[Postural and locomotor evaluation of normal pressure hydrocephalus: a case report]

Generally, the diagnosis of idiopathic normal pressure hydrocephalus (NPH) is raised in elderly patients with an association of gait disturbances, cognitive impairment, urinary incontinence and widening of the ventricles. Gait disturbances appear as the predominant clinical symptom of NPH, and may precede other symptoms. The main objectives of this study were to determine the effect of ventriculoperitoneal shunt (VPS) on gait and to compare the results obtained in HPN with those obtained in Parkinson's disease (PD). The performance of a patient with NPH on specific postural and locomotion tasks was analyzed during three successive experimental sessions: the first one before VPS, the second one week after VPS and the third three months after VPS. The patient was instructed to walk at his natural speed and also to maintain postural control for one minute. Four gait parameters (mean velocity, stride length, cadency and step width) were calculated for each session to assess the subject's performance. In this NPH patient there was a significant improvement in gait performance before and after VPS. This improvement concerned mean velocity, stride length and step cadency but did not involve the width component which remained unchanged. Before VPS, the NPH patient walked slower and with a shorter stride length than a group of patients with PD. After VPS his performance was better than the PD group except for cadency. Step width remained longer for the HPH patient than in PD patients for all three sessions. From this study, it appears that gait in idiopathic NPH exhibits a specific temporospatial pattern distinct from that in PD or normal age-matched controls. Changes in gait can be evaluated shortly after treatment of NPH. Gait disorders, excepting dynamic balance, may normalize as soon as one week after surgery.