Intractable benign paroxysmal positioning vertigo: long-term follow-up and inner ear abnormality detected by three-dimensional magnetic resonance imaging.

OBJECTIVE: To investigate the occurrence rate, prognosis, and inner ear abnormality in intractable benign paroxysmal positioning vertigo (BPPV). STUDY DESIGN: A prospective study. SETTING: Tertiary referral university hospital. PATIENTS: Intractable BPPV was defined in case of either a persistent nystagmus or a frequent relapse each lasting more than 1 year after the initial diagnosis. INTERVENTION: T2-weighted 3-dimensional fast imaging employing steady-state acquisition sequences of magnetic resonance imaging (MRI) were reconstructed 3-dimensionally for 13 intractable BPPV patients and 14 control volunteers. MAIN OUTCOME MEASURE: Transition and relapse of nystagmus were monitored. Semicircular canals were evaluated for a stenosis or filling defect (obturation). RESULTS: Eighteen patients (4 with posterior canal type, 2 with horizontal canal type with geotropic nystagmus, and 12 with apogeotropic nystagmus) fulfilled the above criteria for intractability among 495 BPPV patients. The occurrence rate of intractable BPPV was 3.6%. Also, the rate of nystagmus transition was significantly higher in patients with geotropic nystagmus and the posterior canal type (100%) compared with those with apogeotropic nystagmus (33.3%). Of the 13 intractable BPPV patients who underwent MRI, 11 (84.6%) had a total of 23 canals with abnormal appearance (29.5%), showing a significantly higher incidence compared with controls. There was no correlation between the affected canal diagnosed by MRI and the type of nystagmus. CONCLUSION: The low incidence of nystagmus transition in patients with apogeotropic nystagmus suggests a difference in pathophysiology between apogeotropic nystagmus and other types of BPPV. Stenosis and filling defect (obturation) of canals on MRI, which would indicate an innate narrowing and/or an otoconial jam of the semicircular canal, may account for the intractability of BPPV.

Differential radiation sensitivity to morphological, functional and molecular changes of human thyroid tissues and bone marrow cells maintained in SCID mice.

Morphology and function of human organs and tissues are well maintained in the improved SCID (severe combined immunodeficient) mice for a long period (approximately 3 years). To study the radiation-induced damage on human thyroid gland, human thyroid tissues transplanted to SCID mice were consecutively exposed to X-rays or 137Cs gamma-rays at high and low dose rates for approximately 2 years. Consecutive irradiation resulted in the disappearance of follicles and significant decrease of thyroid hormone secretion. Mutations in p53 and c-kit genes were induced significantly in human thyroid tissues from old head and neck cancer patients (av. 56.8 years, 4 males) and a Graves' disease patient (20 years, male) over the dose of 24 Gy (44.7+/-5.9 Gy, mean+/-S.E) and 11 Gy (20.2+/-7.8 Gy), respectively, while mutations were not detected at lower doses nor in unexposed matched controls (p < 0.01). There were significant differences in mutation frequency in the transplanted human thyroid tissues (31 years, female) between high dose rate (1.19 Gy/min; 8 in 20 tissues) and low dose rate (0.00023 Gy/min; 0 in 14 tissues) exposures (p < 0.01). Mutations were not detected in RET, K-ras and beta-catenin genes. Expression analysis by GeneChip indicated that gene expression was also well maintained in the transplanted human thyroid tissues. However, lower doses (1 or 3 Gy) of 137Cs gamma-rays can induce changes in gene expression in the transplanted human thyroid tissues. Furthermore, fatally irradiated SCID mice could survive with human bone marrow cell transplantation. When about half of mouse bone marrows were replaced by human bone marrow cells, the human bone marrow cells showed high sensitivity to gamma-irradiation; 28.0% and 0.45% survival after 0.5 and 2.0 Gy exposures, respectively.

[A case of advanced hypopharyngeal carcinoma successfully treated with superselective intra-arterial infusion of docetaxel].

Docetaxel is an excellent agent with a high antitumor effect for advanced/recurrent head and neck cancer. A 67-year-old male with advanced hypopharyngeal cancer (T3N2bM1: Stage IV) underwent two courses of superselective intra-arterial infusion of docetaxel and intravenous administration of CDDP and 5-FU. Using a coaxial technique, a microcatheter was placed in the feeding artery. Using imaging techniques docetaxel (60 mg/body and 30 mg/body) was infused into the vessels. During chemotherapy the patient received concomitant radiotherapy (50 Gy). MRI after chemoradiation showed a complete response for the primary tumor and a partial response for the neck metastasis. Grade 4 leukopenia and neutropenia and grade 3 pharyngitis/esophagitis were observed during chemoradiotherapy, but these adverse effects abated immediately and were not critical. We conclude that this superselective intra-arterial infusion of docetaxel will be useful and safe for head and neck cancer.