Gait abnormalities induced by acquired bilateral pallidal lesions

Abstract

Bilateral pallidal lesions induce a range of cognitive and motor disorders, principally a parkinsonian syndrome in which severe disturbances of gait and gait initiation are frequently reported. However, the precise clinical features of these disorders (and the role of the pallidum therein) remain to be established. The goal of this study was to characterise gait and gait initiation disorders within the context of a parkinsonian syndrome in patients with acquired, bilateral, pallidal lesions (PAL patients), to compare these disorders to those seen in Parkinson's disease (PD), and to assess the corresponding physiopathological implications. By using a video motion analysis system (VICON), we studied gait kinematic parameters in two patients presenting with bilateral, pallidal lesions. Kinematic and kinetic parameters were also determined during gait initiation. The two patients were compared with a group of 17 PD patients and to 20 healthy controls. In both PAL and PD patients, kinematic parameters (gait and gait initiation) and kinetic parameters (gait initiation) were similarly impaired, evidenced by akinesia (difficulty in initiating gait characterized by impairment of anticipatory postural adjustments). Hypokinesia and bradykinesia (respectively reduced stride length and reduced speed during gait) were also noted. The gait and gait initiation disorders seen in cases of bilateral pallidal lesions (namely akinesia, hypokinesia and bradykinesia) are similar to those observed in PD. Subject to confirmation in more extensive studies, we hypothesize that bipallidal patients may present higher level gait disorders,with potential mediation by cognitive impairment.