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Biomedical subjects

J Mazziotta

Publications and source records attributed to J Mazziotta.

5 recordsLinked to original sources
PubMed1995

The neurochemical and metabolic cascade following brain injury: moving from animal models to man.

Experimental traumatic brain injury produces a series of cellular events contributing to a neurochemical and neurometabolic cascade. This cascade is defined by the release of neurotransmitters resulting in a massive ionic flux, which, consequently, produces an increase in glycolysis. This increase in glycolysis is followed by a metabolic diaschisis, which is related to the degree and extent of behavioral deficits. Clinical efforts have now determined that a similar cascade occurs in human head injury, validating the animal model as well as providing new assessment strategies for the management and treatment of brain injury.

Animals↗
PubMed1994

Asymmetric interictal glucose hypometabolism and cognitive performance in epileptic patients.

OBJECTIVE: To relate hemispheric metabolic asymmetries to cognitive performance in patients with unilateral mesial temporal lobe epilepsy. DESIGN: Asymmetrical cerebral glucose metabolisms on interictal fludeoxyglucose F 18 positron emission tomograms (FDG-PET) were correlated with cognitive measures. Analyses included partial correlations that controlled for the correlation between metabolic asymmetries of the lateral temporal lobe and other brain regions and the correlation of IQ scores with affected cognitive scores. SETTING: A university epilepsy surgery center. PATIENTS: Subjects included 13 patients who had intractable complex partial seizures originating from a mesial temporal lobe. INTERVENTION: Patients underwent FDG-PET scanning as part of their diagnostic work-up. Asymmetry indexes for cerebral metabolic rates were determined for whole hemisphere, lateral temporal lobe, mesial temporal lobe, frontal lobe, thalamus, and parietal lobe. MAIN OUTCOME MEASURES: The following cognitive domains were assessed: psychometric intelligence, mental control/attention, language, and verbal and nonverbal memory. Neuropsychological measures were obtained within 14 days of FDG-PET scanning. RESULTS: Relative reductions in glucose metabolism of the left hemisphere and left lateral temporal lobe correlated with a lower verbal IQ score and a lower score on a verbal memory task, recall of logical prose. Relative reduction in metabolism of the left side of the thalamus also correlated with lower scores for recall of logical prose. CONCLUSION: Relative hypometabolism of the left hemisphere correlates with lower cognitive performance. Hypometabolism of the left lateral temporal lobe and thalamus independently correlates with the verbal memory difficulties seen in this epileptic patient population.

Adult↗
PubMed1994

Thallium-201 SPECT and positron emission tomography equal predictors of glioma grade and recurrence.

Quantitative indexes based on regions of interest ratios from preoperative thallium-201 SPECT and F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) scans were compared for their ability to predict the histological grade of cerebral gliomas. Of the five different ratios used to determine the index for each PET scan, the ratio of tumour versus ipsilateral hemisphere in the same plane as the tumour showed the most significant correlation with glioma grade (p < 0.001). A large study of 62 thallium-201 SPECT scans showed equally good correlation with glioma grade (p < 0.0005). The use of thallium-201 SPECT for detection of tumour recurrence had 100% sensitivity in this series, while PET scans had 90.9% sensitivity. Patients with a rate of change in serial thallium indexes of 0.475 +/- 0.278 per month survived 5.93 +/- 2.25 months from onset of index increase, while those with little change in the index (0.069 +/- 0.063 per month) survived 17.93 +/- 5.25 months from onset of index increase. Results indicate thallium-201 SPECT correlates well with tumour grade and is equally efficient as PET in screening for glioma recurrence.

Brain Neoplasms↗
PubMed1988

Cerebral correlates of depressed behavior in rats, visualized using 14C-2-deoxyglucose autoradiography.

14C-2-Deoxyglucose (2DG) was used to investigate changes in the rate of cerebral metabolism in 3 rat models of depressed behavior. The models had already been established in the literature and were induced by injections of alpha-methyl-para-tyrosine, withdrawal from chronic amphetamine, or stress. We verified that exploratory behaviors were depressed in each model and that an antidepressant drug, tranylcypromine, prevented the depressed behavior in each model. 2DG studies revealed that the rate of regional glucose metabolism was elevated bilaterally in the lateral habenula of each of the 3 models. Regional metabolic rates were reduced in each model in the dorsal medial prefrontal cortex, anterior ventral nucleus of the thalamus, and inferior colliculus. Forebrain global metabolic rates were also reduced in each of the models. Tranylcypromine prevented the elevated rate of lateral habenula metabolism seen in each of the models alone but did not significantly affect the rates of global metabolism. Our findings of identical metabolic changes in each of the models indicate that these changes are not idiosyncratic to a particular model; rather, they correlate with a generalizable state of depressed exploratory behavior in rats.

Amphetamine↗