[Clinical and physiological study of apraxia of gait and frozen gait].

A study of clinical features and an analysis of gait with floor reaction forces and EMG of leg flexors and extensors were made in patients with multiple cerebral infarction or patients with Parkinson's disease having frozen gait. A case with occlusion of the bilateral anterior cerebral arteries resulting in massive infarction of the infero-medial part of the frontal lobes was also studied as he showed a unique disorder characterized by apraxia of gait. Frozen gait is characterized by shuffling steps, broad-based stance, positive foot grasp, kinesia paradoxa and disturbance of postural reflexes. The vector angle which shows foot pressure in forward locomotion was decreased in patients with frozen gait. EMGs of lower leg muscles in frozen gait were grouping of potentials corresponding to the shuffle and reciprocity between flexors and extensors was preserved. The patient with infarction of the bilateral anterior cerebral arteries showed a peculiar disorder of gait which was characterized by an inability to initiate stepping. It is considered as "apraxia of gait" in a classical sense, which differs from frozen gait. Observation of this patient suggests that the infero-medical part of the frontal lobe plays an important role in the initiation of gait. Furthermore, common features of frozen gait in patients with Parkinson's disease and in patients with multiple cerebral infarction involving the frontal lobe suggest that the nigrostriatal structures and the frontal lobe are important in CNS mechanisms subserving smooth locomotion.