Clinical manifestations and immunomodulatory treatment experiences in psychiatric patients with suspected autoimmune encephalitis: a case series of 91 patients from Germany.

Autoimmune encephalitis (AE) can rarely manifest as a predominantly psychiatric syndrome without overt neurological symptoms. This study's aim was to characterize psychiatric patients with AE; therefore, anonymized data on patients with suspected AE with predominantly or isolated psychiatric syndromes were retrospectively collected. Patients with readily detectable neurological symptoms suggestive of AE (e.g., epileptic seizures) were excluded. Patients were classified as "probable psychiatric AE (pAE)," if well-characterized neuronal IgG autoantibodies were detected or "possible pAE" (e.g., with detection of nonclassical neuronal autoantibodies or compatible cerebrospinal fluid (CSF) changes). Of the 91 patients included, 21 (23%) fulfilled our criteria for probable (autoantibody-defined) pAE and 70 (77%) those for possible pAE. Among patients with probable pAE, 90% had anti-NMDA receptor (NMDA-R) autoantibodies. Overall, most patients suffered from paranoid-hallucinatory syndromes (53%). Patients with probable pAE suffered more often from disorientation (p < 0.001) and impaired memory (p = 0.001) than patients with possible pAE. Immunotherapies were performed in 69% of all cases, mostly with high-dose corticosteroids. Altogether, 93% of the patients with probable pAE and 80% of patients with possible pAE reportedly benefited from immunotherapies (p = 0.251). In summary, this explorative, cross-sectional evaluation confirms that autoantibody-associated AE syndromes can predominantly manifest as psychiatric syndromes, especially in anti-NMDA-R encephalitis. However, in three out of four patients, diagnosis of possible pAE was based on nonspecific findings (e.g., slight CSF pleocytosis), and well-characterized neuronal autoantibodies were absent. As such, the spectrum of psychiatric syndromes potentially responding to immunotherapies seems not to be limited to currently known autoantibody-associated AE. Further trials are needed.

Effects of behavioral therapy or pharmacotherapy on brain glucose metabolism in subjects with obsessive-compulsive disorder as assessed by brain FDG PET.

This prospective study investigated the effect of pharmacotherapy (PT) and cognitive behavioral therapy (CBT) on cerebral glucose metabolism in adults with obsessive-compulsive disorder (OCD). Dynamic positron emission tomography (PET) of the brain with F-18-fluorodeoxyglucose (FDG) was performed before and after treatment in 16 subjects diagnosed for OCD for at least 2 years (PT: n=7). Pre-to-post-treatment change of scaled local metabolic rate of glucose (SLMRGlc) was assessed separately in therapy responders and non-responders. Correlation was tested between SLMRGlc change and change of OCD, depression, or anxiety symptoms. SLMRGlc increased in the right caudate after successful therapy. The increase tended to correlate with the improvement of OCD symptom severity. The finding of increased local caudate activity after successful therapy is in contrast to most previous studies. Possible explanations include effects of therapy on concomitant depression symptoms and/or the large proportion of early-onset OCD in the present sample.

A voxel-based PET investigation of the long-term effects of "Ecstasy" consumption on brain serotonin transporters.

OBJECTIVE: Recent functional imaging studies have reported evidence of alterations in the serotonergic system induced by 3,4-methylenedioxymethamphetamine (MDMA), or "Ecstasy." However, these studies have often been limited by small sample size, lack of tracer selectivity, unreliable assessment of MDMA doses, insufficiently matched comparison groups, or region-of-interest analysis. METHOD: Positron emission tomography (PET) using the specific serotonin transporter ligand [(11)C](+)McN5652 was performed in 117 subjects: 30 current MDMA users, 29 former MDMA users, 29 drug-naive comparison subjects, and 29 users of drugs other than MDMA (polydrug comparison subjects). Self-assessment of drug history was checked by analyzing hair samples. Local serotonin transporter availability was computed by a regularized reference tissue approach. Voxel-based comparison of serotonin transporter availability was performed using statistical parametric mapping (SPM 99). RESULTS: Serotonin transporter availability in current MDMA users was significantly reduced in the mesencephalon, thalamus, left caudate, hippocampus, occipital cortex, temporal lobes, and posterior cingulate gyrus compared with all other groups. Reduction was more pronounced in female than in male subjects. There was no significant difference of serotonin transporter availability among former MDMA users and the drug-naive and polydrug comparison subjects. A negative correlation between serotonin transporter availability and mean MDMA dose was found in occipital visual areas and in the left precentral sulcus of current MDMA users. In addition, there was a significant positive correlation between the serotonin transporter availability and the MDMA abstention period in brainstem and in the basal forebrain in all MDMA users. CONCLUSIONS: These findings support the hypothesis of MDMA-induced protracted alterations of the serotonergic system and indicate that the reduced availability of serotonin transporter, as measured by PET, might be reversible. Women appear to be more susceptible than men to MDMA-induced alterations of the serotonergic system.

Long-term effects of "ecstasy" use on serotonin transporters of the brain investigated by PET.

UNLABELLED: Alterations of the serotonergic system due to ecstasy consumption have been extensively documented in recent literature. However, reversibility of these neurotoxic effects still remains unclear. To address this question, PET was performed using the serotonin transporter (SERT) ligand (11)C-(+)-McN5652 in a total of 117 subjects subdivided into 4 groups: actual ecstasy users (n = 30), former ecstasy users (n = 29), drug-naive control subjects (n = 29), and subjects with abuse of psychoactive agents other than ecstasy (n = 29). METHODS: About 500 MBq (11)C-(+)-McN5652 were injected intravenously. Thirty-five scans were acquired according to a dynamic scan protocol of 90 min using a full-ring whole-body PET system. Transaxial slices were reconstructed using an iterative method. Individual brains were transformed to a template defined earlier. Distribution volume ratios (DVRs) were derived by application of a reference tissue approach for reversible binding. Gray matter of the cerebellum served as reference. SERT-rich brain regions--mesencephalon, putamen, caudate, and thalamus--were selected for the evaluation of SERT availability using volumes of interest predefined in the template. RESULTS: Compared with drug-naive control subjects, the DVR in actual ecstasy users was significantly reduced in the mesencephalon (P = 0.004) and the thalamus (P = 0.044). The DVR in former ecstasy users was very close to the DVR in drug-naive control subjects in all brain regions. The DVR in polydrug users was slightly higher than that in the drug-naive control subjects in all SERT-rich regions (not statistically significant). CONCLUSION: Our findings further support the hypothesis of ecstasy-induced protracted alterations of the SERT. In addition, they might indicate reversibility of the availability of SERT as measured by PET. However, this does not imply full reversibility of the neurotoxic effects.

Reversibility of ecstasy-induced reduction in serotonin transporter availability in polydrug ecstasy users.

PURPOSE: Animal data suggest that the synthetic drug ecstasy may damage brain serotonin neurons. Previously we reported protracted reductions in the availability of the serotonin transporter (SERT), an index of integrity of the axon terminals of brain serotonergic neurons, in SERT-rich brain regions in current human ecstasy users. Comparison of current ecstasy users and former ecstasy users yielded some evidence that this reduction might be reversible. However, participant selection effects could not be ruled out. Therefore, follow-up examinations were performed in these subjects to test the following a priori hypothesis in a prospective longitudinal design that eliminates participant selection effects to a large extent: availability of the SERT increases towards normal levels when ecstasy use is stopped, and remains unchanged or is further decreased if use is continued. METHODS: Two follow-up positron emission tomography measurements using the SERT ligand [11C](+)McN5652 were completed by 15 current and nine former ecstasy users. All subjects used illicit drugs other than ecstasy, too. The time interval between repeated measurements was about 1 year. The time course of the availability of the SERT was analysed in the following SERT-rich regions: mesencephalon, putamen, caudate and thalamus. RESULTS: Current ecstasy users showed a consistent increase in the availability of the SERT in the mesencephalon during the study (Friedman test: p = 0.010), which most likely was caused by a decrease in the intensity of ecstasy consumption (Spearman correlation coefficient -0.725, p = 0.002). Former ecstasy users showed a consistent increase in SERT availability in the thalamus (Friedman test: p = 0.006). CONCLUSION: Ecstasy-induced protracted alterations in the availability of the SERT might be reversible.