TY - JOUR T1 - Onset age and severity of motor impairment are associated with reduction of myocardial <sup>123</sup>I-MIBG uptake in Parkinson’s disease JF - Journal of Neurology, Neurosurgery &amp; Psychiatry JO - J Neurol Neurosurg Psychiatry SP - 423 LP - 426 DO - 10.1136/jnnp.74.4.423 VL - 74 IS - 4 AU - K Hamada AU - M Hirayama AU - H Watanabe AU - R Kobayashi AU - H Ito AU - T Ieda AU - Y Koike AU - G Sobue Y1 - 2003/04/01 UR - http://jnnp.bmj.com/content/74/4/423.abstract N2 - Objectives: To elucidate the factors associated with severity of cardiac sympathetic nerve involvement in idiopathic Parkinson’s disease (PD). Methods:123I-metaiodobenzylguanidine uptake was examined in 88 patients with PD. The ratio of the uptake in the heart (H) to that in the mediastinum (M) (the H/M ratio) was calculated and correlated with age at onset, age at examination, and disease severity and duration. Twenty five healthy people were also examined as a control. Results: There was a mild but significant negative correlation between H/M ratio and age at onset (early, r = −0.33, p = 0.002; delayed, r = −0.34, p = 0.001) and between Hoehn and Yahr (H-Y) stage (early, r = −0.30, p = 0.006; delayed, r = −0.32, p = 0.003). There was no significant correlation between disease duration and H/M ratio. When patients with PD were classified into four subgroups on the basis of age at onset (&gt; 62 or &lt; 62 years) and disease severity (H-Y &gt; III or H-Y ⩽ II), the median H/M ratio of the older and more severe group was significantly lower than that of the younger and less severe group (p = 0.005). Conclusion: This study suggests that late onset, high severity PD is associated with myocardial sympathetic dysfunction. ER -