Maintenance Repetitive Transcranial Magnetic Stimulation Can Inhibit the Return

[Redazione di acufeni.net]

Mennemeier M, Chelette KC, Myhill J, Taylor-Cooke P, Bartel T, Triggs W, Kimbrell T, Dornhoffer J.

From the Department of Neurobiology and Developmental Sciences (m.m., k.c.c., p.t.-c., j.d.), the Department of Otolaryngology–Head and Neck Surgery (j.m., j.d.), and the Department of Radiology, Division of Nuclear Medicine (t.b.), University of Arkansas for Medical Sciences, Little Rock, Arkansas; the Department of Neurology (w.t.), University of Florida, Gainesville, Florida; and the Department of Psychiatry (t.k.), University of Arkansas for Medical Sciences and Mental Health Service, Central Arkansas Veterans Healthcare System, North Little Rock, Arkansas, U.S.A.

OBJECTIVES/HYPOTHESIS: A single patient was tested to examine the safety and feasibility of using maintenance sessions of low-frequency repetitive transcranial magnetic stimulation (1 Hz rTMS) to reduce tinnitus loudness and prevent its return over time.

STUDY DESIGN: Interrupted time series with multiple replications.

METHODS: Tinnitus loudness was assessed using a visual analogue rating (VAR) with 0 = no tinnitus, and 100 = loudest tinnitus experienced; 1,800 TMS pulses delivered at 1 Hz and 110% of motor threshold were administered over the posterior, superior lateral temporal gyrus of the subject's right hemisphere until subjective tinnitus fell to a VAR of 25. TMS was reapplied as tinnitus returned to a VAR of 25 or higher. Cerebral metabolism was measured using positron emission tomography before and after treatment.

RESULTS: In this patient, tinnitus could be reduced to a VAR of 6 or lower each time it reoccurred using one to three maintenance sessions of rTMS. Tinnitus loudness remained at or below a VAR of 25 and was reported to be unobtrusive in daily life when last assessed 4 months after the third and final round of maintenance treatment. Asymmetric increased cerebral metabolism in the right hemisphere reduced following treatment and as tinnitus improved. Maintenance treatment was well tolerated with no side effects.

CONCLUSIONS: Although a case study cannot establish treatment efficacy, this study demonstrates for the first time that it is feasible to use maintenance rTMS to manage chronic tinnitus. Maintenance rTMS might impede cortical expansion of the tinnitus frequency into adjacent cortical areas, but group studies are necessary to confirm this speculation.