Background: There are few studies analysing the clinical and neurophysiological characteristics of postural tremor in Spain.
Patients and method: We studied prospectively 300 consecutive patients referred to a Movement Disorders Section because of postural tremor of the upper limbs. Syndromic diagnosis of postural tremor was made according to clinical criteria with the aid of neurophysiological criteria (accelerometric and EMG data). In patients diagnosed with essential tremor (ET), diagnostic sensitivity studies, correlation studies of clinical and neurophysiological data and multivariate analysis were performed.
Results: Most frequent syndromic diagnoses were ET (77%), parkinsonian postural tremor (10%) and exaggerated physiological tremor (6%). Fifty percent of ET patients reported having affected relatives, and 7% reported that their tremor improved with alcohol. Mostly specific variables for the diagnosis of ET were: affected relatives (77%), cephalic tremor (80%), alcohol improvement (100%), and synchronous EMG pattern (79%). The presence of affected relatives and a synchronous EMG pattern were significant predictive variables on a multivariate analysis. We found a significant correlation between age at time of consulting and frequency (rs = 0.561; p < 0.0005) and amplitude (rs = 0.470; p < 0.0005) of tremor.
Conclusions: In the present study, ET was the most common cause of reference for postural tremor. Selective clinical data and neurophysiological evaluation are useful for the diagnosis of postural tremor.