[Neuropsychiatric symptoms in mild cognitive impairment and Alzheimer's disease].

Introduction: To describe the neuropsychiatric symptoms (NPS) in elderly patients with either mild cognitive impairment (MCI) or Alzheimer's disease (AD) and their relevance in the differential diagnosis between the two entities.

Material And Methods: A total of 179 subjects, aged more than 64 years old, with either MCI (n=90) or AD (n=89) and Global Deterioration Scale stage 4-5 were studied. NPS were assessed using the Neuropsychiatric Inventory scale. We identified the prevalence of the symptoms in each group and determined the risk conferred by each symptom to the differential diagnosis between the two entities.

Results: Sixty-seven patients with MCI (74.4%) and 82 with AD (92.1%) showed at least one NPS (p<0.01), the most prevalent being depression and apathy in both groups. The mean number of NPS was 2.1 in MCI and 3.2 in AD. NPS were more frequent in patients with more white matter ischemic lesions (WMIL) (p<0.05). The presence of at least one NPS increased the risk of being diagnosed with AD rather than MCI (odds ratio [OR] 3.6: 95% confidence interval [CI] 1.4-5.7; p<0.01) adjusted by age, sex, Mini-Mental State Examination and WMIL. The NPS independently associated with a diagnosis of AD were delusions (OR 4.9; 95% CI 1.3-18.6; p<0.05), apathy (OR 2.5; 95% CI 1.3-4.7 p<0.01), disinhibition (OR 3.1; 95% CI 1.5-6.4; p<0.01) and aberrant motor behavior (OR 6.3; 95% CI 1.7-23.4; p<0.01).

Conclusions: NPS are frequent in elderly individuals with MCI and mild-moderate AD and may help to differentiate between these two entities.