We report on a rare case of foot and ankle clonus as the initial presentation of progressive multifocal leukoencephalopathy in a young patient with no known history of HIV or AIDS and no significant past medical or social history. The patient came to the emergency department with a chief complaint of muscle spasms in his lower extremities and unsteadiness in gait. The patient was diagnosed as having bilateral ankle clonus. Work-up revealed an absolute lymphocyte CD4+ count of 18, an HIV viral load of 1,690,000, and a positive John Cunningham virus polymerase chain reaction in the cerebral spinal fluid, indicating that the patient had progressive multifocal leukoencephalopathy and AIDS. The diagnosis of progressive multifocal leukoencephalopathy should be in the foot and ankle surgeon's differential diagnosis when a patient presents with neurological symptoms in the lower extremities.
Background: This pilot study examined the effect of custom and prefabricated foot orthoses on self-selected walking speed, walking speed variability, and dynamic balance in the mediolateral direction.
Methods: The gait of four healthy participants was analyzed with a body-worn sensor system across a distance of at least 30 m outside of the gait laboratory. Participants walked at their habitual speed in four conditions: barefoot, regular shoes, prefabricated foot orthoses, and custom foot orthoses.
Results: In the custom foot orthoses condition, gait speed was improved on average 13.5% over the barefoot condition and 9.8% over the regular shoe condition. The mediolateral range of motion of center of mass was reduced 55% and 56% compared with the shoes alone and prefabricated foot orthoses conditions, respectively. This may suggest better gait efficiency and lower energy cost with custom foot orthoses. This tendency remained after normalizing center of mass by gait speed, suggesting that irrespective of gait speed, custom foot orthoses improve center of mass motion in the mediolateral direction compared with other footwear conditions. Gait intercycle variability, measured by intercycle coefficient of variation of gait speed, was decreased on average by 25% and 19% compared with the barefoot and shoes-alone conditions, respectively. The decrease in gait unsteadiness after wearing custom foot orthoses may suggest improved proprioception from the increased contact area of custom foot orthoses versus the barefoot condition.
Conclusions: These findings may open new avenues for objective assessment of the impact of prescribed footwear on dynamic balance and spatiotemporal parameters of gait and assess gait adaptation after use of custom foot orthoses. (J Am Podiatr Med Assoc 100(4): 242–250, 2010)