Spontaneous intracranial hypotension has become a well-recognized clinical entity, but it remains an uncommonly, and probably underdiagnosed, cause of headache; its estimated prevalence is only one in 50,000 individuals. The clinical spectrum of spontaneous intracranial hypotension is quite variable and includes headache, neck stiffness, cranial nerve dysfunction, radicular arm pain, and symptoms of diencephalic or hindbrain herniation. Leakage of the spinal cerebrospinal fluid (CSF) is the most common cause of spontaneous intracranial hypotension. A combination of an underlying weakness of the spinal meninges and a more or less trivial traumatic event is often found to cause this event in these patients. Typical magnetic resonance imaging findings include diffuse pachymeningeal enhancement, sub-dural fluid collections, and downward displacement of the brain, sometimes mimicking a Chiari I malformation. Opening pressure is often, but not always, low, and examination of CSF may reveal pleocytosis, an elevated protein count, and xanthochromia. The use of myelography computerized tomography scanning is the most reliable method for the accurate localization of the CSF leak. Most CSF leaks are found at the cervicothoracic junction or in the thoracic spine. The initial treatment of choice is a lumbar epidural blood patch, regardless of the location of the CSF leak. If the epidural blood patch fails, the blood patch procedure can be repeated at the lumbar level, or a blood patch can be directed at the exact site of the leak. Surgical repair of the CSF leak is safe and generally successful, although a distinct structural cause of the leak often is not found.
Wouter I. Schievink
Wouter I. Schievink and Robert F. Spetzler
Object. Isolated polycystic liver disease, that is, polycystic liver disease without kidney cysts, is an entity distinct from polycystic kidney disease. It is not known whether patients with isolated polycystic liver disease are at an increased risk for developing intracranial aneurysms, similar to patients with polycystic kidney disease. The authors screened individuals for intracranial aneurysms in a family in which isolated polycystic liver disease occurred to study the relationship between these two disorders.
Methods. Six siblings requested screening for intracranial aneurysms. Their father had died of a middle cerebral artery aneurysm. Isolated polycystic liver disease was found at autopsy. Their paternal aunt had died of a basilar artery aneurysm, but no autopsy had been performed in that case. Screening with magnetic resonance (MR) angiography and subsequent conventional angiography showed a 5-mm posterior communicating artery aneurysm in one sibling in whom abdominal ultrasound examination yielded normal findings and a posterior communicating artery infundibulum in another sibling in whom an ultrasound examination detected isolated polycystic liver disease. Screening did not detect aneurysms or polycystic liver disease in the other siblings. Thus, of the two patients with isolated polycystic liver disease in this family, one had a ruptured aneurysm and the other had an infundibulum.
Conclusions. Findings in this family suggest an association between isolated polycystic liver disease and intracranial aneurysms. However, because of the delay in onset of the appearance of liver cysts in individuals who carry the disease gene, abdominal ultrasonography is not a useful method to exclude those family members at risk for aneurysm development.
Wouter I. Schievink and James Tourje
✓ Meningeal enhancement on magnetic resonance (MR) imaging is considered the hallmark radiological feature of intracranial hypotension. The authors report on a patient who exhibited progressively symptomatic intracranial hypotension due to a lumbar cerebrospinal fluid (CSF) leak, but in whom MR imaging demonstrated no pachymeningeal enhancement.
This 24-year-old man presented with a 6-week history of progressive orthostatic headaches that were associated with photo- and phonophobia. Four weeks before the onset of the headaches, the patient had undergone a lumbar laminectomy. Brain MR images revealed subdural fluid collections and brain sagging; however, meningeal enhancement was not present. Myelography demonstrated a CSF leak at the site of the laminectomy. At surgery, a large dural tear was repaired. The patient recovered well from the surgery, with complete resolution of his headaches.
The absence of meningeal enhancement on MR imaging does not exclude a diagnosis of symptomatic intracranial hypotension.
Wouter I. Schievink and M. Marcel Maya
Headache occurs after dural puncture in about 1%–25% of children who undergo the procedure—a rate similar to that seen in adults. Persistence of post–dural puncture headache in spite of bed rest, increased fluid intake, and epidural blood patch treatment, however, is rare. The authors reviewed the medical records and imaging studies of all patients 19 years of age or younger who they evaluated between 2001 and 2010 for intracranial hypotension, and they identified 8 children who had persistent post–dural puncture headache despite maximal medical treatment and placement of epidural blood patches. A CSF leak could be demonstrated radiologically and treated surgically in 3 of these patients, and the authors report these 3 cases.
The patients were 2 girls (ages 14 and 16 years) who had undergone lumbar puncture for evaluation of headache and fever and 1 boy (age 13 years) who had undergone placement of a lumboperitoneal shunt using a Tuohy needle for treatment of pseudotumor cerebri. The boy also had undergone a laminectomy and exploration of the posterior dural sac, but no CSF leak could be identified. All 3 patients presented with new-onset orthostatic headaches, and in all 3 cases MRI demonstrated a large ventral lumbar or thoracolumbar CSF collection. Conventional myelography or digital subtraction myelography revealed a ventral dural defect at L2–3 requiring surgical repair. Through a posterior transdural approach, the dural defect was repaired using 6-0 Prolene sutures and a dural substitute. Postoperative recovery was uneventful, with complete resolution of orthostatic headache and of the ventral cerebrospinal fluid leak on MRI.
The authors conclude that persistent postdural puncture headache requiring surgical repair is rare in children. They note that the CSF leak may be located ventrally and may require conventional or digital subtraction myelography for exact localization and that transdural repair is safe and effective in eliminating the headaches.
Report of three cases
Wouter I. Schievink, David G. Piepgras and Fremont P. Wirth
✓ In a recent study from the Mayo Clinic on the natural history of intact saccular intracranial aneurysms, none of the aneurysms smaller than 10 mm in diameter ruptured. It was concluded that these aneurysms carry a negligible risk for future hemorrhage and that surgery for their repair could not be recommended. These findings and recommendations have been the subject of much controversy. The authors report three patients with previously documented asymptomatic intact saccular intracranial aneurysms smaller than 5 mm in diameter that subsequently ruptured. In Case 1, a 70-year-old man bled from a 4-mm middle cerebral artery aneurysm that had been discovered incidentally 2½ years previously during evaluation of cerebral ischemic symptoms. A 10-mm internal carotid artery aneurysm and a contralateral 4-mm middle cerebral artery aneurysm had not ruptured. Case 2 was that of a 66-year-old woman who bled from a 4-mm pericallosal aneurysm that had been present 9½ years previously when she suffered subarachnoid hemorrhage (SAH) from a 7 × 9-mm posterior inferior cerebellar artery aneurysm. Although the pericallosal aneurysm had not enlarged in the intervening years, a daughter aneurysm had developed. The third patient was a 45-year-old woman who bled from a 4- to 5-mm posterior inferior cerebellar artery aneurysm that had measured approximately 2 mm on an angiogram obtained 4 years previously; at that time she had suffered SAH due to rupture of a 5 × 12-mm posterior communicating artery aneurysm. These cases show that small asymptomatic intact saccular intracranial aneurysms are not innocuous and that careful consideration must be given to their surgical repair and long-term follow-up study.
Wouter I. Schievink, M. Marcel Maya and Mary Riedinger
Object. Intracranial hypotension due to a spontaneous spinal cerebrospinal fluid (CSF) leak is an increasingly recognized cause of postural headaches, but reliable follow-up data are lacking. The authors undertook a study to determine the risk of a recurrent spontaneous spinal CSF leak.
Methods. The patient population consisted of a consecutive group of 18 patients who had been evaluated for consideration of surgical repair of a spontaneous spinal CSF leak. The mean age of the 15 women and three men was 38 years (range 22–55 years). The mean duration of follow up was 36 months (range 6–132 months). The total follow-up time was 654 months. A recurrent spinal CSF leak was defined on the basis of computerized tomography myelography evidence of a CSF leak in a previously visualized but unaffected spinal location. Five patients (28%) developed a recurrent spinal CSF leak; the mean age of these four women and one man was 36 years. A recurrent CSF leak developed in five (38%) of 13 patients who had undergone surgical CSF leak repair, compared with none (0%) of five patients who had been treated non-surgically (p = 0.249). The recurrent leak occurred between 10 and 77 months after the initial CSF leak, but within 2 or 3 months of successful surgical repair of the leak in all patients.
Conclusions. Recurrent spontaneous spinal CSF leaks are not rare, and the recent successful repair of such a leak at another site may be an important risk factor.
Wouter I. Schievink, M. Marcel Maya and Franklin M. Moser
✓ Spontaneous intracranial hypotension due to a cerebrospinal fluid (CSF) leak in the spine is an important cause of new, daily persistent headaches. Most patients respond well to conservative treatments including epidural blood patching. Limited options for effective treatment are available for patients in whom these treatments fail. The authors treated four patients (mean age 38 years; range 26–43 years) with percutaneous placement of a fibrin sealant. All these patients presented with intractable positional headaches. The CSF leak was located in the lower cervical spine in three patients and in the lower thoracic spine in one patient. Four to 20 milliliters of fibrin sealant was injected at the site of the CSF leak. Two of the four patients became asymptomatic within days of the procedure and thus avoided surgery. There were no complications of this procedure. Percutaneous placement of a fibrin sealant is a safe, minimally invasive treatment for spontaneous spinal CSF leaks and should be considered in patients in whom conservative treatment has failed.
Wouter I. Schievink and M. Marcel Maya
Spontaneous intracranial hypotension (SIH) is a significant cause of new-onset daily persistent headache. A generalized connective tissue disorder also involving the intracranial arteries has been suspected in the population with SIH. Therefore, the authors reviewed angiographic studies for the presence of intracranial aneurysms in a group of patients with SIH.
Magnetic resonance angiography studies of the brain were performed in 93 patients with SIH (mean age 43 years, range 14–86 years) and in 291 controls (mean age 56 years, range 28–78 years).
Intracranial aneurysms were detected in 8 (8.6%) of the 93 patients with SIH (95% CI 2.9%–14.3%). This incidence was higher than in the control population (3 (1.0%) of 291 (95% CI 0%–2.2%; p = 0.0007). In 7 patients the aneurysms were incidental, and in 1 patient SIH developed 5 weeks after an aneurysmal subarachnoid hemorrhage.
In this retrospective case-control study, the frequency of intracranial aneurysms among patients with SIH was significantly higher than in the control population.
Wouter I. Schievink, Philip Wasserstein and M. Marcel Maya
Spontaneous intracranial hypotension due to a spinal CSF leak has become a well-recognized cause of headaches, but such spinal CSF leaks also are found in approximately half of patients with superficial siderosis of the CNS. It has been hypothesized that friable vessels at the site of the spinal CSF leak are the likely source of chronic bleeding in these patients, but such an intraspinal hemorrhage has never been visualized. The authors report on 2 patients with spontaneous intracranial hypotension and intraspinal hemorrhage, offering support for this hypothesis. A 33-year-old man and a 62-year-old woman with spontaneous intracranial hypotension were found to have a hemorrhage within the ventral spinal CSF collection and within the thecal sac, respectively. Treatment consisted of microsurgical repair of a ventral dural tear in the first patient and epidural blood patching in the second patient. The authors suggest that spontaneous intracranial hypotension should be included in the differential diagnosis of spontaneous intraspinal hemorrhage, and that the intraspinal hemorrhage can account for the finding of superficial siderosis when the CSF leak remains untreated.
Wouter I. Schievink, M. Marcel Maya and James Tourje
Object. Spontaneous intracranial hypotension due to a spinal cerebrospinal fluid (CSF) leak is an important cause of new daily persistent headaches. Spinal neuroimaging is important in the treatment of these patients, particularly when direct repair of the CSF leak is contemplated. Retrospinal C1–2 fluid collections may be noted on spinal imaging and these are generally believed to correspond to the site of the CSF leak. The authors undertook a study to determine the significance of these C1–2 fluid collections.
Methods. The patient population consisted of a consecutive group of 25 patients (18 female and seven male) who were evaluated for surgical repair of a spontaneous spinal CSF leak. The mean age of the 18 patients was 38 years (range 13–72 years). All patients underwent computerized tomography myelography. Three patients (12%) had extensive retrospinal C1–2 fluid collections; the mean age of this woman and these two men was 41 years (range 39–43 years). The actual site of the CSF leak was located at the lower cervical spine in these patients and did not correspond to the site of the retrospinal C1–2 fluid collection.
Conclusions. A retrospinal fluid collection at the C1–2 level does not necessarily indicate the site of the CSF leak in patients with spontaneous intracranial hypotension. This is an important consideration in the treatment of these patients because therapy may be inadvertently directed at this site.