Postoperative Spinal Cerebrospinal Fluid-Venous Fistulas Associated With Dural Tears in Patients With Intracranial Hypotension or Superficial Siderosis-A Digital Subtraction Myelography Study.

BACKGROUND: Postoperative spinal cerebrospinal fluid (CSF) leaks are common but rarely cause extensive CSF collections that require specialized imaging to detect the site of the dural breach. OBJECTIVE: To investigate the use of digital subtraction myelography (DSM) for patients with extensive extradural CSF collections after spine surgery. METHODS: A retrospective review was performed to identify a consecutive group of patients with extensive postoperative spinal CSF leaks who underwent DSM. RESULTS: Twenty-one patients (9 men and 12 women) were identified. The mean age was 46.7 years (range, 17-75 years). The mean duration of the postoperative CSF leak was 3.3 years (range, 3 months to 21 years). MRI showed superficial siderosis in 6 patients. DSM showed the exact location of the CSF leak in 19 (90%) of the 21 patients. These 19 patients all underwent surgery to repair the CSF leak, and the location of the CSF leak could be confirmed intraoperatively in all 19 patients. In 4 (19%) of the 21 patients, DSM also showed a CSF-venous fistula at the same location as the postoperative dural tear. CONCLUSION: In this study, DSM had a 90% detection rate of visualizing the exact site of the dural breach in patients with extensive postoperative spinal CSF leaks. The coexistence of a CSF-venous fistula in addition to the primary dural tear was present in about one-fifth of patients. The presence of a CSF-venous fistula should be considered if CSF leak symptoms persist in spite of successful repair of a durotomy.

Three-dimensional simultaneous brain T1 , T2 , and ADC mapping with MR Multitasking.

PURPOSE: To develop a simultaneous T1 , T2 , and ADC mapping method that provides co-registered, distortion-free images and enables multiparametric quantification of 3D brain coverage in a clinically feasible scan time with the MR Multitasking framework. METHODS: The T1 /T2 /diffusion weighting was generated by a series of T2 preparations and diffusion preparations. The underlying multidimensional image containing 3 spatial dimensions, 1 T1 weighting dimension, 1 T2 -preparation duration dimension, 1 b-value dimension, and 1 diffusion direction dimension was modeled as a 5-way low-rank tensor. A separate real-time low-rank model incorporating time-resolved phase correction was also used to compensate for both inter-shot and intra-shot phase inconsistency induced by physiological motion. The proposed method was validated on both phantom and 16 healthy subjects. The quantification of T1 /T2 /ADC was evaluated for each case. Three post-surgery brain tumor patients were scanned for demonstration of clinical feasibility. RESULTS: Multitasking T1 /T2 /ADC maps were perfectly co-registered and free from image distortion. Phantom studies showed substantial quantitative agreement ( R2=0.999 ) with reference protocols for T1 /T2 /ADC. In vivo studies showed nonsignificant T1 (P = .248), T2 (P = .97), ADC (P = .328) differences among the frontal, parietal, and occipital regions. Although Multitasking showed significant differences of T1 (P = .03), T2 (P < .001), and ADC (P = .001) biases against the references, the mean bias estimates were small (ΔT1 % < 5%, ΔT2 % < 7%, ΔADC% < 5%), with all intraclass correlation coefficients greater than 0.82 indicating "excellent" agreement. Patient studies showed that Multitasking T1 /T2 /ADC maps were consistent with the clinical qualitative images. CONCLUSION: The Multitasking approach simultaneously quantifies T1 /T2 /ADC with substantial agreement with the references and is promising for clinical applications.

False localizing signs of spinal CSF-venous fistulas in spontaneous intracranial hypotension: report of 2 cases.

A spinal CSF-venous fistula is one of three specific types of spinal CSF leak that can be seen in patients with spontaneous intracranial hypotension (SIH). They are best demonstrated on specialized imaging, such as digital subtraction myelography (DSM) or dynamic myelography, but often they are diagnosed on the basis of increased contrast density in the draining veins (the so-called hyperdense paraspinal vein sign) on early postmyelography CT scans. The authors report on 2 patients who underwent directed treatment (surgery in one patient and glue injection in the other) based on the hyperdense paraspinal vein sign, in whom the actual site of the fistula did not correspond to the level or laterality of the hyperdense paraspinal vein sign. The authors suggest consideration of DSM or dynamic myelography prior to undertaking treatment directed at these fistulas.

Coma: A serious complication of spontaneous intracranial hypotension.

OBJECTIVE: To review our experience with patients with spontaneous intracranial hypotension (SIH) and coma because, although disorders of consciousness may complicate SIH, no comprehensive study of such patients has been reported. METHODS: Using a prospectively maintained registry, we identified all patients with SIH in whom coma developed. Patients or their caregivers/families were contacted for follow-up. Patients were compared to a cohort of patients with SIH without coma. RESULTS: The mean age of the 12 men and 3 women with SIH was 56.2 years (range 34-72 years) at the time of onset of coma. In one-third of patients, coma developed after craniotomy for subdural hematomas or for an unrelated intracranial pathology. Imaging showed brain sagging, including bilateral temporal lobe herniation, in all 15 patients and brainstem edema in 8 patients (53%). Overall, coma was reversible in 7 of 15 patients treated with epidural blood patches, in 2 of 4 treated with percutaneous glue injections, and in 6 of 6 treated surgically. Only 1 patient had residual neurologic deficit related to coma (Glasgow Outcome Scale score 4 [moderate disability]). Compared to patients with SIH without coma (n = 568), those with coma were older, more often were male, and more often underwent surgery. CONCLUSIONS: Coma in SIH is rare, reversible, and invariably associated with brain sagging. Coma due to SIH may be refractory to the usual percutaneous procedures, and surgical closure of the CSF leak may be required to regain consciousness.

Behavioral Variant Frontotemporal Dementia as a Serious Complication of Spontaneous Intracranial Hypotension.

BACKGROUND: Behavioral variant frontotemporal dementia (bvFTD) is a devastating early onset dementia. Symptoms of bvFTD may be caused by spontaneous intracranial hypotension (SIH), a treatable disorder, but no comprehensive study of such patients has been reported. OBJECTIVE: To describe detailed characteristics of a large cohort of patients with SIH and symptoms of bvFTD. METHODS: We identified patients with SIH who met clinical criteria for bvFTD. Patients were compared to a cohort of SIH patients without bvFTD. RESULTS: The mean age for the 21 men and 8 women was 52.9 yr (range, 37-65 yr). All 29 patients with bvFTD symptoms had hypersomnolence. Magnetic resonance imaging showed brain sagging in all patients, cerebrospinal fluid (CSF) opening pressure low in about half of patients, but a spinal CSF leak could not be detected in any patient. All patients underwent epidural blood patching, but 26 patients eventually underwent 1 or more surgical procedures. Overall, a good outcome was obtained in 21 patients (72%); 20 (91%) of 22 patients who had not undergone prior Chiari surgery compared to 1 (14%) of 7 patients who did undergo Chiari surgery (P < .003). Compared to SIH patients without symptoms of bvFTD (n = 547), those with bvFTD symptoms were older, more often male, less often demonstrated CSF leak on spinal imaging, and more often underwent surgery (P < .02). CONCLUSION: bvFTD in SIH is rare and associated with brain sagging and hypersomnolence. Spinal CSF leaks are rarely detected. bvFTD symptoms are often refractory to the usual percutaneous procedures but most patients can be cured.

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.

False localizing sign of cervico-thoracic CSF leak in spontaneous intracranial hypotension.

OBJECTIVE: Spontaneous spinal CSF leaks are an important cause of new-onset headaches. Such leaks are reported to be particularly common at the cervico-thoracic junction. The authors undertook a study to determine the significance of these cervico-thoracic CSF leaks. METHODS: The patient population consisted of a consecutive group of 13 patients who underwent surgery for CSF leak repair based on CT myelography showing CSF extravasation at the cervico-thoracic junction but without any evidence of an underlying structural lesion. RESULTS: The mean age of the 9 women and 4 men was 41.2 years. Extensive extrathecal longitudinal CSF collections were demonstrated in 11 patients. At surgery, small leaking arachnoid cysts were found in 2 patients. In the remaining 11 patients, no clear source of CSF leakage could be identified at surgery. Resolution of symptoms was achieved in both patients with leaking arachnoid cysts, but in only 3 of the 11 patients with negative intraoperative findings. Postoperative spinal imaging was performed in 9 of the 11 patients with negative intraoperative findings and showed persistence of the longitudinal intraspinal extradural CSF. Further imaging revealed the site of the CSF leak to be ventral to the thoracic spinal cord. Five of these patients underwent microsurgical repair of the ventral CSF leak with resolution of symptoms in all 5 patients. CONCLUSIONS: Cervico-thoracic extravasation of dye on myelography does not necessarily indicate the site of the CSF leak. Treatment directed at this site should not be expected to have a high probability of sustained improvement of symptoms.

Differentiation of solitary brain metastasis from glioblastoma multiforme: a predictive multiparametric approach using combined MR diffusion and perfusion.

INTRODUCTION: Solitary brain metastasis (MET) and glioblastoma multiforme (GBM) can appear similar on conventional MRI. The purpose of this study was to identify magnetic resonance (MR) perfusion and diffusion-weighted biomarkers that can differentiate MET from GBM. METHODS: In this retrospective study, patients were included if they met the following criteria: underwent resection of a solitary enhancing brain tumor and had preoperative 3.0 T MRI encompassing diffusion tensor imaging (DTI), dynamic contrast-enhanced (DCE), and dynamic susceptibility contrast (DSC) perfusion. Using co-registered images, voxel-based fractional anisotropy (FA), mean diffusivity (MD), K(trans), and relative cerebral blood volume (rCBV) values were obtained in the enhancing tumor and non-enhancing peritumoral T2 hyperintense region (NET2). Data were analyzed by logistic regression and analysis of variance. Receiver operating characteristic (ROC) analysis was performed to determine the optimal parameter/s and threshold for predicting of GBM vs. MET. RESULTS: Twenty-three patients (14 M, age 32-78 years old) met our inclusion criteria. Pathology revealed 13 GBMs and 10 METs. In the enhancing tumor, rCBV, K(trans), and FA were higher in GBM, whereas MD was lower, neither without statistical significance. In the NET2, rCBV was significantly higher (p = 0.05) in GBM, but MD was significantly lower (p < 0.01) in GBM. FA and K(trans) were higher in GBM, though not reaching significance. The best discriminative power was obtained in NET2 from a combination of rCBV, FA, and MD, resulting in an area under the curve (AUC) of 0.98. CONCLUSION: The combination of MR diffusion and perfusion matrices in NET2 can help differentiate GBM over solitary MET with diagnostic accuracy of 98%.

Anti-NMDA encephalitis: an uncommon, autoimmune mediated form of encephalitis.

We report an interesting case of a 19 year old female with findings on MRI suggestive of viral encephalitis. An extensive workup was negative for infectious causes and she was subsequently diagnosed with anti-NMDA encephalitis. Anti-NMDA encephalitis is a highly lethal but treatable form of autoimmune encephalitis that has recently been characterized. It is frequently found in young women and associated with an underlying teratoma. Although rare, this diagnosis should be considered in young females for whom a rapid onset of encephalitis cannot be explained by more common causes.

Lack of causal association between spontaneous intracranial hypotension and cranial cerebrospinal fluid leaks.

OBJECT: Spontaneous intracranial hypotension is an important cause of headaches and an underlying spinal CSF leak can be demonstrated in most patients. Whether CSF leaks at the level of the skull base can cause spontaneous intracranial hypotension remains a matter of controversy. The authors' aim was to examine the frequency of skull base CSF leaks as the cause of spontaneous intracranial hypotension. METHODS: Demographic, clinical, and radiological data were collected from a consecutive group of patients evaluated for spontaneous intracranial hypotension during a 9-year period. RESULTS: Among 273 patients who met the diagnostic criteria for spontaneous intracranial hypotension and 42 who did not, not a single instance of CSF leak at the skull base was encountered. Clear nasal drainage was reported by 41 patients, but a diagnosis of CSF rhinorrhea could not be established. Four patients underwent exploratory surgery for presumed CSF rhinorrhea. In addition, the authors treated 3 patients who had a postoperative CSF leak at the skull base following the resection of a cerebellopontine angle tumor and developed orthostatic headaches; spinal imaging, however, demonstrated the presence of a spinal source of CSF leakage in all 3 patients. CONCLUSIONS: There is no evidence for an association between spontaneous intracranial hypotension and CSF leaks at the level of the skull base. Moreover, the authors' study suggests that a spinal source for CSF leakage should even be suspected in patients with orthostatic headaches who have a documented skull base CSF leak.

Treatment of spontaneous intracranial hypotension with percutaneous placement of a fibrin sealant. Report of four cases.

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.