Man with gait disturbance and urinary retention

Clinical history A 64-year-old man was referred to our hospital with progressing abnormalities of gait and sensation in his legs, and urinary dysfunction. Nine months ago, he had suddenly slumped due to a loss of strength in both legs. After about ten minutes he was able to walk again normally. A similar episode occurred on the same day, and from then on he had varying degrees of gait disturbance: sometimes he was able to walk even long distances, on other days he was not able to walk at all. About the same time, he started noticing numbness and a tingling sensation in both legs. Three months before admission he had been treated for urinary retention, which had been interpreted as due to prostatic hypertrophy, even though the prostate volume was normal. Examination A clinical examination on admission showed paraparesis, more pronounced proximally and on the left, with levels of strength ranging from 4/5 to 5/5. Muscle tone was slightly elevated and tendon reflexes were hyperactive in the legs; Babinski’s sign was negative. Sensation was reduced caudal to the fifth thoracic segment.