[Spontaneous regression of lumbar disk hernia]

Four cases of spontaneous regression of herniated nucleus polposus are described, which were followed after conservative medical treatment. Three female and one male patients who suffered from severe lumbago were evaluated; their age ranged 24-59 years. From the first CT scan on which herniation was diagnosed to follow-up control after complete regression of symptoms an average period of 14 months elapsed. Comparing ours with literature data, a substantial agreement was observed of both timing of spontaneous regression and location (most often involved was the last lumbar intervertebral space). The age of one of our patients (59 years) is to be stressed, which is well above the mean age reported in literature (35 years). The pathogenesis of regression is still unknown. The most reliable hypothesis seems to be that of dehydration and progressive atrophy of the herniated nucleus polposus. The appearance, in some cases, of the vacuum disk phenomenon seems to support such a thesis. Therefore, the diagnosis of a herniated nucleus polposus of relatively small size, still contained in an intact posterior longitudinal ligament, widely justifies the choice of waiting tactics.