OCCULT SPINAL DYSRAPHISM PRESENTING AS ASEPTIC MENINGITIS Introduction: Spinal dysraphism is known to have diverse consequences. We describe a case of chemical meningitis resulting from ruptured dermoid cyst with associated congenital dermal sinus. Case report A 17-years old college boy presented with three days of headache, vomiting, photophobia and low grade fever. The symptoms started after minor head injury. Headache was constant, moderate in intensity, over occipital and neck regions. Examination revealed signs of meningism. His fundoscopy showed papilledema. He was noticed to have a hyper- pigmented nodule at the back of his neck at level C3 of spine. CSF analysis had high white cell count (97% neutrophils), high protein(58mg/dl) with normal glucose level. CSF gram stain, culture, PCR for different viruses and mycobacterium were negative. MRI Spine showed multiple foci of fat densities in the subarachnoid space and within the ventricles, ( Fig: 1 A & B ) while the cervical CT scan and MRI showed evidence of an intradural extramedullary rounded mass at C1 level with a fibrous band extending from the dorsal aspect of the cervical spinal cord to the subcutaneous tissues at C1-C2 level. There was associated spina bifida of the posterior neural arch of C1& C2 ( Fig: 2 & 3) S. Nahrir 1, Eman Bakhsh 2, A. Alshanbari 1, K.A. Siddiqui 1, S. Sinha 1 1 Neurology, National Neurosciences Institute, King Fahad Medical City, Riyadh, 2 Neuroradiology, King Fahad Medical City, riyadh, Saudi Arabia CONCLUSIONS. This case is peculiar since the patient presented lately with ruptured dermoid cyst due sheer force of trauma leading to spillage of its content into the subarachnoid space causing chemical reaction leading to leuckocysts response and meningitis. This case emphasis the need of vigilant work up for spinal dysraphism in cases of aspectic meningiti s Referrences J G Cha, S-H Paik, J-S Park, S-J Park, D-H Kim, H-K Lee. Ruptured spinal dermoid cyst with disseminated intracranial fat droplets. British Journal of Radiology; 79, Robert A Schwartz, Zbigniew Ruszczak Dermoid Cyst. emedicine.medscape.com/article/ overview In-Young Kim, Shin Jung, Tae-Young Jung, Sam-Suk Kang, Tae-Sun Kim. Traumatic rupture of an intracranial dermoid cyst. Case Report / Journal of Clinical Neuroscience; 15, 469–471 Stendel R, Pietila¨ TA, Lehmann K, Kurth R, Suess O, Brock M. Ruptured intracranial dermoid cysts. Surg Neurol; 57,391–398Hosanna Au. Recurrent meningitis in a child due to an occult spinal lesion. CMAJ; 26; 175(7): 737.  Discussion Congenital spinal dermal sinus (CDS) is a type of spinal dysraphism and a rare condition resulting from the failure of cutaneous ectoderm to separate from the neuroepithelial ectoderm to separate A CDS has both dermal and epidermal elements since the primitive ectoderm has the capacity to form all components of the skin CDS can peter out into a connective tissue band or nodule or may enlarge to form one or more dermoid cysts The capsule of the dermoid is usually quite adherent to the surrounding neural structures they more commonly occur at its terminus. Clinical presentation dimple or sinus Concomitant cutaneous stigmata are very often present and may include angiomata, abnormalities of pigmentation, abnormal hair pattern, subcutaneous lipomata, skin tags Debris or purulent material may drain from the site. A CDS often goes unnoticed until the patient presents with infection, either meningitis or an extra- or intradural abscess Rupture of dermoid cyst results in spillage of its contents into the ventricles and/or subarachnoid space. Spread of cyst contents through the subarachnoid and or ventricular system can be followed by a wide spectrum of clinical manifestations such as acute aseptic chemical meningitis, vasospasm with consecutive infarction, increased intracranial pressure or chronic granulomatous arachnoiditis patient sustained a trauma, the sheer force resulted in rupture of the cyst leading to spillage of its content to the surrounding CSF space fat droplets travelled through the CSF pathway chemical reaction leading to leukocyte response The trend toward earlier diagnosis &referral has allowed for neurosurgical intervention in a more timely manner has most likely decreased the development of complications relating to a more delayed presentation secondary to infection or tumor progression, which are usually associated with a worse outcome Figure 1 A parasagittal and mid sagittal T1 weighted images showing a spontaneously high signal intensity rounded lesions located in the ambient cistern and within the ventricles ( arrows ) representing the fat droplets Figure 1 B Coronal T2 weighted Image with fat saturation technique confirming the fat nature of the interventricular lesion ( arrow head) Figure 2 A Sagittal T1 weighted image of the cervical spine demonstrating rounded intradural lesion posterior to the spinal cord with hyperintense walls ( arrow ) in conjunction with a band like soft tissue signal intensity causing tethering of the cord ( curved arrow ) Figure 3 axial CT of the cervical spine showing multiple fat densities posterior to the cord ( arrow) AB A B Figure 2 B- axial T2 gradient echo image of the cervical spine showing the cord tethering and associated spina bifida ( arrow ) Figure 3 sagittal reformate of cervical CT study re demonesterating the fibrous band with cord tethering ( arrow head ) A B XXth World Congress of Neurology (WCN 2011) Abstract: A · [KAS1] Put a citation here. 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