3D-CT Epidurography Can Detect Cerebrospinal-Fluid Leakage in a Patient with Spontaneous Intracranial Hypotension: A Case Report

Abstract

venous plexus in epidural space, descent of the cerebellar tonsil, a flattened brain stem, and pituitary swelling are also valuable for the diagnosis of this condition. CSF leakage from the spinal dural sac can be detected by certain imaging modalities. In radioisotope (RI) cisternography, abnormal RI accumulation in the spinal epidural space, increased clearance of the tracer from the CSF space, or early bladder filling (EBF) of RI are regarded as suggestive of CSF leakage. MRI or MRI/computed tomography (CT) myelography can also identify CSF in the spinal epidural space. 2)Although these are valuable modalities to find CSF leakages, it is difficult to detect the leakage point of CSF in patients with spontaneous intracranial hypotension.In this article, we report a patient with cerebrospinal fluid (CSF) hypovolemia, the leakage of which was not detected by either RI cisternography or MRI, but detected by threedimensional computed tomography (3D-CT) performed just after the epidural injection of the patient's own blood, containing a contrast medium. This finding suggests that 3D-CT epidurography may be a useful tool to detect the fistula of CSF leakage, even in patients in whom other modalities including MRI, CT, or RI cisternography cannot specify the leakage point. Case ReportA 31-year-old female high school teacher with no particular past history was involved in two rear-end collisions 5 years previously. Four years later, she sometimes had headache, these rapidly worsened several weeks before admission. The headache was intractable and uncontrolled by commercially available painkillers, which resulted in her visiting and being admitted to our hospital. She had no specific neurological deficits and no abnormal findings on cranial CT.In spite of bed rest and sufficient hydration, her headache got worse and was enhanced by the orthostatic stress. MRI examined 24 days after admission showed a thickened dura mater, which was diffusely enhanced by intravenous gadolinium injection, narrowing of the prepontine cistern, a swelling of the pituitary, and dilated intracranial venous sinuses (Fig. 1). It also revealed thin chronic subdural hematoma in her frontal region. Spinal MRI of lumbar level showed a narrowing of the intra dural space and epidural fluid collection (Fig. 2). On a cervical level, abnormalities were not shown (Fig. 3). In RI cisternography, the tracer injected intrathecally via lumbar puncture filled the bladder after only 20 minutes. The tracer did not reach the basal Spontaneous intracranial hypotension presents with many symptoms including orthostatic headache, dizziness, and nausea due to cerebrospinal-fluid (CSF) leakage from the spinal dural sac. Although CSF leakage can be estimated by radioisotope (RI) cisternography or computed tomography/magnetic resonance imaging myelography, it is not easy to detect the leakage point using these modalities. Here, we describe a patient with spontaneous intracranial hypotension in whom threedimensional computed tomography (3D-CT) performed just after an epid...