Introduction: High-intensity focused ultrasound (HIFU) thalamotomy has been effective at reducing tremor severity in patients with essential tremor (ET). Burning mouth syndrome (BMS) has not previously been reported as a side effect of HIFU thalamotomy.
Methods: We retrospectively analyzed 194 patients treated with HIFU thalamotomy between March 2022 and July 2024, selecting patients with new onset postoperative BMS. Demographics, procedural parameters, and postoperative outcomes were analyzed.
Results: Two female patients met inclusion criteria. Both achieved complete tremor resolution following sequential bilateral HIFU thalamotomy but developed postoperative dysphagia, dysarthria, and persistent mouth numbness and burning sensations. The first patient experienced temporary left-sided lower extremity weakness, while the second developed temporary ataxia. The first patient’s symptoms began after their initial thalamotomy and worsened with the second, while the second patient’s symptoms appeared after their second procedure. For the initial thalamotomy, both patients received 8 sonications, with mean temperatures for the last two sonications of 55.5°C and 57.0°C in the first and second patient, respectively. Postoperative-day-1 MRI demonstrated lesion sizes of 340.4mm³ and 143.1mm³, with edema sizes of 1,916mm³ and 1,194mm³. The second procedures required 7 and 6 sonications, with mean temperatures of 58.5°C and 56.1°C for the first and second patient in the last two sonications, respectively. Lesion sizes were 201.7mm³ and 258.7mm³, and edema sizes were 1,218mm³ and 1,578mm³. While lesion center laterality relative to anterior commissure-posterior commissure (AC-PC) was comparable (61%; 60%), on average, lesion centers in BMS patients were 23% anterior to the PC, compared to 28% in those without BMS.
Conclusion : These cases suggest a possible association between HIFU thalamotomy and BMS, with a potentially increased risk of worsening symptoms following bilateral procedure, possibly due to lesion positioning. During preoperative counseling, possible adverse effects should include BMS. Further research is warranted to explore BMS and the underlying mechanism in this patient population.
.jpg)
