Objective: To assess the frequency and disability caused by nonmotor fluctuations (NMF) in PD.
Methods: A structured questionnaire was administered to 50 patients with PD with motor fluctuations (MF), focused on 54 nonmotor symptoms classified in three subgroups: 26 dysautonomic, 21 cognitive and psychiatric, and seven pain/sensory NMF. The link between each NMF and the motor state was determined. Patients were asked to grade their disability from 0 (no disability) to 4 (maximum discomfort) and to specify which kind of fluctuation subgroup (motor or nonmotor) was the most incapacitating. A statistical analysis was performed to determine the frequency of each NMF and to determine whether the level of disability resulting from NMF could be correlated to the main characteristics of the population.
Results: All patients had had at least one type of NMF, most of which were associated with the "off" state. Anxiety (66%), drenching sweats (64%), slowness of thinking (58%), fatigue (56%), and akathisia (54%) were the most frequent NMF. Some symptoms such as anxiety or dyspnea correlated with a greater level of disability. The total number of NMF was found to be correlated with the motor disability. Incapacity resulting from the dysautonomic fluctuations was also significantly correlated with levodopa treatment. Surprisingly, 28% of the patients stated that NMF involved a greater degree of disability than MF.
Conclusion: Nonmotor fluctuations are frequent and debilitating in PD.