Postoperative Cognitive Dysfunction (POCD) is a prevalent condition with significant clinical, social, and financial impacts on patients and healthcare services. The term POCD refers to any signs of new cognitive impairment that exceed the expected time for recovery from the acute effects of surgery and anesthesia. Mild Cognitive Impairment (MCI) is among the main risk factors and is defined as a small cognitive decline from the previous level of performance in one or more cognitive domains, without interfering with daily activities. Considering the aging population linked to an increase in the number of individuals with MCI and a growing demand for surgery, the identification of interventions that can prevent the occurrence of POCD is necessary. Non-invasive brain stimulation (NIBS) techniques such as TMS (Transcranial Magnetic Stimulation) are widely used in research and clinical practice and involve the modulation of excitability and brain activity, potentially improving the individual's cognitive performance. The aim of this study is to assess the efficacy of a Theta Burst rTMS protocol with few sessions in preventing postoperative cognitive dysfunction in elderly individuals with mild neurocognitive disorder. Methodology: This will be a randomized, blinded clinical trial with volunteers aged \> 60 years, candidates for elective surgeries, who will be randomly allocated into 2 groups: the groups will receive real or sham TBS 15 days before surgery. There will be 3 intervention sessions, with a 72-hour interval between them. Outcome measures will be cognitive psychological assessment and Stroop Test cognitive task performance before and after transcranial magnetic stimulation, after surgery and at the 3-month follow-up. There will be a non-surgical control group with cognitive impairment according to the study inclusion criteria and will receive active stimulation.
Patients over 60 years old
Patients scheduled for elective surgeries of moderate or large scale and candidates for general or spinal anesthesia;
Patients who demonstrate possible or probable cognitive impairment based on pre-operative screening using the 10-CS (10-point cognitive screening) tool; - For Non-surgical Control Intervention Group, only the first and third criteria will be applied.
Contraindications for the use of Transcranial Magnetic Stimulation (metal implants in the head, history of seizures or epilepsy, brain trauma or surgery, intracranial hypertension, and complications from exposure to magnetic fields);
Medical diagnosis of Major Neurocognitive Disorder (any form of dementia, regardless of the stage);
Indication for skull surgery;
Conditions that interfere with cognitive testing (presence of severe hearing and vision loss, inability to understand Portuguese);
Parallel
Theta Burst Stimulation
Other interventionTranscranial Magnetic Stimulation (TMS): A non-invasive brain stimulation (NIBS) technique that involves modulating brain excitability and activity, which can increase or decrease depending on the parameters used. Theta Burst Stimulation (TBS) mimics the brain's natural firing patterns more closely and may have greater effects on cognitive performance.
Theta Burst Stimulation Sham
Other interventionTheta Burst Stimulation simulated with 90º coil orientation with lower part external to the scalp.
Changes in Verbal Learning
Hopkins Verbal Learning Test (HVLT) - This test consists of a list of 12 words. After the examiner reads the list, the patient is asked to repeat as many words as possible in any order. This procedure is repeated two more times, and after 25 minutes, a delayed recall is requested. The score is based on the number of words recalled in the delayed recall.
Changes in Attention and Executive Function:
Trail Making Test (A and B) - The test is divided into two parts: the first part (TMT A) involves simple visual search and motor speed, while the second part (TMT B) requires complex visual search due to the alternation of stimuli, thus assessing executive function performance. In part A, the person must connect numbered circles in ascending order. In part B, they must draw lines alternating between numbers in ascending order and letters in alphabetical order. The test evaluates not only selective and alternating attention but also complex visual tracking and motor dexterity (Part A) as well as executive processes (Part B). The time spent and the number of errors made in each part are assessed.
Changes in Attention and Processing Speed
Stroop Test - The Stroop test assesses selective attention, the ability to maintain focus on a task, and the inhibition of the tendency to provide impulsive responses, as well as the speed of information processing. In this task, 99 trials are presented on a computer, featuring the words "green," "red," and "blue," displayed in their respective colors (or not). It measures the response time to name the colors of words that are colored in their actual color (congruent trials) or to state the colors of words with different colors (incongruent trials). It also evaluates the number of correct responses in the trials. Data will be synchronized using MATLAB software.
Changes in Motor Skills
The Grooved Pegboard Test - This is a manual dexterity test consisting of a board with 25 holes of the same shape (similar to a keyhole) and size, but arranged in a random orientation, along with small pegs that must be placed into the holes following a predetermined order, using only one hand. The raw data corresponds to the time taken to complete the task, measured in seconds. The dominant hand is tested first, followed by the non-dominant hand.
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