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Biomedical subjects

M D Graham

Publications and source records attributed to M D Graham.

At least 73 records · Page 4Linked to original sources
PubMed1985

The investigation and management of petrous apex erosion.

Disease of the apex of the petrous temporal bone, while rarely encountered, can present a unique challenge to the otologist. Lesions tend to be advanced at presentation, as massive bony erosion can remain asymptomatic. When symptoms occur, they reflect involvement of the neurovascular contents of the temporal bone. The earliest clinical features, such as headache, facial numbness and middle-ear effusion, do not immediately suggest the site or gravity of the underlying pathology. Anterior extension of disease may produce ophthalmoplegia and diplopia whilst posterior spread involves the lower cranial nerves, within the internal auditory canal, jugular foramen and hypoglossal canal. Evaluation of apical disease relies on radiological evidence of bony erosion and should include polytomography, CT scanning and angiography. The clinical features and radiological findings in a series of patients with various apical lesions are presented. The surgical approaches reviewed aim to reconcile the need for adequate access to this remote site, with the desire to preserve residual facial nerve and cochlear function and to protect the brain-stem.

Adult↗
PubMed1985

Epidermoidomas of the cerebellopontine angle and temporal bone: CT and MR aspects.

Epidermoidomas were found in four locations within and adjacent to the temporal bone: cerebellopontine angle, petrous apex, facial geniculate ganglion region, and tympanic-mastoid cavity. Lesions in each of these locations presented different clinical and imaging characteristics. Cerebellopontine angle epidermoidomas were seen on computed tomography (CT) as low-attenuation masses in the posterior fossa. Petrous apex and geniculate ganglion region lesions destroyed and expanded the bone of their respective regions. Tympanic-mastoid cavity epidermoidomas were relatively nonspecific, soft-tissue masses. CT study of the brain and temporal bone was the single most informative imaging procedure in the preoperative evaluation of these lesions. Magnetic resonance images complemented CT scans for evaluation of the size and extent of the abnormality but were relatively nonspecific and did not allow preoperative differentiation of epidermoidomas from other temporal bone lesions.

Adolescent↗
PubMed1985

Ear-eye reflexes while riding in a car.

Persons with diminished or absent vestibulo-ocular reflexes (VORs) are thought to have difficulty with ocular stabilization during sufficiently rapid head movements. This suggests the hypothesis that labyrinthine defective individuals might have impaired visual abilities when in a moving motor vehicle. Ten licensed drivers likely to have abnormal VORs were recruited to assess this possibility. Their labyrinthine function was indexed by measurements of ocular counterroll responses to static head tilt and the nystagmus induced with caloric stimulations. Each person was evaluated on a visual task, i.e., answers to questions about alphanumeric information read from a stationary sign while sitting still and while riding in a car. Comparisons of vision scores tend to be lower in the moving than in the still condition. Furthermore, these decrements appear more closely related to the magnitudes of ocular counterroll than to the caloric reflexes. These results have implications concerning otolithic vs. semicircular canal function, vehicle operations by vestibular-impaired individuals, and evaluations of clinical treatments which employ vestibulotoxic drugs.

Automobiles↗
PubMed1985

The giant cholesterol cyst of the petrous apex: a distinct clinical entity.

The giant cholesterol cyst (GCC) of the petrous apex may now be considered a distinct clinical entity and should be considered in the differential diagnosis of lesions of the midcranial skull base. This benign cystic lesion of the petrous apex gradually enlarges and may produce progressive bone erosion and serial neurologic deficits of the cranial nerves within the temporal bone and jugular foramen. We report here five instances of this lesion (3 patients with unilateral and 1 patient with bilateral petrous apex lesions) and describe the natural history, diagnostic evaluation, pathology, and surgical management.

Adult↗
PubMed1985

Intraoperative facial nerve monitoring: a comparison of stimulating electrodes.

Preservation of the facial nerve during acoustic neuroma resection may be enhanced by the use of intraoperative electrical stimulation. Although stimulation of the extratemporal facial nerve is an effective and established procedure, anatomic differences of the intradural facial nerve and its microenvironment demand more exacting stimulus protocols. The absence of epineurium may make the intradural nerve more susceptible to mechanical or electrical trauma while intermittent pooling of cerebrospinal fluid (CSF) at the cerebellopontine angle may shunt current away from nerve. Four stimulus configurations were examined under varying conditions simulating CSF pooling. The results indicated that: 1. insulation of stimulating electrodes prevents CSF current shunting and allows utilization of a constant current source, and 2. monopolar and bipolar configurations demonstrate significantly different electrical characteristics which may be employed selectively based upon specific clinical goals.

Adult↗
PubMed1985

Bell's palsy: delayed recovery after one year with surgical confirmation.

An instance of Bell's palsy with complete flaccid peripheral facial paralysis at one year with surgical confirmation by total facial nerve decompression and incision of the intratemporal facial nerve sheath confirmation is presented. This individual, with a most unusual duration of total facial paralysis in an instance of Bell's palsy, nevertheless developed eventual recovery typical of the delayed recovery from Bell's palsy, with considerable improvement in facial symmetry at rest, eyelid closure, and facial motion.

Eyelids↗
PubMed1985

Middle ear surgery in fibrous dysplasia of the temporal bone.

Fibrous dysplasia of the temporal bone is uncommon. When it does occur, surgery may be necessary because of cholesteatoma or chronic infection behind bony obstruction of the external auditory canal. Cosmetic surgery may also be performed because of bony deformity. When a surgical procedure is undertaken for hearing improvement, special problems may be encountered. The case presented illustrates middle ear pathologic changes found with fibrous dysplasia and specific surgical difficulties.

Adolescent↗
PubMed1985

Hearing loss with delayed onset of vertigo.

The association between the delayed onset of episodic true vertigo and previous sensorineural hearing loss has been previously described. We have reviewed our series of sixty consecutive labyrinthectomies to determine the prevalence of this disorder in this population, and found a variety of etiologic agents of sensorineural hearing loss with subsequent delayed vertigo. Relief from vertigo following surgery has confirmed that the previously deafened ear has been the cause of the vertigo. Case histories are presented and the literature is reviewed.

Adolescent↗
PubMed1985

Cryptococcal meningitis: presentation as sudden deafness.

A patient presented with a bilateral profound hearing loss of sudden onset following a two-month neurologic illness. Microscopy and culture of cerebrospinal fluid revealed Cryptococcus neoformans. Treatment with amphotericin B and 5-fluorocytosine failed to restore hearing. Auditory brain stem response and electrical promontory stimulation suggest a profound deafness with poor neuronal survival. This is consistent with previous temporal bone histopathology reports in individuals dying of cryptococcal meningitis, suggesting a retrocochlear lesion. It is important to exclude this occult pathologic factor in a patient with the sudden onset of sensorineural deafness prior to embarking upon a course of steroid therapy.

Amphotericin B↗
PubMed1984

Acoustic tumors in the young adult.

Despite the widely held notion that acoustic neuroma is a disease of the middle and late years of life, this neoplasm frequently begins in young adults. It has been reported as occurring in a patient as young as seven years of age. Often, patients in their 20s or 30s may have minimal symptoms despite sizable tumors. Constant alertness for such lesions is essential for early diagnosis and optimal prognosis.

Adult↗
PubMed1984

Gamma-carboxyglutamate in normal and pathological human middle ear bones.

The presence of the amino acid gamma-carboxyglutamate (GLA) was established in human middle ear bones. Proteins containing GLA have been described as being associated with normal as well as pathological calcifications. The GLA content of human incus, malleus, and stapes with 1-2 nmol/mg bone is in the range previously reported for a variety of bone. A limited number of samples with middle ear pathology, including otosclerosis, did not show altered GLA levels.

1-Carboxyglutamic Acid↗
PubMed1984

Pitfalls in the diagnosis of acoustic neuroma.

The patient with an acoustic neuroma may present to the otologist with a variety of clinical features. Classically these include a retrocochlear pattern of sensorineural hearing loss, reduced vestibular response on caloric testing and radiological asymmetry of the internal auditory canals (IAC). The absence of any or all of these features, however, does not exclude the presence of tumour. Five cases are presented to illustrate the potential for diagnostic delay unless a routine battery of investigations is undertaken in patients with neuro-otological disorders. All patterns of subjective audiometry are encountered, auditory brain stem response testing may be unreliable where hearing loss is profound, vestibular testing is normal in half of small tumours and the intracanalicular tumour may be radiologically undetectable unless IAC meatography is employed.

Adult↗
PubMed1984

Titration streptomycin therapy for bilateral Meniere's disease: a preliminary report.

Intramuscular dosages of streptomycin sulfate were titrated in eight patients with bilateral Meniere's disease in an attempt to alleviate disabling vertigo and hearing loss. It appears possible to eliminate the vertiginous episodes, preserve or improve hearing, and avoid ataxia and oscillopsia in most of these individuals. At present we consider this treatment regimen our first choice of therapy in people with bilateral active Meniere's disease or in patients whose only hearing ear is actively fluctuating and in whom associated disabling vertigo is present. Great caution and supervision should be exercised in the use of streptomycin titration therapy in the individual with bilateral Meniere's disease, as further experience is required to determine the efficacy of this form of management.

Adult↗
PubMed1984

Total en bloc resection of the temporal bone and carotid artery for malignant tumors of the ear and temporal bone.

A technique for single stage total en bloc resection of the temporal bone and intratemporal carotid artery with immediate reconstruction has been described. This formidable procedure requires the collaborative efforts of neurotologic skull base surgeons, neurosurgeons, and head and neck surgeons. Two patients have undergone this procedure; one with squamous cell carcinoma and one with extensive basal cell carcinoma. The quality of life following this procedure is adequate and the cosmetic deformity can be minimized. Longer follow-up is necessary to determine the value and overall impact of this approach to cancer of the temporal bone on disease free interval and patient survival. Further experience with the technical aspects of this procedure should reduce the operating time, blood loss, and resultant morbidity.

Basal Cell Carcinoma↗
PubMed1984

Intralabyrinthine schwannoma.

The diagnosis of intralabyrinthine schwannoma has been made either accidentally at the time of surgery or at postmortem examination. Brain stem evoked response audiometry and computerized tomography do not add to our ability to make this diagnosis clinically. A case is presented of an intralabyrinthine schwannoma found at the time of transmastoid labyrinthectomy. The literature is reviewed and a composite clinical picture is presented.

Audiometry, Evoked Response↗
PubMed1984

Benign intracranial hypertension complicating glomus jugulare tumor surgery.

A case is reported in which excision of the jugular bulb during glomus tumor surgery resulted in the development of postoperative benign intracranial hypertension. The pathogenesis of this previously unreported complication of glomus tumor surgery is discussed, and the principles of management are reviewed.

Adult↗