The goal of this clinical trial is to investigate the effectiveness of standardized and personalized transcranial alternating current stimulation (tACS) in patients with delirium. To investigate this, will perform a double-blind, randomized, sham-controlled, multicenter trial. To test the safety and feasibility of tACS in delirious patients, the first 30 patients will be randomized to receive either active or sham tACS treatment in a 1:1 ratio through a pilot study. For the main phase of the study, patients will be randomized, resulting in an overall 1:1:1 allocation to standardized tACS, personalized tACS or sham treatment. Electroencephalogram (EEG) will be measured directly before and directly after the first stimulation session to assess whether tACS can reduce relative delta power. tACS or sham treatment will be given once daily for a maximum of 14 days, or until resolution of delirium or discharge (whichever comes first). During the treatment phase, presence and severity of delirium will be assessed daily. After the treatment phase, an additional EEG will be measured. Cognitive status will be assessed three months after the initial tACS session.
Delirium, a prevalent neuropsychiatric syndrome caused by an underlying medical condition, characterized by cognitive deficits such as inattention, extends hospital stay, increases healthcare costs and increases the risk of long-term cognitive decline. Prolonged and severe delirium is associated with worse long-term outcomes. There is currently no treatment that reduces the duration or severity of delirium. Delirium is consistently characterized by diffuse oscillatory slowing of the EEG, including pronounced loss of alpha activity and increased relative delta power. Additionally, functional connectivity between brain regions is decreased during delirium. In light of this, tACS is a potential treatment option that directly addresses the brain dysfunction observed in delirium. Because tACS has shown the ability to improve multiple domains of cognition, including attention, and modify functional connectivity, we aim to investigate the effectiveness of tACS as treatment for delirium. We will utilize the EEG to measure the effects of tACS, using relative delta power as a primary outcome measure. Additionally, EEG measurements can capture individual spectral and connectivity changes targeted with tACS, making EEG a promising input for personalized tACS treatment. Neural mass modelling is a way to model the behavior of groups of neurons resulting in oscillatory output similar to EEG. This type of model is able to represent delirium pathology and, when combined with individual EEG input, can be employed to optimize treatment effectiveness, leading to personalized tACS treatment. The overarching aim of the study is to investigate whether treatment with tACS, either standardized or personalized, induces EEG alterations indicative of reversal of delirium. The primary outcome is relative delta power in the EEG measured after the first tACS session. Secondary outcomes include severity and/or duration of delirium measured with validated delirium assessment instruments. Patients aged 50 years and older with delirium that persists for at least 2 days, despite adequate treatment of underlying causes will be included in the study (n = 159). Inclusion will take place in the intensive care unit (ICU) and non-ICU wards of the University Medical Centre (UMC) Utrecht, Radboud UMC and HagaZiekenhuis.The proposed tACS protocol is considered safe according to the latest published international safety guidelines. All participants will be screened for their relevant medical history and other tACS safety aspects.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
159
tACS is a non-invasive brain stimulation technique which involves the application of a low intensity electric current between two or more surface electrodes. tACS uses stimulation with a current alternating at a specific frequency that can entrain endogenous neuronal oscillations by inducing neural synchronization. The administration of tACS is proposed to phase-lock large populations of neurons in the superficial layers of the cerebral cortex causing neural synchronization in the corresponding frequency, thereby altering connectivity. tACS will be delivered via a transcranial electrical stimulation (tES) device (Nurostym tES, Brainbox Ltd, United Kingdom). This device has been CE-marked for use as a medical device for the treatment of mental and neurological disorders.
Sham-tACS is a form of non-effective stimulation which can mimic the subjective sensation of active tACS treatment. During sham-tACS, the device will ramp up to 2.0 mA peak-to-peak intensity for 30 seconds, stimulate for 60 seconds and ramp down for 30 seconds, which mimics the sensation of actual tACS stimulation and improves blinding.The sham-tACS will be delivered via a transcranial electrical stimulation (tES) device (Nurostym tES, Brainbox Ltd, United Kingdom). This device has been CE-marked for use as a medical device for the treatment of mental and neurological disorders.
Radboudumc
Nijmegen, Gelderland, Netherlands
RECRUITINGHagaZiekenhuis
The Hague, South Holland, Netherlands
RECRUITINGRelative delta power
Calculated by dividing the absolute power in the delta frequency range by the total power, assessed using 64-channel resting-state EEG directly before and after tACS.
Time frame: 1 day
Duration of delirium
Delirium duration is evaluated by counting the number of days delirium is observed during the treatment period. We utilize the Intensive Care Delirium Screening Checklist (ICDSC), comprising 8 items, with a score of 4 or higher indicating the presence of delirium. Additionally, the Richmond Agitation-Sedation Scale (RASS), a 10-point scale ranging from +4 to -5, is used to assess the level of sedation (-5 indicating total sedation, +4 indicating combative behavior). A RASS score of -4 or lower, followed by an ICDSC score of 4 or higher, is also considered a delirium day.
Time frame: Two weeks
Severity of delirium
The cumulative score on the Intensive Care Delirium Screening Checklist (ICDSC), which includes 8 items and has a score range of 0-8, is documented for each day where delirium is observed during the hospital admission. In instances where the ICDSC score is unavailable, it will be approximated using information retrieved from the electronic patient record and standard delirium assessment tools routinely conducted.
Time frame: Two weeks
Length of hospital stay
The total number of days admitted to hospital
Time frame: 3 months
Cognitive status three months post delirium
Score on the Telephone Interview for Cognitive Status Modified (TICS-M). The TICS-M is a brief, 13-item test of cognitive functioning with scores ranging from 0 to 50, with higher scores indicating better cognitive performance.
Time frame: 3 months
Subjective sensations during treatment
Score on three-point Likert-type scale to assess sensations experienced during transcranial alternating current stimulation (tACS). The scale ranged from 0, indicating 'no sensation,' to 1, indicating 'slight sensation,' and 2, indicating 'intense sensation.' These sensations included itch, pain, burning sensation, heat, iron taste, headache, neck pain, phosphenes, dizziness, and nausea.
Time frame: Two weeks
Average peak frequency
Average peak frequency values will be calculated by averaging, over epochs, the peak frequency, assessed using 64-channel resting-state EEG before and after tACS and during the follow-up measurement.
Time frame: Two weeks
Phase Lag Index
Phase lag index captures phase synchronization between different EEG channels, assessed using 64-channel resting-state EEG before and after tACS and during the follow-up measurement.
Time frame: Two weeks
Corrected Amplitude Envelope Correlation (AECc)
AECc captures amplitude synchronization between different EEG channels, assessed using 64-channel resting-state EEG before and after tACS and during the follow-up measurement.
Time frame: Two weeks
Relative power
Relative power will be calculated by dividing the absolute power of the frequency band by the total absolute power in the EEG, assessed using 64-channel resting-state EEG before and after tACS and during the follow-up measurement.
Time frame: Two weeks
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.