Voice Analysis in Patients with Essential Tremor

The objective of this study was to reveal the phonetic characteristics of patients with or without voice tremor in patients with essential tremor (ET), determine whether these phonetic features are ET specific, and test the influence of ET on vocal tremor.

The study included a total of 30 patients with ET and 29 healthy volunteers. The severity of ET was evaluated using the Washington Heights Inwood Genetic Study of Essential Tremor (WHIGET) tremor rating scale. Patients with major tremor complaints for at least 3 years, WHIGET scoring scores below 15, and patients newly diagnosed in our clinic and for whom drug therapy has not yet been started were selected.

A total of 59 participants (n = 34 with ET and n = 25 as control) were included in the study. The ages of the participants ranged from 20 to 82 years, with a mean age of 54.50 ± 15.04 years. The gender distribution was 57.6% male and 42.4% female, and there was no statistically significant difference between the two groups in terms of age and gender. The study found that individuals with ET had significantly higher jitter, shimmer, S/Z, Pataka, frequency tremor intensity index, amplitude tremor intensity index, and frequency tremor power index values than the control group. However, there was no statistically significant difference between the two groups in terms of MPT, frequency tremor cyclicality, amplitude tremor cyclicality, frequency tremor frequency, and amplitude tremor frequency values.

Our study shows that, even in the absence of essential voice tremor, there is an effect of ET on voice quality. These findings contribute to the understanding of the nonmotor symptoms of ET and may aid in the diagnosis and management of this condition. Further research is needed to explore the potential use of acoustic analysis parameters in the diagnosis and monitoring of ET.