This study evaluates brain perfusion in long-term inhalant abusers of tolue
ne, acetone, benzene and derivatives. Ten patients in the age range 16-18 y
ears (mean, 17.3 +/- 0.67 years), who had been inhalant dependent for a mea
n period of 48.3 +/- 6.2 months, but who had stopped using inhalants for 1-
11 months (mean, 5.4 +/- 2.1 months), and ten controls (mean age, 17.3 +/-
0.67 years) were included in the study. Psychiatric tests, biochemical test
s and Tc-99m-hexamethylpropyleneamine oxime (Tc-99m-HMPAO) brain single pho
ton emission computed tomography (SPECT) were performed on all patients. Br
ain SPECT images were evaluated qualitatively and quantitatively.
The mean IQ level was found to be 84 (by psychological tests). Brain SPECT
showed non-homogeneous Tc-99m-HMPAO uptake and hypoperfusion areas in all p
atients (five left temporal, one right temporal, two left temporal plus bil
ateral parietooccipital, one biparietal and one left temporoparietal). Seve
n patients had hyperperfused foci (unifocal in five patients and multifocal
in two patients). Six hyperperfused foci were in a parietal and one in a t
emporoparietal location.
This study suggests that inhalant dependents exhibit serious abnormalities
in brain SPECT images, including hypo-hyperperfusion foci and non-homogeneo
us uptake of the radiopharmaceutical. A further study with a larger number
of patients and long-term follow-up may help to reach a more specific concl
usion. ((C) 2000 Lippincott Williams & Wilkins).