Single Proton Emission Computed Tomography Research Articles

The Chronic Hallucinatory‐Paranoid State of Symptomatic Localization‐Related Epilepsy Studied by CCTV/EEG Monitoring

Purpose: Because an epileptogenic zone is considered an important factor in the genesis of the hallucinatory–paranoid state of symptomatic localization‐related epilepsy, the epileptogenic zones of patients with chronic hallucinatory‐paranoid states were studied. Methods: The 10 patients (P1‐P10) studied were right‐handed and had both symptomatic localization‐related epilepsy and chronic hallucinatory‐paranoid states, without a family history of either psychosis or epilepsy. Their average age was 30.3 years at examination, 11.5 years at the onset of epilepsy, and 20.2 years at the onset of psychosis. The duration of the follow‐up was 7.6 years the localizations of epileptogenic zones were investigated by seizure manifestations, and the findings from interictal and ictal EEG, computed tomography (CT), magnetic resonance imaging (MRI), single‐proton‐emission CT (SPECT), and electromyogram (EMG). Results: The patients had auditory hallucinations of voices speaking directly to them or in conversation with other voices, and also had delusions of reference and persecution and delusional perception and mood (“Wahnstimmung”). Four patients had a prefrontal syndrome, which appeared and deteroirated before the onset of psychosis, and showed attention deficits, hyperreactivity, puerilism, disinhibition of impulsive behavior, irritability, and paranoid tendencies (P1, P2, P3, and P4) in addition to euphoria (P1, P2, and P4) and moria (P1 and P2). PS had memory disturbances, anomia, and irritability, and both P6 and P10 had a state indistinguishable from the residual phase of schizophrenia, showing autism, bizarre behaviors, blunted affect, poverty of content of thought, and lack of volition, which progressed after the onset of psychosis. P1, P2, P3, P4, and P8 had seizures of frontal origin such as tonic posturing and complex gestural automatism. P5, P6, P7, P9, and P10 showed seizures of the temporal lobe origin such as au‐tonomic signs, impairment of consciousness, and motionless staring. Interictal epileptogenic discharges were observed bilaterally in the frontal areas of P1, P2, P3, and P4, in the right or left temporal areas or both of P5, P6, P7, and P8, in the right of left frontotemporal areas of P9, and bilaterally in the temporofrontal or occipital areas of P10. The onset of ictal discharges seemed to be at the left frontal area of PI and P2, the central area of P3, the right temporal area of P6. the right or left frontotemporal areas of P9, and the right hemisphere or the left occipital area of P10. Organic lesions were observed in the left lateral (P1), left medial (P2), and medial (P4) parts of prefrontal lobe, in the right (P6 and P9) and left (P7) temporal lobes, and in multiple lobes (P10) consisting of the left temporal and the occipital lobes bilaterally. The epileptogenic zones were suggested to he in the prefrontal lobe of P1, P2, P3, and P4, the temporal lobe of P5, P6, and P7, either the temporal or the frontal lobe or the area extending over the temporal and frontal lobes of P8 and P9, and the temporal lobe or the area extending temporal to the occipital area of P10. Conclusions: The results suggest that the frontal and temporal lobes participate in the genesis of the seizures of patients with chronic hallucinatory–paranoid states. The hallucinatory–paranoid state is shared in common by patients with epileptogenic zones of both the temporal and frontal lobes, whereas changes in behavior and personality differ depending on whether the site of epileptogenic zones is in the temporal or frontal lobes.

Regional HmPAO SPECT and CT Measurements in the Diagnosis of Alzheimer's Disease

This study investigated the hypothesis that the combination of regional CT brain atrophy measurements and semiquantitative SPECT regional blood flow ratios could produce a diagnostic test for Alzheimer's disease (AD) with an accuracy comparable to that achieved with the present clinical gold standard of the NINCDS-ADRDA criteria. Single proton emission computed tomography (SPECT) and CT head scans were performed on 122 subjects referred an UBC Alzheimer clinic and diagnosed as either 'not demented' (ND-37) or 'possible/probable AD' (AD-85) by the NINCDS-ADRDA criteria. Stepwise discriminant analysis (SDA) was performed on the bilateral SPECT regions of interest and compared to bilateral CT qualitative/quantitative assessment in the frontal, parietal and temporal lobes to determine which were most accurate at ND/AD distinction. Receiver operating curves (ROC) were then constructed for these variables individually and for their combined discriminant function. The left temporal qualitative cortical atrophy score (CT) and left temporal perfusion ratio (SPECT) were selected in the SDA. The combined discriminant function was more specific at AD/ND distinction than either of CT or SPECT alone. The accuracy of AD/ND distinction with the combined discriminant function was below that achieved by clinical diagnosis according to the NINCDS-ADRDA criteria and was not significantly different from that achieved with SPECT or CT alone as defined by ROC curve analysis. The measurements of left temporal cortical atrophy and regional cerebral blood flow were most indicative of AD; however they lacked the sensitivity and specificity to recommend their use as a diagnostic test for AD.

Single photon emission computed tomography studies of partial epilepsies

At present, in the field of clinical epilepsy, it has been established that single proton emission computed tomography (SPECT) is useful for the regional determination of epileptic foci. In particular, it seems to be of great advantage to the field of clinical epilepsy that epileptic foci situation in the deep regions of the brain are detectable by the three-dimensional resolution power in SPECT, because such foci are not often represented on routine scalp electroencephalograph (EEG). In reference to our review published previously, recent findings in SPECT studies of partial epilepsies are surveyed here.