One-year treatment of Alzheimer's disease with acetylcholinesterase inhibitors: improvement on ADAS-cog and TMT A, no change or worsening on other tests.

The aim of this study was to assess cognitive functioning measured by selected psychometric and neuropsychological tools in patients with Alzheimer's disease (AD) after 1-year treatment with acetylcholinesterase inhibitors. Seventy-six patients (22 male and 54 female) with a mild to moderate stage of AD, aged 56-86 (mean 68) years, were treated. Forty-seven received donepezil (mean dose 9.3 mg/d) and 29 rivastigmine (mean dose 8.5 mg/d). Cognitive measurements included: the mini mental state examination (MMSE), the Alzheimer disease assessment scale-cognitive (ADAS- cog), the trail making test (TMT) and the Stroop color word interference test. The assessments were made before and after 3, 6 and 12 months of treatment. A significant improvement in ADAS-cog (p < 0.001, 83% of patients improved) and a worsening in MMSE (84% of patients worsened, p < 0.01 after 6 and 12 months) was noted after the 1 year treatment. A majority of patients (57%) improved in the TMT-A (p < 0.001), measuring psychomotor speed and worsened in the TMT-B (p < 0.01, after 12 months), and Stroop B test (p < 0.001), measuring working memory and executive functions, 53% and 61%, respectively. Most patients (83%) did not change their performance in the Stroop A (improvement after 3 months, p < 0.001, worsening after 6 and 12 months p < 0.01) test measuring verbal abilities, after 1 year treatment. The results obtained suggest that the treatment with cholinergic drugs may improve global cognitive functioning (ADAS-cog) and psychomotor speed (TMT A), however, such treatment is unable to prevent the deterioration of working memory and executive functions. Copyright (c) 2005 John Wiley & Sons, Ltd.