Hypnosis as a Non-Pharmacologic Adjunct in Magnetic Resonance-Guided Focused Ultrasound Thalamotomy for Essential Tremor: A Case Report

Introduction

Essential tremor (ET) is the most common movement disorder in adults, affecting up to 5% of the population. ET is typically diagnosed clinically, based on a bilateral, symmetric postural or kinetic tremor of the hands and forearms, usually persisting for more than 3 years, in the absence of other neurological signs. Additional features may include head or voice tremor; the condition is often relieved by small amounts of alcohol. First-line management consists of pharmacologic agents such as propranolol and primidone, whereas second-line options include gabapentin, topiramate, and benzodiazepines. However, many patients remain refractory or experience limiting side effects (SEs); in such cases, interventional therapies such as deep brain stimulation or transcranial magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy may be considered [1]. Incisionless transcranial ablation of thalamic nuclei using MRgFUS thalamotomy is an established technique for the treatment of ET that has been validated in case series and clinical trials [2–8]. The procedure relies on the creation of a targeted thermal lesion in specific brain regions, most commonly the ventral intermediate nucleus of the thalamus or the pallidothalamic tract [9]. This approach has demonstrated substantial improvement in tremor severity, both at rest and during action, along with positive effects on rigidity, bradykinesia, and non-motor symptoms; it is generally associated with a low incidence of adverse effects [3,10,11].

Nevertheless, MRgFUS requires the patient to remain awake, alert, and fully cooperative throughout the procedure, which can last several hours in a supine, fixed-head position within the magnetic resonance imaging (MRI) scanner. This presents unique anesthetic and procedural challenges. Intraprocedural SEs such as vertigo, scalp burning sensation, nausea, perioral paresthesia, headache, somnolence, agitation, or loss of cooperation are not uncommon [12,13]. These issues can result in interruption, prolongation, or even abortion of the procedure.

Although pharmacologic strategies have been proposed to address SEs associated with MRgFUS, they carry the risk of reducing patient responsiveness or interfering with intraoperative neurological monitoring [13]. An alternative to pharmacologic strategies is clinical hypnosis, a well-established non-pharmacologic technique used in various fields of anesthesia and perioperative medicine. Hypnosis is defined as a relaxation technique that induces a modified state of consciousness characterized by altered perception and dissociation from external stimuli, including time and bodily sensations [14–16]. Functional neuroimaging studies have demonstrated that hypnotic suggestions can modulate specific cerebral activity patterns, particularly those related to pain processing, pain management, and anxiety disorders [17,18]. Techniques often combine therapist-guided hypnosis with self-hypnosis to optimize outcomes [18]. Although less conventional in the context of neurological conditions, hypnosis has shown promise as an adjunctive treatment for functional stroke [19]. It has been reported to reduce anxiety, modulate pain perception, and improve patient comfort without compromising cognitive or neurologic assessment [20]. The use of hypnosis for pain and anxiety management is particularly well documented in neurosurgical settings, including awake craniotomies and brain tumor resections [21–23]. Robust clinical trials of hypnosis during ET treatment remain limited, but available evidence suggests that hypnosis can help manage ET by reducing stress, addressing emotional triggers, and potentially influencing the brain’s control of motor functions.

To our knowledge, hypnosis has not yet been reported as a supportive strategy during MRgFUS thalamotomy for ET; its safety and effectiveness in relation to MRgFUS-specific SEs require investigation. This report describes the case of a 75-year-old woman with medication-resistant ET who was successfully treated with MRgFUS thalamotomy performed with hypnosis.

Case Report

PREOPERATIVE HYPNOSIS PROTOCOL:

The hypnosis technique implemented for this patient was based on the approach described by Erickson and Rossi [26], aimed at induction of a transient dissociative state. This state was particularly beneficial because it preserved the patient’s capacity to undergo repeated neuropsychological assessments without awareness of discomfort. During trance, the patient’s perception of bodily and temporal experience was altered, allowing her to engage with the procedure while remaining detached from its physical demands. The hypnotic experience was anchored in the concept of a “safe place,” as described in Ericksonian hypnotherapy – a mental environment evoking safety and calm, associated with altered sensory awareness and time distortion.

Hypnotic induction was facilitated by the anesthesiologist through verbal interaction, directing the patient’s attention inward and establishing the appropriate cognitive environment for exogenous (guided) and endogenous (self-directed) hypnotic suggestions [23]. The patient underwent 2 preoperative hypnosis sessions conducted by an anesthesiologist certified in clinical hypnosis. The primary goals of these preparatory sessions were to assess expectations, introduce the concept of hypnosis, clarify misconceptions, and provide the patient with tools to manage the anticipated physical and emotional challenges of the procedure.

During the first session, the patient was guided into a hypnotic trance state and helped to define a personal “safe place” – a familiar walk through the old town district – that would serve as an anchor during the procedure. Specific hypnotic strategies were developed to mitigate expected SEs. For instance, the sensation of vertigo would be countered by imagining her feet firmly grounded in a new pair of boots, whereas the burning scalp sensation would be addressed by visualizing herself wearing a protective hat. Particular attention was given to the psychological impact of the full scalp trichotomy. Through guided suggestion, the patient was able to symbolically integrate this technique as part of her transformation toward a tremor-free life.

The second session reinforced the imagery and strategies introduced earlier. Emphasis was placed on instruction in self-hypnosis techniques and the establishment of a reliable alert signal to allow the anesthesiologist to intervene – if necessary – without disrupting the trance state. Between sessions, the patient engaged in cognitive rehearsal, such as walking through the old town to strengthen the imagery associated with her “safe place,” further enhancing the efficacy of the hypnotic state during the procedure.

DAY OF THE PROCEDURE:

The perioperative hypnosis protocol was carried out by the same anesthesiologist who had conducted the preparatory sessions. On the day of the procedure, a full hypnotic induction was performed to support the frame fixation phase, which was also assisted by local anesthesia. The patient was guided into her previously established “safe place,” with suggestions integrating procedural elements into the imagery – for example, the local anesthetic was described as a sensation of gentle rain falling on the skin.

A second hypnotic induction was performed upon arrival in the MRI room. This induction was then maintained by the patient herself through practiced self-hypnosis techniques during the sonication phase. Throughout the procedure, the patient remained calm, cooperative, and communicative. No additional hypnotic suggestions or anesthesiologist interventions were required during the sonications. At the conclusion of the intervention, after removal of the stereotactic frame, the anesthesiologist confirmed that the patient had fully and comfortably emerged from the hypnotic state.

To ensure safety throughout the procedure, the patient was provided a hand-held emergency stop button, allowing immediate interruption of treatment in case of distress or adverse events. Standard MRI-compatible physiologic monitoring was applied, including non-invasive blood pressure, pulse oximetry, and continuous electrocardiographic monitoring. Given the prolonged duration of the MRgFUS procedure and the requirement for immobility, these measures were essential to detect early signs of discomfort or physiologic instability, particularly in the absence of sedative or anxiolytic medication.

One hour prior to transfer to the MRI suite, a prophylactic pharmacologic regimen was administered. This included paracetamol 1000 mg for analgesia, dexamethasone 8 mg and ondansetron 4 mg for antiemetic coverage, and esomeprazole 40 mg for gastroprotection. Local anesthesia for frame placement consisted of subcutaneous and periosteal infiltration with 10 mL lidocaine 2%, applied to the scalp at fixation points. No sedative or anxiolytic medications were administered at any time during the perioperative period to preserve the integrity of neuropsychological assessments and patient cooperation during hypnosis.

A complete scalp trichotomy was performed the day before the intervention. On the morning of the procedure, a dedicated stereotactic frame was positioned under local anesthesia, after hypnotic induction to support patient comfort and compliance. The patient was then placed on the focused ultrasound platform (Exablate Neuro, Insightec, Israel), which was advanced into the MRI scanner.

INTRAOPERATIVE COURSE:

Prior to sonication, a second hypnotic induction was conducted. Initial targeting on T2-weighted MRI localized the left ventral intermediate nucleus at 14.5 mm lateral from the midline, 6.4 mm anterior to the posterior commissure (PC), and 1 mm superior to the anterior commissure–posterior commissure (AC-PC) plane. Alignment sonications were performed to fine-tune the focus of the ultrasound beam. Based on initial responses, the target coordinates were progressively adjusted: laterally to 15.5 mm, ventrally to the AC-PC plane (0 mm), and posteriorly by 1 mm (to 5.4 mm anterior to the PC). At this final position, a favorable tremor response was observed without SEs. A “treat low” sonication was then delivered at this location with good efficacy, followed by a “treat high” sonication at the same coordinates. The latter induced clinically significant improvement, although slight dysmetria was noted. A final sonication was performed 0.5 mm dorsally, resulting in further tremor reduction without additional adverse effects.

The patient successfully suspended self-hypnosis to complete each assessment, ensuring that the evaluations were not influenced by hypnotic or pharmacologic sedation. The healthcare team confirmed the accuracy and consistency of these assessments during the procedure.

After delivery of therapeutic sonications, the presence of a lesion was immediately confirmed on MRI. Procedural findings included a left thalamic lesion extending to the mesencephalic substantia nigra and the posterior limb of the ipsilateral internal capsule. The lesion exhibited heterogeneous T2-weighted hyperintensity, T1-weighted hypointensity, and peripheral edema characterized by T2 hyperintensity. The axial dimensions of the lesion measured 15×9 mm.

Throughout the intervention, 5 intraoperative neuropsychological assessments were conducted using subsection 2 of the Clinical Rating Scale for Tremor (CRST), which evaluates motor tasks such as handwriting and drawing. The full CRST comprises 3 subsections: tremor severity (score out of 88), task performance (out of 36), and functional disability (out of 32), for a total of 156 points. Clinical efficacy was assessed with the CRST at baseline and at 6 months post-procedure. Preoperatively, the patient’s total CRST score was 44/156, with subscores of 19 (tremor severity), 16 (task performance), and 9 (functional disability). At 6 months, the total score had decreased to 25/156, with subscores of 8, 13, and 4, respectively, corresponding to approximately 43% improvement from baseline. Additionally, global functional impairment was rated by both the patient and the examiner on a scale of 0 to 4 (0=none, 4=total impairment). The global rating of functional incapacity decreased from 4 (patient) and 2 (examiner) at baseline to 1 (both patient and examiner) at follow-up. Handwriting samples, spirals, and line drawings completed by the patient using her dominant right hand – collected preoperatively and at 6 months – demonstrated clear improvement (Figxure 1).

FOLLOW-UP ASSESSMENTS:

The efficacy and subjective impact of the hypnosis protocol were evaluated using 2 validated instruments. The first was the Patient Satisfaction Assessment Questionnaire (PSAQ), based on tools developed by Labarriere et al. and Jaouen et al. [27,28]. This instrument evaluates 6 domains: comfort, perceived helpfulness, adequacy of information, expectations, willingness to repeat the experience, and likelihood of recommending hypnosis. The patient rated each item on a visual analog scale ranging from 1 (very dissatisfied) to 10 (very satisfied); an overall Global Satisfaction Index (GSI) was calculated accordingly. She rated the maximum score on all 6 PSAQ items at both the 1-month and 6-month follow-up visits. Her calculated GSI was 9/10 at 1 month and 10/10 at 6 months.

The second instrument was the Impact of Event Scale – Revised (IES-R), used to evaluate the psychological impact of the intervention and to screen for symptoms consistent with post-traumatic stress disorder (PTSD) [29,30]. The questionnaire specifically focused on the patient’s experience of the MRgFUS procedure under hypnosis. The IES-R was administered at 1 month and 6 months post-intervention to detect any late-onset psychological distress. The patient’s IES-R scores were 8 at 1 month and 4 at 6 months (Table 1).

During a structured post-procedure debriefing, all members of the multidisciplinary care team – a neurosurgeon responsible for stereotactic planning and lesion creation; a neurologist and a psychiatrist, in charge of neuropsychological test selection and evaluation; a neuroradiologist, who guided imaging acquisition and interpretation; an anesthesiologist, who conducted hypnosis induction and intraoperative monitoring; and a medical physicist specializing in focused ultrasound, who oversaw the technical aspects of the procedure – expressed high levels of satisfaction with the patient’s cooperation and noted that the hypnosis protocol did not interfere with any aspect of the intervention. The patient’s calm demeanor and sustained engagement positively contributed to workflow efficiency and the overall atmosphere in the MRI suite, particularly during lengthy sonication phases.

Discussion

Our case illustrates that clinical hypnosis can be safely and effectively integrated into MRgFUS thalamotomy for essential tremor, offering a non-pharmacologic strategy to enhance procedural tolerance and patient comfort without compromising intraoperative assessments. We have described a 75-year-old woman with medication-resistant benign ET who was successfully treated via MRgFUS thalamotomy combined with hypnosis. The mean total CRST score improvement from baseline at 6 months was comparable to previous studies of MRgFUS thalamotomy in patients with ET [2,5,8]. Similar outcomes have been documented in specific prior reports. For example, Meng et al. demonstrated that tremor improvement was sustained at 2 years post-MRgFUS thalamotomy in a cohort of patients with medication-refractory ET, underlining the durability of the effect [8]. Moreover, Paff et al. reported successful and well-tolerated MRgFUS thalamotomy outcomes in 2 nonagenarian patients, suggesting that advanced age should not preclude the procedure [7].

The clinical presentation in our case – longstanding bilateral, medication-refractory tremor with functional impairment – was consistent with typical clinical criteria for ET and mirrored the medication-refractory profiles treated in prior MRgFUS cohorts [1,7,8]. In terms of clinical course, the 6-month improvement on the CRST (44 to 25; ~43%) aligned with ranges reported in previous series [2,5,8]. Unlike those reports, however, the present case incorporated therapist-guided and self-hypnosis as a non-pharmacologic adjunct, which was associated with excellent intra-procedural tolerance without sedatives or interruptions, highlighting a potential strategy to enhance cooperation and comfort during MRgFUS.

In anesthesiology, hypnosis has increasingly been utilized as a non-pharmacologic tool, particularly in contexts such as non-operating room anesthesia, where unique challenges are encountered [31,32]. Although noninvasive, the MRgFUS procedure for ET requires prolonged immobilization on an MRI table, placement of a stereotactic head frame, and complete patient cooperation throughout the intervention. A retrospective analysis of 82 MRgFUS thalamotomy cases examined specific drug and procedural details, revealing that 29% of patients required sedation to tolerate the procedure [13]. However, procedural constraints make airway access difficult and limit the feasibility of pharmacologic sedation or anxiolysis; these measures may compromise both patient safety and the ability to perform intraoperative neurological evaluations [33]. Hypnosis offers an attractive alternative by preserving spontaneous ventilation, maintaining cognitive function, and allowing real-time patient interaction.

Despite the total procedure duration of approximately 4 h, the patient reported a considerably shortened subjective perception of time. Throughout the intervention, she remained calm and did not experience any of the commonly reported SEs, such as vertigo, nausea, or discomfort. Notably, no anxiolytic or sedative medications were required at any point.

Patient satisfaction at the 1-month and 6-month follow-up visits, assessed via the PSAQ, reflected a high level of acceptance and appreciation for the hypnosis-supported experience. The patient’s IES-R scores at 1 month and 6 months were both well below the clinical threshold of 36 that suggests possible PTSD [29,30], indicating no evidence of psychological distress related to the hypnosis-assisted procedure and further supporting the emotional and cognitive benefit perceived by the patient. A retrospective analysis of 52 patients with pharmacoresistant tremor disorders who underwent MRgFUS thalamotomy showed that, despite the occurrence of SEs, 87% of patients would undergo MRgFUS again because most placed greater value on tremor suppression [34]. Although no formal satisfaction questionnaire was distributed to the multidisciplinary healthcare team, informal feedback emphasized the utility of hypnosis in addressing procedural demands and enhancing patient comfort without pharmacologic intervention.

A notable limitation in hypnosis-assisted procedures is the absence of a reliable, real-time objective measure to confirm hypnotic trance, particularly when the anesthesiologist is not in constant proximity to the patient. Although several studies have shown that hypnosis may alter brainwave activity measurable with electroencephalography [35–39], it remains challenging to differentiate between hypnosis and simple relaxation [40]. Technologies such as the Bispectral Index monitor have been proposed for trance quantification [41], but their use in MRI settings, particularly during transcranial ultrasound procedures, is currently limited.

From a clinical perspective, our case highlights the broader role of the anesthesiologist as a perioperative care partner, even when conventional anesthetic agents are not required. Through structured hypnotic consultations, patients can be actively engaged in their care; the psychological and symbolic dimensions of the procedure can be explored and reframed to foster agency and acceptance [42–44]. The use of hypnosis in neurosurgical contexts has been well documented, particularly for awake craniotomies and tumor resections [21–23]. However, to our knowledge, the present case represents the first documented use of hypnosis during MRgFUS thalamotomy for ET. In addition to its anesthetic-sparing effects, hypnosis contributed to the management of preprocedural anxiety, enhanced comfort during frame fixation, and reduced the subjective perception of time during sonication.

Conclusions

To our knowledge, this is the first reported case of MRgFUS thalamotomy for ET performed under hypnosis without sedative medications. The procedure was completed without interruption; levels of patient cooperation and satisfaction were high. Hypnosis proved to be a valuable non-pharmacologic tool, addressing both the emotional and physical demands of the intervention, facilitating frame placement, managing anticipated SEs, and supporting patient engagement throughout the sonication process. Further research, particularly prospective studies comparing hypnosis-assisted MRgFUS with standard care, is warranted to assess efficacy, reproducibility, and patient-reported outcomes in broader populations. These findings support the feasibility and safety of integrating hypnosis into MRgFUS workflows and highlight its potential to optimize patient-centered care in functional neurosurgical procedures that require prolonged awake participation.