PubMed Health⌕ Search

Biomedical subjects

C M Mehringer

Publications and source records attributed to C M Mehringer.

78 records · Page 5Linked to original sources
PubMedDate not supplied

CT of the temporal bone in achondroplasia.

In an attempt to better define the changes affecting the temporal bone that might predispose achondroplastic dwarfs to otitis media, nine achondroplastic subjects who were evaluated for hearing loss underwent high-resolution CT scanning of the temporal bone. Comparisons were made with 10 nonachondroplastic subjects. A number of morphologic changes were seen, including (1) poor development of mastoid air cells, (2) foreshortening of the carotid canals, (3) narrowing of the skull base, (4) "towering" petrous ridges, and (5) relative "rotation" of the cochlea and other temporal bone structures. The most significant change was the rotational effect, which was more pronounced medially, resulting in an abnormal orientation of inner ear structures relative to middle ear structures and of middle ear structures relative to the external auditory canal. There was a notable lack of evidence for otitis media or its sequelae in any of the achondroplastic subjects. Audiograms were obtained in six of the nine achondroplastic subjects (two adults and four children). There was evidence of mixed hearing loss in the four children, but only of sensorineural hearing loss in the adults. We believe that the persistent hearing loss in achondroplasia is not due to sequelae of otitis media as some authors have suggested. Intrinsic vestibulocochlear changes below the limits of resolution of high-resolution CT scanning may be responsible.

Achondroplasia↗
PubMedDate not supplied

Therapeutic embolization for vascular trauma of the head and neck.

Therapeutic embolization is an effective and relatively safe method for managing many cases of head and neck trauma. In the last 5 years, 78 traumatic vascular lesions--10 arterial transections and 68 arteriovenous fistula--were treated by intravascular embolization at four medical centers. Selection of embolic materials is discussed and different types of lesions are illustrated. Treatment was successful in every instance. Complications were limited to one case of cerebral infarction and two cases of temporary oculomotor weakness. The indications for embolization have widened beyond life-threatening hemorrhage alone, and continued improvement in techniques and embolic agents should see an increased use of this form of treatment.

Adult↗
PubMedDate not supplied

Delayed effects in the treatment of carotid-cavernous fistulas.

Carotid-cavernous fistulas may be classified into: (1) internal carotid, (2) external carotid, or (3) a combination of both. They may result from traumatic or spontaneous rupture of the carotid artery into the cavernous sinus. Intravascular embolization has become the treatment of choice for the management of carotid cavernous fistulas. The authors report the delayed effects after the treatment of carotid-cavernous fistulas with experience of 74 cases over the past 6 years. The delayed effects may be summarized as follows: (1) progressive spontaneous occlusion of the fistula after partial balloon embolization, (2) false aneurysms may decrease in size and be spontaneously sealed off, (3) transient and persistent third or sixth cranial nerve palsy may be seen in about 16% of 74 cases, (4) posttraumatic fibrosis with narrowing of the carotid artery may be apparent after total occlusion of the fistula, (5) a prematurely deflated balloon may be dislodged into the carotid artery or its branch, and (6) spontaneous obliteration of common channels from internal carotid artery may occur after total occlusion of external carotid channels in those cases with a combination of internal carotid- and external carotid-cavernous fistulas. Certainly the delayed effect will alter our future planning in the treatment of carotid cavernous fistulas.

Arteriovenous Fistula↗
PubMedDate not supplied

Computed tomography in acute posterior fossa infarcts.

Thirty-one cases of acute posterior fossa infarcts are reported. CT evidence of obliterated posterior fossa cisterns and hydrocephalus indicates a grave prognosis due to brainstem compression. Progressive obliteration of posterior fossa cisterns may be used as an indicator for surgical decompression. Patients with intact posterior fossa cisterns had good recoveries without surgical treatment. CT can be used to diagnose the very early phase of an acute posterior fossa infarct and has prognostic value in predicting the outcome.

Adult↗
PubMedDate not supplied

Adult cerebellar medulloblastoma: imaging features with emphasis on MR findings.

PURPOSE: To describe the MR imaging features of cerebellar medulloblastoma in the adult. MATERIALS AND METHODS: The neuroimages and records of 15 adults with proved cerebellar medulloblastoma were retrospectively evaluated. In 12 patients, preoperative MR scans were reviewed; nine had Gd-DTPA-enhanced scans. RESULTS: Of the 12 tumors evaluated preoperatively, eight were hemispheric, two hemispheric-vermian, and two vermian. Tumor margins were well demarcated, except in three cases, two of which had large infiltrative tumors. In 10 cases, tumor extended to the brain surface, and in five of these, contiguity with the tentorium or cerebellopontine angle cistern was such than an extraaxial tumor was considered. The tumors were typically hypointense on T1 but a spectrum was seen on T2-weighted images. Enhancement ranged from minimal and patchy to marked. One tumor became isointense after Gd-DTPA. Other features included cystic changes, hemorrhage, exophytic invasion at the cerebellopontine angle, spinal cerebrospinal fluid seeding, intraventricular seeding, and bone metastasis. CONCLUSION: Although there is no pathognomonic MR appearance of adult cerebellar medulloblastoma, the finding of a well-demarcated, mild to moderately enhancing hemispheric mass involving the brain surface in a young adult is suggestive of medulloblastoma. Awareness that this tumor may resemble meningioma may avoid misdiagnosis and aid surgical planning.

Adolescent↗