Juvenile parkinsonism: ventricular CSF biopterin levels and clinical features

Total biopterin (T-BP) levels in the ventricular cerebrospinal fluid (CSF) and clinical features of 19 patients with juvenile parkinsonism (JP: Parkinson's disease manifesting below the age of 40) were evaluated and compared with 61 patients with classical Parkinson's disease (classical PD: symptoms developing at the age of 40 or above). The JP patients were divided into two subgroups: JP-I; those with good response to levodopa followed by marked motor fluctuations and dopa-induced dyskinesias (DID), JP-II; those with milder response than JP-I with less fluctuations and DID being more similar to classical PD. Both of the mean ventricular CSF T-BP concentrations in the JP and classical PD patients were significantly lower than that in neurological controls. Moreover, the mean T-BP level in the JP-I was markedly lower than that in the JP-II or classical PD. Total biopterin levels revealed a gaussian distribution in the classical PD. However, a bimodal distribution was noted in the JP, with the lower peak consisting of only JP-I patients. These results seem to indicate that JP-II represents early-onset classical PD, while JP-I represents a distinct subgroup having a different physiopathology from classical PD.