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Recurrent Spontaneous Intracranial Hypotension With Rapid Csf Leak Requiring Digital Subtraction Myelography 2013

Category Interventional Iftikhar Ahmad
Stephan Kralik
Chang Y. Ho
Annette C. Douglas
Purpose 1. To demonstrate the brain and spinal imaging features in recurrent spontaneous intracranial hypotension(SIH) in a pediatric patient with clinically diagnosed Ehlers-Danlos Syndrome evaluated by traditional imaging techniques and Digital Subtraction Myelography (DSM). 2. To discuss, how to meet the  challenges to a correct SIH diagnosis, and  localize a rapid CSF leak source. Materials & Methods A 15 year-old female patient presented to an outside hospital emergency department with gradual worsening headaches of moderate intensity over the period of 3 weeks that was associated with photophobia and hypacusis. Prior to presentation, she had been treated with propranolol and Imitrex for migraine headaches without a favorable result. The external MRI was reported as abnormal meningeal enhancement concerning for meningitis and the patient was transferred for inpatient neurology admission and treatment for meningitis. Review of the external MRI demonstrated 6 mm of caudal displacement of the cerebellar tonsils, prominent pituitary gland, obliteration of pre pontine, suprasellar and interpeduncular cisterns, mild distention of the dural venous sinuses, and diffuse smooth pachymenigeal enhancement consistent with SIH rather than meningitis.  She had no pertinent history of trauma, LP or other related procedures. Spinal MRI was recommended and demonstrated arachnoid cysts in posterior thecal sac at T3-T4 and T5-T7, the largest one at T5-T7 with copious subdural clear fluid. Lumbar puncture was performed with a CSF pressure of 6cm; a blood patch was performed without improvement of symptoms. Spinal CT myelography(CTM) was performed and demonstrated extensive extradural contrast leak diffusely filling the spinal canal and surrounding several of the unusual CSF loculations. Consequently, identification of one or more sites of leak could not be determined. Options at this point were to perform multiple sites of surgical exploration, or perform a different technique to pinpoint a  rapid CSF leak. A DSM was therefore determined to be of value in the patient. Using digital subtraction myelography as described by Hoxworth et al, there was high quality diagnostic imaging delineation of the spinal cord and nerve roots up at the T3-4 level.  There was a sudden and dramatic extravasation of contrast at the level of the upper arachnoid cyst at T3-T4 level that had been seen on MR spine and CTM.   A total of 18 ml of Isovue was injected at the rate of 1cc /sec. In addition there were small dural diverticula along the exiting nerve roots at multilevel, the largest being at T10-T11. Consequently, surgical exploration was performed and a T3-T4 laminectomy demonstrated a large arachnoid cyst with a dural defect leaking CSF that was repaired. The postop period was uneventful with dramatic improvement of symptoms and patient discharged home. She recovered well and resumed her school. After 6 weeks of discharge she again developed moderate- severe headache with hypacusis similar to one she experience before the first surgery. A DSM demonstrated brisk leak at around T11 likely from previously visualized largest dural  diverticla with subsequent CTM showed copious amount contrast in subdural space.  Given her dramatic symptomatology and the previous failure to improve with a blood patch, it was prudent to perform a surgical repair of the leak.  Surgical exploration demonstrated a cystic area just inferior to the nerve root at T11 that was leaking.  The cyst was surgically resected and dural repair was performed. She again presented with moderate headache however without hypacusis in ER after 8 weeks of 2nd repair. Digital subtraction myelogram was suggestive of no brisk CSF leak.  However at CTM there was suspicion of very slow leak at around the first surgery site.  She was conservatively managed and doing well since then Results Spontaneous Intracranial hypotension (SIH) is an uncommon diagnosis that is related to a dural defect that cannot be attributed to a prior procedure or trauma . Clinical symptoms include orthostatic headache, nausea, vomiting, photophobia, hearing loss and rarely decreased level of consciousness. The brain MRI imaging findings include any combination of sagging of the brain, smooth pachymeningeal enhancement, enlarged dural sinuses, enlargement of pituitary gland, and subdural collections . Surgical spinal exploration may find defects with meningeal diverticula along the spinal nerve roots, total absence of the dural covering, often at the level of the exiting nerve roots, and frank holes or tears. Approximately 2/3rd of patients with SIH demonstrate finding suggestive of connective tissue disorders including Marfan or Ehlers-Danlos syndromes . Spinal CT or MR myelography is commonly performed to identify the site of a spinal leak in patients that may require surgical or interventional procedures.  Spinal leaks are frequently slow, intermittent or not detectable, and require delayed spinal CT or MR myelography for detection.  Occasionally a rapid CSF leak may be encountered and spinal CT myelography (CTM) may demonstrate an unexpected extensive contrast leak which compromises accurate identification of the leak site. Digital subtraction myelography and dynamic CT myelography are novel techniques that have been described to localize the rapid CSF leaks  in these patients, particularly if multiple anatomic abnormalities are present. DSM has recently been  described however its application in a pediatric patient in context of SIH has not been previously reported to the best of our knowledge. We will also adress the radaition dose issue in a pediatric patient vs benefits achieved. Conclusion Spontaneous Intracranial hypotension is uncommon in the pediatric population but may occur with connective tissue disorder like Ehlers-Danlos Syndrome. In the setting of a rapid CSF leak, DSM may be very helpful  to localize a rapid CSF leak and thus avoiding extensive surgical exploration , and to guide an interventional procedure. As such DSM is extremly helpful to pinpoint rapid CSF leaks and helpful to avoid an inadvertent non targeted surgery. References (1) Ghavanini AA, Scott CA, Chan DK, Tang-Wai DF. Management of patients with spontaneous intracranial hypotension causing altered level of consciousness: Report of two cases and review of literature. Cephalalgia 2012 Nov 9. (2) Yuh EL, Dillon WP. Intracranial hypotension and intracranial hypertension. Neuroimaging Clin N Am 2010 Nov;20(4):597-617. (3) Veeravagu A, Gupta G, Jiang B, Berta SC, Mindea SA, Chang SD. Spontaneous intracranial hypotension secondary to anterior thoracic osteophyte: Resolution after primary dural repair via posterior approach. Int J Surg Case Rep 2012 Aug 2;4(1):26-29. (4) Albes G, Weng H, Horvath D, Musahl C, Bazner H, Henkes H. Detection and treatment of spinal CSF leaks in idiopathic intracranial hypotension. Neuroradiology 2012 Jul 6. (5) Hoxworth JM, Patel AC, Bosch EP, Nelson KD. Localization of a rapid CSF leak with digital subtraction myelography. AJNR Am J Neuroradiol 2009 Mar;30(3):516-519. (6) Hoxworth JM, Trentman TL, Kotsenas AL, Thielen KR, Nelson KD, Dodick DW. The role of digital subtraction myelography in the diagnosis and localization of spontaneous spinal CSF leaks. AJR Am J Roentgenol 2012 Sep;199(3):649-653.