Usefulness of P300 in Subjective Memory Complaints

Abstract

The existing studies about the utility of P300 latency for diagnostically classifying patients in preclinical stages of dementia are cross-sectional rather than longitudinal in design, and their results are inconclusive. The authors investigated the P300 value in a series of patients with subjective memory complaints using a prospective design. The study was performed in a consecutive series of 116 outpatients with subjective memory complaints as the predominant symptom. P300 (auditory oddball task) was performed immediately after the first clinical evaluation, and at 12 and 24 months. Final cognitive syndrome diagnosis (mean follow-up period, 27.7 months) was then made by a neurologist who was blinded to the neurophysiologic results. Diagnosis at the end of follow-up was 30 cases of normal cognition, 30 cases of mild cognitive impairment, 28 cases of dementia of Alzheimer's type (DAT), five cases of vascular dementia, and one case of frontotemporal dementia; 22 patients were lost to follow-up. P300 latency was significantly higher for the DAT group (analysis of variance: P=0.023) throughout the study. The diagnostic value of P300 latency at baseline examination for DAT had a sensitivity of 52.9% and a specificity of 76.9%; the odds ratio was 3.75 (95% confidence interval, 1.23-11.41). Findings from the present study suggest that assessment of evoked related potentials may contribute to the early detection of DAT.

Parallel Improvement of Cognitive Functions and P300 Latency Following Donepezil Treatment in Patients With Alzheimer's Disease

“…The N200 component represents an early alternation of cognitive ability, such as target discrimination (Ritter et al, 1982), while the P300 component reflects information processing, such as target evaluation, judgment, and decision making (Gironell et al, 2005;Katada et al, 2004). Our finding that the patients after 22 to 23 weeks with DPZ showed P300 latency measured at Pz improved but not in N200 latency.…”

Patients with MCI and N400 or P600 abnormalities are at very high risk for conversion to dementia

“…15 We are only aware of one published longitudinal ERP study of MCI, in which three annual auditory P300 assessments were obtained in elderly subjects with memory complaints. 33 Thirty of these subjects received a final clinical diagnosis (2 years later) of MCI and 28 had a final diagnosis of AD. While P300 latency was delayed at baseline and 24 months in AD, no significant P300 abnormalities were found in MCI.…”

Evaluation of cognitive performance by using P300 auditory event related potentials (ERPs) in patients with growth hormone (GH) deficiency and acromegaly

“…Therefore lower P300 amplitude and prolonged P300 latency may represent the impairment of the relevant components of the cognitive performance [19]. In a recent study P300 ERPs have been successfully used in detecting early cognitive deficits in patients with dementia [21]. We have previously demonstrated the prolongation of P300 latencies in Sheehan's syndrome patients with severe GH deficiency [22].…”