Effects of analysis window on 40-Hz auditory steady-state responses in cochlear implant users.

Auditory steady-state responses (ASSRs) are phase-locked responses of the auditory system to the envelope of a stimulus. These responses can be used as an objective proxy to assess temporal envelope processing and its related functional outcomes such as hearing thresholds and speech perception, in normal-hearing listeners, in persons with hearing impairment, as well as in cochlear-implant (CI) users. While ASSRs are traditionally measured using a continuous stimulation paradigm, an alternative is the intermittent stimulation paradigm, whereby stimuli are presented with silence intervals in between. This paradigm could be more useful in a clinical setting as it allows for other neural responses to be analysed concurrently. One clinical use case of the intermittent paradigm is to objectively program CIs during an automatic fitting session whereby electrically evoked ASSRs (eASSRs) as well as other evoked potentials are used to predict behavioural thresholds. However, there is no consensus yet about the optimal analysis parameters for an intermittent paradigm in order to detect and measure eASSRs reliably. In this study, we used the intermittent paradigm to evoke eASSRs in adult CI users and investigated whether the early response buildup affects the response measurement outcomes. To this end, we varied the starting timepoint and length of the analysis window within which the responses were analysed. We used the amplitude, signal-to-noise ratio (SNR), phase, and pairwise phase consistency (PPC) to characterize the responses. Moreover, we set out to find the optimal stimulus duration for efficient and reliable eASSR measurements. These analyses were performed at two stimulation levels, i.e., 100% and 50% of the dynamic range of each participant. Results revealed that inclusion of the first 300 ms in the analysis window leads to overestimation of response amplitude and underestimation of response phase. Additionally, the response SNR and PPC were not affected by the inclusion of the first 300 ms in the analysis window. However, the latter two metrics were highly dependent on the stimulus duration which complicates comparisons across studies. Finally, the optimal stimulus duration for quick and reliable characterization of eASSRs was found to be around 800 ms for the stimulation level of 100% DR. These findings suggest that inclusion of the early onset period of eASSR recordings negatively influences the response measurement outcomes and that efficient and reliable eASSR measurements are possible using stimuli of around 800 ms long. This will pave the path for the development of a clinically feasible eASSR measurement in CI users.

Multimodal prehabilitation in patients with non-small cell lung cancer undergoing anatomical resection: protocol of a non-randomised feasibility study.

BACKGROUND: The preoperative period can be used to enhance a patient's functional capacity with multimodal prehabilitation and consequently improve and fasten postoperative recovery. Especially, non-small cell lung cancer (NSCLC) surgical patients may benefit from this intervention, since the affected and resected organ is an essential part of the cardiorespiratory fitness. Drafting a prehabilitation programme is challenging, since many disciplines are involved, and time between diagnosis of NSCLC and surgery is limited. We designed a multimodal prehabilitation programme prior to NSCLC surgery and aimed to conduct a study to assess feasibility and indicative evidence of efficacy of this programme. Publication of this protocol may help other healthcare facilities to implement such a programme. METHODS: The multimodal prehabilitation programme consists of an exercise programme, nutritional support, psychological support, smoking cessation, patient empowerment and respiratory optimisation. In two Dutch teaching hospitals, 40 adult patients with proven or suspected NSCLC will be included. In a non-randomised fashion, 20 patients follow the multimodal prehabilitation programme, and 20 will be assessed in the control group, according to patient preference. Assessments will take place at four time points: baseline, the week before surgery, 6 weeks postoperatively and 3 months postoperatively. Feasibility and indicative evidence of efficacy of the prehabilitation programme will be assessed as primary outcomes. DISCUSSION: Since the time between diagnosis of NSCLC and surgery is limited, it is a challenge to implement a prehabilitation programme. This study will assess whether this is feasible, and evidence of efficacy can be found. The non-randomised fashion of the study might result in a selection and confounding bias. However, the control group may help putting the results of the prehabilitation group in perspective. By publishing this protocol, we aim to facilitate others to evaluate and implement a multimodal prehabilitation programme for surgical NSCLC patients. TRIAL REGISTRATION: The current study is registered as NL8080 in the Netherlands Trial Register on the 10th of October 2019, https://www.trialregister.nl/trial/8080 . Secondary identifiers: CCMO (Central Committee on Research Involving Human Subjects) number NL70578.015.19, reference number of the Medical Ethical Review Committee of Máxima MC W19.045.

Effect of Multimodal Prehabilitation on Reducing Postoperative Complications and Enhancing Functional Capacity Following Colorectal Cancer Surgery: The PREHAB Randomized Clinical Trial.

Importance: Colorectal surgery is associated with substantial morbidity rates and a lowered functional capacity. Optimization of the patient's condition in the weeks prior to surgery may attenuate these unfavorable sequelae. Objective: To determine whether multimodal prehabilitation before colorectal cancer surgery can reduce postoperative complications and enhance functional recovery. Design, Setting, and Participants: The PREHAB randomized clinical trial was an international, multicenter trial conducted in teaching hospitals with implemented enhanced recovery after surgery programs. Adult patients with nonmetastasized colorectal cancer were assessed for eligibility and randomized to either prehabilitation or standard care. Both arms received standard perioperative care. Patients were enrolled from June 2017 to December 2020, and follow-up was completed in December 2021. However, this trial was prematurely stopped due to the COVID-19 pandemic. Interventions: The 4-week in-hospital supervised multimodal prehabilitation program consisted of a high-intensity exercise program 3 times per week, a nutritional intervention, psychological support, and a smoking cessation program when needed. Main Outcomes and Measures: Comprehensive Complication Index (CCI) score, number of patients with CCI score more than 20, and improved walking capacity expressed as the 6-minute walking distance 4 weeks postoperatively. Results: In the intention-to-treat population of 251 participants (median [IQR] age, 69 [60-76] years; 138 [55%] male), 206 (82%) had tumors located in the colon and 234 (93%) underwent laparoscopic- or robotic-assisted surgery. The number of severe complications (CCI score >20) was significantly lower favoring prehabilitation compared with standard care (21 of 123 [17.1%] vs 38 of 128 [29.7%]; odds ratio, 0.47 [95% CI, 0.26-0.87]; P = .02). Participants in prehabilitation encountered fewer medical complications (eg, respiratory) compared with participants receiving standard care (19 of 123 [15.4%] vs 35 of 128 [27.3%]; odds ratio, 0.48 [95% CI, 0.26-0.89]; P = .02). Four weeks after surgery, 6-minute walking distance did not differ significantly between groups when compared with baseline (mean difference prehabilitation vs standard care 15.6 m [95% CI, -1.4 to 32.6]; P = .07). Secondary parameters of functional capacity in the postoperative period generally favored prehabilitation compared with standard care. Conclusions and Relevance: This PREHAB trial demonstrates the benefit of a multimodal prehabilitation program before colorectal cancer surgery as reflected by fewer severe and medical complications postoperatively and an optimized postoperative recovery compared with standard care. Trial Registration: trialregister.nl Identifier: NTR5947.

Evaluation of phase-locking to parameterized speech envelopes.

Humans rely on the temporal processing ability of the auditory system to perceive speech during everyday communication. The temporal envelope of speech is essential for speech perception, particularly envelope modulations below 20 Hz. In the literature, the neural representation of this speech envelope is usually investigated by recording neural phase-locked responses to speech stimuli. However, these phase-locked responses are not only associated with envelope modulation processing, but also with processing of linguistic information at a higher-order level when speech is comprehended. It is thus difficult to disentangle the responses into components from the acoustic envelope itself and the linguistic structures in speech (such as words, phrases and sentences). Another way to investigate neural modulation processing is to use sinusoidal amplitude-modulated stimuli at different modulation frequencies to obtain the temporal modulation transfer function. However, these transfer functions are considerably variable across modulation frequencies and individual listeners. To tackle the issues of both speech and sinusoidal amplitude-modulated stimuli, the recently introduced Temporal Speech Envelope Tracking (TEMPEST) framework proposed the use of stimuli with a distribution of envelope modulations. The framework aims to assess the brain's capability to process temporal envelopes in different frequency bands using stimuli with speech-like envelope modulations. In this study, we provide a proof-of-concept of the framework using stimuli with modulation frequency bands around the syllable and phoneme rate in natural speech. We evaluated whether the evoked phase-locked neural activity correlates with the speech-weighted modulation transfer function measured using sinusoidal amplitude-modulated stimuli in normal-hearing listeners. Since many studies on modulation processing employ different metrics and comparing their results is difficult, we included different power- and phase-based metrics and investigate how these metrics relate to each other. Results reveal a strong correspondence across listeners between the neural activity evoked by the speech-like stimuli and the activity evoked by the sinusoidal amplitude-modulated stimuli. Furthermore, strong correspondence was also apparent between each metric, facilitating comparisons between studies using different metrics. These findings indicate the potential of the TEMPEST framework to efficiently assess the neural capability to process temporal envelope modulations within a frequency band that is important for speech perception.