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Biomedical subjects

M Tenner

Publications and source records attributed to M Tenner.

18 recordsLinked to original sources

Giant petrous carotid aneurysm treated by submandibular carotid-saphenous vein bypass. Case report.

Petrous and cavernous sinus carotid artery (CA) aneurysms that are not amenable to clip ligation or endovascular therapy may be successfully treated by a saphenous vein bypass, thereby preserving the patency of the CA. The authors report the unique case of a 47-year-old man with a giant fusiform aneurysm of the petrous CA, who presented with a rapid onset of a lateral rectus palsy and diplopia. The lesion was treated by trapping the aneurysm and performing a saphenous vein bypass from the cervical to the intracranial CA. The saphenous vein graft was routed beneath the condyle of the mandible to reduce the overall length of the graft, thereby increasing the likelihood of long-term patency and offering protection to the graft by the mandible, temporal muscle zygomatic process, and masseter and temporal muscles. The presentation and technical aspects of the bypass graft in this unique case are discussed.

Anastomosis, Surgical↗

Open-ring imaging sign: highly specific for atypical brain demyelination.

OBJECTIVE: To test the specificity for demyelination of a new neuroimaging sign: contrast enhancement shaped as an open ring or a crescent circumscribed to the white matter. BACKGROUND: Brain demyelination can cause ring enhancement mimicking neoplasm or infection on CT or MRI. METHODS: A MEDLINE search of pathology-proved demyelination yielded 32 illustrated cases of ring-enhancing lesions published between 1981 and 1995. Controls consisted of the same number of published images of neoplasms and infections, pathology proved, and matched by year of publication, and age and gender of the patient. Two neuroradiologists read the images twice independently 1 year apart. RESULTS: Interrater agreement was good (kappa = 0.64 and 0.66 for either reading). Test-retest reliability was high (kappa = 0.75 and 0.74 for either rater). The open-ring sign clearly distinguished demyelinating lesions from neoplasms and infections. For demyelination versus neoplasm or infection, the specificity of the reading by the first neuroradiologist was 93.8 (95% CI, 86 to 98), and that of the second was 84.4 (95% CI, 74 to 92). The likelihood ratio of demyelination versus neoplasm averaged 5.2, and versus infection, 17.2. That is, if the lesions had the same incidence in the population, in the presence of an open-ring sign demyelination would be five times more likely than neoplasm and 17 times more likely than infection. However, given the much higher incidence of neoplasms and infections, these lesions are still frequently responsible for open-ring enhancement. CONCLUSIONS: The open-ring sign is often present in large, contrast-enhancing demyelinating lesions and helps to differentiate them from neoplasms and infections.

Adult↗

Neuroradiology.

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Humans↗

ACTH-producing pituitary carcinoma presenting as the cauda equina syndrome.

A 43-year-old woman presented with incontinence, weakness, and paresthesia, consistent with the cauda equina syndrome, 10 years after having a pituitary tumor surgically removed and 4 years after excision of two "meningiomas" of the cervical cord. The patient was also hypertensive and had a cushingoid habitus. Emergent surgical decompression of the spinal cord revealed intradural metastatic adrenocorticotropic hormone-producing pituitary carcinoma. Pituitary carcinomas are rare. The majority of reported cases of adrenocorticotropic hormone-producing carcinoma have exhibited metastases outside the central nervous system. To our knowledge, this represents the first case of an adrenocorticotropic hormone-producing pituitary carcinoma presenting with the cauda equina syndrome. A review of all reported cases of pituitary carcinoma indicated that central nervous system metastases were more common than metastases to distant sites, and patients with distant metastases experienced a shorter duration of disease than did those with central nervous system metastases.

Adrenocorticotropic Hormone↗

A microsporidian previously undescribed in humans, infecting enterocytes and macrophages, and associated with diarrhea in an acquired immunodeficiency syndrome patient.

To date, the only microsporidian that has been associated with diarrhea and weight loss in acquired immunodeficiency syndrome patients is the newly identified Enterocytozoon bieneusi. A second species is now described that was associated with intestinal symptoms in a 32-year-old, human immunodeficiency virus- seropositive, Native American male homosexual. Stool studies and routine light microscopy of multiple small intestinal biopsies that showed atrophy with acute and chronic inflammation were without apparent pathogens. Light microscopy of semi-thin plastic sections, cytochemical stains of paraffin sections, and ultrastructural studies revealed extensive microsporidial infection of enterocytes and submucosal macrophages. No other pathogens were identified. Unlike E bieneusi, this microsporidian appeared to develop within septated parasitophorous vacuoles, and lacked polar disks and clear clefts. It most closely resembled, but was distinguishable from, members of the genus Encephalitozoon. Awareness of the microsporidia as potential opportunists in acquired immunodeficiency syndrome patients is increasing the incidence of identification of these organisms.

Adult↗

Localization of infection by the microsporidian Enterocytozoon bieneusi in the gastrointestinal tract of AIDS patients with diarrhea.

OBJECTIVE: We compared the level of Enterocytozoon bieneusi infection at different sites within the small intestine among patients with AIDS. DESIGN: The level of E. bieneusi infection of each patient biopsy was determined and compared using semi-thin plastic section light microscopy and transmission electron microscopy (TEM). PATIENTS, PARTICIPANTS: Nine subjects with chronic diarrhea who had endoscopic biopsies of either proximal (bulb) or distal (fourth portion) duodenum plus proximal jejunum (just past ligament of Treitz), either simultaneously or within a few months of each other were studied. All patients had TEM-confirmed diagnoses of E. bieneusi intestinal microsporidiosis. RESULTS: The intensity of infection was always greater in biopsies taken from the patients' jejunum compared with those taken from the duodenal bulb. In one patient, the duodenal bulb biopsy was negative while the jejunal biopsy, taken at the same time, was positive. The distal duodenum was usually, but not always, equal to the jejunum in terms of parasite burden. Esophageal, gastric, and colorectal biopsies from these and other patients were negative for E. bieneusi. CONCLUSIONS: For the diagnosis of E. bieneusi to evaluate chronic diarrhea in AIDS patients, upper intestinal endoscopy biopsies should be taken at the most distal site possible.

Acquired Immunodeficiency Syndrome↗

Preoperative arteriographic spasm and outcome from aneurysm operation.

The timing of intracranial operation for the treatment of ruptured cerebral aneurysm remains controversial. To find objective parameters to guide us, we performed angiography 24 to 72 hours before contemplated operation in 35 Grade I patients in whom subarachnoid hemorrhage had occurred at least 1 week earlier. Operation in the presence of angiographic vasospasm in Grade I patients over 1 week after SAH was associated with increased morbidity and mortality rates. Only 1 of 28 patients in whom spasm was absent or mild at the time of operation had an unsatisfactory outcome from operation (P less than 0.003). There was no correlation between clinical grade and significant spasm; 17 patients who were clinically Grade I over 1 week after SAH had moderate or severe angiographic spasm. These data suggest that all patients should undergo angiography just before contemplated operation and that operation should be postponed if vasospasm is present.

Carotid Artery, Internal↗

Carcinoma of choroid plexus in a premature infant.

A histologically proven case of choroid plexus carcinoma in a 5-week-old infant is presented. Computed tomography showed invasion through the ventricular wall, suggesting its malignant nature.

Adenocarcinoma, Papillary↗

The postoperative myelogram. Radiographic evaluation of arachnoiditis and dural/arachnoidal tears.

Either arachnoriditis or dural/arachnoidal tears may cause symptoms in the postoperative spinal patient. Surgery and myelography as causes of arachnoiditis are discussed. Intradural arachnoid cyst formation and intramedullary cavitation may present as unusual sequelae of arachnoiditis. Extra-dural cysts and cerebrospinal fluid fistulas resulting from dural/arachnoidal tears are unusual postoperative complications presenting striking myelographic features. Their mechanisms of formation, clinical significance, and radiographic features are discussed.

Animals↗

Hyperdipsia associated with hypothalamic-midbrain hemorrhage.

A case of diencephalic-midbrain hemorrhage presenting with excessive thirst, coma, and death is discussed. Some diencephalic dysfunction syndromes are reviewed, as well as their physiological basis. Thirst and drinking behavior can provide a valuable localizing symptom and sign in clinical-pathological correlations.

Adult↗

Orbital neurofibromatosis: involvement of the orbital floor.

Neurofibromatosis has been reported to involve the eye and orbit by causing irregularities of the sphenoid and other facial bones and enlargement of the foramina. To our knowledge, abnormalities of the orbital floor, however, have not been attributed to this disease in the literature until now. Two patients with neurofibromatosis had orbital floor involvement. Multiple neurofibromas eroding the orbital floor threatened vision in one patient. The other case, seen after trauma, had a condition simulating that of a blow-out fracture. Diagnostic workup with adequate roentgenography, especially tomography, helped to establish the diagnosis. We believe this is of importance in modifying the surgical approach, obviating the need for surgical intervention at times.

Female↗

Non-filling of the subependymal veins of the lateral ventricles.

Four cases of non-filling of the subependymal veins of the lateral ventricles and internal cerebral vein at carotid angiography are reported. The patients were all children ranging in age from 4 months to 2 years and had a variety of neurologic conditions. Several hypotheses are suggested as to the possible pathogenesis of these findings.

Angiomatosis↗

The spectrum of growing skull fracture in children.

The genesis and complications of the growing skull fracture in children is discussed. Four patients are presented to illustrate the common and uncommon features of growing skull fractures. The need for complete radiological evaluation as well as the timing of follow-up examinations is stressed.

Brain Diseases↗