[A case of spontaneous intracranial hypotension successfully treated with an epidural blood patch].

A 76-year-old woman was admitted to our hospital with complaints of a three-day history of severe postural headache without any apparent cause. Neurological examination revealed nuchal rigidity, and right auditory nerve paresis. Lumbar puncture yielded a low opening pressure of 50mmH2O and an elevated total protein up to 77mg/dl. Cranial magnetic resonance imaging (MRI) using gadolinium revealed diffuse dural enhancement, and effacement of the prepontine cistern. Spontaneous intracranial hypotension was strongly suspected, and to ascertain the presence of a cerebrospinal fluid (CSF) leak, radionuclide cisternography (RNC) was performed, which demonstrated a spinal CSF leak along the nerve root at the level of the lower lumbar spine. Interestingly, computed tomography-myelography (CTM) did not detect these abnormalities. An epidural blood patch with 15 ml of autologous blood at the L3-L4 interspace brought a dramatic symptomatic relief. Follow-up MRI, RNC, and CSF analysis demonstrated that the abnormal findings had disappeared. It is speculated that RNC is more sensitive for detecting small dural tears and CTM for anatomical anomalies including meningeal diverticula and perineural (Tarlov) cysts. We wish to stress, however, that RNC and CTM are complementary and sometimes interchangeable diagnostic modalities, and should be actively employed for detecting CSF leakage in SIH and for appropriate treatment.