Yoshiaki Harada

A pathologic study of lumbar disc herniation in the elderly.

Twenty-nine fragments from hemlated lumbar discs of patients over 60 years of age were studied pathohlstologlcally. For comparison, 109 discs from patients under 59 years of age also were observed. They were classified into seven types according to their composition. In 70% of discs from patients between 60 and 69 and In 80% of discs from patients over 70, the fragments were composed of the anulus fibrosus and the cartilaginous end-plate. The authors concluded that the cartilaginous end-plate had avulsed from the vertebral body and hernlated with the anulus fibrosus in these cases. This type of herniation occurs more often than herniation of the nucleus pulposus over 30, and may be most common in elderly patients because of their advanced disc degeneration.

Recovery from exercise-induced desaturation in the paraspinal muscles in idiopathic scoliosis.

STUDY DESIGN A study using near-infrared light spectroscopy to measure recovery from exercise-induced desaturation in the paraspinal muscles of patients with idiopathic scoliosis. OBJECTIVES To measure oxygenation of the paraspinal muscles and obtain differences between the convex and concave sides. SUMMARY OF BACKGROUND DATA Authors of previous studies have reported that some patients experience pain on the convex side of the paraspinal muscles. The muscles on the convex side are more stretched and stressed than those on the concave side. The current authors investigated the degree of stress by measuring oxygenation and blood volume changes. METHODS Paraspinal muscle spectral properties at L3 were investigated using near-infrared light spectroscopy. Thirty-six patients (8 men and 28 women) underwent this procedure. To assess a level of peripheral adaptations to exercise, the half-time of Oxyhemoglobin/Myoglobin recovery was measured, which indicates the recovery from energy deficit after exercise. RESULTS The average half-time recovery on the convex side was 3.38 seconds (range, 1.5-5.5 seconds), whereas that on the concave side was 1.51 seconds (range, 0.7-4.0 seconds). The average difference between the convex side and the concave side was 1.87 seconds (range, 0.9-3.5 seconds). CONCLUSIONS Half-time recovery on the convex side in the patients with idiopathic scoliosis was slower than that in healthy adults (P < 0.05). Half-time recovery on the concave side in such patients was faster than that on the convex side (P < 0.01). The authors consider half-time recovery an indication of back muscle stress.

Giant schwannoma of the back.

Abstract We treated a patient with giant schwannoma of the back. The tumor measured 35 × 25 × 12 cm and weighted 1840 g. Histological diagnosis was benign schwannoma. To our knowledge, there is no previous report of such a large schwannoma of the back.