Cerebral perfusion and automated individual analysis using SPECT among an obsessive-compulsive population

Euclides Timóteo Da Rocha,Carlos Alberto Buchpiguel,Geraldo Busatto Filho,Stela Verzinhase Peres,Euripedes Constantino Miguel

doi:10.1590/s0047-20852011000100001

Abstract

OBJECTIVE: To make individual assessments using automated quantification methodology in order to screen for perfusion abnormalities in cerebral SPECT examinations among a sample of subjects with OCD. METHODS: Statistical parametric mapping (SPM) was used to compare 26 brain SPECT images from patients with OCD individually with an image bank of 32 normal subjects, using the statistical threshold of p < 0.05 (corrected for multiple comparisons at the level of individual voxels or clusters). The maps were analyzed, and regions presenting voxels that remained above this threshold were sought. RESULTS: Six patients from a sample of 26 OCD images showed abnormalities at cluster or voxel level, considering the criteria described above, which represented 23.07%. However, seven images from the normal group of 32 were also indicated as cases of perfusional abnormality, representing 21.8% of the sample. CONCLUSION: The automated quantification method was not considered to be a useful tool for clinical practice, for analyses complementary to visual inspection.

Highlights

The neurobiology of obsessive-compulsive disorder (OCD) has been widely investigated over the past decades
Despite the great impact that neuroimaging studies have had with regard to elucidating the pathophysiology of the so-called functional psychiatric disorders such as major depressive disorder, OCD and psychoses, the results from such investigations have generally come from statistical comparisons of means from cerebral measurements, between groups of patients and normal controls
There has been a scarcity of systematic studies which suggest that such neuroimaging examinations could be useful for practical clinical diagnostic purposes in the individual evaluation of subjects with functional psychiatric disorders

Summary

Introduction

The neurobiology of obsessive-compulsive disorder (OCD) has been widely investigated over the past decades. A series of published papers has indicated functional brain abnormalities in group comparisons of OCD patients relative to healthy controls, involving the orbitofrontal cortex, anterior cingulate cortex, basal ganglia and thalamus[1,2,3,4] Cortical regions such as the orbitofrontal cortex and the cingulate gyrus have been recognized to be heterogeneous among humans, with evidence of the existence of subregions that possibly perform specific roles in the pathophysiology of OCD5,6. On the other hand, when brain functional images of any type are inspected individually, abnormalities are only detected in a certain proportion of patients with psychiatric disorders, and with considerable variability regarding the nature and cerebral location In this respect, there has been a scarcity of systematic studies which suggest that such neuroimaging examinations could be useful for practical clinical diagnostic purposes in the individual evaluation of subjects with functional psychiatric disorders. This is in sharp contrast with the well-established practical applications for functional neuroimaging methods in the differential diagnosis of neurological diseases that presumably present well-defined cerebral pathological findings[7,8,9]

Methods

Results

Conclusion