Decrease in EEG Slow-Wave Activity Can Predict Response to Rivastigmine in AD: Presented at ADI
By Jenny Powers
THESSALONIKI, Greece -- March 15, 2010 -- Decreases in electroencephalogram (EEG) theta power significantly correlate with positive response to rivastigmine treatment and is useful in predicting which patients with Alzheimer’s disease (AD) would benefit from long-term treatment, according to a study presented here at the 25th Conference of Alzheimer’s Disease International (ADI).
Georg Adler, MD, Clinical Studies, Institut für Studien zur psychischen Gesundheit, Mannheim, Germany, presented data here on March 11 from a prospective study that sought to find a predictor for long-term patient response to cholinesterase inhibitors because large individual differences in response to this treatment have been observed.
The researchers used measurement of slow brain wave activity, which has demonstrated a correlation to response to treatment and improved cognitive performance.
EEG and neuropsychological parameters were assessed before and after 2 weeks of rivastigmine treatment in 50 patients with AD with Mini-Mental State Exam (MMSE) scores of 12 to 24, with a follow-up examination at 6 months.
EEG theta power decreases and neuropsychological parameters were correlated to rivastigmine treatment response. The primary endpoint was improvement of short-term memory.
At 6 months, the initial decrease in EEG theta power after 2 weeks of rivastigmine treatment was significantly associated with continued treatment response, as defined by an increase in cognitive functional abilities.
Patients who displayed an early decrease in theta power continued to respond to treatment at 6 months, whereas the nonresponders at 6 months had displayed no early reduction.
MMSE scores of treated patients increased from a baseline average of 18.9-20.3 (P = .007), and short-term memory increased from 1.1 to 1.8 post treatment (P = .005). Theta values were decreased after 2 weeks of rivastigmine treatment (P = .044).
A positive correlation was also seen between various baseline neuropsychological domains, particularly visuospatial capabilities, and treatment response. Taken together, theta power decrease and visuospatial capabilities enabled a correct prediction of treatment response in 74% of the patients.
The researchers concluded that a decrease in EEG theta power seen at 2 weeks of treatment was significantly associated with treatment response at 6 months. A decrease in theta power was seen in twice as many responders as in nonresponders, and this response to short-term treatment can predict long-term responders.
[Presentation title: Prediction of Treatment Response to Rivastigmine in Alzheimer’s Dementia: A Prospective Multicenter Study. Abstract P056]
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