Diagnosis of cognitive impairment onset in older adults based on limitations in language skills / Diagnóstico del inicio del deterioro cognitivo en mayores a partir de limitaciones en las capacidades lingüísticas

Can Phonemic Verbal Fluency Be Used to Predict Alzheimer's Disease?

BACKGROUND

Among the cognitive markers, the deterioration of semantic and phonemic verbal fluency seems to be an early indicator of Alzheimer's disease (AD). The aims of this study are (1) to evaluate both types of verbal fluency in the early stages of AD in order to know which of them deteriorates earlier and (2) to investigate if verbal fluency tasks can help to differentiate between patients with Mild Cognitive Impairment (MCI) who will progress to AD two years later (progress) and those who will not (non-progress).

METHOD

A verbal fluency task was administered to 25 patients with MCI and their respective control subjects. All patients underwent a neuropsychological evaluation twice in order for us to follow up on their global cognitive status. The second time, eight of them converted to AD.

RESULTS

On the one hand, phonemic verbal fluency deteriorates earlier than semantic verbal fluency in MCI patients; on the other hand, although we found statistically significant differences between patients with MCI and AD in both types of fluency tasks, none were found when comparing the performance of progress and non-progress.

CONCLUSIONS

These results point to a greater impairment in phonemic verbal fluency in MCI patients and its potential capacity to predict conversion to AD.

Accuracy of verbal fluency tests in the discrimination of mild cognitive impairment and probable Alzheimer's disease in older Spanish monolingual individuals

The main objetive was to analyze the accuracy of different verbal fluency tests (VFTs) in discriminating cognitively healthy subjects from individuals with mild cognitive impairment (MCI) and probable Alzheimer's disease (AD) in a cohort of older Spanish speaking adults. As a result, we aimed to identify the VFT that best predicts conversion from MCI to probable AD. 287 subjects: 170 controls (HC), 90 stable MCI and 27 patients with MCI that evolved into probable AD (MCI-AD) were assessed with a neuropsychological battery test and five VFTs. The animal fluency test produced the best differentiation of HC from MCI (p < .001), of HC from MCI-AD (p < .001) and of MCI from MCI-AD converters (p < .001), with sensitivities 98.8%, 98.8% and 75.6%, respectively. Logistic regression showed that the animal fluency test (p < 0.001) appears to be the most useful and neuropsychological VFT to predict conversion to probable dementia.