Trastorno de la marcha en la enfermedad de Parkinson: freezing y perspectivas actuales / Freezing and gait disorders in Parkinson's disease

More than one third of patients with Parkinson disease experience freezing. It is characterized by the feeling that one's feet are "glued to the floor", and it is more common in the later stages of the disease. The causes of this gait disorder are not yet fully established, but it may lead patients to suffer falls and lose their independence. As a consequence, the development of therapeutic measures which can overcome freezing is of fundamental important for the autonomy of such individuals. There is no consensus in the literature on the most recommended therapeutic measures for the prevention or attenuation of freezing in gait. What seems to be defined are the phenomenological aspects of the disorder and good therapy, represented by the association between drug therapy and sensorial stimuli or motor coordination training geared towards the specificities to avoid motor difficulties of freezing, when triggering factors are present.

A simple method to assess freezing of gait in Parkinson's disease patients

Freezing of gait (FOG) can be assessed by clinical and instrumental methods. Clinical examination has the advantage of being available to most clinicians; however, it requires experience and may not reveal FOG even for cases confirmed by the medical history. Instrumental methods have an advantage in that they may be used for ambulatory monitoring. The aim of the present study was to describe and evaluate a new instrumental method based on a force sensitive resistor and Pearson's correlation coefficient (Pcc) for the assessment of FOG. Nine patients with Parkinson's disease in the "on" state walked through a corridor, passed through a doorway and made a U-turn. We analyzed 24 FOG episodes by computing the Pcc between one "regular/normal" step and the rest of the steps. The Pcc reached ±1 for "normal" locomotion, while correlation diminished due to the lack of periodicity during FOG episodes. Gait was assessed in parallel with video. FOG episodes determined from the video were all detected with the proposed method. The computed duration of the FOG episodes was compared with those estimated from the video. The method was sensitive to various types of freezing; although no differences due to different types of freezing were detected. The study showed that Pcc analysis permitted the computerized detection of FOG in a simple manner analogous to human visual judgment, and its automation may be useful in clinical practice to provide a record of the history of FOG.