Changes in regional cerebral blood flow demonstrated by single photon emission computed tomography in depressive disorders: comparison of unipolar vs. bipolar subtypes.

Single photon emission tomography (SPECT) with 99mTc-HMPAO was used to compare regional cerebral blood flow (rCBF) in patients with unipolar and bipolar depression. The study group consisted of 10 unipolar depressed patients and seven bipolar depressed patients who met the DSM-III-R criteria for major depressive disorder (MDD). Nine physically and mentally healthy volunteers served as control subjects. SPECT images were obtained in the patients at two time points: (1) during the major depressive episode before patients had received medication; and (2) at the beginning of the remitted state while patients were receiving antidepressant medication. During the depressive episode, unmedicated unipolar depressed patients showed relatively increased left frontal rCBF compared both with the control subjects and the bipolar patients (P < 0.05). No significant differences in rCBF emerged between the bipolar patients and the control subjects. The data suggest that unipolar depressed patients, unlike bipolar patients, have relatively increased rCBF in the left frontal lobes during the depressive episode, but these differences tend to disappear during the period of remission.

Transient frontal hypoperfusion in Tc-99m hexamethylpropyleneamineoxime single photon emission computed tomography imaging during alcohol withdrawal.

BACKGROUND: Regional brain perfusion in patients during alcohol-withdrawal has been relatively less studied with brain SPECT technique. In this study, the hypothesis that possible regional cerebral blood flow (rCBF) alterations due to alcohol withdrawal might be transitory in a homogenous group of alcoholic patients in terms of their physical-nutritional and cognitive functional conditions was investigated. METHODS: Fifteen right-handed male inpatients with alcohol-withdrawal, diagnosed according to DSM-IIIR criteria, and 6 male physically-mentally healthy control subjects were included in the study. The first Technetium 99m-hexamethylpropyleneamineoxime (Tc-99m-HMPAO) brain SPECT investigation was performed on the day of admission in nonmedicated conditions and the second one was performed after all the withdrawal symptoms had subsided in the patients. As an indicator of the change in the brain perfusion, a relative perfusion index was used and the relative tracer activity was expressed as the ratio of mean cortical region of interest activity to mean the whole cortical brain activity. RESULTS: We found significantly reduced left frontal and right frontal, parietal and temporal rCBF values in the patients during the alcohol-withdrawal compared to those of their remitted state while they were not different from in the control group (p < 0.05). CONCLUSIONS: Our data indicate that the alterations in rCBF during the alcohol-withdrawal are more pronounced both in the frontal cortex and in overall right hemisphere regions. Furthermore, the frontal hypoperfusion may be transitory with recovery from alcohol-withdrawal whereas temporal hypoperfusion may continue after recovery probably depending on the previously administered high-dose benzodiazepines.

Value of thallium-201 scintigraphy for primary tumour detection in patients with malignant neck masses.

The aim of this study was to assess the contribution of thallium-201 scintigraphy to primary tumour detection in patients with malignant neck masses and to evaluate its sensitivity and specificity. A total of 30 patients with histopathologically proven malignant tumours were included in the study. The sensitivity, specificity and accuracy of 201Tl scintigraphy were found to be 54%, 75% and 57% respectively. These results suggest that 201Tl scintigraphy has a limited value in the detection of the primary tumour in patients with malignant masses of the neck.

201Tl imaging for differentiating between malignant and benign neck masses.

The aim of this study was to assess the ability of 201Tl scintigraphy to differentiate between malignant and benign neck masses. Fifty-eight patients with neck masses, whose diagnoses were confirmed by histological examination, were examined. The sensitivity, specificity and accuracy of 201Tl scintigraphy were 80%, 96% and 88% respectively; when salivary gland masses were excluded, these values were 87%, 95% and 91% respectively. Our results suggest that 201Tl scintigraphy is highly reliable in determining the malignancy of neck masses, especially when salivary gland masses are excluded.