Cerebral granulomatosis as a manifestation of Crohn's disease.

Background: Crohn's disease (CD) is associated with a variety of extra-intestinal manifestations. Most commonly these involve the eye, skin, joints, coagulation system and liver. Cerebral manifestations of CD have been reported to a far lesser extent. The extensive detrimental impact of neurological symptoms on a patient's quality of life makes an early diagnosis and treatment particularly important. In previous case-reports, diagnosis of cerebral manifestations in CD often relied upon magnetic resonance imaging (MRI) and computed tomography (CT) alone. To our knowledge, only one case-report has documented a histologically confirmed case of cerebral lesions associated with CD so far.

Case Presentation: A 39-year-old right-handed woman with a history of CD was referred to our hospital with etiologically unexplained Gadolinium (Gd)-enhancing cortical lesions, triggering epileptic seizures. A CT-scan of the thorax and bronchoalveolar lavage found no signs of sarcoidosis. Lumbar punctures and laboratory testing found no underlying infection or coincidental autoimmune disorders and MRI-scans showed progression of lesion load. Consequently, the patient underwent stereotactic biopsy of a cortical lesion. Histological examination revealed a mixed lympho-histiocytic and tuberculoid granulomatous inflammation surrounding small vessels and no signs for infection. After exclusion of other granulomatous diseases and the typical histological findings we diagnosed a cerebral granulomatosis as a manifestation of CD. The patient was initially started on azathioprine, which had to be switched to corticosteroids and methotrexate because of an azathioprine related pancreatitis. The patient has not suffered any further epileptic seizures to date.

Conclusion: Cerebral manifestation of CD is a possibly underreported entity that may respond well to immunosuppressive treatment. In contrast to earlier reports of cerebral manifestations in CD, our patient showed no coincident gastrointestinal symptoms indicating an activity of CD during the progression of cortical lesion load, suggesting that similar to other extra-intestinal manifestations in CD, the activity of gastrointestinal symptoms does not necessarily reflect the activity of CD associated cerebral vasculitis. Therefore, diagnosis and therapy of cerebral manifestation may be delayed when focusing on gastrointestinal symptoms alone.