The role of Tc-99m HMPAO functional brain imaging in detection of cerebral radionecrosis.

BACKGROUND: Cerebral radionecrosis is a possible complication of brain radiation therapy in patients with primary or metastatic tumors. This retrospective study evaluated the role of Tc-99m hexamethyl propyleneamine oxime (HMPAO) scintigraphy in monitoring the effects of radiation on the brain. METHODS: Ninety-eight patients (41 female, 57 male) with a mean age of 51 years (range, 16-82 years) underwent 128 sets of single-photon emission computed tomography studies. TI-201 and Tc-99m HMPAO single-photon emission computed tomography studies were performed for tumor localization and evaluation of the effect of radiation on the cerebral cortex. Thirty concomitant neuropsychological tests and 96 anatomic imaging (computed tomography/magnetic resonance imaging) were performed. The average radiation dose was 52 Gy delivered as 1.8 to 2 Gy/fraction. Thirty-two patients received an average dose of 160 mCi of I-125 EGFr concomitantly. The average follow-up period was 34 months. Abnormalities away from the tumor site were interpreted as positive on HMPAO studies, neuropsychological testing, or anatomic imaging; otherwise, they were classified as negative. RESULTS: There were 10/45 (22%) and 75/83 (90%) abnormal HMPAO study results before and after radiation therapy. The HMPAO studies compared with neuropsychological testing showed 3/13 (23%) and 14/17 (82%) concordant abnormalities in addition to tumor site in patients pre- versus postradiation therapy. There was better concordance of HMPAO and anatomic imaging in 22/30 (76%) patients versus 24/67 (36%) patients before radiation therapy. HMPAO imaging after radiation therapy revealed significantly more perfusion abnormalities. There were significant differences between all of the aforementioned parameters. CONCLUSION Tc-99m HMPAO imaging is useful in the evaluation of the effects of radiation therapy on the brain and is highly concordant with neuropsychological testing. It is superior to anatomic studies in identifying radiation-induced changes.

Effects of experimentally-induced emotional states on frontal lobe cognitive task performance.

A growing body of evidence suggests that dysphoric and euphoric emotional states are associated with reliable patterns of frontal lobe activity. Specifically, dysphoric affect coincides with greater right than left frontal lobe activity, and euphoric affect tends to correspond with a converse pattern of activity. The present study examined whether cognitive outcomes associated with the left and right frontal lobes are differentially influenced by dysphoric and euphoric affect. In a completely between-groups design, 60 dextral women were administered either the positive or negative conditions of the Velten Mood Induction Procedure, and they subsequently completed either a verbal or figural fluency test. Euphoria resulted in better verbal than figural fluency performance, and dysphoria yielded better figural than verbal fluency outcomes. These findings are consistent with electrophysiological data concerning frontal lobe activity during euphoric and dysphoric affect, and they underscore the notion that affective influences upon cognition are more complicated than previously thought.

Standardized assessment of concussion (SAC): on-site mental status evaluation of the athlete.

OBJECTIVE: This study investigated the clinical utility of the Standardized Assessment of Concussion (SAC) in detecting concussion in athletes. METHOD: Athletic trainers administered the SAC to 568 nonconcussed high school and college football players prior to the 1995 and 1996 football seasons. Thirty-three of these players experienced concussion and were tested immediately following injury; 28 of the 33 underwent additional follow-up testing 48 hours after the injury. RESULTS: Concussed players scored significantly below nonconcussed controls on all SAC measures and significantly below their own pre-injury baseline performance. Follow-up testing documented return to preinjury baseline. CONCLUSION: These findings support the SAC's effectiveness in detecting concussion and tracking recovery in order to determine a player's fitness to return to play.