Accelerated rTMS for Post-Stroke Apathy

Repetitive transcranial magnetic stimulation (rTMS) is a well-established FDA-approved treatment for several psychiatric indications including treatment-resistant depression, obsessive-compulsive disorder, and smoking cessation. Traditional rTMS targets the dorsolateral prefrontal cortex (dlPFC) with repetitive treatments delivered for six weeks. Recent innovations have led to the development of accelerated, high-dose rTMS protocols, with recent FDA-approval, that are capable of delivering a full treatment course within a single week.

Accumulating evidence suggests that similar neuromodulation protocols may be helpful in targeting neuropsychiatric symptoms across a range of neurologic and neurodegenerative conditions including dementia, movement disorders, and stroke. Apathy is a distinct neuropsychiatric symptom characterized by loss of motivation, withdrawal, and decreased goal-directed activity seen across a wide range of neuropsychiatric conditions. Apathy contributes significantly to lower quality of life, caregiver burnout, and poorer rehabilitation outcomes. Meanwhile, there are currently no FDA-approved treatments targeting apathy specifically. The mPFC has been well-established as a safe and feasible target for traditional rTMS, and may be a desirable stimulation site in targeting apathy due to its superficial location and integral association with other brain structures implicated in apathy pathophysiology such as the anterior cingulate cortex (ACC) and ventral striatum (VL).

This phase I open-label pilot study will investigate high-dose, accelerated rTMS at the medial prefrontal cortex (mPFC) to target apathy in individuals with chronic stroke. The primary aims of the study will be to: (1) establish the safety, feasibility, tolerability, and acceptability of an accelerated repetitive transcranial magnetic stimulation (rTMS) protocol for apathy in chronic stroke; (2) establish the feasibility of individualized resting-state functional magnetic resonance imaging (fMRI) connectivity for targeting rTMS in post-stroke apathy; (3) establish preliminary efficacy of an accelerated rTMS protocol for post-stroke apathy. Given the limited power of this small pilot study, this aim will be considered exploratory with the intention to guide future research.

Sixteen chronic stroke patients with symptomatic apathy will complete (1) structural as well as resting state functional MRI at baseline for targeting parcellations. (2) A battery of validated clinical assessments of apathy-related symptoms (3) a battery of neuropsychological, cognitive, and symptom measures to assess safety, tolerability, and feasibility. Treatment will consist of open-label, high-dose rTMS to left mPFC delivered following a standard protocol consisting of 600 pulses, twelve times per day, for three treatment days (contiguous or non-contiguous) within a seven-day period. Safety assessments will be monitored throughout treatment. A battery of clinical assessments will be repeated at the end of treatment and weekly for one month post-treatment.

Inclusion criteria

• 40 years old or greater
• Right- or left-hemisphere ischemic or hemorrhagic stroke with at least 6 months chronicity
• Symptomatic apathy as confirmed by (A) total score on the Apathy Evaluation Scale (AES) of ≥39 as rated by the participant or caregiver informant
• Intact cortex under the coil at the stimulation target site confirmed by neuroimaging
• Ability to participate in psychometric testing and cognitive tasks

Exclusion criteria

• Primary extra-axial hemorrhage (subdural or subarachnoid) without ischemic stroke or intraparenchymal hemorrhage
• Concomitant neurological disorders affecting motor or cognitive function (e.g. dementia)
• Moderate or severe global aphasia
• Visual impairment precluding completion of cognitive tasks
• Presence of contraindications to MRI or TMS including electrically, magnetically or mechanically activated metal or nonmetal implants such as cardiac pacemakers, intracerebral vascular clips, or any other electrically sensitive support system;
• Pregnancy (to be later confirmed by UPT in any premenopausal female participants)
• History of a seizure disorder
• Preexisting scalp lesion, wound, bone defect, or hemicraniectomy
• Claustrophobia precluding the ability to undergo an MRI
• Active substance use disorder
• Psychotic disorders
• Bipolar 1 Disorder
• Acute suicidality as assessed by the Columbia Suicide Severity Rating Scale (C-SSRS) or suicide attempt in the previous year