Solitary extramedullary plasmacytoma of the premaxilla

Solitary extramedullary plasmacytoma is a rare tumour with radiotherapy playing an important role in its management. This report describes the case history of a man with a solitary extramedullary plasmacytoma at an extremely rare site, the premaxilla, that posed certain diagnostic and therapeutic dilemmas. The patient underwent surgery followed by postoperative radiotherapy. The use of two modalities of treatment for this localized tumour has been justified by briefly reviewing the literature and defining the various prognostic factors. These prognostic factors in turn should guide the treatment of these uncommon tumours.     

Reasons for rejecting potential donors from a sperm bank program

Purpose: Recruiting donors to a sperm bank program is difficult and slow because of high dropout rates and high rejection rates. The profile of successful and unsuccessful donors was determined at our sperm bank. Methods: A total of 199 men was screened from 1986 to 1994 in the anonymous sperm bank donor program; 174 (87%) men dropped out or did not meet minimum guidelines. The study included 25 accepted donors and 20 rejected men (of 52 rejected donors, only 20 donors who came for two consecutive semen analyses were selected). Sperm quality variables and demographic data were compared between the groups. Results: Accepted donors had significantly better semen quality in motility, velocity, linearity, and ALH than did rejected donors (P < 0.01). More rejected donors than accepted donors were single (P < 0.01). A higher percentage of accepted donors consumed caffeine (P < 0.001), and they were more likely to have college degrees (P < 0.03). Conclusions: These results indicate that loss of interest and poor semen quality were the major reasons for rejection of donors in our anonymous donor sperm bank program.     

Perioperative complications in acoustic neuroma (vestibular schwannoma) surgery.

OBJECTIVE: Retrospective study and review of the complications other than those related to the facial nerve and hearing, encountered in acoustic neuroma surgery. Also, an evaluation of hospital stay and its relation with various factors. STUDY DESIGN: Retrospective case review. SETTING: Tertiary neurotologic and skull base referral center. PATIENTS: A series of 707 patients who underwent surgical removal of acoustic neuroma from April 1987 to December 2001. INTERVENTIONS: The surgical approaches used were the enlarged translabyrinthine approach, the enlarged middle fossa approach, and the retrosigmoid approach. In a small number of cases, the operations were performed through other approaches. MAIN OUTCOME MEASURES: The duration of hospital stay and appearance of complications in the perioperative period along with their management. Results related to the facial nerve and hearing were not considered in this study. RESULTS: The most frequent complication was abdominal subcutaneous hematoma (site of fat harvest), which occurred in 23 patients (3.2%). Cerebrospinal fluid leak was present in 20 patients (2.8%), 15 of whom needed revision surgery. Other complications included VIth cranial nerve dysfunction in 12 cases (1.68%), subdural hematoma in 3 cases (0.4%), cerebellopontine angle hematoma in 4 cases (0.6%), cerebellar edema in 2 cases (0.28%), brainstem hematoma in 1 case (0.14%), transitory aphasia in 1 case (0.14%), and lower cranial nerve dysfunction in 1 case (0.14%). Mortality occurred in only one case (0.14%). Medical complications seldom occurred. The postoperative hospital stay ranged from 2 to 36 days, with an average of 6.4 days. The overall hospital stay diminished over time from 10.2 days in 1987 to 1990, to 4.9 days in 2001. There was a significant relation between hospital stay and tumor size, approach used, and presence/absence of complications. CONCLUSIONS: Perioperative complications in acoustic neuroma surgery do exist, but this study demonstrated how low the incidence is. The authors believe that the low percentage of complications is mainly attributable to the majority of operations being carried out in specialized clinics, where they are considered routine operations. They believe that following individualized approaches, depending on tumor size and on the preoperative function of the cranial nerves, is the proper way to reach a significant reduction in complications while maintaining a high percentage of total tumor removal. The results of this study, considered as a basis of comparison with other studies, will certainly be useful in preoperative patient counseling.     

Management of the internal carotid artery in tumors of the lateral skull base: preoperative permanent balloon occlusion without reconstruction.

OBJECTIVE: To present our experience with permanent preoperative balloon occlusion of the internal carotid artery while dealing with different abnormalities of the lateral skull base and a comparison with the results mentioned in the literature. STUDY DESIGN: Retrospective case review. SETTING: Private neurotologic and skull base tertiary referral center. PATIENTS: Fifteen patients who underwent preoperative balloon occlusion of the internal carotid artery and surgery subsequently for various abnormalities of the lateral skull base between 1989 and 2002. INTERVENTIONS: Each patient was subjected to four-vessel angiography along with the manual cross-compression test and balloon test occlusion to assess the efficacy of the collateral circulation. After angiography, each patient underwent a preoperative balloon occlusion, after which a lateral skull base procedure was performed for removal of the abnormality. MAIN OUTCOME MEASURES: Only those patients showing evidence of adequate collateral cerebral circulation and a less than 1-second delay between the angiographic phases of the two cerebral hemispheres on angiography were considered fit for preoperative balloon occlusion. While under going the preoperative balloon occlusion, the patients were clinically assessed for the development of any neurologic symptoms and signs. Long-term follow-up after surgery was also based on the development of symptoms and signs of neurovascular compromise. RESULTS: A major complication in the form of long-lasting hemiplegia occurred in one patient (6.7%). This complication was the result of technical factors rather than an effect of cerebral ischemia, because it was caused by an intimal dissection produced by the catheter. A defect in the visual field occurred in one patient (6.7%) that resolved partially after antiplatelet therapy. There was no mortality in our series related to preoperative balloon occlusion of the internal carotid artery. CONCLUSION: Preoperative balloon occlusion of the internal carotid artery can still be considered a viable option for the management of the internal carotid artery during lateral skull base surgery. Proper preoperative evaluation of the adequacy and efficacy of the collateral cerebral circulation reduces the chances of postoperative neurovascular complications.     

XPS Investigation on Improving Hydrogen Sorption Kinetics of the KSiH3 System by Using Zr-Based Catalysts

The superior hydrogen storage properties makes the KSiH₃ system a potential hydrogen storage material for practical applications. A theoretical capacity of 4.3 wt% bring this material to the front line of all the available hydrogen storage materials; however, the activation barrier of the reaction restricts the system to absorb and desorb hydrogen reversibly at elevated temperatures even if the thermodynamics suggest its room temperature operation. Several catalysts have already been tested to enhance its kinetic properties. In this work, the efforts were made to reduce the activation energy by using Zr-based catalysts to the KSi/KSiH₃ system. The value of activation energy was found to be lowest (i.e., 87 kJ mol⁻¹⁾ for the ZrH₂-added KSiH₃ system. The mechanism of this improvement was investigated by using X-ray photoelectron spectroscopy (XPS).     

Neuro-ophthalmological manifestations of diabetes mellitus during COVID-19-related lockdown in India

Purpose:The coronavirus disease 19 (COVID-19) pandemic has resulted in a huge impact on the health care system. Diversion of health care workforce toward management of a high number of COVID-19 cases and lockdown restrictions have affected the follow-up of patients. The objective of this study was to analyze the impact of this situation on the control of diabetes, eventually resulting in related neuro-ophthalmological complications.Methods:This retrospective case series included diabetic patients visiting the neuro-ophthalmology clinic at a tertiary care eye center in India from 25 March 2020 to 25 September 2020 during the lockdown. The incidence of diabetes-related neuro-ophthalmological complications, including third, fourth, sixth nerve palsies and non-arteritic anterior ischemic optic neuropathy (NAION) was evaluated and compared with that of the same period during 2019.Results:Overall disease incidence rate was significantly higher in the year 2020 (60.2%) compared to the previous year of 2019 (29.8%). The proportion of third nerve palsy (4.8% vs 16.3%, P < 0.001) and NAION (0.3% vs 14.3%, P < 0.001) had increased. Even though the percentage of sixth nerve palsy was 25% in 2020, this was not significantly different from 2019. There was a reduction in the percentage of fourth nerve palsy cases from the year 2019 to 2020.Conclusion:There was a significant increase in diabetes-related neuro-ophthalmic complications during the COVID-19 lockdown. This can possibly be attributed to worsening of glycemic control in diabetic patients.