Frequency and predictors of autonomic dysfunction in Parkinson's disease: a study of African patients in Lagos, Nigeria.

ABSTRACT

UNLABELLED The degenerative changes in PD also affect the autonomic nervous system. The frequency and predictors of such involvement in Africans with PD has not been reported. OBJECTIVE: i) To determine the frequency and type of autonomic dysfunction in Nigerians with idiopathic Parkinson's disease (PD). ii) To determine the predictors of autonomic dysfunction in PD. METHODS: Cardiovascular autonomic function assessed in 33 study subjects with PD and 33 age-matched controls, utilising heart rate variability to deep breathing, standing and the Valsalva manoeuvre, and the blood pressure (BP) response to standing. The results were compared based on treatment category, grade of severity on the Columbia scale of Hoehn and Yahr, duration of PD, age at onset of PD, present age and occurrence of autonomic symptoms. RESULTS: Parasympathetic function was abnormal in 51.5% of PD subjects, significantly higher than controls (P<0.001). Of these, 76.5% had early parasympathetic involvement and 23.5% definite parasympathetic involvement. Age above 65 years (at time of study or onset of PD) was the only clinical variable associated with parasympathetic autonomic dysfunction (p<0.05). Symptoms dysfunction occurred in 60.6% of PD patients and only 6.1% of controls (p<0. 001). There was however no demonstrable relationship between the occurrence of symptoms and objective evidence of autonomic dysfunction 41.2% of PD patients with parasympathetic dysfunction had no symptoms. CONCLUSION: Autonomic dysfunction was found to be common in Africans with PD, particularly those above 65 years and tends to affect the parasympathetic system. However, the abnormality may be detectable even before symptoms appear. As such, we recommend that cardiovascular tests of autonomic function be a routine aspect of the evaluation of PD patients, especially with advancing age.