Biomedical subjects
Publications and source records attributed to S C Levine.
Measurement of the acoustic-stapedius reflex is useful in the diagnosis of certain otologic diseases. The anatomy and physiology of the middle ear muscles and the acoustic reflex arc are reviewed for normal and pathologic ears. The application of acoustic reflex measures to clinical diagnosis is illustrated by a series of case studies.
The effects of early unilateral brain lesions on subsequent intellectual functioning were explored in hemiplegic children with congenital or acquired lesions. For congenital hemiplegics who sustained damage pre- or perinatally, lower intellectual functioning (IQ) was most highly associated with longer elapsed time since lesion. Moreover, including lesion size as an additional predictor of IQ did not account for significantly more variance than elapsed time since lesion alone. In contrast, for acquired hemiplegics who sustained damage after birth, lower intellectual functioning was highly associated with larger lesion size. In this group neither elapsed time since lesion nor age at testing accounted for significantly more IQ variance than lesion size alone. Possible effects of maturational factors and functional plasticity are considered in interpreting this pattern of results.
The current research investigates sources of variability in subjects' asymmetry scores on commonly used laterality tasks. In particular, subjects' asymmetry scores on four bilateral tachistoscopic tasks and one free-vision task were entered into a principal component analysis (PCA) in order to investigate components that explain the maximum variance of the sample. The results indicate that about half of the variation (45.2%) in asymmetry scores on both tachistoscopic and free-vision tasks is attributable to individual differences in characteristic perceptual asymmetry. The amount of variance explained by this characteristic perceptual asymmetry component is similar in a sample of dextrals and a sample of sinistrals. No significant relation was revealed between individual differences in characteristic perceptual asymmetry and performance on various verbal and spatial cognitive tasks.
A set of neurological tasks was administered to normal three- and five-year-old preschool children as well as to equal-age children identified as being at-risk for learning disabilities. 12 neurological test items were identified that differentiated normal from at-risk children at one or both ages. Follow-up of the five-year-olds at age seven showed a significant linear relation between scores on neurological tasks and the Wechsler Intelligence Test for Children. The neurological examination at age five also had predictive value regarding class placement at age seven. The findings suggest that a simple neurological test may be helpful for the early identification of preschool children who are at risk for learning difficulties.
Arachnoid cysts of the posterior fossa are rare. When arachnoid cysts are encountered, the presenting symptoms are frequently otologic, with hearing loss and imbalance occurring commonly. Three cases are presented with a previously unreported otologic symptom, that of bilateral hearing loss, which in one case was fluctuant. None of the patients had the common symptoms of unilateral hearing loss and headache. With the advent of computed tomography and magnetic resonance imaging, these cysts may be readily identified, usually with diagnostic imaging alone. Unfortunately there is often a delay in diagnosis because of the vague and fleeting nature of the symptoms. Because no single diagnostic symptom pattern is able to characterize all cases, it is believed computed tomography or magnetic resonance imaging or both are indicated in patients with long-standing otologic complaints--even in the absence of unilateral symptoms. Treatment of posterior fossa arachnoid cysts primarily consists of surgical procedures designed to decompress the cyst. In this series, treatment with diuretics alone resulted in improvement of symptoms during several years of followup, with no evidence of enlargement of the cysts.
Ten years after labyrinthectomy, 38 patients responded to a questionnaire. There was a slight decline in relief of vertigo from 93% to 76%. Symptoms following the procedure are discussed. It is believed that the reason for the decline is secondary to the age of the patients, the occasional bilateral nature of Meniere's disease, and possibly postsurgical neuroma formation. The ramifications of this study are discussed with respect to hearing-conservation procedures.
Hemangiomas of the external auditory canal rarely occur. These lesions have been reported to involve men in their sixth decade. This case report represents the fourth such lesion reported in the literature and the first to be seen in a woman. The clinical presentation, surgical therapy, and pathology are discussed. This tumor represents an unusual cause of hearing loss.
Cochlear implantation is becoming an increasingly accepted rehabilitative procedure for post lingually deafened adults. The testing, evaluation, and surgery have become standardized procedures. In this case results of two different promontory tests were contradictory. A constant voltage stimulation test was negative, while a later constant current stimulation test indicated good residual function. The CT scan accurately predicted the location of the round window remanent. In order to gain access to the cochlea, a partial labyrinthectomy was performed. Successful implantation was ultimately achieved. This implies that a previous labyrinthectomy may not be an absolute contraindication to cochlear implantation.
Face-recognition ability has been claimed to be qualitatively different from other pattern-recognition abilities. One argument for this claim is the finding of a significant right hemisphere advantage for the recognition of upright but not inverted faces. However, this argument is justified only if this orientation-sensitive pattern is unique to faces. In the present study, comparable patterns of orientation-sensitive involvement of the right hemisphere are found for the recognition of faces and houses. This finding is interpreted as evidence for a right hemisphere schema formation capacity that is applied not only to upright faces but also to other familiar classes of stimuli in their canonical upright orientation. It is suggested that any greater right hemisphere involvement in the recognition of upright faces is due to our greater expertise at recognizing faces than other stimulus types. We also find evidence that only a subset of right-handed adults show orientation-sensitive right hemisphere involvement in the recognition of faces and houses: in particular, those dextrals with a characteristic hemispheric arousal asymmetry in favor of the right hemisphere. In contrast, dextrals with a characteristic arousal asymmetry in favor of the left hemisphere do not show significant visual field asymmetries for faces or houses in either upright or inverted orientations.
The clinical picture determines the workup of the patient. The referring physicians' high index of suspicion for an acoustic tumor compelled them to persist with the evaluation and referral of this patient, despite a normal MRI. No one can argue that MRI is a technological breakthrough, but it has its limitations like any other test. The quality of the MRI study depends on the cooperation of the patient, and the capabilities of both the machine and physicians. The fact that it depends on completely different physical and chemical properties than conventional radiography suggests to us that it will be an important adjunct rather than a replacement for CT scanning.
Primary adenocarcinoma of the temporal bone is a rare disorder. Fewer than 40 cases have been reported in the English literature, most of these being single case reports. Exclusion of metastatic adenocarcinoma is imperative. Adenocarcinomas must be differentiated from benign adenomas. Adenocarcinomas are best managed by aggressive surgical resection, with postoperative irradiation used in cases of incomplete resection or high-grade tumors.
The results of psychological testing, EEGs and CT scans were examined for 41 children with congenital or early acquired hemiplegia. On average, IQ was depressed and the magnitude of this depression was highly correlated with lesion size, degree of hemiparesis and EEG abnormality, but not with location of lesion. There were no significant effects of lesion laterality on Verbal vs. Performance IQ on Wechsler tests. However, receptive vocabulary, as measured by the Peabody Picture Vocabulary Test, was differentially depressed by left-hemisphere damage. Further, on a variety of verbal tasks, patients with congenital lesions performed better than those with acquired lesions. In contrast, no significant differences were found between the two groups on spatial tasks.
Eighty-two revision stapedectomies were analyzed to determine causes of primary and revision stapedectomy failure. The specific cause of failure can often be anticipated preoperatively by analysis of the patient's audiogram, symptoms, type of prosthesis initially used, and the duration of time between initial surgery and the onset of symptoms. Guidelines for performance of revision stapedectomy are discussed.
As a discipline, skull-base surgery via the transtemporal route has matured since 1975. Previously considered unresectable, skull-base tumors with intracranial extension can now be successfully removed by means of modification of contemporary exposures with neurosurgical collaboration. Between September 1970 and February 1986, 126 skull-base tumors have been operated on by The Otology Group, P.C. Of these, 49 had intracranial extension. In this article, techniques for tumor removal and dural defect reconstruction are outlined. A single-staged procedure is advised. The advantages of and exceptions to this format are described. Techniques that will prevent postoperative cerebrospinal fluid leakage are highlighted. Results and complications of this surgical series are discussed, and team aspects of this surgery are emphasized.
Explore the source record for details and available documents.
The first 100 patients in a series of 616 cerebellopontine angle tumors were compared to the most recent 100 patients. All of the first 100 patients were evaluated prior to the common use of CT or ABR. Recently, improved diagnostic studies have resulted in the discovery of significantly smaller tumors. The later group of patients was also found to have their symptoms for a shorter period of time and had better overall hearing at the time of diagnosis. Reductions in the rates of various complications were also observed. These trends are felt to be the direct result of improved audiologic and radiologic diagnostic studies. A heightened awareness of all otolaryngologists to seek the diagnosis of acoustic neuroma also improved early diagnosis.
A 13-month-old child was seen and evaluated for persistent aural bleeding following the placement of a pressure equalizing tube. A vascular mass was identified in the middle ear space. The radiologic evaluation is discussed. The mass was surgically resected for both diagnostic and therapeutic reasons. Pathologic examination revealed a benign hemangioma. The significance of this diagnosis is discussed.
Between the years of 1978 and 1986 attempts have been made to save the hearing in 47 patients with unilateral pathologically confirmed acoustic neuromas. The middle fossa approach has been used in 32 cases and the suboccipital approach in 15 cases. Our review demonstrates an advantage using the suboccipital approach to excise most of these tumors. The success rate is higher (47% vs. 31%) and complications fewer using the suboccipital route. Despite these findings the middle fossa approach may be preferable in selected tumors located laterally in the internal auditory canal. In an effort to better select patients for hearing conservation surgery, an analysis of preoperative data (demographics, audiometry, evoked auditory response testing, and tumor size) was performed. Although certain guidelines have evolved to more accurately select hearing conservation surgery candidates, we are still unable to do so reliably. Preoperative auditory brain stem response testing, however, may evolve as a useful indicator for a successful hearing operation. The findings of our preoperative data analysis, surgical results, and complications are reviewed.