Intradural Disc Herniation Can Be Intra-Arachnoid or Extra-Arachnoid: 2 Case Reports with MRI Diagnosis and Non-Surgical Management

Intradural disc herniation is rare and often diagnosed during surgery. We present two patients with the disease, one with an intra-arachnoid type, the other with an extra-arachnoid location. The teaching point of those cases is that this very frequent pathology can take a variety of forms, depending on the structures that are infiltrated. The key point in correctly diagnosing the intradural disc herniation is to look at the angle between the fragment and the dura. Is it pushing it (as in the usual disc herniation), embedded in it (those with the extra-arachnoid type) or does it go through to fall into the CSF (In the intra-arachnoid type)? It could be diagnosed on MRI preoperatively. Contrary to many published cases of intradural disc herniation, the two patients could be managed non-surgically.