---
title: The Influence of Age on EEG Signals and Consciousness During Anesthesia
nct_id: NCT04765046
overall_status: COMPLETED
phase: NA
sponsor: Medtronic - MITG
study_type: INTERVENTIONAL
primary_condition: Anesthesia
countries: Israel, Netherlands
canonical_url: "https://parkinsonspathways.com/agent/trials/NCT04765046.md"
clinicaltrials_gov: "https://clinicaltrials.gov/study/NCT04765046"
ct_last_update_post_date: 2024-07-03
last_seen_at: "2026-05-12T06:14:38.285Z"
source: ClinicalTrials.gov (mirrored, no enrichment)
---
# The Influence of Age on EEG Signals and Consciousness During Anesthesia

**Official Title:** The Influence of Age on EEG Signals and Consciousness During Anesthesia (TIARA)

**NCT ID:** [NCT04765046](https://clinicaltrials.gov/study/NCT04765046)

## Key Facts

- **Status:** COMPLETED
- **Phase:** NA
- **Study Type:** INTERVENTIONAL
- **Target Enrollment:** 90
- **Lead Sponsor:** Medtronic - MITG
- **Conditions:** Anesthesia
- **Start Date:** 2021-08-18
- **Completion Date:** 2023-04-03
- **CT.gov Last Update:** 2024-07-03

## Brief Summary

This is a prospective, multi-center, non-invasive, interventional, data collection study to improve the current BIS algorithm in the elderly adult population.

## Detailed Description

This is a prospective, multi-center, non-invasive, interventional, data collection study to improve the current BIS algorithm in the elderly adult population. The BIS system will be used on-label as approved in the respective study site countries to monitor and non-invasively measure and interpret brain wave activity directly related to the effects of anesthetic agents. The study's purpose is to evaluate the relationship between BIS parameters, age, and depth of anesthesia in patients undergoing surgery under general anesthesia.

## Eligibility

- **Minimum age:** 18 Years
- **Sex:** ALL
- **Healthy Volunteers:** No

```
Inclusion Criteria:

A potential subject may be included for participation in the study if the subject has/is:

1. ≥18 years of age
2. American Society of Anesthesiologists (ASA) physical status I-III
3. Able and willing to participate in the study and sign the informed consent form
4. Will undergo non-ambulatory elective surgery under general anesthesia
5. Has an expected surgery time \>2 hours

Exclusion Criteria:

A potential subject will be excluded from participating in the study if the subject has/is:

1. Pregnant
2. Unwilling to undergo EEG measurement
3. Undergone brain surgery procedure or had a cerebrovascular accident or severe head trauma in the last 10 years
4. Alcohol or illicit drug use, which prevents normal functioning in society or has led to organ toxicity. Chronic use of opioids, narcotics, or analgesics, which may limit a subject's responsiveness to analgesic dosages.
5. Known or suspected electroencephalograph abnormality (e.g., epilepsy or scarring)
6. Presence of a major psychiatric condition such as Bipolar disorder/ schizophrenia/ Alzheimer's disease/ dementia/ Parkinson's disease /major depression
7. Severe visual or auditory disorder
8. Cannot understand or is unwilling to perform the study assessments, according to the investigator's judgment
```

## Arms

- **BIS™ System** (OTHER) — Enrolled subjects who are undergoing a standard of care elective surgery under general anesthesia, will be equipped with the BIS system to non-invasively measure and interpret brain waive activity directly related to the effects of anesthetic agents during the surgery duration.

## Interventions

- **Bispectral (BIS™) Complete Monitoring System** (DEVICE) — The BIS™ Complete Monitoring System is a user-configurable patient monitoring system designed to monitor the hypnotic state of the brain based on the acquisition and processing of EEG signals. The BIS technology converts raw EEG data acquired from the frontal cortex into a single number to measure the level of consciousness, called the BIS index. A bilateral sensor is to be placed on the patient's forehead to collect the EEG signals and transmit them back to the system.

## Primary Outcomes

- **BIS50** _(time frame: 8 hours)_ — The Bispectral Index (BIS) value, a scale 0-100 with 0 being no brain activity and 100 being fully conscious, at which 50% of subjects are anesthetized at a level they are considered uncounscious based on the MOAA/S score of 0-2

## Locations (2)

- Rambam Health Care Campus, Haifa, Israel
- Leiden University Medical Center, Leiden, Netherlands

## Recent Field Changes (last 30 days)

- `status.overallStatus` — added _(2026-05-12)_
- `status.primaryCompletionDate` — added _(2026-05-12)_
- `status.completionDate` — added _(2026-05-12)_
- `status.lastUpdatePostDate` — added _(2026-05-12)_
- `design.phases` — added _(2026-05-12)_
- `design.enrollmentCount` — added _(2026-05-12)_
- `eligibility.criteria` — added _(2026-05-12)_
- `eligibility.minAge` — added _(2026-05-12)_
- `eligibility.sex` — added _(2026-05-12)_
- `outcomes.primary` — added _(2026-05-12)_
- `armsInterventions.arms` — added _(2026-05-12)_
- `armsInterventions.interventions` — added _(2026-05-12)_
- `sponsor.lead` — added _(2026-05-12)_
- `results.hasResults` — added _(2026-05-12)_
- `locations.rambam health care campus|haifa||israel` — added _(2026-05-12)_
- `locations.leiden university medical center|leiden||netherlands` — added _(2026-05-12)_

---

*Canonical: https://parkinsonspathways.com/agent/trials/NCT04765046.md*  
*Source data (authoritative): https://clinicaltrials.gov/study/NCT04765046*  
*This page is a raw mirror with no AI summary, no editorial enrichment, and no Parkinson's-specific filtering.*