Reduced maximal range of ocular movements and its response to acute levodopa challenge in Parkinson's disease.

Introduction: Although restriction of vertical ocular range of motion is known to be the hallmark of progressive supranuclear palsy (PSP), the maximal amplitude of ocular movement has not been quantitatively assessed despite of accumulating evidences of oculomotor dysfunction in Parkinson's disease (PD). Here, we evaluated the maximal oculomotor range and its response to levodopa in PD, and compare findings to atypical parkinsonism. Methods: We recruited 159 healthy controls (HC) as well as 154 PD, 30 PSP, and 16 multiple system atrophy (MSA) patients. Oculomotor range was assessed using a kinetic perimeter-adapted device for the vertical and horizontal axes (four positions). Parameters were reassessed after levodopa challenge and compared among PD, PSP, and MSA patients. Results: Maximum oculomotor range in PD patients was reduced as compared to HC. Levodopa improved oculomotor range in all directions; corrective effects of upward range positively correlated with improvements in Unified Parkinson's Disease Rating Scale III and bradykinesia sub-scores among PD patients. Although oculomotor range was markedly restricted among PSP and MSA patients, the beneficial effects of levodopa was less pronounced. Reduced oculomotor range of motion was more significant among PSP as compared to PD or MSA patients; MSA patients did not significantly differ from PD patients. The range of upward gaze was optimally sensitive for differentiating among PD, PSP, and MSA patients. Conclusion: Maximum oculomotor range was reduced among PD patients significantly improved by levodopa treatment. Variations in, as well as the positively effects of levodopa on, the range of upward gaze assist diagnostic differentiation among PD, PSP, and MSA patients.

Cerebral blood flow alterations specific to freezing of gait in Parkinson's disease.

BACKGROUND: Freezing of gait (FOG) have been associated with deficits in the cortico-basal ganglia-thalamic network. However, the resting-state cerebral blood flow (CBF) alterations specific to FOG in Parkinson's disease (PD) remain unknown. METHODS: In total, sixty PD individuals, including 30 PD with FOG (PD-FOG) and 30 PD without FOG (PD-NFOG), and 30 healthy controls (HC) underwent arterial spin labeling magnetic resonance image. The CBF were voxel-wise compared among the three groups and validated in a different cohort of PD-FOG and PD-NFOG. RESULTS: The results revealed that patients with PD-FOG had increased CBF in bilateral thalamus and the left caudate nucleus and decreased CBF in the left inferior parietal cortex compared to patients with PD-NFOG. The inter-group differences of CBF between PD-FOG and PD-NFOG was confirmed in a different cohort in the validation analysis. Moreover, the CBF in left caudate nucleus was positively correlated with severity of FOG in PD-FOG patients. CONCLUSIONS: Perfusion alterations in both cortical and subcortical regions in the cortico-basal ganglia-thalamic network are related to the development of FOG in PD patients.

Early-onset parkinsonism linked to combined heterozygous mutations in PANK2 and PLA2G6: A case report.

Homozygous mutations as well as compound heterozygous mutations in PANK2 or PLA2G6 have been reported to bring about early-onset parkinsonism (EOP). However, EOP caused by joint heterozygous mutations of the two genes is unusual. Here, we report a case of complex heterozygous mutations involving both the PANK2 and PLA2G6 genes in a Chinese woman.