Biomedical subjects

D Dungan

Publications and source records attributed to D Dungan.

4 recordsLinked to original sources

PubMed1998

Bilateral temporal hypometabolism in epilepsy.

PURPOSE: Positron emission tomography (PET) has proven useful in epilepsy surgery for its ability to identify unilateral temporal hypometabolism (UTH), which is predictive of good surgical outcome. The significance of bilateral temporal hypometabolism (BTH) is not known. METHODS: We identified all patients who had marked bilateral reduction in temporal lobe metabolism relative to the cerebellar hemispheres and compared their clinical features and treatment outcomes with those of control patients with UTH. RESULTS: BTH was evident in 10% of PET scans for epilepsy at our institution. We compared these patients with age-matched controls with UTH. The BTH patients had a higher percentage of generalized seizures; were more likely to have bilateral, diffuse or extratemporal seizure onsets; and had bilateral or diffuse magnetic resonance imaging (MRI) findings. UTH patients were more likely to have unilateral mesial temporal atrophy on MRI. Even when electrical seizure onsets were well localized, surgical outcomes were markedly worse in these patients than in controls. Medical treatment was also less successful. Social and cognitive functioning was worse in the BTH group. The only death occurred in the group with BTH. CONCLUSIONS: Patients with BTH have features distinct from those with UTH and have a worse prognosis for seizure remission after surgery.

Adolescent↗

PubMed1998

Potential pitfalls in the work-up and diagnosis of choanal atresia.

To increase an awareness of the developmental anatomy of the nasal cavity as it applies to the radiologic work-up of choanal atresia and frontoethmoidal cephaloceles, we report two cases that demonstrate potentially serious imaging pitfalls. Two neonates with nasopharyngeal obstruction were imaged with CT and MR. Both patients had surgically proved bilateral bony choanal atresia. In addition to choanal atresia, CT showed a radiolucent, or nonossified cribriform plate and mucoid secretions within the nasal fossa, adjacent to the cribriform plate, which approximated the attenuation of brain parenchyma. In one of the patients, a preoperative diagnosis of nasopharyngeal encephalocele resulted in surgical exploration. At surgery, however, the cartilaginous cribriform plate was found to be intact.

Choanal Atresia↗

PubMed1994

MR imaging of tibial collateral ligament injury: comparison with clinical examination.

We sought to clarify the capability of routine magnetic resonance (MR) imaging of the knee to detect and grade tibial collateral ligament (TCL) injury. We also wanted to define the exact MR findings that were the most important for diagnosis. Sixty-three patients were clinically evaluated for TCL injury prior to MR imaging of the knee on a 1.5-tesla system. MR studies were scored with respect to multiple direct and indirect findings. By discriminant analysis, the overall accuracy of classification (into clinical grades 1, 2, 3 and normal) on the basis of MR was 65%. Accuracy for detection of abnormal TCLs was 87%. The most useful MR findings for detection and grading of TCL injury were direct signs: subcutaneous edema over the TCL, focal disruption of the TCL, increased signal in the TCL on T2-weighted images, and longitudinal striations within the TCL. Indirect signs such as trabecular trauma were less useful for TCL evaluation. The presence of a tear of the anterior cruciate ligament, however, correlated with TCL injury of a higher grade. T2-weighted coronal images, by better depicting intraligamentous edema and fiber disruption, improved the MR assessment of the TCL.

Humans↗

PubMedDate not supplied

Posttraumatic epistaxis from injury to the pterygovaginal artery.

Facial and skull base trauma can cause clinically significant epistaxis. Optimal evaluation and treatment require knowledge of the pertinent vascular and skull base anatomy. We describe a patient with extensive skull base injury and epistaxis in whom CT revealed a fracture through the roof of the nasopharynx and arteriography showed injury to the pterygovaginal (pharyngeal) artery. The fracture was successfully treated with transarterial particulate embolization.

Adolescent↗