Imaging of neurosarcoidosis: common, uncommon, and rare

Application of the modified Zajicek criteria to diagnose probable spinal cord neurosarcoidosis

“…MRI typically demonstrates high‐intensity lesions on T1 weighting, with postgadolinium enhancement . Characteristic findings include nodular leptomeningeal enhancement, preferential basilar involvement of the brain, and noncontiguous lesions of the spinal cord affecting more than three segments . Involvement of spinal roots and caudae is also observed in neurosarcoidosis, with nodular leptomeningeal enhancement being characteristic …”

“…4 Involvement of spinal roots and caudae is also observed in neurosarcoidosis, with nodular leptomeningeal enhancement being characteristic. 12 The diagnosis of neurosarcoidosis represents a significant challenge as there is a wide differential including infections such as TB, HIV, neurosyphilis, boriella, listeria, and toxoplasmosis; immune-mediated conditions such as IgG4-related meningeal disease, CNS vasculitis, granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, Behçets disease, Sjögrens disease and systemic lupus erythematosus; malignancies including CNS lymphoma, carcinomatous meningitis, leptomeningeal metastasis, and germ cell tumors; and demyelinating conditions such as multiple sclerosis, neuromyelytis optica, and acute demyelinating encephalomyelitis. 4,14 The modified Zajicek diagnostic criteria [3][4][5] are outlined in Table 1.…”

A practical approach to the diagnosis of spinal cord lesions

“…80 Intramedullary lesions can affect the cervical or thoracic cord73 75 with a mean lesion length of 3.9 segments (range1–9) 72 74. Additional supporting features are overlying leptomeningeal involvement72 (especially with meningomyelitis in the context of sarcoid meningitis75), nerve root involvement81 or persistent enhancement of the lesion on follow-up MRI for more than 2 months despite treatment 52. Clues to additional brain involvement are leptomeningeal enhancement, hydrocephalus (if basal meninges involved), cranial neuropathies (particularly VII and VIII) and involvement of the hypothalamic-pituitary axis or, more rarely, the cavernous sinus 75 82…”

MRI differential diagnosis of suspected multiple sclerosis

“…Large neurosarcoid dural masses with MRI characteristics similar to a meningioma (isointense to grey matter on T1-weighted, low T2-weighted and uniform enhancement) have been described. 34,36 Neurosarcoidosis can also affect any cranial nerve with the 7 th cranial nerve being most commonly affected clinically, but this is usually radiologically occult. 34 Neurosarcoid parenchymal deposits are seen as periventricular T2-weighted hyperintensities and enhancing masses (Fig 9).…”

“…35 A small portion of the parenchymal lesions can demonstrate low T2-weighted signal due to high cellularity; this can act as a relative distinguishing feature from MS. A subset of patients with neurosarcoidosis develops ischaemic and haemorrhagic stroke, which is thought to be a complication of associated vasculitis. Intramedullary spinal cord signal abnormalities are rare in neurosarcoidosis compared to MS. 34,36 Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) CLIPPERS is an increasingly recognised syndrome since its first description in 2010 by Pittock et al as a form of immune-mediated inflammatory pontine-centric encephalitis. 37,38 It is characterised pathologically as T cellpredominant infiltration along the white matter perivascular spaces with pathological features suggestive of vasculitis.…”