Spontaneous Regression of Recurred Cervical Calcified Ligamentum Flavum : Possible Effect of Pregabalin―A Case Report―

Calcification of ligamentum flavum （ CLF ） is a degenerative spinal disease in which calcium crystals deposit in the ligamentum flavum. The CLF may cause spinal cord compression, and the patient may need decompressive surgery. However, CLF can spontaneously regress with some medications as well as no treatment. Here, the authors reported a case in which small CLF remain-ing after cervical decompression surgery markedly enlarged during the follow ‒ up period and spontaneously regressed after pregabalin administration. Therefore, pregabalin might be involved in the spontaneous regression of CLF. The improved showed small residual CLF Six after and numbness cervical MRI showed a marked increase of CLF at C6 / 7. The pain disappeared after the administration of pregabalin. Six months later, a marked reduction of CLF was observed on MRI. It has been reported that the administration of cimetidine or etidronate resulted in the regression of CLF. Cimetidine affects calcium metabolism via parathyroid hormone （ PTH ） , and etidronate has an inhibitory effect on calcification. It was reported that the serum PTH was markedly reduced in a uremic patient after the administration of pregabalin. The efficacy of pregabalin was also reported for a case with refractory paroxysmal kinesigenic choreoathetosis whose parathyroid glands were removed. It is presumed that pregabalin was involved in calcification regression via PTH metabolism in this case.