The aim of this study is to describe patients who represent spontaneous regression of lumbar disc herniations (LDHs) subsequent to conservative treatments. In this retrospective study, medical records of 862 patients who had presented to our neurosurgery department with LDHs between May 2014 and May 2016 were studied. All of these patients had a history of low back pain and radiculopathy. Lumbar magnetic resonance imaging (MRI) scans were performed to diagnose them.LDHs were categorized into four subtypes including disc bulging, protrusion, extrusion, and sequestration. Five patients developed spontaneous regression of LDHs according to spinal MRI scans. All patients relieved radiculopathy symptoms in 2 to 4 weeks and low back pain symptoms in 3 to 8 weeks except one patient. In one patient hypoesthesia symptom, in one patient motor deficit, and in one patient low back painremained after the regression. The clinical and diagnostic imaging characteristics and outcomes of these five patients are described and the pertinent literature regarding spontaneous regression of LDHs is reviewed. Sequestrated disc herniations represent the main candidates for spontaneous regression according to our clinical research and the pertinent literature. Dehydration and inflammation-related resorption are the main mechanisms for this event. Conservative treatment modalities should not be underestimated for the treatment of such patients in the absence of definitive surgical indications.
Keywords: Lumbar disc herniation; sequestrated; spontaneous regression.