Mild cognitive impairment with subcortical vascular features: clinical characteristics and outcome.

OBJECTIVES: To identify non-demented individuals with cognitive impairment due to a cerebrovascular etiology among those coming to observation of a memory clinic and to describe their clinical features and outcome.
METHODS: Patients were enrolled in a prospective study on early cognitive impairment carried out in a Memory Clinic. Mild cognitive impairment of the vascular type (MCI-V) was defined based on modified criteria for subcortical vascular dementia (SVD) by Erkinjuntti and colleagues. Twenty-nine patients with MCI-V (age 78 +/- 7, Mini Mental State Exam (MMSE) 24 +/- 3) were compared with 14 with mild cognitive impairment of degenerative etiology (MCI) based on the Mayo Clinic criteria (age 72 +/- 9, MMSE 25 +/- 2), and to 21 patients with frank SVD (age 80 +/- 6, MMSE 21 +/- 3). Patients were followed over time for 32 +/- 8 months.
RESULTS: MCI-V patients had a neuropsychological profile characterized by poor performance on frontal tests (Wisconsin card sorting and word fluency) and neurological features of parkinsonism without tremor (impairment of balance and gait). Of those followed for at least 40 months, 50 % of patients with MCI-V and SVD had died, while all MCI patients were still alive ( P = 0.03). Of those alive, 68 % of the MCI-V, 52 % of the SVD, and 17 % of the MCI patients had reached one of the following outcomes at 40 months: nursing home placement, functional loss, and cognitive deterioration ( P = 0.02).
CONCLUSIONS: Patients with MCI-V have a distinctive clinical picture and can be identified in a clinical setting. Because of the high frequency of adverse outcomes, very early preventive measures need to be devised.