Neurosarcoidosis: a review of its intracranial manifestation

Abstract

Sarcoidosis is a multisystem disease of unknown cause and with a worldwide distribution. Involvement of the central nervous system occurs in a relatively small number of patients with sarcoidosis. Isolated neurosarcoidosis without signs of systemic disease is a rarity. Because of its non-specific clinical presentation and neuroradiological imaging characteristics, intracranial neurosarcoidosis remains a very difficult diagnosis, particularly in the absence of systemic signs of the disease. Intracranial neurosarcoidosis has a predilection for the basal leptomeninges commonly affecting the cranial nerves, but any part of the brain may be involved, resulting in a wide spectrum of clinical syndromes. Cranial nerve involvement is the most common single symptom. Intracranial sarcoid manifests as nodular or diffuse leptomeningeal thickening and extraor intra-axial parenchymatous lesions. Intracranial sarcoid may mimic various forms of meningitis, including carcinomatous and intracranial mass lesions such as meningioma, lymphoma and glioma, based on neuroradiological imaging. Magnetic resonance imaging is a very sensitive diagnostic tool for detecting intracranial abnormalities due to neurosarcoidosis. Lumbar puncture is useful in ruling out other neurological disorders, in particular infectious, but cerebrospinal fluid findings are not specific. Angiotensin-converting enzyme in serum and cerebrospinal fluid may be increased, decreased or normal. Therapy consists of immunosuppressive agents and should be initiated with corticosteroids. Other immunosuppressive drugs should be added in severe cases or after frequent recurrences. We review here all aspects of intracranial neurosarcoidosis from the clinical point of view, with special emphasis on presentation, diagnostic procedures, differential diagnostic considerations and treatment.

Hypertrophic pachymeningitis: case report

“…The incidence of sarcoidosis strictly confined to the central nervous system is very low, less than 0.2 per 100.000. Neurological manifestations can be the initial presentation in 30% to 50% of patients that will later be diagnosed as having neurosarcoidosis 22,23 . The clinical presentation is varied and depends on the area affected.…”

“…The most common intracranial symptoms are cranial nerve deficits, headache and seizures. The facial and optic nerves are the most affected 23,24 . Optic neuritis and papillitis were found in 38% of patients in a recent series 22 .…”

“…Meningeal involvement in neurosarcoidosis is predominantly leptomeningeal and MRI shows homogeneous or diffuse enhancement of the affected meninges. The basal cisterns and hypothalamic areas are commonly affected 4,23,25 . The origin of the disease remains unknown but there are speculations on the participation of genetic and environmental factors.…”

“…What causes the activation of the immune system to form the granulomas is still unknown. Some authors have found specificity to one single antigen while others attribute the process to various sarcoid antigens 23,29 .…”

An Unusual Presentation of Neurosarcoidosis in an 11-Year-Old Boy

“…Diagnosis requires biopsy confirmation of noncaseating granulomatous inflammation, and histological evidence of epithelioid differentiation of macrophages in the center of noncaseating non-infectious lesions with surrounding lymphocytes 10 . Meningeal and conjunctival biopsies, the latter often performed blindly, are the most common means of confirming a histological diagnosis 11 .…”