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Biomedical subjects

J T Benitez

Publications and source records attributed to J T Benitez.

At least 19 recordsLinked to original sources
PubMed1994

BAER, EOG, MRI and 3-D MR angiography correlates in a case of Locked-In syndrome.

A case of Locked-in syndrome is reported with correlation of BAER and EOG with MRI for localization and identification of brain lesions, and 3-D MRA and 2-D gradient echo MR imaging, a non-invasive new diagnostic modality for confirmation and visualization of vascular pathology. There was thrombosis of the basilar artery with extensive infarct of ventral pons and lower mid-brain. The patient had ocular bobbing. This eye movement in its classical form consists of irregular vertical oscillations, the fast component being downward with complete absence of horizontal eye movements. To our knowledge, the change from ocular bobbing to upbeat nystagmus has not been previously reported in the Locked-in syndrome. Bilateral involvement of the lateral lemniscus might have contributed to its appearance in our patient.

Basilar Artery↗
PubMed1990

Vestibular effects of chronic perilymph fistula in the cat.

Chronic, unilateral perilymph fistulae were created in cats by removal of the round window membrane and placement of a tympanostomy tube into the round window. Rotary chair, fistula, caloric, and vestibulospinal tests were performed before and after fistulization, and periodically for 2 weeks. At 2 weeks, patency of the fistula was documented by fluorescein injection into the spinal fluid and visualization of leakage into the middle ear bulla via the fistula. All the cats had a patent fistula at 2 weeks, but one of the three cats had a greater perilymph leak than the others. The cat with the more active leak had a spontaneous nystagmus toward the side of the fistula on the first postoperative day; this changed to nystagmus toward the opposite side by the third postoperative day. The other cats had a spontaneous nystagmus toward the opposite side from the first postoperative day. Most abnormal test results returned to normal in the first week after fistulization. Histologic study of the temporal bones revealed that the cat with the greater leak had a wider cochlear aqueduct than the other cats.

Animals↗
PubMed1990

Evidence of central vestibulo-auditory dysfunction in atypical Cogan's syndrome: a case report.

Auditory and vestibular functions were investigated in a patient with atypical Cogan's Syndrome. The brainstem auditory evoked response revealed bilateral severe distortion of morphology and voltage diminution after potential I, greater in right ear recordings. Interwave latency I-III was increased bilaterally. Electronystagmographic studies showed nonfatigable direction changing positional nystagmus greater with right ear undermost and bilateral failure of optic suppression. Findings suggested bilateral pontocerebellar dysfunction. Correlation was found with the side of greater clinical manifestations. The patient had excellent recovery of auditory and vestibular functions with administration of corticosteroids within 2 weeks of the onset of hearing impairment. She was followed up with auditory and vestibular studies for 30 months.

Adult↗
PubMed1989

Brainstem auditory evoked response sensitivity: comparison with other neurologic tests in the detection of retrocochlear lesions.

Brainstem auditory evoked response (BAER) tests were obtained in 3 patients with suspected retrocochlear lesions. Subsequently, CT scans and the surgical procedure demonstrated tumors of about the same size (2 cm) in the cerebellopontine angle. One was an VIIIth-nerve schwannoma, one a meningioma, and one a VIIth-nerve neuroma. BAER recordings were analyzed with results of other tests: conventional audiometry, stapedius reflex measurements and electronystagmography (ENG). A striking finding was a normal BAER in the patient with the VIIIth-nerve schwannoma. ENG recordings in this case showed ipsilateral impairment of optokinetic nystagmus. The BAER was abnormal in the other 2 patients. A consistent abnormality for the 3 patients was absence of stapedius reflex in the ear in question. This study disclosed the advantage of utilizing a battery of tests in the investigation of retrocochlear lesions. The ENG recordings should include evaluation of the vestibulo-oculomotor pathways.

Acoustic Impedance Tests↗
PubMed1988

Otopathology of Egyptian mummy Pum II: final report.

Otoscopic examination of the ears of Egyptian mummy PUM II with the operating microscope revealed a small oval perforation of the right tympanic membrane in the posteroinferior quadrant. The smooth and concise margins suggested an etiology of middle ear infection. A method which allows decalcification of ancient specimens without disintegration of the eardrum and other soft tissues within the temporal bone was described. There was evidence of histological repair at the margins of the perforation consistent with sequela of otitis media. No other abnormalities were observed in the temporal bones of this individual. There was no evidence of otosclerosis bilaterally. To our knowledge, this is the first time that a pathological tympanic membrane perforation has been histologically documented in an ancient temporal bone.

Cochlea↗
PubMed1986

Brain stem auditory evoked response correlates in patients with spinocerebellar lesions.

Brain stem auditory evoked responses were obtained in three patients with spinocerebellar dysfunction for assessment of brain stem involvement and lateralization. Computed tomography scan in the three cases showed negative findings for the brain stem. The evoked potentials demonstrated involvement of the pontine tegmentum. Correlation was found for lateralization to the site of greater neurologic deficit. Brain stem auditory evoked response abnormalities reflect disturbance of neural function rather than the underlying anatomic change of that disturbance. It therefore appears to be a more sensitive type of testing than the computed tomography scan in detecting lesions that alter electrophysiology but do not produce alterations of morphology and radiodensity.

Adolescent↗
PubMed1983

Caprine beta-mannosidosis: clinical and pathological features.

Beta-mannosidosis, an inherited defect of glycoprotein catabolism associated with deficiency of tissue beta-mannosidase and accumulation of Man(beta 1-4)GlcNAc and Man(beta 1-4)GlcNAc(beta 1-4)GlcNAc, appeared in four of 13 offspring of a single pair of clinically normal, related Nubian goats. Neurological examinations revealed that all four affected goats were unable to rise or walk. All had facial dysmorphism, dome-shaped skulls, small palpebral fissures, carpal contractures, hyperextension of the pastern joints, proximal muscle atrophy, intermittent ocular oscillations resembling pendular nystagmus, marked intention tremor, and deafness. With intensive care, three affected kids were hand-reared and then killed at 1, 7, and 21 days of age. Macroscopically, there were paucity of myelin in the cerebral and cerebellar hemispheres and ventricular dilatation. Microscopically, the extent and distribution of cytoplasmic vacuolation, myelin paucity, axonal spheroids, and filamentous expansions were evaluated in the cerebrum, cerebellum, brainstem, spinal cord, and peripheral nerves of the four affected kids and two age-matched, clinically normal kids. Widespread cytoplasmic vacuolation correlated with the previously reported accumulation of oligosaccharides in the brain and kidney and the deficiency of tissue beta-mannosidase. beta-Mannosidosis, not yet identified in man or other species, is characterized by distinctive neonatal clinical, pathological and biochemical features which differentiate it from the alpha-mannosidosis and other inherited diseases of glycoprotein catabolism.

Animals↗
PubMed1981

The paleopathology of an Aleutian mummy.

A multidisciplinary team examined an Aleutian mummy from the collection of the Peabody Museum of Archeology and Ethnology of Harvard University, Cambridge, Mass. The mummy, dating from the early 18th century, was of a middle-aged woman who had suffered from pulmonary and ear infections, atherosclerosis, pediculosis, and degenerative joint disease. Another finding was anthracosis, common in ancient bodies and related to indoor heating and cooking fires. Skeletal lead was not found, in contrast with the high levels seen in modern persons. No neoplasms were identified, again consistent with the results of previous studies of ancient human remains. Such comparisons of ancient and modern morbidity and mortality provide a historical perspective on the evolution and cause of human disease.

Alaska↗
PubMed1980

Pathology of deafness and disequilibrium in head injury:a human temporal bone study.

A Caucasian male suffered a skull fracture at age twenty-two. There was bilateral deafness with partial recovery of hearing in the left ear. He was able successfully to wear a hearing aid in this ear for only thirteen years. His balance remained impaired until death at age fifty of unrelated causes. Temporal bone histologic studies revealed bilateral transverse fractures extending through the ampullated end of the three semicircular canals and vestibula. The cochleae were not involved. In the right ear, the organ of Corti was missing in the basal 14 mm and shrunken in the remainder of the cochlea. In the left ear, the organ of Corti was missing in the basal 14 mm and present with partial hair cell loss in the remainder of the cochlea. Spiral ganglion neuron loss correlated in severity with the organ of Corti lesions bilaterally. The membranous vestibular labyrinth showed distension and ruptures with total loss of sensory epithelium of the cristae and maculae bilaterally. Progressive deterioration of left ear residual hearing cannot be explained on the basis of sensorineural deficit; it probably was the result of biochemical alterations. Total loss of vestibular sensory epithelium bilaterally explained the persistent disequilibrium.

Adult↗
PubMed1979

Sequential audiometric evaluations of cats with regrowing tympanic membranes.

Audiometric evaluations were made for cats which were undergoing TM regeneration. For a one month period of regrowth and testing, there was an improvement in thresholds over the range of frequencies which were tested and the final evaluations (complete TM regrown) indicated greater auditory deficits in the high frequencies. The greater high frequency losses started at 1 to 2 kHz. and increased with frequency. The pattern of greater high frequency loss is thought to result from the fact that the regrown TMs did not adhere to the manubrium, but rather grew straight from the fibrous annulus and formed a flat rather than conical membrane.

Animals↗
PubMed1977

Stapedectomy and fatal meningitis. A human temporal bone study.

Temporal bone histopathology is reported on a case of acute suppurative otitis media, acute suppurative labyrinthitis, and meningitis with death of the patient 20 days after stapes surgery. Purulent exudate invaded the vestibule by the oval window through a displaced footplate. The main pathway of infection to the menings was extension along the branches of the vesticular nerve to the internal auditory meatus and to the subarachnoid space.

Aged↗
PubMed1975

Temporal bone studies: findings with undecalcified sections in a 2,600-year-old Egyptian mummy.

Roentgenologic studies by polytomography of the temporal bones of a 2,600-year-old Egyptian mummy (PUM-II) revealed an increase in radiographic density throughout the left temporal bone. The superior portions of the petrous bones were removed with an electric saw for study by undecalcified techniques. For histological control, a similar specimen was removed from a cadaver immediately after autopsy. Light microscopy of sections showed excellent preservation of the Haversian systems. The vascular channels were clearly seen, and they were similar in appearance to those of the fresh specimen. The lacunae contained osteocytes with good preservation of the nucleus. Osteoid seams were identified and the osteon activity was described for the first time in an Egyptian mummy. There was a low turnover type of bone, but there was no evidence of metabolic bone disease. We postulate that the increased radiological density of the left temporal bone was due to a greater amount of resin infiltration in this bone as compared to the right. It appeared that the resin acted as a fixative preserving the bone cells and related elements.

Cell Nucleus↗