proposed as a contributor to multiple sclerosis (MS), occurs rarely in patients with MS and in controls, according to a study published online ahead of print October 8 in Lancet. Researchers performed an assessor-blinded, case-control, multicenter study of 79 people with MS, 55 unaffected siblings, and 43 unrelated healthy volunteers. Catheter venography criteria for CCSVI were positive for 2% of people with MS, 2% of siblings, and 3% of unrelated controls. Greater than 50% narrowing of any major vein was present in 74% of people with MS, 66% of siblings, and 70% of unrelated controls. The Zamboni ultrasound criteria are neither sensitive nor specific for narrowing on catheter venography, and the significance of venous narrowing to MS remains unknown, said the investigators.
Measures of α-synuclein deposition in cutaneous autonomic nerves may be a useful biomarker in patients with Parkinson’s disease, according to research published online ahead of print October 2 in Neurology. Investigators examined 20 patients with Parkinson’s disease and 14 age- and sex-matched control subjects. The researchers performed autonomic testing and skin biopsies at the distal leg, distal thigh, and proximal thigh for all participants. Deposition of α-synuclein and the density of intraepidermal, sudomotor, and pilomotor nerve fibers were measured. The investigators normalized α-synuclein deposition to nerve fiber density. Patients with Parkinson’s disease had greater α-synuclein deposition and higher α-synuclein ratios than controls within pilomotor nerves and sudomotor nerves, but not sensory nerves. Higher α-synuclein ratios correlated with Hoehn and Yahr scores, sympathetic adrenergic function, and parasympathetic function.
Depression may be an independent risk factor for Parkinson’s disease, according to research published October 22 in Neurology. Investigators conducted a retrospective study of 4,634 patients with depression and 18,544 matched controls who were selected from a national health insurance database. Patients were observed for a maximum of 10 years to determine the rates of new-onset Parkinson’s disease. Cox regression was used to identify the predictors of the disease. During the follow-up period, 66 patients with depression and 97 controls were diagnosed with Parkinson’s disease. After adjusting for age and sex, the researchers found that patients with depression were 3.24 times more likely to develop Parkinson’s disease, compared with the control patients. The investigators observed that age and difficult-to-treat depression are independent risk factors for Parkinson’s disease in patients with depression.
The levels of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in red blood cells may have no association with age-associated cognitive decline, researchers reported in the October 22 issue of Neurology. The investigators conducted a retrospective cohort study of 2,157 women with normal cognition who were followed with annual cognitive testing for a median of 5.9 years. End points were composite cognitive function and performance in seven cognitive domains. After adjustment for demographic, clinical, and behavioral characteristics, the investigators found no significant cross-sectional cognitive differences between women in the high and low DHA and EPA tertiles at the first annual cognitive battery. In addition, no significant differences were found between the high and low DHA and EPA tertiles in the rate of cognitive change over time.
Common psychosocial stressors (eg, divorce, widowhood, work problems, and illness in a relative) may have severe and long-standing physiologic and psychologic consequences such as dementia, according to research published September 30 in BMJ Open. In a prospective longitudinal population study, clinicians performed psychiatric examinations for 800 women born in 1914, 1918, 1922, and 1930. Baseline examinations took place in 1968, and follow-up occurred in 1974, 1980, 1992, 2000, and 2005. During follow-up, 153 women developed dementia. The number of psychosocial stressors in 1968 was associated with higher incidence of dementia and Alzheimer’s disease (AD) between 1968 and 2005 in multivariate Cox regressions. The number of psychosocial stressors in 1968 was also associated with distress in 1968, 1974, 1980, 2000, and 2005 in multivariate logistic regressions.