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Advances in the Diagnosis and Management of Intracranial Hypotension: Lessons Learned from Treatment of 30 Patients 2013

Category Interventional Austin C. Bourgeois, MD, BS
Eric Biesbroeck, MD, BS
Ted Chang, MD, BA
Jerome Kao, MD
Geoffrey Laing, MD, BS
Purpose Headache is one of the most common symptoms leading to imaging by computed tomography (CT) and magnetic resonance imaging (MRI).  A large proportion of CT and MRI imaging reveals no causative etiology to explain the patient’s symptoms. Intracranial hypotension is an often-underestimated cause of headache, which classically increases in severity in the upright position.  It may be spontaneous in nature, or iatrogenic, which usually results from spine surgery or lumbar puncture (LP). Given the vague clinical symptoms and often-subtle imaging findings, many of these studies are interpreted as normal. Aside from postural headache, clinical symptoms of intracranial hypotension are commonly variable, including visual disturbances and cranial nerve palsy.  Rare cases of severe encephalopathy and death have been reported as well.  This educational presentation examines recent cases of intracranial hypotension in a tertiary care hospital, including a focused discussion of:  1) Classic imaging findings in the spine and brain by CT and MRI.  2) Diagnostic criteria.  3) Treatment techniques and outcomes.  Materials & Methods Following IRB approval, a retrospective medical record review was performed.  30 patients with clinical features of intracranial hypotension and CT or MR imaging performed within 60 days of diagnosis were reviewed. Pre-procedural, intraprocedural, and post procedural cross-sectional imaging studies were reviewed for radiologic evidence of intracranial hypotension. Patching procedures were performed utilizing CT-fluoroscopy guidance.  22-guage spinal needles were inserted into the epidural space via both interlaminar and transforminal approaches.  Loss-of-resistance technique and injection of 2-10cc isovue-300 contrast were utilized to confirm epidural location.   Up to 20cc of the patients own blood or Vitagel ™ were employed into the epidural space to achieve patching.  Results The classic imaging characteristics associated with intracranial hypotension include: 1) Slit-like lateral ventricles 2) Midbrain “slumping” 3) Subdural hygromas 4) Extradural CSF collections in the spine 5)  Diffuse dural thickening and enhancement 6) Perineural root sleeve cysts or flaring  7)  Venous dural sinus distension.  These findings, while highly suggestive of intracranial hypotension, are present with relative infrequency.  Conclusion CT and MRI maintain a primary role in the evaluation of headache. The recognition of the classic and less common findings of intracranial hypotension is critical in providing adequate therapy and preventing unnecessary, invasive, and ineffective therapies. At out institution, thin slice T2 MRI images of the spine have proven beneficial in localizing CSF leak.  Patching procedures utilizing transforminal and interlaminar approaches approaches are generally safe and efficacious for treating intracranial hypotension.   References Wouter I. Schievink.  Spontaneous Spinal Cerebrospinal Fluid Leaks and Intracranial Hypotension.  JAMA. 2006;295(19):2286-2296 (doi:10.1001/jama.295.19.2286) W.I. Schievink,, M.M. Maya, C. Louy, F.G. Moser, and J. Tourje.  Diagnostic Criteria for Spontaneous Spinal CSF Leaks and Intracranial Hypotension.AJNR Am J Neuroradiol May 2008 29: 853-856. Barry M. Rabin, Sudipta Roychowdhury, Joel R. Meyer, Bruce A. Cohen, Kenneth D. LaPat, and Eric J. Russell.  Spontaneous Intracranial Hypotension: Spinal MR Findings.  AJNR Am J Neuroradiol 19:1034 –1039, June 1998 R.I. Farb, R. Forghani, S.K. Lee, D.J. Mikulis, R. Agid.  The Venous Distension Sign: A Diagnostic Sign of Intracranial Hypotension at MR Imaging of the Brain.  doi: 10.3174/ajnr.A0621AJNR September 2007 28: 1489-149.