Surgical Ligation of Spinal CSF-Venous Fistulas after Transvenous Embolization in Patients with Spontaneous Intracranial Hypotension.

A spinal CSF-venous fistula is an increasingly recognized type of CSF leak that causes spontaneous intracranial hypotension. The detection of these fistulas requires specialized imaging such as digital subtraction myelography or dynamic CT myelography, and several treatment options are available. A novel treatment for these CSF-venous fistulas consisting of transvenous embolization with the liquid embolic agent Onyx has been described recently, but some patients require further treatment if embolization fails. The purpose of this study was to evaluate the safety and effectiveness of surgery following transvenous embolization. In a series of 6 consecutive patients who underwent surgical ligation of the fistula after endovascular embolization, there were no surgical complications. Postoperatively, complete resolution of symptoms was reported by 5 of the 6 patients, and brain MR imaging findings of spontaneous intracranial hypotension resolved in all patients. This study suggests that surgical ligation of spontaneous spinal CSF-venous fistulas after endovascular embolization is effective and safe.

Spinal CSF-Venous Fistulas in Morbidly and Super Obese Patients with Spontaneous Intracranial Hypotension.

BACKGROUND AND PURPOSE: Spinal CSF-venous fistulas are increasingly recognized as the cause of spontaneous intracranial hypotension. Here, we describe the challenges in the care of patients with CSF-venous fistulas who are morbidly or super obese. MATERIALS AND METHODS: A review was undertaken of all patients with spontaneous intracranial hypotension and a body mass index of >40 who underwent digital subtraction myelography in the lateral decubitus position to look for CSF-venous fistulas. RESULTS: Eight patients with spontaneous intracranial hypotension with a body mass index of >40 underwent lateral decubitus digital subtraction myelography. The mean age of these 5 women and 3 men was 53 years (range, 45 to 68 years). Six patients were morbidly obese (body mass indexes = 40.2, 40.6, 41, 41.8, 45.4, and 46.9), and 2 were super obese (body mass indexes = 53.7 and 56.3). Lumbar puncture showed an elevated opening pressure in 5 patients (26.5-47 cm H2O). The combination of an elevated opening pressure and normal conventional spine imaging findings resulted in a misdiagnosis (midbrain glioma and demyelinating disease, respectively) in 2 patients. Prior treatment included surgical nerve root ligation for suspected CSF-venous fistula in 3 patients. Digital subtraction myelography demonstrated a CSF-venous fistula in 6 patients (75%). Rebound high-pressure headache occurred in all 6 patients following surgical ligation of the fistula, and papilledema developed in 3. CONCLUSIONS: In our series, opening pressure was generally elevated in patients with morbid or super obesity. The yield of identifying CSF-venous fistulas with digital subtraction myelography in this patient population can approach that of the nonobese patient population. These patients may be at higher risk of developing rebound high-pressure headaches and papilledema.

The "Hyperdense Paraspinal Vein" Sign: A Marker of CSF-Venous Fistula.

CSF-venous fistula is a recently reported cause of spontaneous intracranial hypotension that may occur in the absence of myelographic evidence of CSF leak. Information about this entity is currently very limited, but it is of potential importance given the large percentage of cases of spontaneous intracranial hypotension associated with negative myelography findings. We report 3 additional cases of CSF-venous fistula and describe the "hyperdense paraspinal vein" sign, which may aid in its detection.

Spontaneous spinal cerebrospinal fluid leaks.

Spontaneous intracranial hypotension is an uncommon but not rare cause of new onset daily persistent headaches. A delay in diagnosis is the norm. Women are affected more commonly than men and most are in the fifth or sixth decade of life. The underlying cause is a spontaneous spinal cerebrospinal fluid (CSF) leak. Typically the headache is orthostatic in nature but other headache patterns occur as well. Associated symptoms are common and include neck pain, a change in hearing, diplopia, facial numbness, cognitive abnormalities and even coma. Typical imaging findings consist of subdural fluid collections, pachymeningeal enhancement, pituitary hyperaemia and brain sagging, but magnetic resonance imaging may be normal. Myelography is the study of choice to identify the CSF leak but is not always necessary to make the diagnosis. Treatment consists of bedrest, abdominal binder, epidural blood patching, percutaneous fibrin glue injection or surgical CSF leak repair. Outcomes have been poorly studied.

Diagnostic criteria for spontaneous spinal CSF leaks and intracranial hypotension.

BACKGROUND AND PURPOSE: Comprehensive diagnostic criteria encompassing the varied clinical and radiographic manifestations of spontaneous intracranial hypotension are not available. Therefore, we propose a new set of diagnostic criteria. MATERIALS AND METHODS: The diagnostic criteria are based on results of brain and spine imaging, clinical manifestations, results of lumbar puncture, and response to epidural blood patching. The diagnostic criteria include criterion A, the demonstration of extrathecal CSF on spinal imaging. If criterion A is not met, criterion B, which is cranial MR imaging findings of spontaneous intracranial hypotension, follows, with at least one of the following: 1) low opening pressure, 2) spinal meningeal diverticulum, or 3) improvement of symptoms after epidural blood patch. If criteria A and B are not met, there is criterion C, the presence of all of the following or at least 2 of the following if typical orthostatic headaches are present: 1) low opening pressure, 2) spinal meningeal diverticulum, and 3) improvement of symptoms after epidural blood patch. These criteria were applied to a group of 107 consecutive patients evaluated for spontaneous spinal CSF leaks and intracranial hypotension. RESULTS: The diagnosis was confirmed in 94 patients, with use of criterion A in 78 patients, criterion B in 11 patients, and criterion C in 5 patients. CONCLUSIONS: A new diagnostic scheme is presented reflecting the wide spectrum of clinical and radiographic manifestations of spontaneous spinal CSF leaks and intracranial hypotension.

Haploinsufficiency for one COL3A1 allele of type III procollagen results in a phenotype similar to the vascular form of Ehlers-Danlos syndrome, Ehlers-Danlos syndrome type IV.

Mutations in the COL3A1 gene that encodes the chains of type III procollagen result in the vascular form of Ehlers-Danlos syndrome (EDS), EDS type IV, if they alter the sequence in the triple-helical domain. Although other fibrillar collagen-gene mutations that lead to allele instability or failure to incorporate proalpha-chains into trimers-and that thus reduce the amount of mature molecules produced-result in clinically apparent phenotypes, no such mutations have been identified in COL3A1. Furthermore, mice heterozygous for Col3a1 "null" alleles have no identified phenotype. We have now found three frameshift mutations (1832delAA, 413delC, and 555delT) that lead to premature termination codons (PTCs) in exons 27, 6, and 9, respectively, and to allele-product instability. The mRNA from each mutant allele was transcribed efficiently but rapidly degraded, presumably by the mechanisms of nonsense-mediated decay. In a fourth patient, we identified a point mutation, in the final exon, that resulted in a PTC (4294C-->T [Arg1432Ter]). In this last instance, the mRNA was stable but led to synthesis of a truncated protein that was not incorporated into mature type III procollagen molecules. In all probands, the presenting feature was vascular aneurysm or rupture. Thus, in contrast to mutations in genes that encode the dominant protein of a tissue (e.g., COL1A1 and COL2A1), in which "null" mutations result in phenotypes milder than those caused by mutations that alter protein sequence, the phenotypes produced by these mutations in COL3A1 overlap with those of the vascular form of EDS. This suggests that the major effect of many of these dominant mutations in the "minor" collagen genes may be expressed through protein deficiency rather than through incorporation of structurally altered molecules into fibrils.

Spontaneous retroclival hematoma presenting as a thunderclap headache. Case report.

An excruciating headache of instantaneous onset, or thunderclap headache, may be caused by a variety of serious disorders, including aneurysmal subarachnoid hemorrhage, cerebral venous sinus thrombosis, pituitary apoplexy, and carotid artery or vertebral artery dissection. The authors describe a patient with this type of headache who was found to have a spontaneous retroclival hematoma. A 49-year-old woman experienced an instantaneous excruciating headache. Results of computerized tomography (CT) scans of the head were normal, but on examination of the cerebrospinal fluid xanthochromia was found. Magnetic resonance (MR) imaging of the cervical spine revealed a retroclival hematoma. Three cerebral angiographic studies did not reveal the source of the hemorrhage and a repeated MR image demonstrated resolution of the hematoma. The patient made an uneventful recovery. Spontaneous retroclival hematoma is an exceedingly rare type of intracranial hemorrhage and may be associated with normal findings on CT scans. Spontaneous retroclival hematoma should be included in the differential diagnosis of thunderclap headache.

Spontaneous intracranial hypotension mimicking aneurysmal subarachnoid hemorrhage.

OBJECTIVE: An excruciating headache of instantaneous onset is known as a thunderclap headache. A subarachnoid hemorrhage is the prototypical cause, but other serious disorders may also present with a thunderclap headache, including cerebral venous sinus thrombosis, carotid artery dissection, and pituitary apoplexy. We report a group of patients with thunderclap headaches as the initial manifestation of spontaneous intracranial hypotension caused by a spinal cerebrospinal fluid leak. METHODS: Among 28 patients with spontaneous intracranial hypotension due to a documented spinal cerebrospinal fluid leak, four (14%) initially experienced an excruciating headaches of instantaneous onset. RESULTS: The mean age of the four patients (two men and two women) was 35 years (range, 24-45 yr). Nuchal rigidity was present in the three patients who sought early medical attention, and they underwent emergency computed tomographic scanning, lumbar puncture, and cerebral angiography to rule out an aneurysmal subarachnoid hemorrhage. The delay between the onset of headache and diagnosis of intracranial hypotension ranged from 4 days to 5 weeks. A fourth patient did not seek medical attention until 1 month after the ictus. CONCLUSION: Spontaneous intracranial hypotension should be included in the differential diagnosis of thunderclap headache, even when meningismus is present.

The treatment of spontaneous carotid and vertebral artery dissections.

Spontaneous dissections of the carotid and vertebral arteries in the neck are a common cause of stroke in young and middle-aged people. Moreover, they are increasingly recognized as the cause of a wide variety of other, more subtle, neurologic signs and symptoms. The cause of these arterial dissections largely remains unexplained but probably involves a combination of genetic and environmental factors. Magnetic resonance imaging has largely surpassed angiography as the imaging study of choice. The treatment of carotid and vertebral artery dissections is based on rather incomplete evidence. Anticoagulation with heparin followed by warfarin remains the treatment of choice in most major medical centers and is supported by the demonstration of emboli as the most common cause of stroke in these patients. The burgeoning interest in endovascular techniques has resulted in many patients being treated for carotid and vertebral artery dissections with percutaneous angioplasty and stent deployment. Although the treatment of dissections is generally well tolerated and the radiographic results are impressive, most dissections heal spontaneously and the associated aneurysms never rupture and rarely cause delayed ischemic symptoms. Surgical treatment of dissections, consisting of an in situ interposition graft or extracranial-intracranial bypass, is indicated only for those patients with persistent symptoms refractory to maximal medical therapy who are not candidates for endovascular treatment.

Origin of pretruncal nonaneurysmal subarachnoid hemorrhage: ruptured vein, perforating artery, or intramural hematoma?

Pretruncal (perimesencephalic) nonaneurysmal subarachnoid hemorrhage (SAH) is a benign variant of SAH. Although angiography fails to show a source of the hemorrhage, mild basilar artery narrowing may be observed. The cause of pretruncal nonaneurysmal SAH has not been established. Recent imaging studies have demonstrated that the center of this type of SAH is not around the mesencephalon but is in the prepontine or interpeduncular cistern with the hemorrhage closely associated with the basilar artery. We review the possible sources of hemorrhage in these cisterns and hypothesize that pretruncal nonaneurysmal SAH is caused by a primary intramural hematoma of the basilar artery. Such an intramural hematoma would explain bleeding under low pressure, the location of the hemorrhage anterior to the brainstem, and the typical findings of hemorrhage adjacent to the basilar artery lumen on magnetic resonance imaging and mild basilar artery narrowing on angiography. Although an intramural hematoma of the basilar artery would be easily identified at surgical exploration, such surgeries have never included the extensive base-of-the-skull approaches that are necessary to visualize the artery in the prepontine cistern.

Superficial temporal artery to middle cerebral artery bypass and external carotid reconstruction for carotid restenosis after angioplasty and stent placement.

The recent proliferation of endovascular treatment of carotid atherosclerotic disease will increase the number of patients who require treatment for recurrent carotid stenosis after angioplasty and stent placement. The optimal management of these patients has not yet been defined. We describe a 66-year-old woman who required 2 surgical procedures for recurrent in-stent carotid stenosis. She experienced numerous transient ischemic attacks 5 months after left extracranial internal carotid artery angioplasty and stenting for asymptomatic stenosis. Angiography showed high-grade in-stent restenosis, left intracranial carotid artery stenosis, and poor collateral flow to the left middle cerebral artery circulation. The patient underwent a superficial temporal artery to middle cerebral artery bypass, and the transient ischemic attacks resolved. Five months later, angiography showed progressive stenosis of the external carotid artery at the site of the stent. The patient underwent successful external carotid reconstruction with an on-lay patch. Extracranial-intracranial bypass grafting may be used successfully in the treatment of recurrent extracranial carotid artery stenosis after angioplasty and stent placement. Also, external carotid artery reconstruction at the site of an internal carotid artery stent can be performed safely.

Diffuse vasospasm after pretruncal nonaneurysmal subarachnoid hemorrhage.

Pretruncal (perimesencephalic) nonaneurysmal hemorrhage is a benign form of subarachnoid hemorrhage (SAH). Angiographic changes of vasospasm are uncommon in patients with this type of hemorrhage, and if vasospasm is present, it is mild and focal. We report two patients with pretruncal nonaneurysmal SAH who developed severe and diffuse vasospasm, expanding the clinical spectrum of this type of SAH. The first patient was a 40-year-old woman who suffered pretruncal nonaneurysmal SAH. Angiography performed on the seventh day post hemorrhage showed diffuse and severe vasospasm affecting both the anterior and the posterior circulation. The patient was treated with hypervolemia, and she remained asymptomatic. Follow-up angiography showed resolution of the vasospasm. The second patient was a 67-year-old woman who suffered pretruncal nonaneurysmal SAH. The results of the initial angiography were normal. Repeat angiography on the ninth day post hemorrhage showed severe vasospasm in the anterior circulation and moderate vasospasm in the posterior circulation. Nine hours later, the patient developed transient dysphasia, and she was treated with hypervolemia. Three days later, a transcranial Doppler examination showed normalization of blood velocities. The presence of diffuse and severe vasospasm does not exclude a diagnosis of pretruncal nonaneurysmal SAH.

Intracranial hypotension without meningeal enhancement on magnetic resonance imaging. Case report.

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.

Chronic subdural hematoma in autosomal dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) has been associated with an increased incidence of aneurysmal subarachnoid hemorrhage and intracerebral hematomas. We describe five patients with chronic subdural hematomas, a previously unrecognized complication of ADPKD. In four of the five cases, no trigger was apparent. Clinical presentation was subtle, with mild hemiparesis, headache, or both in four patients and transient neurological deficits mimicking transient ischemic attacks in one patient. In three of the five patients, a retrocerebellar arachnoid cyst was found, suggesting a plausible causal relation between the intracranial arachnoid cysts and the subdural hematomas. In one patient, subdural hematoma was in close proximity to the frontally located arachnoid cyst.

Spontaneous spinal cerebrospinal fluid leaks: a review.

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, subdural 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.