Franklin G. Moser

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.

Frequency of spontaneous intracranial hypotension in the emergency department

Spontaneous intracranial hypotension is considered a rare disorder. We conducted a study on the frequency of spontaneous intracranial hypotension in the emergency department (ED). We identified patients with spontaneous intracranial hypotension evaluated in the ED of a large urban hospital between 1 January 2003 and 31 December 2006. For comparison, we also identified all patients with spontaneous subarachnoid haemorrhage (SAH). Eleven patients with previously undiagnosed spontaneous intracranial hypotension were evaluated in the ED during the four-year time period. All patients presented with positional headaches and the duration of symptoms varied from one day to three months. None of the patients were correctly diagnosed with spontaneous intracranial hypotension in the ED. During the same time period, 23 patients with aneurysmal SAH were evaluated. Spontaneous intracranial hypotension is more common than previously appreciated and the diagnosis in the ED remains problematic.

Pseudo-subarachnoid hemorrhage: a CT-finding in spontaneous intracranial hypotension.

Increased attenuation in the basilar cisterns or along the tentorium cerebelli resembling subarachnoid hemorrhage (SAH) may be found on CT in the absence of blood (pseudo-SAH). The authors found pseudo-SAH on CT in four of 40 patients with spontaneous intracranial hypotension. All four patients had brain sagging with obliteration of the cisterns and pachymeningeal enhancement along the tentorium cerebelli. Spontaneous intracranial hypotension should be included in the differential diagnosis of pseudo-SAH.

ANAPHYLACTIC REACTIONS TO FIBRIN SEALANT INJECTION FOR SPONTANEOUS SPINAL CSF LEAKS

Spontaneous intracranial hypotension due to a spontaneous spinal CSF leak is an important cause of new-onset headaches, particularly in young and middle-aged adults.1 Treatment has traditionally involved epidural blood patching or surgical CSF leak repair if conservative treatment, e.g., bed rest, fails.1 Recently, percutaneous placement of fibrin sealant has emerged as an alternate therapy.1-3 The fibrin sealant is injected through a large-bore needle into the epidural space at the site of the CSF leak. Allergic reactions following topical placement of fibrin sealants are caused by the presence of aprotinin, a proteinase inhibitor derived from bovine lung, but they are extremely rare (0.005% of applications).4-6 Fibrin sealants contain a small amount of aprotinin to prevent lysis of the clot. Allergic reactions following intravascular administration of aprotinin during cardiac surgery are more common, occurring in less than 0.1% of initial applications but in 3% upon re-exposure.6 In approving aprotinin, the Food and Drug Administration recommended against its …

Reversal of coma with an injection of glue.

In June, 2006, a 68-year-old man was transferred to our hospital in a coma. He had a 2-day history of new-onset generalised headache followed by a decrease in his level of consciousness. He was on warfarin for atrial fi brillation. There was no history of trauma. On examination, the Glasgow coma scale score was 7 (E1 M4 V2) and there were bilateral Babinski signs. CT showed bilateral acute-on-chronic subdural haematomas (fi gure A). Laboratory test results showed a prolonged prothrombin time of 27·3 s (normal 10·6–14·0) and an INR of 2·4 (normal 0·8–1·3). We administered fresh frozen plasma. On further questioning, the patient’s wife revealed that his headache had been exquisitely positional, occurring only when he was upright and resolving completely within 1–2 min when he lay down. MRI confi rmed the clinical suspicion of spontaneous intracranial hypotension: it showed sagging of the brain, enhancement of the pachymeninges, and subdural fl uid collections (fi gure B). The patient was placed in the Trendelenburg position at a 45° angle, following which his level of consciousness improved rapidly (Glasgow coma scale score 14 [E4 M6 V4]). CT myelography showed an opening pressure of 3 cm water (normal 6·5–19·5) and a thoracic meningeal diverticulum associated with a cerebrospinal fl uid (CSF) leak. The patient received a lumbar epidural blood patch of 50 mL autologous blood. The patient then regained full consciousness for about 48 h, after which he deteriorated with a widely fl uctuating level of consciousness, his Glasgow coma scale scores varying between 6 and 14 depending on his position. 2 mL fi brin glue (Tisseel, Baxter BioScience, Westlake Village, CA, USA) was administered percutaneously through an 18 gauge needle at the site of the CSF leak. The next day, the patient was able to walk; he had a normal sensorium and no headache. An MRI scan showed that the brain was sagging less and the subdural haematomas were smaller; the pachymeninges were no longer enhanced. When last seen at follow-up in January, 2007, the patient was well. Spontaneous intracranial hypotension is caused by a spontaneous spinal CSF leak and is an important cause of new headaches in young and middle-aged adults. Mechanical factors combine with an underlying connective-tissue disorder to produce the CSF leak. Spontaneous intracranial hypotension is not rare, but it is frequently misdiagnosed. A positional headache is the prototypical symptom but other headache patterns occur as well. Various associated clinical manifestations have been reported, including coma: which, in this case, was caused by severe sagging of the brain leading to diencephalic deformation. Subdural haematomas are found in about 20% of cases. The typical MRI fi ndings are subdural fl uid collections, enhancement of the pachymeninges, engorgement of venous structures, pituitary hyperaemia, and sagging of the brain (mnemonic, SEEPS). Treatments should be directed at the CSF leak. They include—in order of invasiveness— bed rest, epidural blood patching, percutaneous injection of fi brin glue, and surgical repair. Although subdural haematomas can appear quite ominous, with a signifi cant mass eff ect, their primary treatment is rarely indicated. Indeed, evacuation of subdural haematomas in the setting of spontaneous intracranial hypotension is associated with a high risk of worsening or recurrence of the subdural haematomas if the CSF leak is left untreated. Careful history-taking is therefore required when patients present with new-onset headaches and coma. In this case, the subdural haematomas could easily have been attributed solely to the warfarin use, even in the absence of any trauma; the coma could have been attributed (incorrectly) to the subdural haematomas: but the positional feature of the headaches suggested the diagnosis of spontaneous intracranial hypotension.

CSF–venous fistula in spontaneous intracranial hypotension

Spontaneous intracranial hypotension (SIH) is an important cause of new daily persistent headaches.1 In most patients, the underlying cause is a CSF leak, always at the level of the spine.2 Once escaped into the epidural space, CSF is rapidly absorbed by the spinal epidural venous plexus, which is often maximally dilated in the setting of SIH. With conventional imaging, the presence of contrast in epidural veins has not been demonstrated in SIH, but indirect evidence for rapid venous absorption such as contrast in the renal collection system on CT myelography or early activity of tracer in the bladder on nuclear cisternography is common.1 We report the radiographic demonstration of direct CSF–venous fistulae in patients with SIH using digital subtraction myelography (DSM). DSM allows real-time high-resolution imaging of contrast injected through a lumbar puncture.3–5

A classification system of spontaneous spinal CSF leaks

Objective: Spontaneous spinal CSF leaks cause spontaneous intracranial hypotension but no systematic study of the different types of these CSF leaks has been reported. Based on our experience with spontaneous intracranial hypotension, we propose a classification system of spontaneous spinal CSF leaks. Methods: We reviewed the medical records, radiographic studies, operative notes, and any intraoperative photographs of a group of consecutive patients with spontaneous intracranial hypotension. Results: The mean age of the 568 patients (373 [65.7%] women) was 45.7 years. Three types of CSF leak could be identified. Type 1 CSF leaks consisted of a dural tear (151 patients [26.6%]) and these were almost exclusively associated with an extradural CSF collection. Type 1a represented ventral CSF leaks (96%) and type 1b posterolateral CSF leaks (4%). Type 2 CSF leaks consisted of meningeal diverticula (240 patients [42.3%]) and were the source of an extradural CSF collection in 53 of these patients (22.1%). Type 2a represented simple diverticula (90.8%) and type 2b complex meningeal diverticula/dural ectasia (9.2%). Type 3 CSF leaks consisted of direct CSF-venous fistulas (14 patients [2.5%]) and these were not associated with extradural CSF collections. A total of 163 patients (28.7%) had an indeterminate type and extradural CSF collections were noted in 84 (51.5%) of these patients. Conclusions: We identified 3 types of spontaneous spinal CSF leak in this observational study: the dural tear, the meningeal diverticulum, and the CSF-venous fistula. These 3 types and the presence or absence of extradural CSF form the basis of a comprehensive classification system.

Resolution of pachymeningeal enhancement following dural puncture and blood patch

We describe thickening and contrast enhancement of the intracranial pachymeninges, revealed by MRI in a patient with presumed low-pressure headache following dural puncture and a blood patch. The clinical and radiological abnormalities resolved within 2 weeks.

Digital subtraction myelography for the identification of spontaneous spinal CSF-venous fistulas.

OBJECTIVE In most patients with spontaneous intracranial hypotension, a spinal CSF leak can be found, but occasionally, no leak can be demonstrated despite extensive spinal imaging. Failure to localize a CSF leak limits treatment options. The authors recently reported the discovery of CSF-venous fistulas in patients with spontaneous intracranial hypotension and now report on the use of digital subtraction myelography in patients with spontaneous intracranial hypotension but no CSF leak identifiable on conventional spinal imaging (i.e., non-digital subtraction myelography). METHODS The patient population consisted of 53 consecutive patients with spontaneous intracranial hypotension who underwent digital subtraction myelography but in whom no spinal CSF leak (i.e., presence of extradural CSF) was identifiable on conventional spinal imaging. RESULTS The mean age of the 33 women and 20 men was 53.4 years (range 29-71 years). A CSF-venous fistula was demonstrated in 10 (19%) of the 53 patients. A CSF-venous fistula was found in 9 (27%) of the 33 women and in 1 (5%) of the 20 men (p = 0.0697). One patient was treated successfully with percutaneous injection of fibrin sealant. Nine patients underwent surgery for the fistula. Surgery resulted in complete resolution of symptoms in 8 patients (follow-up 7-25 months), and in 1 patient, symptoms recurred after 4 months. CONCLUSIONS In this study, the authors found a CSF-venous fistula in approximately one-fifth of the patients with recalcitrant spontaneous intracranial hypotension but no CSF leak identifiable on conventional spinal imaging. The authors suggest that digital subtraction myelography be considered in this patient population.

Spontaneous retroclival hematoma in pituitary apoplexy: case series

OBJECT Pituitary apoplexy is a rare and potentially life-threatening disorder that is most commonly characterized by a combination of sudden headache, visual disturbance, and hypothalamic/hormonal dysfunction. In many cases, there is hemorrhagic infarction of an underlying pituitary adenoma. The resulting clinical symptoms are due to compression of the remaining pituitary, cavernous sinuses, or cranial nerves. However, there are only 2 case reports in the literature describing spontaneous retroclival expansion of hemorrhage secondary to pituitary apoplexy. Ten cases of this entity with a review of the literature are presented here. METHODS This is a single-institution retrospective review of 2598 patients with sellar and parasellar masses during the 10-year period between 1999 and 2009. The pituitary and brain MRI and MRI studies were reviewed by 2 neuroradiologists for evidence of apoplexy, with particular attention given to retroclival extension. RESULTS Eighteen patients (13 men and 5 women; mean age 54 years) were identified with presenting symptoms of sudden onset of headache and ophthalmoplegia, and laboratory findings consistent with pituitary apoplexy. Ten of these patients (8 men and 2 women; mean age 55 years) had imaging findings consistent with retroclival hematoma. CONCLUSIONS Retroclival hemorrhage was seen in the majority of cases of pituitary apoplexy (56%), suggesting that it is more common than previously thought.