Some of Dr. Tanya Meyer's patients contend with chronic neuromuscular conditions that can turn smooth, unencumbered speech into raspy paroxysms of sound. Fortunately, this can be managed with periodic botulinum toxin injections—yes, Botox—in the throat, which block the unwelcome nerve signals that make vocal muscles spasm.

Meyer and colleague Neel Bhatt, laryngologists with UW Medicine in Seattle, have co-authored recently published research in JAMA Otolaryngology–Head & Neck Surgery that confirmed their suspicion: Some people with laryngeal dystonia and essential tremor of the vocal tract benefit from Botox injections more frequently than the three-month interval that most health insurers allow.

"We found that more than 25% of patients needed more frequent treatments to stay in good voice. We would like to have the flexibility to target these patients' disease processes in a more tailored, individualized way," Meyer said.

In the retrospective study of 255 patients who received injections for either condition, 27% received doses at intervals shorter than 90 days, which indicates variability in patients' onset of symptoms and the durations of Botox-provided relief.

Insurers' adherence to a three-month interval of injections, Meyer said, is primarily based on Botox therapy to relieve a related disorder, torticollis, in which neck muscles spasm and cause the head to rotate at an odd angle. The Botox doses to calm torticollis are much greater than those injected to relax spasming laryngeal muscles, she added, so it raises the question of why some voice-disordered patients should wait for a tiny, insurance-authorized dose while their voices fray.

A physician can petition an insurer to waive the guideline and cover more frequent Botox doses for a patient, but the process requires the doctor to write multiple letters and obtain confirmation of the patient's need from a clinical peer. Many doctors are uninclined to take the extra steps, and patients who need more frequent doses end up paying thousands of dollars out of pocket simply to continue to communicate effectively, Meyer said. 

The researchers' findings give laryngologists and neurologists scientific evidence to advocate for patients' easier access to shorter-interval injections, she added.

"When insurance companies say there's no studies or precedent for short-interval treatment, they're wrong," she said. "Across three major institutions, we're doing this with over a quarter of our patients, who are having good outcomes. It's safe, it's effective and it's appropriate patient care."