Mokri, Bahram

Abstract Objective: Spontaneous intracranial hypotension is typically caused by a spontaneous spinal cerebrospinal fluid (CSF) leak. The configuration of the related dural defects can be complex. We describe our experience with the surgical anatomy of these defects. Methods: Thirteen consecutive patients with spontaneous spinal CSF leaks who underwent surgical exploration at Mayo Clinic between 1994 and 2003 were studied. All patients' records, imaging studies, detailed intraoperative findings, and outcomes were reviewed. Results: There were four men and nine women with an average age of 40 years (range, 12–62 yr). Preoperative imaging studies revealed a single site of CSF leak in eight patients, two sites in three patients, and multiple sites in two patients. Intraoperatively, the exact site of leakage could not be found in four patients. Among the other nine patients, primary closure of a meningeal diverticulum was achieved in one patient. Significant regional attenuation of the dura prevented primary repair of the leak site in eight patients. Muscle, fibrin glue, and Gelfoam (Upjohn Co., Kalamazoo, MI) soaked in patient's own blood were commonly used to pack the epidural space in an attempt to seal the site of the leak. Ligation of two nonappendicular nerve roots allowed closure of the leak in one of these patients. Postoperatively, resolution of symptoms occurred in eight patients, significant improvement was noted in three patients, and only transient resolution in two. The mean duration of follow-up was 20.5 months. Conclusion: Surgery for closure of spontaneous spinal CSF leaks may not be straightforward. Even when extradural CSF leakage is discovered preoperatively by imaging studies, it may not always be possible to identify the exact site of the leakage intraoperatively. Furthermore, the anatomy of the dural defects may be complex and not amenable to primary closure. In such cases, the use of adjuvant techniques during surgical exploration may be effective.

Two patients with cerebrospinal fluid (CSF) leak, one at the level of fourth thoracic spine and another with undetermined level of leak, presented with paradoxical postural headaches in that the headaches were present when in a horizontal position and resolved if the patients were upright. One patient improved spontaneously and the other responded to a targeted epidural blood patch. Paradoxical postural headache is yet another headache type that can be associated with CSF leak and CSF volume depletion. Its mechanism is uncertain, but it could be related to congestion and dilatation of cerebral venous sinuses and large veins.

Spontaneous CSF leaks are increasingly recognized, and a broader clinical and imaging spectrum of the disorder is emerging. The headaches of CSF leaks are typically orthostatic, but sometimes especially with chronicity the orthostatic features are blurred into lingering chronic daily headaches. Additional types of headache are also increasingly recognized. Two patients with spontaneous CSF leaks presented with intermittent transient severe headaches provoked by Valsalva-type manoeuvres. Orthostatic features were absent and the patients were asymptomatic if they avoided the provoking manoeuvres. One patient had been treated for 6 years for benign exertional headaches and had failed many medical treatments, including courses of indomethacin. He was found to have a leak from cribriform plate. The second patient had been symptomatic for several months, had diffuse pachymeningeal gadolinium enhancement on head magnetic resonance imaging, spinal meningeal diverticula, and CSF leak at the thoracic spine level. Headaches that mimic benign exertional headaches are yet another mode of the still broadening clinical presentation of spontaneous CSF leaks.

Cerebrospinal fluid (CSF) leak is recognized to cause headaches that typically but not invariably have orthostatic features (present in upright posture, relieved by recumbency). Head magnetic resonance imaging (MRI) typically shows diffuse pachymeningeal enhancement. A 24-year-old woman, after resection of a right temporoparietal glioma, developed CSF leak from the craniotomy site, resulting in subgaleal fluid collection and associated with diffuse pachymeningeal gadolinium enhancement as well as posture-related headaches. The headaches, however, were present in a recumbent position and relieved after several minutes of being in an upright position. It is postulated that CSF leak took place when the patient was recumbent and ceased when she was upright, a position in which there is decrease in intracranial pressure. After cessation of the leak, along with disappearance of subgaleal collection of CSF, both the headaches and the pachymeningeal enhancement resolved.