Abstracts 2012

Hoxworth JM, Trentman TL, Kotsenas AL, Thielen KR, Nelson KD, Dodick DW.
Am J Roentgenol. 2012 Sep;199(3):649-53.
doi: 10.2214/AJR.11.8238.
Abstract
OBJECTIVE:
The objective of our study was to review the clinical utility of digital subtraction myelography for the diagnosis of spinal CSF leaks in patients with spontaneous intracranial hypotension (SIH) and those with superficial siderosis.
MATERIALS AND METHODS:
Procedure logs from 2007 to 2011 were reviewed to identify cases in which digital subtraction myelography was performed to diagnose spinal CSF leaks. Electronic medical records were reviewed to obtain information regarding diagnosis and outcome. For patients to be included in the study, preprocedural spinal MRI had to show an extradural fluid collection spanning more than one vertebral level and postmyelographic CT had to confirm the presence of an active CSF leak. If digital subtraction myelography successfully showed the site of the CSF leak, the location was documented.
RESULTS:
Eleven patients (seven men and four women; mean age, 49.0 years) underwent digital subtraction myelography during the study period. Six patients had SIH and five patients had superficial siderosis. The extradural fluid collection on spinal MRI averaged a length of 15.5 vertebral levels. Digital subtraction myelography successfully showed the site of the CSF leak in nine of the 11 patients, and all of the dural tears were located in the thoracic spine between T3 and T11.
CONCLUSION:
Digital subtraction myelography is a valuable diagnostic tool for the localization of rapid spinal CSF leaks and should be considered in patients who are clinically suspected to have a dural tear that is accompanied by a
longitudinally extensive extradural fluid collection on spinal MRI.
PMID: 22915407
Full text

Loya JJ, Mindea SA, Yu H, Venkatasubramanian C, Chang SD, Burns TC.
J Neurosurg. 2012 Sep;117(3):615-28.
doi: 10.3171/2012.4.JNS112030.
Abstract
Intracranial hypotension is a disorder of CSF hypovolemia due to iatrogenic or spontaneous spinal CSF leakage. Rarely, positional headaches may progress to coma, with frequent misdiagnosis. The authors review reported cases of verified intracranial hypotension-associated coma, including 3 previously unpublished cases, totaling 29. Most patients presented with headache prior to neurological deterioration, with positional symptoms elicited in almost half. Eight patients had recently undergone a spinal procedure such as lumbar drainage. Diagnostic workup almost always began with a head CT scan. Subdural collections were present in 86%; however, intracranial hypotension was frequently unrecognized as the underlying cause. Twelve patients underwent one or more procedures to evacuate the collections, sometimes with transiently improved mental status. However, no patient experienced lasting neurological improvement after subdural fluid evacuation alone, and some deteriorated further. Intracranial hypotension was diagnosed in most patients via MRI studies, which were often obtained due to failure to improve after subdural hematoma (SDH) evacuation. Once the diagnosis of intracranial hypotension was made, placement of epidural blood patches was curative in 85% of patients. Twenty-seven patients (93%) experienced favorable outcomes after diagnosis and treatment; 1 patient died, and 1 patient had a morbid outcome secondary to duret hemorrhages. The literature review revealed that numerous additional patients with clinical histories consistent with intracranial hypotension but no radiological confirmation developed SDH following a spinal procedure. Several such patients experienced poor outcomes, and there were multiple deaths. To facilitate recognition of this treatable but potentially life-threatening condition, the authors propose criteria that should prompt intracranial hypotension workup in the comatose patient and present a stepwise management algorithm to guide the appropriate diagnosis and treatment of these patients.
PMID: 22725982
Full text

Carstensen M, Chaudhary N, Leung A, Ng W.
J Radiol Case Rep. 2012 Sep;6(9):1-9.
doi: 10.3941/jrcr.v6i9.1002.
Abstract
A patient with spontaneous intracranial hypotension due to a spinal cerebrospinal fluid (CSF) leak required localization of the leakage site prior to surgical management. Conventional, computed tomography and prone digital subtraction myelography failed to localize the dural tear, which was postulated to be dorsally located. We present here a digital subtraction myelographic approach to accurately localize a dorsal site of CSF leakage by injecting iodinated contrast via a lumbar drain with the patient in the supine position.
PMID: 23378882
full text: PMC3558254

Schievink WI, Schwartz MS, Maya MM, Moser FG, Rozen TD.
J Neurosurg. 2012 Apr;116(4):749-54.
doi: 10.3171/2011.12.JNS111474.
Abstract
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.
PMID: 22264184
full text: thejns.org/doi/pdf/10.3171/2011.12.JNS111474

Luetmer PH, Schwartz KM, Eckel LJ, Hunt CH, Carter RE, Diehn FE.
AJNR Am J Neuroradiol. 2012 Apr;33(4):690-4.
doi: 10.3174/ajnr.A2849.
Abstract
BACKGROUND AND PURPOSE:
Some patients with SIH have fast CSF leaks requiring dynamic CTM for localization; however, patients generally undergo conventional CTM before a dynamic study. Our aim was to determine whether findings on head MR imaging, spine MR imaging, or opening pressure measurements can predict fast spinal CSF leaks.
MATERIALS AND METHODS:
A retrospective review was performed on 151 consecutive patients referred for CTM to evaluate for spinal CSF leak. Head MR imaging was evaluated for diffuse dural enhancement and “brain sag,” and spine MR imaging for presence of an extradural fluid collection. The opening pressure was recorded. The CTM was scored as no leak, slow leak localized on conventional CTM, or fast leak that required dynamic CTM.
RESULTS:
Fast CSF leaks were identified in 32 (21%), slow leaks in 36 (24%), and no leak in 83 (55%) of 151 patients on initial CTM. There was significant association between spinal extra-arachnoid fluid on MR imaging and the presence of a fast leak (sensitivity 85%, specificity 79%, P < .0001). There was not significant association between fast leak and findings on head MR imaging (P = .27) or opening pressure (P = .30).
CONCLUSIONS:
If all patients with spinal extra-arachnoid CSF on MR imaging had been sent directly to dynamic CTM, repeat myelography would have been avoided in most patients with fast leaks (23 of 27; 85%). However, a minority of patients with slow or no leaks would have been converted from conventional to dynamic CTM (16 of 77; 21%). Spinal MR imaging is helpful in premyelographic evaluation of SIH.
PMID: 22194380
full text: ajnr.org/content/33/4/690.long

Akbar JJ, Luetmer PH, Schwartz KM, Hunt CH, Diehn FE, Eckel LJ.
AJNR Am J Neuroradiol. 2012 Mar;33(3):535-40.
doi: 10.3174/ajnr.A2815.
Abstract
BACKGROUND AND PURPOSE:
Localization of spinal CSF leaks in CSF hypovolemia is critical in directing focal therapy. In this retrospective review, our aim was to determine whether GdM was helpful in confirming and localizing spinal CSF leaks in patients in whom no leak was identified on a prior CTM.
MATERIALS AND METHODS:
Forty-one symptomatic patients with clinical suspicion of SIH were referred for GdM after undergoing at least 1 CTM between February 2002 and August 2010. A retrospective review of the imaging and electronic medical records was performed on each patient.
RESULTS:
In 17 of the 41 patients (41%), GdM was performed for follow-up of a previously documented leak at CTM. In the remaining 24 patients (59%), in whom GdM was performed for a suspected CSF leak, which was not identified on CTM, GdM localized the CSF leak in 5 of 24 patients (21%). In 1 of these 5 patients, GdM detected the site of leak despite negative findings on brain MR imaging, spine MR imaging, and CTM of the entire spine. Sixteen of 17 patients with previously identified leaks underwent interval treatment, and leaks were again identified in 12 of 17 (71%).
CONCLUSIONS:
GdM is a useful technique in the highly select group of patients who have debilitating symptoms of SIH, a high clinical index of suspicion of spinal CSF leak, and no demonstrated leak on conventional CTM. Intrathecal injection of gadolinium contrast remains an off-label use and should be reserved for those patients who fail conventional CTM.
PMID: 22173753
full text: ajnr.org/content/33/3/535.long

Leep Hunderfund AN, Mokri B.
J Neurol. 2012 Feb;259(2):306-10.
doi: 10.1007/s00415-011-6181-z.
Abstract
Orthostatic headache related to spontaneous cerebrospinal fluid leak (CSF) appears within 2 h of sitting or standing in most patients. However, longer delays to headache onset have been observed, including some patients who have headaches only in the afternoon. The objective of this study is to describe second-half-of-the-day headache as a manifestation of spontaneous CSF leak and propose potential mechanisms. From 142 patients evaluated by one of us (B.M.) during a 10-year period for spontaneous intracranial hypotension, those describing headache occurring exclusively in the afternoon accompanied by typical changes of intracranial hypotension on head MRI were retrospectively identified and their medical records reviewed. Five patients met our pre-defined inclusion criteria (5/142, 3.5%; three women; mean age 50 years). Second-half-of-the-day headache was an initial symptom of intracranial hypotension in one patient, spontaneously evolved from prior all-day orthostatic headache in one patient, and was a residual or recurrent symptom after epidural blood patch in three patients. Head MRI changes due to intracranial hypotension were decreased during second-half-of-the-day-headache compared to typical all-day orthostatic headache in three out of four patients. The timing of second-half-of-the-day headache and orthostatic headache in the clinical course of patients with spontaneous CSF leaks and related MRI findings suggest that second-half-of-the-day headache is likely a manifestation of a slowed or slow-flow CSF leak.
PMID: 21811806