Search

The goal of this work was to investigate iron deposition in the basal ganglia and thalamus in symptomatic and asymptomatic leucine-rich repeat kinase 2 (LRRK2) and Parkin-associated Parkinson's disease (PD), using R2* relaxometry rate.Twenty subjects with genetic PD (four symptomatic and two asymptomatic Parkin subjects, nine symptomatic and five asymptomatic LRRK2 subjects) were compared with 20 patients with idiopathic PD (IPD) and 20 healthy subjects. Images were obtained at 3 teslas, using multi-echo T2 and T2* sequences. R2 and R2* values were calculated in the substantia nigra (SN), the striatum, the globus pallidus, and the thalamus.The R2* values in the SN were increased in IPD and mutation-carrying patients as compared with controls and in mutation-carrying patients as compared with IPD. Asymptomatic mutation carriers showed higher R2* values than controls and did not differ from IPD patients. No changes were seen in the other structures or in R2 values.These results are consistent with increased iron load in LRRK2- and Parkin-mutation carriers. The increased R2* in asymptomatic PD-mutation carriers suggests that iron deposition occurs early during the preclinical phase of the disease. R2* measurements may be used as markers for investigating nigrostriatal damage in preclinical mutation-carrying patients.

Rapid eye movement sleep behavior disorder and sleepiness precede or accompany idiopathic Parkinson's disease (PD), but their presence in subjects with leucine-rich repeat kinase 2 mutations is unknown.Ten patients with leucine-rich repeat kinase 2-associated PD, four healthy leucine-rich repeat kinase 2 mutation carriers, 20 patients with idiopathic PD, and 12 healthy controls underwent clinical assessments and a nighttime video-polysomnography.No sleep changes, no rapid eye movement sleep behavior disorder, or rapid eye movement sleep without atonia was found in the 14 subjects with leucine-rich repeat kinase 2mutations compared with controls, whereas 41% of patients with idiopathic PD had rapid eye movement sleep behavior disorder. Eventually, 20% of patients with leucine-rich repeat kinase 2-associated PD had abnormal periodic leg movements, a frequency similar to the idiopathic PD group frequency.The sleep phenotype in leucine-rich repeat kinase 2 mutations parallels that of idiopathic PD, except for absent rapid eye movement sleep behavior disorder here in the presymptomatic and symptomatic stages.