Clinical History
A 42-year-old female patient with a known pulmonary disease presented with complaints of a very severe headache, paraparesis , left sided facial paralysis and hearing loss, diapedes insipidus and a state of confusion, increasing in severity over three to four months. The laboratory results were normal except for slightly increased serum angiotensin converting enzyme.
Imaging Findings
A 42-year-old female patient with a known pulmonary disease (sarcoidosis) for about one year presented with complaints of a very severe headache, paraparesis , left sided facial paralysis and hearing loss, diapedes insipidus, and a state of confusion, increasing in severity over three to four months. The laboratory results were normal except for slightly increased serum angiotensin converting enzyme. Treatment with oral corticosteroids produced a moderate improvement in 5 weeks. Before starting the treatment of the patient, an MRI has been performed on a 1.5 T MR scanner, with SE T1, FSE T2, FLAIR, post-gadolinium SE T1 weighted images on three planes.
Discussion
Sarcoidosis is a multisystem granulomatous disease, with an unknown etiology. It occurs more commonly in females than in males. Symptomatic CNS involvement occurs in 5 % of cases. Patients can present with chronic headache due to dural involvement; cranial neuropathy, most often facial nerve, due to leptomeningeal involvement; seizures or focal neurological findings due to parenchymal involvement, or diapedes insipidus due to involvement of infundibulum of the hypophysis. The diagnosis of neurosarcoidosis is often difficult, particularly so in patients who lack either pulmonary or systemic manifestations of sarcoidosis. In selected cases with isolated brain involvement, meningeal or cerebral biopsy may be required. Histological examination shows noncaseating granulomata that contain macrophages, epithelioid cells, and multinucleated giant cells. MRI shows a wide range of central nervous abnormalities: hypotalamic-pituitary infiltrating lesions; cerebral parenchymal masses; leptomeningeal lesions; and focal white-matter lesions. Neurosarcoidosis affects leptomeningeal layers and cranial nerves more often than the parenchyma of the brain. MRI reveals dural plaques which are usually isointense on T1 weighted images, and hypointense on T2 weighted images, with homogeneous enhancement of involved dura and leptomeninges following intravenous gadolinium administration. The underlying brain parenchyma may be edematous. Parenchymal lesions generally show nodular enhancement due to invasion of the parenchyma via perivascular spaces of Virchow-Robin. Hydrocephalus is the most common finding due to leptomeningeal inflammations and adhesions. For differential diagnosis, metastases can be ruled out by the presence of a primary malignancy, cerebrospinal fluid (CSF) studies, and at last by biopsy in addition to the imaging findings. Demyelinating plaque lesions, tuberculosis and other granulomatous diseases can be ruled out by clinical, imaging, and CSF findings.
Differential Diagnosis List
