Treatment for Alzheimer’s disease that clears β-amyloid plaques from the brain does not restore cognitive function, according to the results of a study in the April 2 Journal of Neuroscience. Beagles ages 8.4 to 12.4 years with preexisting β-amyloid pathology had no improvement in learning, spatial attention, or spatial memory when immunized with fibrillar β-amyloid(1-42) formulated with aluminum salt for 2.4 years (25 vaccinations). Brain levels of soluble and insoluble β-amyloid(1-40) and β-amyloid(1-42) and the extent of diffuse plaque accumulation decreased significantly in several cortical regions. “However, the amount of soluble oligomers remained unchanged,” noted the researchers. They suggested that immunization before oligomeric or fibrillar β-amyloid formation may have a greater impact on cognition or that clearing preexisting β-amyloid from the brain may be more beneficial to cognition if combined with a second treatment that restores neuron health.
Serum urate reduces progression of Parkinson’s disease, according to findings published in the April 14 online Archives of Neurology. Investigators studied the progression toward clinical disability warranting dopaminergic therapy in 804 participants with early Parkinson’s disease. Hazard ratios (HRs) of reaching this point declined with increasing baseline concentrations of urate, with subjects in the top quintile reaching this point at half the rate of subjects in the bottom quintile (HR, 0.51); the association was stronger in men than in women (HRs, 0.39 vs 0.77).
The brain structure of children who are prenatally exposed to drugs and alcohol may continue to be affected into early adolescence, reported researchers in the April Pediatrics. Volumetric MRI was performed on 35 children (mean age, 12.3) with intrauterine exposure to cocaine, marijuana, alcohol, or tobacco. Those exposed to cocaine (n = 14) had lower mean cortical gray matter and total parenchymal volumes and smaller mean head circumference than did comparison children, although this lost statistical significance after adjustment for other exposures. Prenatal ethanol exposure and prenatal cigarette exposure were also associated with reductions in cortical gray matter volume, total parenchymal volume, and head circumference.
—Marguerite Spellman