A clinical profile of 103 patients with secondary movement disorders: correlation of etiology with phenomenology.

BACKGROUND AND PURPOSE: Studying patients with secondary movement disorders (SMD) provides a unique opportunity to determine the correlation between the etiology and phenomenology of movement disorders.

METHODS

This was a prospective study of 103 patients (43 women, 60 men; age=28.7±17.3 years; range=2-70 years) with SMD, in a tertiary hospital over 4 years.

RESULTS

The mean age of onset of SMD was 24.3±19.7 years, and duration of symptoms was 4.3±7.1 years (42 days to 40 years). Patients with pure tremor, pure dystonia (DYS), or a combination of tremor with dystonia had longest latency (10.9-18.5 months), whereas those with parkinsonism (PAR) and hemiballismus (HMB) had shorter latency (2.7-3.0 weeks). Pure dystonia was most prevalent (30.1%) followed by dystonia plus (13.6%), tremor (12.6%), PAR (11.7%), HMB (8.7%), mixed SMD (7.8%), tremor with dystonia (6.8%), myoclonus (5.8%), and chorea (2.9%). In approximately 60% of patients, the underlying etiologies were vascular (VAS), infections, and space-occupying lesions (SOL), and 25% had SMD following trauma or hypoxia (HYP). With reference to specific etiologies, the most frequent SMDs were tremor following SOL (46%), post-traumatic syndromes (25%), dystonia following HYP (56%), VAS lesions (50%), and infections (28%). With reference to specific SMDs, the most common etiologies were VAS for dystonia (39%), SOL for tremor (67%), and PAR (31%), and both SOL and trauma (37.5% each) for tremor with dystonia.

CONCLUSIONS

Our study highlights the spectrum of SMDs and the lack of correlation between types of SMDs and underlying etiologies. Preventable causes such as infections, HYP, trauma, and kernicterus still play a major role in pathogenesis of SMD.