Head tremor in Parkinson´s Disease, clinical Associations and response to therapy.

Background: Tremor is frequently observed in patients with Parkinsońs disease (PD). Tremor most commonly affects the upper limbs but may also affect the axial muscles in PD. Head tremor (HT) is usually identified in patients with essential tremor (ET) and cervical dystonia (CD), but rarely reported in PD. Objectives Methods: We aimed to assess the frequency, clinical features, correlates, and underlying mechanisms of HT in PD. Results: Among 229 patients with PD, we identified 19 (8.3 %) of patients with HT. There were 11 males and 8 females with a median age at evaluation of 62.0 years. Five patients had slight, ten had mild and four had moderately severe HT. Yes-yes HT was the most common type. HT was associated with PD in 13 patients, eight of them had severe tremor-dominant presentation. In 3 patients there were signs suggesting underlying ET, while 3 patients had CD. Complete resolution of HT was observed with levodopa and/or deep brain stimulation (DBS) in patients with PD only, but inconsistent improvement was observed with comorbid ET or CD. Longer evolution time since PD onset ( Conclusions: HT was identified in 8.3% of patients with PD. It associated with longer evolution since PD onset, the severity of rest tremor and presence of CD. HT is observed in the context of PD only, particularly in those with severe tremor-dominant presentation, comorbid ET or CD. Most patients improve with dopaminergic therapy or DBS.