Radiological Assessment of Mild Spondylolisthesis in Young-Aged Persons

OBJECTIVE: To analyze morphologic differences between only spondylolysis group and mild spondylolisthesis one in young-aged persons and to find useful parameters for radiological assessment of mild spondylolisthesis. METHOD: Twenty patients with only lumbar spondylolysis, 18 patients with mild lumbar spondylolisthesis and 19 normal subjects were recruited in this study. Their radiological findings were examined. The films of subjects were evaluated with respect to variables describing wedging of the spondylolytic vertebra, relative thickness and lengths of the transverse processes. The evaluation was made with attention to possible signs which could mean vertebral slipping. The lumbar index reflects the degree of wedge deformity of the spondylolytic vertebra. RESULTS: Lumbar index was significantly lower in spondylolisthesis group than only spondylolysis group. There was no significant difference in relative thickness of L5 transverse process between two groups. The incidence of a midline lumbar or sacral defect in the spondylolisthesis group was higher than other groups. CONCLUSION: Our results support the usefulness of lumbar index as a supplement parameter for radiological assessment of mild spondylolisthesis.

Effect of Refractive Error on the P100 Latency of Visual Evoked Response

OBJECTIVE: Absolute or relative increase in the latency of the major surface positive component is almost invariably found in patients with demyelination optic neuropathy. Using the pattern- reversal method, our study illustrates the significant changes in the latency of the P100 component when refractive errors are introduced to defocus in normal person. METHOD: Four women and ten men aged 20 to 27 years were selected after a thorough ophthalmological assessment. Visual acuity (VA) was 6/6 or better in all subject and none had dyschromatopsia or significant astigmatism. Refractive errors were created by the combined standard lenses. RESULTS: The mean value of P100 latency were as follows: 93.74 +/- 3.30 msec, naked eyes; 98.14 +/- 7.37 msec, the +2/+x 90 lens; 96.50 +/- 3.76 msec, the +1/ +1 x90 lens; 94.55 +/- 4.20 msec, the -1/ -1x90; 96.29 +/- 2.88 msec, the -2/ -2 x90 lens. The P100 latencies showed singnificant standard lens except with -1/ -1 x90 lens. The P100 latency was prolonged according to the progression of refractive error. CONCLUSION: Because a relative or absolute prolongation of P100 latency is often found in cases of suspected multiple sclerosis, and because of their similarity to the findings of our study, we would emphasize that refractive errors should be reduced or eliminated to minimize the false-positive results.