Objective: Recently described nonmotor fluctuations may cause disability in Parkinson's disease patients. These fluctuations are generally grouped as sensory, autonomic and psychiatric. The clinical spectrum and frequency of these fluctuating symptoms are not well-described.
Methods: We studied the relationship of nonmotor fluctuations with motor symptoms and determined the influence of age at disease onset, duration of disease, dosage and duration of levodopa treatment in the appearance of nonmotor fluctuations.
Results: Statistical analysis showed a relationship of disease-related parameters with sensory and autonomic fluctuations but psychiatric fluctuations were only found to be associated with the duration of levodopa usage. The nonmotor fluctuations included in the study were observed during "on" periods as well as "off' periods.
Conclusion: Nonmotor fluctuations had variable presentations. Moreover, their co-appearance with different types of motor fluctuations may be linked to the effect of other neurotransmitter systems acting synchronously with dopamine. Risk factors for sensory and autonomic fluctuations in patients with Parkinson's disease were early age of disease onset, longer duration and higher dose of levodopa use. Psychiatric fluctuations were only associated with higher doses of levodopa.