Cerebral blood flow in depressed patients with systemic lupus erythematosus.

OBJECTIVE: To characterize the neural circuitry involved in depression associated with systemic lupus erythematosus (SLE), we used single photon emission computed tomography (SPECT) to study regional cerebral blood flow (CBF) in patients with SLE. METHODS: SPECT with (99m)Tc-ethylcysteinate dimer was performed in 30 depressed women patients with SLE, in 14 women patients with SLE and without history of neuropsychiatric disorders, and in 25 healthy women controls. Magnetic resonance imaging was done for all subjects for diagnostic purposes. Analysis of CBF patterns was performed using statistical parametric mapping. Statistical significance was taken at uncorrected p < 0.001 at cluster level. RESULTS: There were no significant differences between depressed and nondepressed patients with SLE for any rheumatologic variable. In comparison to healthy controls, depressed patients with SLE had significantly reduced CBF in bilateral frontal and temporal cortex; global maximum was located in the left precentral gyrus. There were no significant CBF differences between nondepressed patients with SLE and controls. Compared to nondepressed patients with SLE, depressed patients with SLE had significantly lower CBF in 2 clusters that had their local maxima in the right precentral gyrus and in the left superior temporal gyrus. The duration of SLE correlated with decreased perfusion in the left middle and superior frontal gyrus. CONCLUSION: Depressed patients with SLE have CBF reductions in discrete temporal and frontal regions that may account for depressive symptoms.

Higher level gait disorders in subcortical chronic vascular encephalopathy: a single photon emission computed tomography study.

BACKGROUND: the so-called higher level gait disorders include several types of gait disorders in which there are no major modifications in strength, tone, sensitivity, coordination and balance. Brain activation sites related to walking have been investigated using SPECT in humans. The aim of the study was to investigate brain activation during walking in subjects with high-level gait disorders due to chronic subcortical vascular encephalopathy. SUBJECTS: twelve patients with a chronic vascular encephalopathy were enrolled in the study. Seven subjects had apraxic gait while in the other five the gait was normal. All patients had undergone a recent cerebral magnetic resonance that revealed diffused chronic ischemic lesions within the white matter. METHODS: all 12 patients underwent a regional cerebral blood flow (rCBF) brain SPECT study with (99m)Tc-Bicisate on two separate days and under two different conditions: at rest (baseline) and while walking (functional). RESULTS: the rCBF increase induced by the treadmill test (functional-baseline), bilaterally in the medial frontal gyrus and in the anterior lobes of the cerebellum, resulted significantly (P < 0.001) lower in patients with gait apraxia versus those without it. CONCLUSIONS: this study of the brain with SPECT records the areas of perfusion deficit that appear in apraxic subjects when they walk, compared with the recordings obtained with the same investigation performed at rest.

Comparison of different thyroid committed doses in radioiodine therapy for Graves' hyperthyroidism.

Despite vast worldwide experience in the use of 131I for treating Graves' disease (GD), no consensus of opinion exists concerning the optimal method of dose calculation. In one of the most popular equations, the administered (131)I dose is directly proportional to the estimated thyroid gland volume and inversely proportional to the measured 24-hour radioiodine uptake. In this study, we compared the efficiency of different tissue-absorbed doses to induce euthyroidism or hypothyroidism within 1 year after radioiodine therapy in GD patients. The study was carried out in 134 GD patients (age, 53 +/- 14 year; range, 16-82 year; thyroid volume, 28 +/- 18 mL; range, 6-95 mL; average 24-hour thyroid uptake, 72%) treated with (131)I therapy. The average radioiodine activity administered to patients was 518 +/- 226 MBq (range, 111-1110). The corresponding average thyroid absorbed dose, calculated by a modified Medical Internal Radiation Dose (MIRD) equation was 376 +/- 258 Gy (range, 99-1683). One year after treatment, 58 patients (43%) were hypothyroid, 57 patients (43%) were euthyroid, and 19 patients (14%) remained hyperthyroid. The patients were divided into 3 groups: 150 Gy (n = 32), 300 Gy (n = 58) and >300 Gy (n = 44). No significant difference in the rate of recurrent hyperthyroidism was found among the 3 groups (150 Gy: 15%; 300 Gy: 14%; and > or =300 Gy: 14%; chi-square test, p = 0.72). Whereas, the rate of hypothyroidism in the 3 groups was significantly correlated with the dose (150 Gy: 30%; 300 Gy: 46%; >300 Gy: 71%; chi-square test, p = 0.0003). The results obtained in this study show no correlation between dose and outcome of radioiodine therapy (in terms of persistent hyperthyroidism) for thyroid absorbed doses > or =150 Gy, while confirming the relation between the thyroid absorbed dose and the incidence of hypothyroidism in GD patients.