Separation of responsive and unresponsive patients under clinical conditions: comparison of symbolic transfer entropy and permutation entropy.

Electroencephalogram (EEG)-based monitoring during general anesthesia may help prevent harmful effects of high or low doses of general anesthetics. There is currently no convincing evidence in this regard for the proprietary algorithms of commercially available monitors. The purpose of this study was to investigate whether a more mechanism-based parameter of EEG analysis (symbolic transfer entropy, STE) can separate responsive from unresponsive patients better than a strictly probabilistic parameter (permutation entropy, PE) under clinical conditions. In this prospective single-center study, the EEG of 60 surgical ASA I-III patients was recorded perioperatively. During induction of and emergence from anesthesia, patients were asked to squeeze the investigators' hand every 15s. Time of loss of responsiveness (LoR) during induction and return of responsiveness (RoR) during emergence from anesthesia were registered. PE and STE were calculated at -15s and +30s of LoR and RoR and their ability to separate responsive from unresponsive patients was evaluated using accuracy statistics. 56 patients were included in the final analysis. STE and PE values decreased during anesthesia induction and increased during emergence. Intra-individual consistency was higher during induction than during emergence. Accuracy values during LoR and RoR were 0.71 (0.62-0.79) and 0.60 (0.51-0.69), respectively for STE and 0.74 (0.66-0.82) and 0.62 (0.53-0.71), respectively for PE. For the combination of LoR and RoR, values were 0.65 (0.59-0.71) for STE and 0.68 (0.62-0.74) for PE. The ability to differentiate between the clinical status of (un)responsiveness did not significantly differ between STE and PE at any time. Mechanism-based EEG analysis did not improve differentiation of responsive from unresponsive patients compared to the probabilistic PE.Trial registration: German Clinical Trials Register ID: DRKS00030562, November 4, 2022, retrospectively registered.

Obsessive-Compulsive Symptoms are Less Common in Huntington's Disease than Reported Earlier.

BACKGROUND: Previous research using the Symptom-Checklist-90-Revised (SCL-90-R) has shown that compulsive symptoms in Huntington's disease (HD) occur in 10% to 52% of all cases. The "Hamburger-Zwangsinventar" (HZI), a self-rating questionnaire comprising 188 items, taps into the domain of compulsiveness in greater detail, but has not been used in HD so far. In addition, little is known about the association of obsessive-compulsive symptoms with pre-clinical stages of HD. OBJECTIVE: Comparison of OC symptoms measured by the SCL-90-R and the HZI in pre-HD and HD. METHODS: 29 premanifest mutation carriers (pre-HD) and 40 manifest HD patients completed both questionnaires. Clinical characteristics of HD were rated by using the UHDRS. RESULTS: Compared to data from general population prevalence of OC symptoms were not higher as expected in preHD and only slightly elevated in manifest HD if using HZI. Both instruments detected more OC symptoms in HD patients compared to pre-HD. The SCL-90-R more often detects compulsivity than the HZI. Results of both questionnaires showed correlations to cognition, depression, and disease duration. Compared to findings from OCD patients, there was a subordinate role in the HZI subscale for "washing and cleaning" in HD. CONCLUSIONS: OC symptoms in pre-HD occur not more often than in general population. The HZI appears to be useful for examining OC symptoms in detail in pre-HD and HD. HZI-subscale ratings for washing and cleaning compulsions were less pronounced in HD compared to OCD patients, possibly due to loss of disgust. The SCL-90-R might overestimate OC symptoms in both groups.