Detection of movement-related cortical potentials based on subject-independent training

To allow a routinely use of brain-computer interfaces (BCI), there is a need to reduce or completely eliminate the time-consuming part of the individualized training of the user. In this study, we investigate the possibility of avoiding the individual training phase in the detection of movement intention in asynchronous BCIs based on movement-related cortical potential (MRCP). EEG signals were recorded during ballistic ankle dorsiflexions executed (ME) or imagined (MI) by 20 healthy subjects, and attempted by five stroke subjects. These recordings were used to identify a template (as average over all subjects) for the initial negative phase of the MRCPs, after the application of an optimized spatial filtering used for pre-processing. Using this template, the detection accuracy (mean +/- A SD) calculated as true positive rate (estimated with leave-one-out procedure) for ME was 69 +/- A 21 and 58 +/- A 11 % on single trial basis for healthy and stroke subjects, respectively. This performance was similar to that obtained using an individual template for each subject, which led to accuracies of 71 +/- A 6 and 55 +/- A 12 % for healthy and stroke subjects, respectively. The detection accuracy for the MI data was 65 +/- A 22 % with the average template and 60 +/- A 13 % with the individual template. These results indicate the possibility of detecting movement intention without an individual training phase and without a significant loss in performance.Danish Agency for Science and Technology and Innovation; EU project BETTER [247935

a multicentre, randomised, parallel-group, assessor-blinded clinical trial (the TTH48 trial): study protocol for a randomised controlled trial

Background The application of therapeutic hypothermia (TH) for 12 to 24 hours following out-of-hospital cardiac arrest (OHCA) has been associated with decreased mortality and improved neurological function. However, the optimal duration of cooling is not known. We aimed to investigate whether targeted temperature management (TTM) at 33 ± 1 °C for 48 hours compared to 24 hours results in a better long-term neurological outcome. Methods The TTH48 trial is an investigator-initiated pragmatic international trial in which patients resuscitated from OHCA are randomised to TTM at 33 ± 1 °C for either 24 or 48 hours. Inclusion criteria are: age older than 17 and below 80 years; presumed cardiac origin of arrest; and Glasgow Coma Score (GCS) <8, on admission. The primary outcome is neurological outcome at 6 months using the Cerebral Performance Category score (CPC) by an assessor blinded to treatment allocation and dichotomised to good (CPC 1–2) or poor (CPC 3–5) outcome. Secondary outcomes are: 6-month mortality, incidence of infection, bleeding and organ failure and CPC at hospital discharge, at day 28 and at day 90 following OHCA. Assuming that 50 % of the patients treated for 24 hours will have a poor outcome at 6 months, a study including 350 patients (175/arm) will have 80 % power (with a significance level of 5 %) to detect an absolute 15 % difference in primary outcome between treatment groups. A safety interim analysis was performed after the inclusion of 175 patients. Discussion This is the first randomised trial to investigate the effect of the duration of TTM at 33 ± 1 °C in adult OHCA patients. We anticipate that the results of this trial will add significant knowledge regarding the management of cooling procedures in OHCA patients

Time-differentiated target temperature management after out-of-hospital cardiac arrest : a multicentre, randomised, parallel-group, assessor-blinded clinical trial (the TTH48 trial): study protocol for a randomised controlled trial

Background: The application of therapeutic hypothermia (TH) for 12 to 24 hours following out-of-hospital cardiac arrest (OHCA) has been associated with decreased mortality and improved neurological function. However, the optimal duration of cooling is not known. We aimed to investigate whether targeted temperature management (TTM) at 33 +/- 1 degrees C for 48 hours compared to 24 hours results in a better long-term neurological outcome. Methods: The TTH48 trial is an investigator-initiated pragmatic international trial in which patients resuscitated from OHCA are randomised to TTM at 33 +/- 1 degrees C for either 24 or 48 hours. Inclusion criteria are: age older than 17 and below 80 years; presumed cardiac origin of arrest; and Glasgow Coma Score (GCS) <8, on admission. The primary outcome is neurological outcome at 6 months using the Cerebral Performance Category score (CPC) by an assessor blinded to treatment allocation and dichotomised to good (CPC 1-2) or poor (CPC 3-5) outcome. Secondary outcomes are: 6-month mortality, incidence of infection, bleeding and organ failure and CPC at hospital discharge, at day 28 and at day 90 following OHCA. Assuming that 50 % of the patients treated for 24 hours will have a poor outcome at 6 months, a study including 350 patients (175/arm) will have 80 % power (with a significance level of 5 %) to detect an absolute 15 % difference in primary outcome between treatment groups. A safety interim analysis was performed after the inclusion of 175 patients. Discussion: This is the first randomised trial to investigate the effect of the duration of TTM at 33 +/- 1 degrees C in adult OHCA patients. We anticipate that the results of this trial will add significant knowledge regarding the management of cooling procedures in OHCA patients.Peer reviewe

A statistical analysis protocol for the time-differentiated target temperature management after out-of-hospital cardiac arrest (TTH48) clinical trial

Background: The TTH48 trial aims to determine whether prolonged duration (48 hours) of targeted temperature management (TTM) at 33 (+/- 1) degrees C results in better neurological outcomes compared to standard duration (24 hours) after six months in comatose out-of-hospital cardiac arrest (OHCA) patients. Methods: TTH48 is an investigator-initiated, multicentre, assessor-blinded, randomised, controlled superiority trial of 24 and 48 hours of TTM at 33 (+/- 1) degrees C performed in 355 comatose OHCA patients aged 18 to 80 years who were admitted to ten intensive care units (ICUs) in six Northern European countries. The primary outcome of the study is the Cerebral Performance Category (CPC) score observed at six months after cardiac arrest. CPC scores of 1 and 2 are defined as good neurological outcomes, and CPC scores of 3, 4 and 5 are defined as poor neurological outcomes. The secondary outcomes are as follows: mortality within six months after cardiac arrest, CPC at hospital discharge, Glasgow Coma Scale (GCS) score on day 4, length of stay in ICU and at hospital and the presence of any adverse events such as cerebral, circulatory, respiratory, gastrointestinal, renal, metabolic measures, infection or bleeding. With the planned sample size, we have 80% power to detect a 15% improvement in good neurological outcomes at a two-sided statistical significance level of 5%. Discussion: We present a detailed statistical analysis protocol (SAP) that specifies how primary and secondary outcomes should be evaluated. We also predetermine covariates for adjusted analyses and pre-specify sub-groups for sensitivity analyses. This pre-planned SAP will reduce analysis bias and add validity to the findings of this trial on the effect of length of TTM on important clinical outcomes after cardiac arrest.Peer reviewe

Occurrence, presence and severity of bruxism and its association with altered state of consciousness in individuals with severe acquired brain injury

Background: Excessive jaw muscle activity is a frequent complication after acquired brain injury (ABI). Objective: The study aimed to identify the occurrence and severity of jaw muscle activity and its association with altered state of consciousness in patients with ABI. Methods: A total of 14 severe ABI patients with varied altered state of consciousness were recruited. A single-channel electromyographic (EMG) device was used to assess the jaw muscle activity for three consecutive nights during Week 1 and Week 4 following admission. Differences in number of EMG episodes/h between Week 1 and 4 were analysed using non-parametric tests and association between the EMG activity and altered state of consciousness were analysed using Spearman's correlation test. Results: Nine of fourteen (64%) patients showed indications of bruxism (cutoff: &gt;15 EMG episodes/h). The average EMG episodes/h at admission were 44.5 ± 13.6 with no significant changes after Week 4 of admission (43 ± 12.9; p = .917). The EMG episodes/h ranged from 2 to 184 during Week 1 and 4-154 during Week 4. There were no significant correlations between the number of EMG episodes/h during the three nights and the individuals altered state of consciousness during Week 1 and Week 4. Conclusion: Patients with ABI had a conspicuously high but variable level of jaw muscle activity at admission and it tend to remain high after 4 week of hospitalisation which could potentially lead to adverse effects such as excessive tooth wear, headaches and pain in jaw muscles. The lack of associations between individuals altered level of consciousness and EMG activity could be due to low sample size and further studies are clearly warranted in this patient group with special needs. Single-channel EMG devices can record jaw muscle activity early in the hospitalisation period and might be a helpful tools for early detection of bruxism in ABI patients

Characterization of persistent post-traumatic headache and management strategies in adolescents and young adults following mild traumatic brain injury

Characteristics of persistent post-traumatic headache (PTH) in young individuals are poorly known leading to diagnostic problems and diverse management. We aimed to describe headache phenotypes and self-reported management strategies in young individuals with PTH following mild traumatic brain injury (mTBI). A comprehensive structured questionnaire was used to evaluate headache phenotypes/characteristics and management strategies to relieve headache in 107, 15–30-year-old individuals with PTH. Around 4 months post-injury, migraine-like headache in combination with tension-type like headache (40%) was the most commonly encountered headache phenotype followed by migraine-like headache (36%). Around 50% reported aura-like symptoms before/during the headache attack. Medication-overuse headache was diagnosed in 10%. Stress, sleep disturbances, and bright lights were the most common trigger factors. More than 80% reported that their headache was worsened by work-related activity and alleviated by rest/lying down. Simple analgesics were commonly used (88%) whereas prophylactic drugs were rarely used (5%). Bedrest and physiotherapy were also commonly used as management strategies by 56% and 34% of the participants, respectively. In conclusion, most young individuals with PTH after mTBI presented with combined migraine-like and tension-type-like headache followed by migraine-like headache, only. Preventive headache medication was rarely used, while simple analgesics and bedrest were commonly used for short-term headache relief