Introduction: Epidemiological studies have found a significant negative association between cigarette smoking and Parkinson's disease (PD). Some studies also suggested a protective effect of smoking on Alzheimer's disease. No research have been conducted on the substantia nigra hyper-echogenicity (SNH) in smoking and non-smoking patients with PD.
Objective: To identify the relationship between cigarette smoking and cognitive impairment, and area of SNH detected by transcranial sonography (TCS) in Parkinson's disease patients.
Methods: We compared the Unified Parkinson's disease Rating Scale (UPDRS), Mini-Mental State Examination (MMSE), Frontal Assessment Battery (FAB) and Parkinson's Disease-Cognitive Rating Scale (PD-CRS) scores and TCS findings in 86 PD patients with and without smoking history.
Results: The presence of cognitive impairment in PD patients was accompanied by an increase in the SNH area (Spearman MMSE r = −0,30, p = 0,004, FAB r = −0,36, p = 0,0006, PD-CRS r = −0,31, p = 0,004) and an increase in the width of 3 ventricle (Spearman MMSE r = −0,44, p < 0,0001, FAB r = −0,45, p < 0,0001, PD-CRS r = −0,39, p < 0,0001). The average SN area was higher in dementia patients than in patients without dementia (0.36 ± 0.06 cm2 vs. 0.32 ± 0.06 cm2, Mann–Whitney p = 0,003). Our study did not show dependence the results of neuropsychological testing and smoking history, but found that smokers had a smaller SNH area and less severity of motor disorders (Mann–Whitney p = 0,033 and p = 0,025 respectively).
Conclusion: This finding indicates that a history of smoking not only reduces the risk of PD, but also is a factor influencing the course of PD.
Article info
Identification
Copyright
© 2015 Published by Elsevier Inc.
