Stunning phenomenon after a radioactive iodine- ¹³¹I diagnostic whole-body scan: Is it really a point of clinical consideration?

PURPOSE: Stunning of thyroid remnants after diagnostic scanning (Dx-WBS) using radioactive iodine- (¹³¹I) may limit the efficacy of I therapy. We aimed to evaluate this assumption in a prospectively designed study. METHODS: Forty patients who underwent thyroidectomy for differentiated thyroid carcinoma were studied and divided into two identical groups: G1 and G2. In the G1 group, no Dx-WBS was performed and the ablation dose was given directly on the basis of the risk stratification; in the G2 group, Dx-WBS was performed with 185 MBq (5 mCi) of ¹³¹I, and ablation was given for a mean number of 11 ± 1.1 days; stunning was found on a semiquantitative basis in all patients. At a mean of 6.5 ± 0.3 months, the ablation success rate (ASR) was evaluated on the basis of Dx-WBS, thyroglobulin levels, and neck sonography. Complete ASR was considered when no ¹³¹I uptake could be seen in the neck or elsewhere, thyroglobulin was less than 2 ng/ml, and neck sonography was negative for any disease-related abnormalities. RESULTS: G1 and G2 groups were completely identical as no significant differences were found between their different characteristics, including the mean ablative dose. ASR was 81.7 and 78.3% in G1 and G2 groups, respectively (P=0.6). Multivariate Cox regression analysis showed the mean ablation dose to be the most influential factor in ASR (odds ratio 1.045; 95% confidence interval 0.936-1.1189; P=0.01). CONCLUSION: Our data suggest that stunning had no influence on ASR and is not a point of clinical consideration with respect to this aspect.

Silent central nervous system involvement in Egyptian Behçet's disease patients: clinical, psychiatric, and neuroimaging evaluation.

Behçet's disease (BD) is an idiopathic multisystem disorder. Involvement of CNS occurs in 4-48% of cases. This study was designed to evaluate the prevalence of subclinical neuropsychiatric affection in asymptomatic Egyptian BD patients using psychometric tests and brain imaging with single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI), also to assess possibly associated clinical predictive variables. Twenty-five BD patients without overt CNS involvement and ten healthy controls matched for age, education, and sex completed a comprehensive neuropsychological battery including Hamilton scales for anxiety and depression and Wechsler memory scale-revised. Disease activity was assessed using Behçet's Disease Current Activity Form (BDCAF). SPECT was done for all subjects, and 12 patients underwent brain MRI. Compared to controls, 23 (92%) and 24 (96%) patients had anxiety and depression scores respectively above normal range; also, BD patients had significantly lower memory quotient (MQ). SPECT revealed abnormalities in 16/25 (64%), while in 3/12 patients (25%), MRI was abnormal. Subjects with abnormal SPECT had significantly higher ages than those with normal SPECT (P = 0.02) and were more frequently males (P = 0.03). No statistically significant differences between cases with normal or abnormal SPECT were found regarding disease duration, frequency of headache, BDCAF, frequency of active eye disease, major vascular involvement, mean Hamilton anxiety and depression scores, and mean MQ. Early diagnosis of neurological involvement in BD is important in reducing or preventing complications. Neuropsychiatric evaluation and HMPAO brain SPECT were found to be useful for detecting subclinical neurological abnormalities in BD patients.