Dorsal spinal CSF leaks in patients with spontaneous intracranial hypotension: a radiologic-anatomic study

Spontaneous spinal CSF leaks cause spontaneous intracranial hypotension (SIH) and several types have been identified. One rare type is the dorsal CSF leak and performing myelography in the supine or lateral decubitus position allows precise characterization of these leaks. The purpose of the current study is to describe the characteristics of spontaneous dorsal spinal CSF leaks.

Using a prospectively maintained registry, we reviewed the medical records and radiographic studies of a group of consecutive patients with SIH and dorsal spinal CSF leaks who 1) underwent digital subtraction myelography (DSM) in the lateral decubitus or supine position and 2) underwent surgery to repair the dorsal CSF leak at a quaternary referral center for SIH.

The mean age of the 16 study patients (eight female and eight male) was 34.3 years (range, 12 to 75 years) at the time of SIH symptom onset. Two different variants of spontaneous dorsal CSF leak could be identified. Of the 16 patients, 12 patients (75%) had a simple linear dural tear and four patients (25%) had one or more pseudo-meningoceles. An extradural CSF collection, usually extensive spanning many spinal levels, was seen in all patients with a linear dural tear. Half of the dorsal CSF leaks were located in the mid-thoracic spine between T5 and T8. Findings on DSM were concordant with intra-operative findings in all patients.

Spontaneous dorsal spinal CSF leaks affect men and women about equally, across a wide age range, with a predilection for the mid-thoracic spine. Two variants of spontaneous dorsal dural tears can be identified, simple linear dural tears and pseudo-meningoceles. Spontaneous dorsal spinal CSF leaks have unique features that distinguishes them from other spontaneous spinal CSF leaks.