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Spect findings in narcolepsy
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BIOLPSYCHIATRY 1994;35:615-747
sized to be able to compensate for cognitive/perceptual impairment by alternative strategies that are less efficient than those used by normal controis. Subjects are medically healthy males, with IRB informed consent, and are DSM-In-R SPD (n-7) or normal controls (n-5). Subjects are studied on 2 days, one week apart at the same time of day, with tasks counterbalanced. An autcm,~:~ cognitive activation task known to be sensitive to frontal dysfuncti~it Cthe WCST) is compared to a symbol matching task (SMT); 99mTc- HMPAO is infused and registered on a Medimatic 564. Results with this preliminary data set suggest that, compared to normal controls, SPD patients: 1) may increase flow in the dorsolateral prefrontal cortex (DLPFC) in response to WCST, particularly the left DLPFC; 2) appear to have a dissociation of performance from rCBF in the left DLPFC while left DLPFC rCBF in normals is inversely related to rate of perseverative errors; 3) the ratio of rCBF in the DLPFC to the occipital lobe increases significantly during the WCST compared to the SMT only in SPD patients. These results are consistent with the possibility that SPD patients use inefficient strategies to compensate for an underlying prefrontal neurecognitive deficit; these strategies may rely on increasing prefrontal gCBF.
249. SPECT FINDINGS IN NARCOLEPSY S. Shettar, S. Parikh, J.M. Mountz, R. Acton, & C. Inampudl University of Alabama at Birmingham, Birmingham, AL 352330018 Narcolepsy is a neumlngical condition manifested by a tetrad of symptoms, most commonly excessive daytime sleepiness and often by other symptoms such as sleep paralysis, cataplexy & hypnngngic hallucinations. Sometimes symptoms of narcolepsy overlap with depression, schizophrenia-like psychosis and attention deficit disorder and cerebral blood flow studies have been evaluated in the latter disorders. To test the hypothesis that functional abnormalities Involving the frontal or anterior temporal lobes may be present in narcolepsy, regional cerebral blood flow (rCBF) studies in eight patients were performed. Eight chug free patients (M-4;F,-4)aged (18-50 yrs) were diagnosed clinically as narcoleptics by standard polysonmography and multiple sleep latency test. Each underwent 99mTc hexmethyl-pmpyleneamine oxime (99mTc-HMPAO) high resolution brain SPELT imaging. Region of Interest (R01) for analysis were defined using a reference system which defined cortical circumferential R01 at slice levels parallel to and sequentially above the canthomeatal line at +3.5cm, +5.5cm & +7.5cm. The cortex was subdivided in twelve In equal angular regions using a computer automated edge detection program. The caudate nucleus & thalami were also evaluated by reference to an anatomic scan. Regional CBF values were obtained by normalizing cortical counts to both whole brain and cerebellar counts. A onesample t-test revealed a significant decrease in mean tCBF of the R-anterior temporal (p-.001) & R-posterior frontal (p-.043) regions compat~ to normals. A two-sample t-test revealed a significant decrease in mean rCBF of the R-anterior temporal (p-.048) and R-posterior frontal (p-.044) regions of patients with cutaplexy compared to those without. A similar significant decrease In mean rCBF of R-anterior temporal (p-.043) & Rposterior frontal (p-.029) was found between patients with sleepparalysis comparcd to those without, in conclusion, this study suggests that regional decreases In frontal and anterior temporal lobe ~ B F occurs in patients with narcolepsy, and may provide a method to better understand the underlying pathophysiology.
FRIDAE, MAY 20
250. ORBITAL FRONTAL CORTEX METABOLISM AND OBSESSIONALITY IN NORMAL VOLUNTEERS L.W. Kraft, N. Kusubov, R. Tang, M. Young, & T.E. Nordahl University of California, Davis Medical School, Department of Psychiatry, Sacramento, CA 95817 Three studies have demonstrated orbital frontal hypermetabolism in unmedicated patients with obsessive-compulsive disorder (OCD). Another study has found a significant correlation in normal controls between neuroticism and orbital frontal metabolism. We decided to test for correlation between orbital frontal and basal ganglia metabolism with obsessive symptoms in normal controls. Ten normal volunteers (9 males, I females, mean age 31.2 + 12.0 yrs) underwent FDG-PET scans and were administered the Symptom Checklist 90 (SCL-90) which includes an assessment of obsessive-compulsive symptoms. Correlations between the SCL-90 obsessive-compulsive subscale and regional orbital frontal cortical metabolism were significant (r-.82, p<0.005) for the left orbital frontal gyms, but not (r-0.035, N$) for the right orbital frontal gyms. No significant correlations were noted for basal ganglia metabolism and obsessive compulsive symptoms. These preliminary findings further support the linkage of orbital frontal cortex and the symptoms seen in obsessive-compulsive disorder.
251. CEREBRAL METABOLIC CORRELATES OF MONITORING THE SOURCE OF REMEMBERED INFORMATION P.J. Andreason, D. Hemmer, K. Sirocco, & H. Weingartner National Institute on Alcohol Abuse and Alcoholism, DICBR, Laboratory on Clinical Studies, Bethesda, MD 20892 Patients (n-I 3, 9 men and 4 women) with alcohol dependence were studied with tSF-2- flum-2-deoxygiucose (FDG) positron emission tomngraphy (PET) and cognitive testing in order to explore the neumanatomic correlates of monitoring the source of remembered information. Preliminary work has suggested that many alcoholics demonstrate impaired source monitoring and that this impairment occurs in the absence of other memory dysfunction. Subjects were scanned using FDG PET while performing a continuous auditory performance task (CPT) then within two days after scanning underwent evaluation of memory functions including source monitoring (identification of words as originally presented by either the experimenter or self-generated). Scores on source monitoring correlated positively with left prefrontal (df -12, r - .64, p
BIOLPSYCHIATRY 1994;35:615-747
sized to be able to compensate for cognitive/perceptual impairment by alternative strategies that are less efficient than those used by normal controis. Subjects are medically healthy males, with IRB informed consent, and are DSM-In-R SPD (n-7) or normal controls (n-5). Subjects are studied on 2 days, one week apart at the same time of day, with tasks counterbalanced. An autcm,~:~ cognitive activation task known to be sensitive to frontal dysfuncti~it Cthe WCST) is compared to a symbol matching task (SMT); 99mTc- HMPAO is infused and registered on a Medimatic 564. Results with this preliminary data set suggest that, compared to normal controls, SPD patients: 1) may increase flow in the dorsolateral prefrontal cortex (DLPFC) in response to WCST, particularly the left DLPFC; 2) appear to have a dissociation of performance from rCBF in the left DLPFC while left DLPFC rCBF in normals is inversely related to rate of perseverative errors; 3) the ratio of rCBF in the DLPFC to the occipital lobe increases significantly during the WCST compared to the SMT only in SPD patients. These results are consistent with the possibility that SPD patients use inefficient strategies to compensate for an underlying prefrontal neurecognitive deficit; these strategies may rely on increasing prefrontal gCBF.
249. SPECT FINDINGS IN NARCOLEPSY S. Shettar, S. Parikh, J.M. Mountz, R. Acton, & C. Inampudl University of Alabama at Birmingham, Birmingham, AL 352330018 Narcolepsy is a neumlngical condition manifested by a tetrad of symptoms, most commonly excessive daytime sleepiness and often by other symptoms such as sleep paralysis, cataplexy & hypnngngic hallucinations. Sometimes symptoms of narcolepsy overlap with depression, schizophrenia-like psychosis and attention deficit disorder and cerebral blood flow studies have been evaluated in the latter disorders. To test the hypothesis that functional abnormalities Involving the frontal or anterior temporal lobes may be present in narcolepsy, regional cerebral blood flow (rCBF) studies in eight patients were performed. Eight chug free patients (M-4;F,-4)aged (18-50 yrs) were diagnosed clinically as narcoleptics by standard polysonmography and multiple sleep latency test. Each underwent 99mTc hexmethyl-pmpyleneamine oxime (99mTc-HMPAO) high resolution brain SPELT imaging. Region of Interest (R01) for analysis were defined using a reference system which defined cortical circumferential R01 at slice levels parallel to and sequentially above the canthomeatal line at +3.5cm, +5.5cm & +7.5cm. The cortex was subdivided in twelve In equal angular regions using a computer automated edge detection program. The caudate nucleus & thalami were also evaluated by reference to an anatomic scan. Regional CBF values were obtained by normalizing cortical counts to both whole brain and cerebellar counts. A onesample t-test revealed a significant decrease in mean tCBF of the R-anterior temporal (p-.001) & R-posterior frontal (p-.043) regions compat~ to normals. A two-sample t-test revealed a significant decrease in mean rCBF of the R-anterior temporal (p-.048) and R-posterior frontal (p-.044) regions of patients with cutaplexy compared to those without. A similar significant decrease In mean rCBF of R-anterior temporal (p-.043) & Rposterior frontal (p-.029) was found between patients with sleepparalysis comparcd to those without, in conclusion, this study suggests that regional decreases In frontal and anterior temporal lobe ~ B F occurs in patients with narcolepsy, and may provide a method to better understand the underlying pathophysiology.
FRIDAE, MAY 20
250. ORBITAL FRONTAL CORTEX METABOLISM AND OBSESSIONALITY IN NORMAL VOLUNTEERS L.W. Kraft, N. Kusubov, R. Tang, M. Young, & T.E. Nordahl University of California, Davis Medical School, Department of Psychiatry, Sacramento, CA 95817 Three studies have demonstrated orbital frontal hypermetabolism in unmedicated patients with obsessive-compulsive disorder (OCD). Another study has found a significant correlation in normal controls between neuroticism and orbital frontal metabolism. We decided to test for correlation between orbital frontal and basal ganglia metabolism with obsessive symptoms in normal controls. Ten normal volunteers (9 males, I females, mean age 31.2 + 12.0 yrs) underwent FDG-PET scans and were administered the Symptom Checklist 90 (SCL-90) which includes an assessment of obsessive-compulsive symptoms. Correlations between the SCL-90 obsessive-compulsive subscale and regional orbital frontal cortical metabolism were significant (r-.82, p<0.005) for the left orbital frontal gyms, but not (r-0.035, N$) for the right orbital frontal gyms. No significant correlations were noted for basal ganglia metabolism and obsessive compulsive symptoms. These preliminary findings further support the linkage of orbital frontal cortex and the symptoms seen in obsessive-compulsive disorder.
251. CEREBRAL METABOLIC CORRELATES OF MONITORING THE SOURCE OF REMEMBERED INFORMATION P.J. Andreason, D. Hemmer, K. Sirocco, & H. Weingartner National Institute on Alcohol Abuse and Alcoholism, DICBR, Laboratory on Clinical Studies, Bethesda, MD 20892 Patients (n-I 3, 9 men and 4 women) with alcohol dependence were studied with tSF-2- flum-2-deoxygiucose (FDG) positron emission tomngraphy (PET) and cognitive testing in order to explore the neumanatomic correlates of monitoring the source of remembered information. Preliminary work has suggested that many alcoholics demonstrate impaired source monitoring and that this impairment occurs in the absence of other memory dysfunction. Subjects were scanned using FDG PET while performing a continuous auditory performance task (CPT) then within two days after scanning underwent evaluation of memory functions including source monitoring (identification of words as originally presented by either the experimenter or self-generated). Scores on source monitoring correlated positively with left prefrontal (df -12, r - .64, p