Prefrontal Theta Burst Stimulation to Improve Cognitive Impairment After ICU Delirium

Prefrontal Theta Burst Stimulation to Improve Cognitive Impairment After ICU Delirium: A Randomized Sham-Controlled Pilot Trial

Many older adults who survive a stay in the intensive care unit (ICU) experience delirium, a sudden change in attention and awareness caused by serious illness. Although delirium may resolve before hospital discharge, many survivors continue to experience ongoing problems with memory, attention, processing speed, and executive function (such as planning, organizing, and multitasking). These cognitive difficulties can interfere with daily activities and may increase long-term risk for cognitive decline. Currently, there are no proven treatments specifically designed to improve thinking and attention after ICU delirium.

This study is testing whether a noninvasive form of brain stimulation called intermittent theta burst stimulation (iTBS) is safe, feasible, and potentially helpful for improving cognitive function in older ICU survivors who previously experienced delirium. iTBS is a patterned form of transcranial magnetic stimulation (TMS). It involves placing a magnetic coil gently against the scalp to deliver brief pulses of magnetic energy to a targeted region of the brain. In this study, stimulation is directed at the left dorsolateral prefrontal cortex, an area involved in attention, executive function, and cognitive control. The device used in this study is cleared by the U.S. Food and Drug Administration (FDA) for other conditions (such as depression), but its use for post-delirium cognitive impairment is investigational.

This is a randomized, double-blind, sham-controlled pilot trial. Up to 40 community-dwelling adults between the ages of 50 and 75 who are approximately three months after an ICU stay with documented delirium will participate. Individuals with known dementia or certain neurological or psychiatric conditions are excluded to ensure safety and interpretability of results.

Participation lasts approximately six weeks and includes 11 total visits: a baseline visit, 10 stimulation sessions over two weeks (five sessions per week), and a one-month follow-up visit. Each stimulation session lasts about 15-20 minutes. Cognitive testing is performed at baseline, immediately after the two-week stimulation period, and again one month later. The primary outcome measure is change in executive function, assessed using the Trail Making Test Part B. Additional tests measure attention, processing speed, language, and memory.

The primary goals of this pilot study are to evaluate feasibility (ability to recruit and retain participants), safety, and tolerability of the stimulation protocol, and to estimate the magnitude of any cognitive changes. This study is not designed to establish definitive clinical effectiveness but to generate data to inform larger future trials. The broader goal of this research is to explore whether prefrontal neuromodulation could become a future strategy to promote cognitive recovery after ICU delirium.

Study Overview

• Status: Recruiting
• Conditions: Post-delirium Cognitive Impairment
• Intervention / Treatment: Device: Intermittent theta burst stimulation; Device: Sham

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Shixie Jiang, MD; Phone Number: 352-273-5391; Email: delirium-lab@ufl.edu

Study Locations

• United States
  • Florida
    • Gainesville, Florida, United States, 32610
      • Recruiting
      • University of Florida Shands Hospital
      • Contact: Shixie Jiang, MD; Phone Number: 352-273-5391; Email: delirium-lab@ufl.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Eligible individuals must have experienced an ICU admission with documented delirium (confirmed via documented Confusion Assessment Method for the ICU score12 [CAM-ICU] or Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition13(p5) [DSM-5] criteria)
• Age 50 to 75 years old
• 3 months post-ICU discharge at time of enrollment (defined as within 90 ± 14 days)
• English fluency
• Family or close friend for collateral
• Community-dwelling status
• Montreal Cognitive Assessment14 score between 18 and 25.

Exclusion Criteria:

• Diagnosis of mild cognitive impairment or dementia (prior to delirium episode)
• Seizure disorder
• Other significant neurologic disease (e.g., Parkinson's, Huntington's, Normal pressure hydrocephalus, tumor, progressive supranuclear palsy, multiple sclerosis, hematomas, traumatic or anoxic brain injury)
• Structural CT/MRI with evidence of infection or other clinically significant focal lesions (cortical strokes not large enough to distort anatomy and/or multiple lacunar infarctions ≤ 1.5cm and/or extensive white matter disease are allowed)
• Unstable or decompensated cardiac disease (e.g., <3 months myocardial infarction, unstable angina, decompensated congestive heart failure NYHA class 3-4)
• Pacemaker
• Cochlear implants
• Implanted medication pumps
• Intracranial metal implants
• Previous TMS treatment
• Pregnancy (negative urine or serum b-HCG or history of prior surgical sterilization or post-menopausal status [12 months or more of amenorrhea])
• Current depressive disorder (Beck Depression Inventory score15 <13)
• History of suicide attempts
• Schizophrenia
• Bipolar disorder
• Alcohol or substance abuse
• Severe visual/hearing impairment.
• Informant Questionnaire on Cognitive Decline in the Elderly16 (IQCODE) score ≥3.4 (suggesting prior cognitive decline)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Sham Comparator: Sham	Device: Sham; Sham stimulation will be delivered using the same Brain Ultimate M-Series transcranial magnetic stimulation system and figure-of-eight coil used in the active arm. The coil will be positioned at approximately a 45-degree angle relative to the scalp over the left dorsolateral prefrontal cortex (localized using the Beam F3 method) to minimize effective cortical stimulation while preserving auditory and tactile characteristics of active treatment.
Active Comparator: Intermittent theta burst stimulation	Device: Intermittent theta burst stimulation; Intermittent theta burst stimulation (iTBS) will be delivered using an FDA-cleared Brain Ultimate M-Series transcranial magnetic stimulation system. Stimulation will target the left dorsolateral prefrontal cortex (DLPFC), localized using the Beam F3 scalp-based method. Each session consists of 600 magnetic pulses delivered over approximately 3 minutes using a standard intermittent theta burst pattern (bursts of 3 pulses at 50 Hz, repeated at 5 Hz), administered at 120% of the participant's resting motor threshold. Resting motor threshold will be determined by visual confirmation of motor-evoked movement in the right abductor pollicis brevis muscle.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Trails Making Test B	Time (in seconds) required to complete Part B. Lower scores indicate better executive functioning. There is no fixed maximum score; the test is typically discontinued at 300 seconds. Range 0-300 seconds.	From enrollment to one-month after the final TMS session

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Trails Making Test A	Time (in seconds) required to complete Part A. Lower scores indicate better processing speed. Maximum allowable time: 300 seconds.	From enrollment to one-month after final TMS session
Psychomotor Vigilance Task		From enrollment to one-month after final TMS session
Digit Symbol Coding	Total number of correct symbols completed in 120 seconds. Range: 0-135 (depending on version). Higher scores indicate better processing speed.	From enrollment to one-month after final TMS session
Controlled Oral Word Association Test	Total number of correct words generated in 60 seconds. Range: 0 to unlimited. Higher scores indicate better verbal fluency.	From enrollment to one-month after final TMS session
Semantic Verbal Fluency Test	Total number of correct category exemplars generated in 60 seconds. Range: 0 to unlimited. Higher scores indicate better performance.	From enrollment to one-month after final TMS session
Hopkins Verbal Learning Test	Hopkins Verbal Learning Test - Revised (HVLT-R). Total recall score across three learning trials. Range: 0-36. Higher scores indicate better verbal learning. Delayed recall: Range: 0-12. Higher scores indicate better memory retention.	From enrollment to one-month after final TMS session
Logical Memory 1 and 2	Logical Memory 1: 0 to 50 (maximum raw score depends on scoring criteria; confirm exact maximum with manual - typically 50 units). Higher scores indicate better immediate verbal memory. Logical Memory 2: Score range: 0 to 50 (same unit structure as LM I). Higher scores indicate better delayed verbal memory.	From enrollment to one-month after final TMS session
Craft Story 21 Recall	Score range: 0 to 44 Directionality: Higher scores indicate better verbal episodic memory.	From enrollment to one-month after final TMS session
Montreal Cognitive Assessment Test	Total score range: 0-30. Higher scores indicate better global cognitive function	From enrollment to one-month after final TMS session

Collaborators and Investigators

• Sponsor: University of Florida

Publications and helpful links

General Publications

• Pandharipande PP, Girard TD, Jackson JC, Morandi A, Thompson JL, Pun BT, Brummel NE, Hughes CG, Vasilevskis EE, Shintani AK, Moons KG, Geevarghese SK, Canonico A, Hopkins RO, Bernard GR, Dittus RS, Ely EW; BRAIN-ICU Study Investigators. Long-term cognitive impairment after critical illness. N Engl J Med. 2013 Oct 3;369(14):1306-16. doi: 10.1056/NEJMoa1301372.
• Girard TD, Jackson JC, Pandharipande PP, Pun BT, Thompson JL, Shintani AK, Gordon SM, Canonico AE, Dittus RS, Bernard GR, Ely EW. Delirium as a predictor of long-term cognitive impairment in survivors of critical illness. Crit Care Med. 2010 Jul;38(7):1513-20. doi: 10.1097/CCM.0b013e3181e47be1.
• Chou YH, Ton That V, Sundman M. A systematic review and meta-analysis of rTMS effects on cognitive enhancement in mild cognitive impairment and Alzheimer's disease. Neurobiol Aging. 2020 Feb;86:1-10. doi: 10.1016/j.neurobiolaging.2019.08.020. Epub 2019 Aug 27.
• Fuseya K, Mimura Y, Nakajima S, Mimura M, Kasanuki K, Noda Y. A systematic review and meta-analysis on the characteristics of transcranial magnetic stimulation treatment protocols for patients with Alzheimer's disease. J Alzheimers Dis. 2025 May;105(1):28-43. doi: 10.1177/13872877251325887. Epub 2025 Mar 20.
• Pabst A, Proksch S, Mede B, Comstock DC, Ross JM, Balasubramaniam R. A systematic review and meta-analysis of the efficacy of intermittent theta burst stimulation (iTBS) on cognitive enhancement. Neurosci Biobehav Rev. 2022 Apr;135:104587. doi: 10.1016/j.neubiorev.2022.104587. Epub 2022 Feb 22.

Study record dates

Study Major Dates

• Study Start (Actual): February 13, 2026
• Primary Completion (Estimated): March 21, 2027
• Study Completion (Estimated): April 1, 2027

Study Registration Dates

• First Submitted: February 13, 2026
• First Submitted That Met QC Criteria: February 27, 2026
• First Posted (Actual): March 5, 2026

Study Record Updates

• Last Update Posted (Actual): March 11, 2026
• Last Update Submitted That Met QC Criteria: March 9, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: delirium; dementia
• Additional Relevant MeSH Terms: Neurologic Manifestations; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Mental Disorders; Confusion; Neurobehavioral Manifestations; Neurocognitive Disorders; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Delirium; Dementia
• Other Study ID Numbers: IRB202501241

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No