Intracranial neurenteric cyst: A rare cause of chemical meningitis
A 23-year-old unmarried female presented with 4 days history of headache and multiple episodes of vomiting, which was treated with analgesics prior to her admission. Physical signs revealed an afebrile patient with signs of meningeal irritation with neck rigidity and positive Kernig’s sign. The patient had no significant past history and did not recall any such episode in the past. CSF analysis showed a grossly clear CSF with white cell count of 880/sq mm with predominant lymphocytes (65%). The CSF protein was 62 mg/dl and glucose 32 mg/dl. The CSF staining and culture was negative for mycobacteria or other bacterial pathogens. The patient had been empirically put on broad-spectrum antibiotics (Ceftrioxone, vancomycin, and levofloxacin) without any clinical improvement. A CT scan done 2 days after admission revealed lobulated extra-axial hyperdense lesions in the prepontine and cerebello-medullary cisterns []. The neuroparenchyma, ventricular system, and other basal cisterns were normal. Contrast-enhanced MRI was done subsequently, which showed a lobulated extra-axial lesion in the prepontine cistern extending into both cerebello-medullary cisterns. The lesion showed hyperintense signal on T1 [Figures and ] and FLAIR [] images, with mildly hypointense signal on T2-weighted images []. There was no evidence of restricted diffusion on DWI []. Susceptibility-weighted images did not reveal any evidence of blooming within the lesion []. There was no evidence of signal suppression on T1-weighted fat-suppressed images. Post-gadalonium images did not show any intralesional or peripheral rim enhancement. In view of the characteristic location and signal intensity of the lesion, a diagnosis of leaking neuroenteric cyst was made. The patient was put on steroids (inj. dexamethasone 8 mg 8 hrly) with dramatic improvement in the next 24 hours. Neurosurgical consultation was sought; the patient refused operative treatment and is presently on close follow-up.