The Assesment of Cognitive Functions With Neuropsychologic and Neurophysiologic Tests in Diabetes Mellitus

Sevda Erer; Mustafa Bakar; Faruk Turan; Semra Akgöz

Sevda Erer¹, Mustafa Bakar¹, Faruk Turan¹, Semra Akgöz²

¹Department Of Neurology, Uludag University, Faculty Of Medicine, Bursa, Turkey
²Department Of Biostatistics, Uludag University, Faculty Of Medicine, Bursa, Turkey

Keywords: diabetes mellitus, dementia, cognitive dysfunction, mini-mental state examination, event related evoked potentials

Abstract

OBJECTIVE: In our study, we aimed to evaluate cognitive dysfunctions in type II diabetes mellitus (DM) regarding duration, prognosis and complications of the disease. We used transcranial doppler (TCD) ultrasonography to evaluate cerebral perfusion and hemodynamics and performed mini-mental state examination (MMSE), neuropsychometric tests (NPT), event related evoked potentials (ERP), auditory and visual P300 wave latancies.

METHODS: 48 patients (29 females and 19 males) with type 2 DM, aged between 40-65 (mean 53) years, and 20 normal (10 males, 10 females) cases as control group were involved in the study. Routine biochemical tests, cranial tomography (CT) imaging methods and the tests which evaluate cognitive functions, MMSE, NPT, and ERP were performed in subjects. Mean current speed and pulsatility index were measured in 62 patients by using TCD.

RESULTS: The scores of MMSE, auditory and visual P300 waves mean latancies were found statistically significant in patients with DM when compared to control group. Although there was no statistical significance in mean cerebral artery velocity values between two groups, there was significant correlation between pulsatility indexes. Especially verbal, visual memory and concentration modalities of NPT was significalty affected when compared to normal control group.

CONCLUSION: In previous studies, different results have been reported about effects of DM on cognitive functions. We consider that this study may differ from others, as it was carried out on a group of middle aged diabetes subjects and many modalities associated with cognition were evaluated together. We also meant to draw attention to the possibility that, independent from other risk factors, diabetes mellitus may have a memory and attention related effect on cognition, and that chronic diseases such as diabetes may play a critical role in the development of dementia.