 |
| About Bioline | All Journals | Testimonials | Membership | News |
|
||||||
|
||||||
Neurology India, Vol. 59, No. 5, September-October, 2011, pp. 761-762 Letter to Editor An uncommon site of dural tear in a case of spontaneous intracranial hypotention demonstrated using contrast enhanced magnetic resonance cisternography Maya D Bhat1, Chandrajit Prasad1, Nupur Pruthi2, MK Vasudev1, GG Sharath Kumar1 1 Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore, Karnataka, India PMID: 22019666 DOI: 10.4103/0028-3886.86556 Idiopathic or spontaneous intracranial hypotension (SIH) is a rare disorder with a prevalence of about 1 per 50,000 population [1] and presents with characteristic orthostatic headaches. [2] The diagnostic criteria also include the characteristic magnetic resonance imaging (MRI). [3] SIH almost invariably results from spontaneous cerebrospinal fluid (CSF) leak. [4] Several imaging techniques have been studied to demonstrate the site of dural leak, but none of the techniques were reliable. [5] We report an unusually high dural tear at the C2 level demonstrated on MR cisternography. A 35-year-old lady, otherwise healthy, presented with acute-onset holocranial orthostatic headache of one and half months duration which progressed over the next 6 weeks. She also had dull interscapular pain, vomiting, and eye pain. The headache used to get relived on lying down and used to aggravate on bending forward and sitting up. There was no history of trauma. She had similar headache 10 years back just following delivery which subsided with bed rest. Neurologic examinations revealed bilateral early papilloedema and terminal neck stiffness. Computed tomography (CT) showed bilateral subdural hygromas. Initial cranial MRI revealed diffuse pachymeningeal enhancement with bilateral subdural hematomas, tonsillar descent, and decreased mamillopontine distance [Figure - 1]. Spinal MRI using high resolution T2WI and steady state imaging revealed a hyperintense collection in the epidural space from C1-C2. Intrathecal gadolinium-enhanced MR cisternography was obtained using high resolution T1W fat-saturated images of the entire spine. A distinct tear was seen at the C2 level on the left side with contrast extravasation in the epidural space [Figure - 2] and [Figure - 3]. Subsequently the patient underwent surgery with dural repair. Postoperatively, she had complete relief of orthostatic headache. Postoperative MRI of the spine did not reveal any epidural collection [Figure - 4]. SIH was first described by Schaltenbrand and is more common in females (3:1). The characteristic feature is orthostatic headache and other less common features include neck stiffness, nausea and vomiting, cranial neuropathies causing vertigo, tinnitus, photophobia, and diplopia. The characteristic MRI features include diffuse and nonnodular intense thickening and pachymeningeal enhancement with leptomeningeal sparing, subdural collections, downward displacement of brain with sagging of brain stem, engorgement of venous sinuses and enlargement of pitutiary gland. [6] SIH almost always results from a spontaneous CSF leak, often from a spinal dural defect. [4] Previously documented sites of dural tear include cervicothoracic, thoracic, and upper lumbar levels. [5] In our patient, the tear was located at the C1-C2 level, posterolaterally on the left side. Since the defect was large, epidural patch therapy was not contemplated and the patient underwent partial left C2 laminectomy. The dural rent was identified at the C2 nerve root sleeve and was closed using gel foam and muscle patch. In our patient, the dural tear could be demonstrated by MR cisternography which was corroborated by the intraopertive findings. Contrast enhanced MR cisternography was first described by Di Chiro et al. [7] to detect intracranial CSF fistulae in Beagle dogs. Intrathecal gadopentetate dimegulmine administration in 95 people has been found to be safe with no complications. [8] Most of the studies have used 0.5 ml of intrathecal contrast diluted in 5 ml of CSF given slowly over 3-5 min. Contrast enhanced MR cisternography serves as a useful diagnostic method in cases where the site dural defect is difficult to identify. References
Copyright 2011 - Neurology India The following images related to this document are available:Photo images[ni11226f1.jpg] [ni11226f3.jpg] [ni11226f2.jpg] [ni11226f4.jpg] |
| |||||||||
