Biomedical subjects
M L Pensak
Publications and source records attributed to M L Pensak.
Techniques of and reconstruction after temporal bone resection.
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Prediction of bithermal caloric response from monothermal stimulation.
The use of either cold or warm caloric stimulation alone as a screening tool for unilateral weakness has been suggested as a means of both shortening testing time and reducing patient discomfort. The validity of the monothermal caloric test must be well established before it can be routinely used in clinical situations. The purpose of this investigation was to re-evaluate the monothermal caloric test by examining the correlations between unilateral weakness derived from bithermal caloric stimulation compared to monothermal caloric results using either warm or cool stimulation alone. A retrospective analysis of 200 patients indicated significant correlations between bithermal and monothermal unilateral weakness for patients with unilateral weakness of less than 15% and greater than 30% for both warm and cool water stimulation. For patients with 15% to 30% unilateral weakness, the bithermal and monothermal calorics were significantly correlated for only the cool condition. When predicting normal or greater than 20% unilateral weakness, either of the monothermal calorics have greater than 85% efficiency, with specificity greater than 94% and sensitivity greater than 64%. However, the false-negative rate is 29% for warm and 36% for cool calorics. The high rate of false-negative findings indicates that screening tests have no place in a diagnostic battery, especially in view of the implications for missing significant pathology.
Temporal bone resection.
It must be emphasized that the greatest impact of survival can only be obtained through an early diagnosis and a radical treatment program. Any granulation tissue must be sent for biopsy to rule out the possibility of malignancy in the setting of chronic otitis media. Once carcinoma is diagnosed, imaging studies must be obtained to define the extent of the tumor. Under diagnosis is the rule with these malignancies. Tumors limited to the external auditory canal can be adequately resected with a lateral temporal bone resection. Extension into the middle ear and mastoid aircell systems requires either a subtotal temporal bone resection or a lateral temporal bone resection with a radical mastoidectomy and petrousectomy. The inclusion of the petrous apex with the resection, as in a temporal bone resection, does not add to survival but increases morbidity. Radical postoperative radiation therapy is essential for maximum local control and survival with these malignancies.
The fluoroquinolones.
At the Eastern Section Meeting of the Triological Society January 26, 1990, Levinson et al reported outstanding success with ciprofloxacin in the treatment of malignant otitis externa. Moreover, several of the individuals so managed had been refractory to conventional therapy with semisynthetic penicillin and aminoglycoside protocols. This new class of antibiotics may result in a profound change in our management of patients with otologic, neurotologic, and skull base infections.
Central auditory function.
Central auditory disorders in children and adults have become more widely recognized in patients seen by otolaryngologists and audiologists. This article briefly defines those clinical entities, discusses the historic background of testing, and describes current and future test approaches to assessment of central auditory disorders.
Differential diagnosis of chronic facial, head, and neck pain conditions.
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Thoughts on the management of chronic facial, head, and neck pain.
As previously stated in this paper, the therapeutic goal in the management of patients with chronic pain conditions in the face, head and neck is management and rehabilitation, striving for a 50 percent decrease in pain, a 50 percent increase in function and mobility, and a 50 percent decrease in medication with the elimination of agents with an addicting potential. These results will best be obtained through proper diagnosis and utilization of the aforementioned techniques in an interdisciplinary fashion as has been described.
A paraneoplastic syndrome associated with glomus tumors of the skull base? Early observations.
Independent secretion of vasoactive substances by glomus tumors of the skull base is widely recognized. Surgical removal of these tumors often results in an unexplained prolonged postoperative ileus, even in cases in which the vagus nerve is preserved. There is evidence that these tumors may secrete neuropeptides, such as cholecystokinin, in addition to catecholamines. A retrospective analysis of cases of glomus tumors of the skull base operated on at The Otology Group was carried out to correlate preoperative neuropeptide levels, vagus nerve status at surgery, and duration of postoperative ileus. High circulating levels of cholecystokinin associated with these tumors may be responsible for the unexplained phenomenon of prolonged postoperative ileus. The relevance of neuropeptides to the postoperative management of these patients is discussed. Preventive measures that may avert the potentially lethal complications of aspiration and negative nitrogen balance are described.
Neuroaudiologic abnormalities in patients with type 1 neurofibromatosis.
Although the protean manifestations of neurofibromatosis have been studied for many years, much is yet to be learned about this disease in young children. Specifically, little is known about the prevalence and significance of early neurotologic abnormalities in this population. Our review of the recent literature, however, failed to identify any publication on the use of ABR and acoustic reflex testing in the pediatric neurofibromatosis population. This study reports on a standardized differential diagnostic battery conducted on 44 children diagnosed as having neurofibromatosis. Results of the neuroaudiologic battery indicated that 32% of the children had significant abnormalities on ABR and acoustic reflex dynamic tests. This is a substantially higher prevalence of abnormalities than reported by another group at a recent NIH concensus meeting on neurofibromatosis. Discussion of the implications of these findings regarding evaluation protocols, as well as management for this select patient population, will follow.
Rhabdomyosarcoma of the ear and temporal bone.
Rhabdomyosarcoma, the most common soft tissue sarcoma of childhood, involves the temporal bone in approximately 7% of reported cases. Until recently, the outcome of this disease was always fatal. The recent Intergroup Rhabdomyosarcoma Study Group (IRS-I) reported on the efficacy of multimodality therapy consisting of multiagent chemotherapy, radiation, and surgical resection when indicated. Twelve patients with rhabdomyosarcoma involving the temporal bone were treated between 1966 and 1988. Three patients were treated according to the IRS-I protocols and the remaining nine patients received various combinations of treatment modalities. Ten patients succumbed to their disease, most with distant metastases or intracranial extension. Two patients are alive; one at 5 1/2 years and one at 19 years. It is apparent that, although survival for rhabdomyosarcoma in general has improved with the use of IRS-I protocols, prognosis remains poor for disease involving the temporal bone and other parameningeal sites.
The surgical anatomy and approaches to lesions of the lower basilar artery and vertebral artery union.
The neural and vascular anatomy of the posterior fossa and bony skull base is of interest to both neurosurgeons and otologists charged with the evaluation and management of patients demonstrating lesions in this region. Despite well described approaches to pathology in this area, access to the lower basilar artery and clivus remains a significant challenge. This report highlights the pertinent anatomic details of the fossa, describes the bony dimensions relevant to surgical access, and reviews two unconventional approaches to the lower basilar upper vertebral artery union.