The Clinical Features of Parkinson 's Disease Relation to the Age at Onset

Abstract

The aim of this study is to evaluate the differences in the clinical features of Parkinson 's disease in relation to the age at onset. The data of 143 patients with Parkinson's disease (80 men/ 63 women) were reviewed. The cases were grouped into 3 groups according to the age at onset: Group 1 consisted of patients with age at onset 40 years and younger Group 2 of patients with age at onset between 41 to 59 years and Group 3 of patients with age at onset 60 years and older. These groups were compared according to the presence of a positive family history, initial symptoms additional sings occurring with the disease progression time to start levodopa the duration of levodopa therapy and motor side effects of levodopa. UPDRS and Hoehn-Yahr scales were used to assess the disability of the patients. Family history was positive in 12% of Group 1, 3% of Group 2 and negative in Group 3 (p<0.05). Group 1 cases generally had onset with akinesia/rigidity (50%) as Group 3 had an onset with rest tremor (78%). in Group 2 the frequency of rest tremor and akinesia/rigidity were similar. Motor fluctuations and freezing were more prominent in Group 1 and Group 2 than they were in Group 3 (p<0.0 1, p<0.05 respectively). On-off phenomenon and dyskinesias were more frequent in Group 1. Group 1 developed dyskinesias earlier than the other groups. While there were no differences in the types of dyskinesias in Group 1 the dyskinesias in Group 2 (%83) were mostly generalized and the ones in Grup 3 (%72) were focal. Sensory symptoms were more frequent in Group 1. These results show that Group 1 and 3 have prominent clinical differences and that Group 2 seems to have similarities to both groups. The age at onset in Parkinson's disease does not seem to determine only the initial symptoms but also have some effect on the presence and type of motor fluctuations and the symptoms occurring with the progression of the disease.