Serious head trauma preceding essential tremor: A population-based study (NEDICES).

BACKGROUND

An association between head trauma and essential tremor (ET) has not been formally assessed. Our purpose was to assess the association between serious head trauma and ET.

METHODS

History of head trauma was assessed in 274 ET cases and 3201 controls in the Neurological Disorders in Central Spain (NEDICES) study, a population-based study in central Spain. Head trauma was defined as serious only if the subject reported that the trauma resulted in loss of consciousness, hospitalization, or a visit to the emergency department.

RESULTS

Thirty-two (11.7%) of 274 ET cases vs. 260 (8.1%) of 3201 controls reported a history of serious head trauma (p=0.04). In an adjusted logistic regression analysis, participants who reported serious head trauma were 52% more likely to have ET (odds ratio [OR] 1.52; 95% confidence interval [CI] 1.02-2.27, p=0.04). The odds of ET increased with increasing age of head trauma: adjusted ORs=1.23 (95% CI 0.43-3.46, p = 0.70) for serious head trauma that occurred before age 18 years, adjusted OR=1.49 (95% CI 0.62-3.55, p = 0.37) for serious head trauma between ages 18 to 39 years, and adjusted OR=1.61 (95% CI 1.00-2.57, p = 0.04) for serious head trauma at age 40 years or older.

CONCLUSIONS

Our study suggests that serious head trauma, especially when it occurs after 40 years, is associated with increased odds of ET. Additional studies are needed to reproduce this novel finding.