Abstract
Background: There is presently no information on the behavioural symptoms that are related to cognitive dysfunction in African patients with Parkinson's disease. Objectives: This study highlights the behavioral symptoms that are related to global cognitive dysfunction without dementia, as well as the caregivers' distress they create in a population of Nigerians with idiopathic Parkinson's disease. Methods: Fifty patients with idiopathic Parkinson's disease, confirmed using the United Kingdom Parkinson's Disease Society (UKPDS) Brain Bank Clinical Diagnostic Criteria, were cross-sectionally assessed for cognitive functions using the modified Mini-mental State Examination (MMSE), motor symptoms using the Unified Parkinson's disease Rating Scale (UPDRS), as well as neuropsychiatric symptoms and caregivers' distress using the Neuropsychiatric Inventory (NPI). Additional information obtained from all the participants and their caregivers included demographic data, personal history, psychiatric history, medical history and family history. The behavioural, caregivers' distress and motor correlates of cognitive dysfunction were explored. Results: In all, 24.0% of the patients had cognitive dysfunction according to the local norm of the MMSE. Hallucinations (Chi2 = 5.556, p = 0.018) and agitation (Chi2 = 5.556, p = 0.018) were related to cognitive dysfunctions. There was more behaviour related caregivers' distress in those with cognitive dysfunction than those without (Chi2 = 2.208, p = 0.032). The MMSE scores correlated inversely with the score for rigidity (r = −0.506, p = 0.0002), bradykinesia (r = −0.592, p < 0.0001), and the UPDRS total score (r = −0.503, p = 0.0002). Conclusion: The psychotic symptoms of hallucinations and agitations differentiated Parkinson's disease patients with cognitive dysfunction from those with normal cognition. Generally, the presence of behavioural symptom led to more distress in the caregivers of patients with cognitive dysfunction.