Quantitative electroencephalography power and coherence measurements in the diagnosis of mild and moderate Alzheimer's disease

Medidas de coerência e de potência absoluta no eletroencefalograma quantitativo no diagnóstico da doença de Alzheimer suave e moderado

OPINION

Quantitative electroencephalography power and coherence measurements in the diagnosis of mild and moderate Alzheimer's disease

Medidas de coerência e de potência absoluta no eletroencefalograma quantitativo no diagnóstico da doença de Alzheimer suave e moderado

Lineu Corrêa Fonseca^I; Gloria Maria Almeida Souza Tedrus^I; Larissa Rodrigues Prandi^II; Ana Carolina Amaral de Andrade^III

^IProfessor of Neurology, Faculdade de Medicina da Pontifícia Universidade Católica de Campinas (PUC-Campinas), Campinas SP, Brazil

^IIPlacement scholarship student (FAPIC)/Reitoria, PUC-Campinas, Campinas SP, Brazil

^IIIPlacement scholarship student PIBIQ/CNPq, PUC-Campinas, Campinas SP, Brazil

^{Correspondence}

Authors' reply

Dear Editors,

We are grateful to Golimstok et al.¹ for their interest in our work², as also for the comments and questions they raised.

The fundamental question raised was: "it is very difficult to explain a control group with significant lower education compared to Alzheimer's disease (AD) patients, mainly because this variable might affect on Mimi Mental State Examination (MMSE) and precisely, this instrument was used to differentiate cases from control group".

We would like to present the following considerations on this question:

1. The diagnostic criteria were presented in the following way in our article: "dementia according to the Diagnostic and Statistical Manual of Mental Disorders (DSM IV, 1994)³, and the diagnosis of AD (slight or moderate stages) according to the criteria of the NINCDS/ADRDA (National Institute of Neurological and Communicative Disorders and Stroke and Alzheimer´s disease)^4".

2. MMSE should always be interpreted in the light of the educational level according to the criteria studied in our sphere⁵, but is just one of the elements used in the characterization of dementia and Alzheimer's disease according to the diagnostic criteria used, as presented. These criteria are widely accepted for their validity, reliability and usefulness in research.

With respect to the score on the Hachinski scale, this was indeed used as a criterion for exclusion, score above 4 and not below, which was a typing error, as suggested by Golimstok et al.¹.

With respect to the relationship between depression and quantitative electroencephalography (qEEG) indicated by Pozi et al. (1995)⁶, we must emphasize that the evaluation of factors involved in alterations on the qEEG was not an objective of our article; the basic objective was to evaluate its value in the differential diagnosis between AD and the controls. On the other hand, the presence of depression should not be an exclusion factor in the diagnosis of AD.

As pointed out by Golimski et al., the qEEG has attracted much research on its relationships with mild cognitive impairment and dementia.

Received 26 July 2012

Accepted 02 August 2012

• 1. Golimstok Á, Rojas JI, Cristiano E. qEEG and Alzheimer's disease. Arq Neuropsiquiatr 2012;70:476.
• 2. Fonseca LC, Tedrus GM, Prandi LR, Andrade AC. Quantitative electroencephalography power and coherence measurements in the diagnosis of mild and moderate Alzheimer's disease. Arq Neuropsiquiatr 2011;69:297-303.
• 3. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4^th ed. Washington: American Psychiatric Association; 1994.
• 4. McKhann G, Drachman D, Folstein M, Katzman R, Price D, Stadlan EM. Clinical diagnosis of Alzheimer's disease: report of the NINCDS-ADRDA Work Group under the auspices of Department of Health and Human Services Task force on Alzheimer's disease. Neurology 1984;34:939-944.
• 5. Brucki SM, Nitrini R, Caramelli P, Bertolucci PH, Okamoto IH. Suggestions for utilization of the mini-mental state examination in Brazil. Arq Neuropsiquiatr 2003;61:777-781.
• 6. Pozzi D, Golimski A, Petracchi M, García H, Starkstein S. Quantified electreoncephalographic changes in depressed patients with and without dementia. Biol Psychiatry 1995;38:677-683.

Publication Dates

• Publication in this collection
  03 Jan 2013
• Date of issue
  Dec 2012