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Active, Not Recruiting

NCT Number: NCT05464355

Biomarkers Associated With Postoperative Cognitive Dysfunction

Loss of cognitive function after major surgery is a significant risk in older people. It can occur acutely in the days after surgery as delirium or in months to years later as a persistent reduction in brain function termed neurocognitive decline. Together these conditions are called post operative cognitive dysfunction (POCD). They can be acutely distressing for patients and are associated with other problems after surgery.

The causes of post operative cognitive dysfunction are poorly understood. Studies have been limited by a lack of biomarkers to predict which patients are at high risk of developing POCD. Research suggests silent strokes occurring during surgery and different sensitivities to anaesthetic medicines are associated with POCD.

The project consists of a feasibility study to investigate markers that might predict people over 65 years old getting POCD. The first biomarker is a non-invasive monitor of anaesthetics effects on brain function called electroencephalography (EEG): The investigators will identify which EEG patterns predict delirium within five days surgery. The second set of biomarkers are two blood tests of proteins that increase after strokes: these are neurofilament light chains and tau proteins. The investigators will establish if these can be used to predict having POCD up to one year after surgery and long term cognitive impairment up to 5 years after surgery.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Delirium Brain Diseases Central Nervous System Diseases Charcot-Marie-Tooth disease, Type 1F Cognition Disorders Cognitive Decline Cognitive Dysfunction Cognitive Impairment Confusion Dementia Frontotemporal Dementia Frontotemporal Lobar Degeneration Mental Disorders Metabolic Diseases Nervous System Diseases Neurobehavioral Manifestations Neurocognitive Disorders Neurodegenerative Diseases Neurologic Manifestations Nutritional and Metabolic Diseases Pathologic Processes Pathological Conditions, Signs and Symptoms Postoperative Cognitive Complications Postoperative Cognitive Dysfunction Postoperative Complications Proteostasis Deficiencies Signs and Symptoms TDP-43 Proteinopathies

Age range

65 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Royal Berkshire NHS Foundation Trust

Reading, Berkshire, RG1 5AN, United Kingdom

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Greater than or equal to 65 years of age
  • Having elective non-cardiac surgery under general anaesthesia
  • Anticipated to have at least 48 hours of inpatient admission
  • Able & willing to give informed consent

Exclusion criteria

  • Unable to participate in neurocognitive assessments
  • Presence of delirium prior to surgery
  • Contraindication to use of EEG electrodes (e.g. known allergy to a component of the electrodes)
  • Known history of severe traumatic brain injury
  • Learning disability specifically with a known structural brain lesion
  • Known history of dementia
  • Participants undergoing operations on the carotid artery

Treatment and study plan

Intraoperative electroencephalography recording

Procedure

Intraoperative electroencephalography measurements, a non-invasive routine monitoring device used during anaesthesia to measure the brain's electrical activity

Other names: EEG recording

Neurofilament light chain measurement

Procedure

Measurement of the level of neurofilament light chain in a blood sample

Other names: NfL

Tau protein measurement

Procedure

Measurement of the level of tau protein in a blood sample

Primary outcomes

  1. Feasibility to conduct the study

    Time frame: 1 year after surgery

    The total number of participants who are successfully recruited, receive the study procedures and complete both 90 day and 1 year follow up after surgery.

Secondary outcomes

  1. Postoperative delirium incidence and severity

    Time frame: Up to 5 days after surgery

    Postoperative delirium identified as being present according to a positive result using 3-Minute Diagnostic Interview for Confusion Assessment Method (3D-CAM) and severity according to the absolute value on the 3D-CAM-Severity which is a scale converting the 3-Minute Diagnostic Interview for Confusion Assessment Method into a scale from 0-7. Higher scores are associated with worse outcome.

  2. Days alive and at home up to 90 days after surgery

    Time frame: 90 days after surgery

    The number of days a participant is alive and how many are spent at home after surgery

  3. Change in neurofilament light chains and tau proteins levels pre- to post operatively

    Time frame: Up to 2 days after surgery

    Measurements of the level of the biomarkers neurofilament light chain and tau protein in plasma

  4. Postoperative neurocognitive dysfunction and severity

    Time frame: Up to 1 year after surgery

    Cognitive impairment measured on Montreal Objective Cognitive Assessment administered by telephone. The scale is 0-22 with higher scores representing better outcome.

  5. Long term cognitive impairment

    Time frame: Up to 5 years after surgery

    Incidence of new diagnosis in primary or secondary care of dementia or mild cognitive impairment

Sponsors and collaborators

Lead sponsor

University of Oxford

Other

Collaborators

  • Oxford University Hospitals NHS Trust

Registry information

Official study title

Feasibility Study of the Use of Biomarkers to Detect Perioperative Brain Injury: the Association Between Serum Neurofilament Light Chains, Tau Proteins, Continuous Intra-operative Electroencephalography, and the Development of Post Operative Cognitive Dysfunction After Surgery

Important dates

Study start
2023
Primary completion
2026
Study completion
2030
First posted
Jul 19, 2022
Registry last updated
Jun 22, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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