Comparative Functional Study of Two Psychiatric Pathologies by means of BrainSPECT Tc 99 HMPAO: Major Depression and Borderline Personality Disorder.

COMPARATIVE FUNCTIONAL STUDY OF TWO PSYCHIATRIC PATHOLOGIES BY MEANS OF BRAINSPECT TC 99 HMPAO: MAJOR DEPRESSION AND BORDERLINE PERSONALITY DISORDER.

STATISTICAL ANALYSIS

The exact Fisher Test was applied to estimate the gender effect in data collected in basal situation and during the test of Wisconsin. It was also used the Student T or the Test of Mann - Whitney, to estimate the age effect. To compare basal results and those obtained with the Wisconsin test, it was used the test of Kruskall - Wallis with correction of Pocock for multiple comparisons in depending samples.

The homocedasticity of data was estimated through the test of Bartlet.

In the cases the test of Bartlet were not significant, it was used the Student T test to compare both groups.

The criteria of statistical meaning is for lower or equal values to 5% (P < 0.05), all the areas which fulfill this criteria, indicate that the change produced between the basal measurement and the measurement obtained during the Wisconsin test, is real (that is, in all the population).

In the analysis of the sample of depressive patients it was used the same statistical analysis as in the case of borderline patients.

Acquisition of NeuroSPECT HMPAO Tc 99 m.

The acquisition of Neurospect in basal conditions and in stimulation through the test of Wisconsin was done according to Protocol published (www.alasbimnioumal.cl/revistas/7/prado.html).

Quantification of the Extension of Hypoperfusion in each Brodmann area.

In order to define with high reproducibility the exact localization of the hypoperfusion areas observed in the borderline patients a matrix was made with the Corel Draw 8 Program with 24 areas of Brodmann by hemisphere involved in behavioral and language activities based in clinic and experimental conditions (about brain functionality and pathologies by areas). For the confection of this matrix it was used the areas of Brodmann as a reference. These areas are projected automatically by the computer over the images of Neurospect in rostral, right lateral, left lateral and both hemispheric mesial projections of the tridimensional brain images obtained. The projection of this matrix is automatic therefore the reproducibility of the results is 100%.

By consensus of the two investigators the extension of each area of Brodmann which appeared hypoperfused and depicted in color blue in the image was estimated; these results were expressed as the percentage of the area of Brodmann that was estimated to be hypoperfused. (Figure I). (Color blue denotes areas that are perfused at more than 2 Standard Deviations below the average perfusion in the brain cortex. Each pixel is normalized to the maximal perfusion in the brain cortex and compared to a normal data base. www.alasbimnjournal.cl/revistas/7/prado.html).

FIGURE I