New potential for long-term reduction of tinnitus loudness
A study conducted at the University of Arkansas for Medical Sciences (UAMS) has shown the potential to markedly improve tinnitus over an extended period of time.
Researchers Mark Mennemeier and John Dornhoffer used a technique called repetitive transcranial magnetic stimulation (rTMS) in a case study of one patient with chronic tinnitus.
During rTMS a weak magnetic field is created when electric current is rapidly switched on and off through a stimulating coil placed over the scalp. The magnetic field reaches up to 2cm into the top layers of the brain, causing electrical stimulation of the neurons that can either activate or inhibit the cells.
Brain imaging studies have shown that tinnitus sufferers have increased activation in parts of the cerebral cortex that process sounds. Previous research has also demonstrated that a course of treatment with rTMS can reduce the perception of tinnitus in more the half the patients tested, however the effect has only been short-lived, with ringing in the ears returning after just 1-2 weeks.
In the current study, the aim was to examine the safety and feasibility of using maintenance sessions of slow rTMS to reduce tinnitus loudness and prevent its return over time.
“We used a PET scan of the patient’s brain to look for excessive neural activity with increased blood flow in the temporal lobe,” said Mennemeier, Associate Professor of Neurobiology and Director of the Transcranial Magnetic Stimulation Laboratory at UAMS. The team then applied rTMS to the area identified with the scan, initially in a series of sessions conducted over 5 days and then at two follow-up sessions, 3 months and 6 months after the original treatment.
“The patient in our case study reported his tinnitus to be unobtrusive in his daily life when he was assessed four months after his final round of maintenance therapy,” Mennemeier continued. No side effects were reported by the patient or detected in formal assessments after the three rounds of maintenance therapy.
An increase in tinnitus loudness has been linked to an expansion of the over-active brain regions seen in tinnitus patients' PET scans. The authors believe that treatment with rTMS may have produced its effect by preventing this region from spreading further. However they also urge caution in interpreting their results as the research was carried out with a single individual. Further work is needed to show whether the maintenance treatment will be effective in other people.
