Annals of Indian Academy of Neurology
: 2017  |  Volume : 20  |  Issue : 2  |  Page : 162--163

Right- versus left-onset Parkinson's disease: Other psychometric parameters

Yassar Abdullah S Alamri 
 Department of Medicine, Brain Research Institute; Department of Medicine, University of Otago; Department of Medicine, Canterbury District Health Board, Christchurch, New Zealand

Correspondence Address:
Yassar Abdullah S Alamri
New Zealand Brain Research Institute, 66 Stewart Street, Christchurch Central, Christchurch 8011
New Zealand

How to cite this article:
Alamri YS. Right- versus left-onset Parkinson's disease: Other psychometric parameters.Ann Indian Acad Neurol 2017;20:162-163

How to cite this URL:
Alamri YS. Right- versus left-onset Parkinson's disease: Other psychometric parameters. Ann Indian Acad Neurol [serial online] 2017 [cited 2020 Mar 30 ];20:162-163
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Full Text


We read the findings by Adwani et al.[1] with great interest. Differences in motor [2] as well as nonmotor [3] manifestations of Parkinson's disease (PD) have been observed in right-sided (R-PD) versus left-sided (L-PD) disease. However, some of these associations have been debated in the literature.

We recently recruited a number of PD patients (n = 31) as part of an ongoing neurocognitive study. The onset of PD was on the right in 16 patients and on the left in 15 patients. Both groups were of similar age (R-PD mean 65.5 years; L-PD mean 68.7 years) and male-to-female ratio (R-PD 75% males; L-PD 87% males). All patients were on dopamine replacement therapy.

Handedness was assessed by the Edinburgh handedness inventory.[4] Except one patient who was ambidextrous, all patients were right handed. We assessed whether handedness-symptomatic side mismatch (i.e., left-sided symptom onset in a right-handed individual) who delay the interval between symptom onset and diagnosis. R-PD patients were diagnosed 2.1 (±1.0) years after symptoms onset, compared with 1.6 (±0.8) years in L-PD patients; this difference was not statistically significant (P = 0.15).

Mild cognitive impairment was equally distributed between R-PD (50%) and L-PD (53%) patients. Disease duration was similar between the two groups: 6.3 (±3.5) years for R-PD and 8.3 (±5.3) years for L-PD (P = 0.23). The extent of motor deficit was not different between the two groups as assessed by the Unified Parkinson's Disease Rating Scale (UPDRS-II) (14.7 vs. 17.3, P= 0.39, respectively) and the UPDRS-III (31.6 vs. 38.6, P= 0.13, respectively). The severity of symptoms of anxiety and depression (as assessed by the Hospital Anxiety and Depression Scale) was also similar between R-PD (mean 9.9 points) and L-PD (mean 9.7 points) patients (P = 0.95).

In conclusion, we found no difference in R-PD versus L-PD patients in relation to motor or psychological symptoms in our sample. Further insights may be obtained by comparing drug-naïve versus medicated PD patients as well as inclusion of PD patients with established PD-dementia.

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Conflicts of interest

There are no conflicts of interest.


1Adwani S, Yadav R, Kumar K, Chandra SR, Pal PK. Neuropsychological profile in early Parkinson's disease: Comparison between patients with right side onset versus left side onset of motor symptoms. Ann Indian Acad Neurol 2016;19:74-8.
2van der Hoorn A, Bartels AL, Leenders KL, de Jong BM. Handedness and dominant side of symptoms in Parkinson's disease. Parkinsonism Relat Disord 2011;17:58-60.
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4Oldfield RC. The assessment and analysis of handedness: The Edinburgh inventory. Neuropsychologia 1971;9:97-113.