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.
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.
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, Paul J. Apostolides, and Robert F. Spetzler
✓ In many patients with superficial siderosis of the central nervous system (CNS) no source of bleeding can be established, despite extensive examinations. The authors report a patient with superficial siderosis and a spinal arteriovenous malformation (AVM) that was not visible on magnetic resonance (MR) imaging or myelography but was identified on angiographic studies.
This 71-year-old man presented with a 2-year history of progressive gait difficulties and hearing loss. Examination showed ataxia, hearing loss, and quadriparesis. On MR imaging superficial siderosis of the brain and spinal cord as seen; however, MR imaging of the CNS, as well as cerebral angiography and myelography studies, did not reveal the source of hemorrhage. Spinal angiography revealed a small slow-flow pial AVM at the C-5 level originating from the anterior spinal artery. A C-5 corpectomy was performed and the AVM was obliterated. The patient did well and reported no further progression of his symptoms during 3 months of follow up.
Spinal angiography is indicated to complete the evaluation of patients with superficial siderosis, even if results of spinal MR imaging and myelography studies are normal. Obliteration of spinal AVMs may successfully prevent the progression of superficial siderosis.
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, M. Marcel Maya, and Miriam Nuño
Spontaneous intracranial hypotension is an important cause of new-onset daily persistent headache. Cerebellar hemorrhage has been identified as a possible feature of spontaneous intracranial hypotension. The authors reviewed the MR imaging studies from a group of patients with spontaneous intracranial hypotension to assess the presence of cerebellar hemorrhage.
Medical records and radiological images were reviewed in 262 cases involving patients with spontaneous intracranial hypotension who had undergone MR imaging of the brain as well as spinal imaging.
Chronic cerebellar hemorrhages were found in 7 (2.7%) of the 262 patients with spontaneous intracranial hypotension. These hemorrhages were found in 7 (19.4%) of the 36 patients with a ventral spinal CSF leak and in none of the 226 patients who did not have such a CSF leak (p < 0.0001). The degree of hemosiderin deposits was variable, ranging from mild involvement of the cerebellar folia to widespread superficial siderosis. Only the 1 patient with superficial siderosis had symptoms due to the hemorrhages. The time period between the onset of symptoms due to spontaneous intracranial hypotension and MR imaging examination was significantly longer in those patients with cerebellar hemorrhage than in those with a ventral spinal CSF leak and no evidence for cerebellar hemorrhage (mean 19.6 years vs 2.3 months, p < 0.0001).
Chronic cerebellar hemorrhage should be included among the manifestations of spontaneous intracranial hypotension. The severity is variable, but the hemorrhage generally is asymptomatic. The underlying spinal CSF leak is ventral and mostly of long duration.
Wouter I. Schievink, Ronald Reimer, and W. Neath Folger
✓ The authors present the case of a 22-year-old woman who developed spontaneous intracranial hypotension as a result of a cerebrospinal fluid leak from a thoracic extradural arachnoid diverticulum. The patient was successfully treated by ligation of the diverticulum. The entity of spontaneous intracranial hypotension and its relevance to neurosurgery are discussed.