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D M Yousem

Publications and source records attributed to D M Yousem.

112 records · Page 7Linked to original sources
PubMedDate not supplied

Herpes zoster ophthalmicus with orbital pseudotumor syndrome complicated by optic nerve infarction and cerebral granulomatous angiitis: MR-pathologic correlation.

The authors describe a 41-year-old woman with herpes zoster ophthalmicus and extensive intracranial and orbital involvement as documented by MR and pathologically. MR showed all of the lesions that led to the ophthalmoplegia and pseudotumor syndrome, the periaxial infarct of the distal optic nerve, pontine infarcts, and granulomatous angiitis of the meningeal vessels. MR is useful in both detection and monitoring of the disease.

Adult↗
PubMedDate not supplied

Posttraumatic olfactory dysfunction: MR and clinical evaluation.

PURPOSE: To evaluate the sites of injury in patients with posttraumatic olfactory deficits and to compare damage with findings on clinical olfactory tests. METHODS: Twenty-five patients with posttraumatic olfactory dysfunction were examined by means of olfactory testing, endoscopy, and MR imaging. MR surface-coil scans through the olfactory bulbs and tracts and head-coil scans of the temporal lobes were evaluated. Quantitative and qualitative gradings of damage to the olfactory bulbs, tracts, subfrontal region, hippocampus, and temporal lobes were compared with results on tests of odor identification, detection, memory, and discrimination. RESULTS: Twelve patients were anosmic, eight had severe impairment, and five were mildly impaired. Injuries to the olfactory bulbs and tracts (88% of patients), subfrontal region (60%), and temporal lobes (32%) were found, but these did not correlate well with individual olfactory test scores. Volumetric analysis showed that patients without smell function had greater volume loss in olfactory bulbs and tracts than did those posttraumatic patients who retained some sense of smell. Qualitative and quantitative assessments of damage showed few significant correlations with olfactory tests, probably because of multifocal injuries, primary olfactory nerve damage, and the constraints of a small sample size on the detection of clinically significant differences. CONCLUSION: MR imaging shows abnormalities in patients with posttraumatic olfactory dysfunction at a very high rate (88%), predominantly in the olfactory bulbs and tracts and the inferior frontal lobes.

Adolescent↗
PubMedDate not supplied

Use of preoperative MR to predict dural, perineural, and venous sinus invasion of skull base tumors.

PURPOSE: To assess the accuracy of MR imaging in predicting dural, venous sinus, and perineural invasion by skull base tumors. METHODS: The preoperative MR images of 22 patients who had resection of skull base neoplasms were evaluated for the following characteristics: dural enhancement, pial enhancement, local perineural invasion by adjacent tumor, and venous sinus invasion by tumor. The greatest width of dural enhancement was measured, and the character of dural enhancement was noted. The pathologic and surgical reports were reviewed retrospectively with specific attention to dural, venous, and local perineural invasion. RESULTS: Of the 22 patients studied, dural invasion by tumor was confirmed in eight patients, vascular invasion in six patients, and perineural invasion in four patients. The sensitivity of dural enhancement in predicting invasion was 88%, the specificity 50%, and the accuracy 64%. When enhancement and focal nodularity were present, the sensitivity remained at 88%; however, specificity was 100% and accuracy 95%. If the dural enhancement was more than 5 mm thick, sensitivity, specificity, and accuracy were 75%, 100%, and 91%, respectively. Predicting tumor invasion of the dura by the presence of pial enhancement was 50% sensitive and 100% specific. Venous sinus/jugular vein invasion was predicted with 100% sensitivity, 94% specificity, and 95% accuracy. Local perineural invasion was predicted with 100% sensitivity, 50% specificity, and 59% accuracy. CONCLUSIONS: The presence of pial enhancement, focal dural nodules, or dural thickening of more than 5 mm is highly accurate in predicting the presence of neoplastic dural invasion. Linear enhancement of dura does not imply dural infiltration by tumor. Venous invasion by tumor can be predicted accurately with preoperative MR imaging.

Adult↗