Miljenko Solter

Variations in shape and dimensions of sigmoid groove, venous portion of jugular foramen, jugular fossa, condylar and mastoid foramina classified by age, sex and body side

SummaryThe authors have examined variations in shape and dimensions in the region of the terminal part of the sigmoid groove, venous portion of jugular foramen and jugular fossa with reference to age, sex, and body side. Examinations were carried out on 300 macerated skulls of both sexes within age limits of 11 up to 88 years. The specimens were divided into three age groups.The jugular fossa becomes deeper with age, whereas there is no substantial variation in the dimensions of the terminal part of the sigmoid groove or the venous portion of the jugular foramen. All the dimensions are larger on the right hand-side but do not differ significantly with sex.It was noted that the venous portion of the jugular foramen appears to be positioned in the transversal direction more frequently in the older age group and on the right-hand side. With the transversal position of the jugular foramen a more pronounced and medially sited lower knee of the sigmoid groove and a reduced lateral edge of the venous portion of jugular foramen were found.Dehiscences in the region of the medial wall of the venous portion of the jugular foramen and the dome of the jugular fossa were examined and found in 14.3 percent of skulls. The importance of dehiscences through which the jugular fossa communicates with the cavum tympani are emphasized. The number of dehiscences increases with age, and they are twice as frequent on the right side as on the left.Frequency and dimensions of condylar and mastoid foramina were examined and the sum of the areas of these foramina was found to be in inverse proportion to the sum of the areas of the venous portion of the jugular foramina on both sides of the skull.

Remission of Graves’ disease is not related to early restoration of euthyroidism with high-dose methimazole therapy

Abstract Introduction and aims: The most recent hypothesis postulated that early restoration of euthyroid state in patients with Graves’ disease changes the course of the disease and leads to better disease control. Therefore, we analyzed the efficacy of methimazole therapy and the course of disease in patients with restored euthyroidism and in patients with active disease on first control visit. Patients and methods: We included 63 patients with total T4 level >190 nmol/L or T3 >7 nmol/L and diffuse goiter with no previous episodes of hyperthyroidism. All patients received initially high doses of methimazole (60–80 mg) followed by a rapid dose reduction. Results: Ten percent of patients were excluded from the study due to side effects. Two different groups emerged after 5 weeks of treatment with same dose of methimazole: group 1 with active disease (48%) and group 2 with restored euthyroidism. Further controls on 12th, 24th and 68th weeks of treatment showed no difference in remission rates, number of iatrogenic hypothyroid episodes, and number of exacerbations between the two groups, regardless of methimazole dose. There was no association between age, gender, thyroid hormone levels, and remission and exacerbation rates. Conclusions: Initially, higher methimazole doses with rapid progressive decrease to maintenance dose result in similar remission rates and are followed by similar incidence of adverse side-effect as fixed low dose therapy. Our results indicate that neither an early restoration of euthyroidism nor the difference in methimazole doses influence the course of Graves’ disease.

Do we treat hypothyroidism properly? A survey of 2488 patients from University Hospital Center, Zagreb, Croatia

OBJECTIVES The objective was to examine the effectiveness of levothyroxine treatment in hypothyroid patients in achieving normal thyroid stimulating hormone (TSH), T4 and T3. MATERIAL AND METHODS Results of the treatment of 2448 hypothyroid patients treated with LT4 for at least 12 months between 2006 and 2011 (1920 with spontaneous hypothyroidism and 528 with hypothyroidism following surgery or 131I) are presented. Serum TSH, T4 and T3 were analyzed and referred as normal, increased or decreased. RESULTS Normal TSH was found in 75 and 68% of patients respectively. In subgroups with increased TSH, 15% and 14% of patients showed borderline or only mildly increased TSH (4.1-5.5 mIU/L). T4 (94 and 86%) and T3 (93 and 90% respectively) were normal in the majority of patients from both groups. LT4 over-treatment is observed in only 4 and 6% of patients respectively. CONCLUSION The results are less favorable for the group with hypothyroidism following surgery or (131)I than in spontaneous hypothyroidism, but in about 90% of patients with spontaneous hypothyroidism and 82% with hypothyroidism following surgery or (131)I, the LT4 dose could remain unchanged. It is discussed whether standard LT4 replacement could render normal TSH and thyroid hormone patterns in all hypothyroid patients.

Decreased sensitivity of thyrotropin-thyroid hormone feedback control in hypothyroid and athyreotic patients treated with levothyroxine. Is serum triiodothyronine involved?

OBJECTIVES The search for optimal therapy for hypothyroidism is challenging and complex and is still going on. We investigated TSH-thyroid hormone feedback control in hypothyroid and athyreotic patients properly treated with levothyroxine (LT4), based on normal TSH values. MATERIAL AND METHODS We randomly selected 150 hypothyroid, 110 athyreotic and 210 euthyroid subjects, determined their serum T4, T3 and TSH values and calculated T4/TSH and T3/T4 ratios. RESULTS The TSH distribution in hypothyroidism was significantly shifted to the higher and that in athyreosis to the lower values from the normal distribution in euthyroid controls. This TSH-thyroid hormone dissociation in hypothyroidism was characterized with higher T4 and higher matched TSH values. We found 5% hypothyroid and 10% athyreotic patients normalize TSH only with hyperthyroxinemia. Serum T3 was lower in both hypothyroid groups and unaffected by a higher LT4 dose and higher serum T4 in athyreosis. CONCLUSION Our results suggest that the decreased serum T3 is a major cause of impaired TSH-thyroid hormone feedback control in hypothyroidism treated with LT4.

Increased thyroidal T4 to T3 conversion in autonomously functioning thyroid adenoma: from euthyroidism to thyrotoxicosis.

AIM The aim was to investigate whether the intrathyroid conversion of T4 to T3 in autonomously functioning thyroid adenoma (AFTA) tissue could influence serum T3 levels and suppression of TSH, especially in patients with borderline thyroid function. PATIENTS AND METHODS In ten patients with AFTA, thyroidal conversion of T4 to T3 was investigated in nodular and paranodular, TSH-suppressed tissue. All patients had normal serum T4 and suppressed TSH. Serum T3 was normal in six, and borderline or slightly increased in four. AFTA and paranodular tissues were surgically removed and frozen at -70°C, then homogenized in a glass homogenizer, centrifuged at 100,000×g, and particulate fraction collected as a pellet. Analysis mixture consisted of thyroid enzyme suspension in 50 μmol/L TRIS buffer with 5 μmol DTT and 200 μL 1.3 μmol T4. Incubation was performed at 37°C and the generation of T3 measured after 5, 10, 20 and 40 minutes respectively. RESULTS T3 production (pmol/mg protein) was significantly higher in AFTA than in paranodular tissues (8.8 1.2/Mean ± SE/vs. 1.8 ± 0.2; p<0.01), and excessively high (9.8, 14.1, 14.2 and 15.0) in four patients with borderline or slightly supranormal serum T3. A significant correlation was found between serum T3 concentrations and T3 generation (T4 conversion) in AFTA tissues. CONCLUSION Results suggest that increased thyroidal T4 to T3 conversion in AFTA tissue could be involved in an increased delivery of T3, increased serum T3 and suppressed serum TSH, particularly in patients with the disease evolving from euthyroid to an early hyperthyroid phase.