Objective: To evaluate in a prospective longitudinal study the evolution of functional disability and the response to dopaminergic therapy in PD patients with and without autonomic involvement.
Methods: Sixty untreated consecutive patients with PD underwent autonomic cardiovascular function evaluation using the five autonomic tests of Ewing. An integrated index (Autonomic Score=AS), taking in account the results of all subtests, was calculated. Patients were treated with pergolide and bromocriptine during a 5-year follow-up until the level of functional disability was sufficient to warrant the initiation of levodopa therapy.
Results: Results of autonomic testing were compared with those of a group of age-matched healthy subjects. A value of AS>2 was considered as indicative of autonomic failure. Eighteen patients with PD (35%) showed AS>2 (autonomically impaired group=AI), the remaining 33 (65%) had AS<2 (nonautonomically impaired group=non-AI). During the follow-up levodopa was added to the treatment regimen of 10/18 (55%) patients in AI group, and 6/33 (18%) patients in non-AI group (p<.01).
Conclusions: The increased occurrence of levodopa adjunct in autonomically impaired PD suggests that there is a more rapid deterioration of functional performance in parkinsonian patients with early autonomic involvement.