Uric acid level may not be reduced in essential tremor

Essential tremor is very common, but characterization is difficult because of its heterogeneity. Neuropathology is important to elucidate the characteristics of neurological disorders. However, pathological findings in essential tremor have been inconsistent among studies. Uric acid is a strong antioxidant and might be a biomarker in neurodegenerative process. We hypothesized that uric acid level would be reduced if essential tremor is a neurodegenerative disease. Our aim was to compare uric acid level between essential tremor patients and healthy individuals.

This was a prospective, case-control, multicenter study with 92 essential tremor patients and 77 healthy subjects. For homogeneity, the essential tremor group was subdivided into two groups (hereditary and sporadic). Clinical and laboratory findings were compared among the essential tremor and healthy groups.

The demographic characteristics were comparable among the groups. The uric acid level was lower in the essential tremor group than in healthy subjects, but the difference did not reach statistical significance. There was a negative correlation between uric acid level and disease duration in the hereditary group (p = .046) and between uric acid level and age at onset in the sporadic group (p = .012). The mean values of total cholesterol were significantly lower in the sporadic group than in the other groups (p = .011). Total cholesterol was positively correlated with age at onset in the hereditary essential tremor group (p = .010).

We did not find any evidence that uric acid levels suggested essential tremor is a neurodegenerative disease. However, further research with more patients might be needed given the negative correlations of disease duration and age at onset with uric acid level.