Sarcoid encephalopathy with diffuse inflammation and focal hydrocephalus shown by sequential CT

Neurosarcoidosis: an update on diagnosis and therapy

INTRODUCTION

Clinically overt granulomatous involvement of the nervous system (i.e., neurosarcoidosis) can be seen in up to 10% of patients with sarcoidosis. Establishing a diagnosis of neurosarcoidosis is often challenging due to the heterogeneity of clinical presentations that are sometimes non-specific, and inaccessibility of tissue confirmation. Recommended treatments are based on expert opinions that are derived from clinical experience and limited data from retrospective studies, as data from randomized controlled studies are limited.

AREA COVERED

In this article, we comprehensively review all available literature on epidemiology, clinical presentations, diagnosis, treatment, and outcomes of neurosarcoidosis. We also offer our opinions on diagnostic approach and treatment strategy.

EXPERT OPINION

Given the invasive nature and the limited sensitivity of biopsy of the nervous system, diagnosis of neurosarcoidosis is usually made when ancillary tests (such as magnetic resonance imaging and cerebrospinal fluid analysis) are compatible, and alternative diagnoses are reasonably excluded in patients with established extraneural sarcoidosis. Several factors must be taken into consideration to formulate the initial treatment strategy, including the extent of the disease, severity, functional impairment, comorbidities and patient's preference. In addition, treatment regimen of neurosarcoidosis should be formulated with an emphasis on long-term strategy.

Autoimmune Neurologic Emergencies

Over the past decade, understanding of autoimmune neurologic disorders has exponentially increased. Many patients present as a neurologic emergency and require timely evaluation with rapid management and intensive care. However, the diagnosis is often either missed or delayed, which may lead to a significant burden of disabling morbidity and even mortality. A high level of suspicion in the at-risk population should be maintained to facilitate more rapid diagnosis and prompt treatment. At present, there is no all-encompassing algorithm specifically applicable to the management of fulminant autoimmune neurologic disorders. This article discusses manifestations and management of various autoimmune neurologic emergencies.

Neurosarcoidosis

Neurosarcoidosis occurs in 3% to 10% of patients with sarcoidosis. Cranial neuropathy and meningeal involvement are the most common manifestations, but any part of the nervous system can be affected. Definite diagnosis requires the presence of noncaseating granuloma in the nervous system, although histopathologic confirmation is often not obtainable. Moderate to high dose of glucocorticoids is the main therapy for neurosarcoidosis. Relapse often occurs after the dose of glucocorticoids is tapered down, often necessitating the use of steroid-sparing immunosuppressive agents.

Neurosarcoidosis as an MS Mimic: The trials and tribulations of making a diagnosis

The clinical presentation of neurosarcoidosis is varied as multiple levels of the neuraxis may be affected. When central nervous system involvement occurs, making an accurate diagnosis of the condition can be challenging, especially given the current definition for definite neurosarcoidosis requires histologic confirmation of the affected tissue (brain biopsy). This article will review our current knowledge and manifestations of neurosarcoidosis, discuss the current diagnostic approach as well as the challenges associated with a condition requiring histologic confirmation, discuss the current treatment approach, and highlight the challenges of this diagnosis with a few real-life clinical cases. We also highlight the selected differential diagnosis of neurosarcoidosis as well as multiple sclerosis which could mimic each other.

Neurosarcoidosis: clinical review of a disorder with challenging inpatient presentations and diagnostic considerations

Neurosarcoidosis is frequently on the differential diagnosis for neurohospitalists. The diagnosis can be challenging due to the wide variety of clinical presentations as well as the limitations of noninvasive diagnostic testing. This article briefly touches on systemic features that may herald suspicion of this disorder and then expands in depth on the neurological clinical presentations. Common patterns of neurological presentations are reviewed and unusual presentations are also included. A discussion of noninvasive testing is undertaken, exploring dilemmas that may be encountered with sensitivity and specificity. Drawing from a broad range of clinical clues and diagnostic data, a systematic approach of pursuing a potential tissue diagnosis is then highlighted. Correctly diagnosing neurosarcoidosis is critical, as treatment with appropriate immunosuppression protocols can then be initiated. Additionally, treatment of refractory disease, the trend toward exploring targeted immunomodulation options, and other therapeutic issues are discussed.

Neurologic manifestations of sarcoidosis

Neurologic manifestations occur in more than 5% of sarcoidosis patients and may be the presenting feature. Neurosarcoidosis can manifest in a myriad of ways including: cranial neuropathy, aseptic meningitis, mass lesions, encephalopathy, vasculopathy, seizures, hypothalamic-pituitary disorders, hydrocephalus, myelopathy, peripheral neuropathy, and myopathy. Because its etiology is unknown, its neurological manifestations are so diverse, and its diagnosis cannot be readily confirmed by laboratory tests, neurosarcoidosis poses many clinical problems. The diagnosis of neurosarcoidosis is usually based on the identification of characteristic neurologic findings in an individual with proven systemic sarcoidosis as established by clinical, imaging, or histologic findings. Although corticosteroids are regarded as the foundation of treatment, they are not always successful and have serious side-effects. Moreover, some patients with neurosarcoidosis are refractory to conventional therapy, and approximately 5-10% die. Optimal management of patients with neurosarcoidosis benefits from an understanding of the broad clinical spectrum of neurosarcoidosis, appreciation of the ways to best confirm a diagnosis, and awareness of the full range of treatment options, including the use of alternative therapies such as immunotherapy.

Neurosarcoidosis with intraparenchymal cystic lesions. A case report

Sarcoidosis is a chronic multi-system granulomatous disorder of unknown etiology. Central nervous system involvement is relatively uncommon in sarcoidosis. Clinical manifestations and radiological appearances of neurosarcoidosis vary widely depending on the site and activity of the lesions. In most cases, the imaging appearance is nonspecific. We report a very rare case of extensive neurosarcoidosis with progressively enlarging cystic lesions in the right temporal lobe.

Neurologic manifestations of sarcoidosis

Sarcoidosis is multisystem granulomatous disease of unknown etiology. Although the nervous system is involved in only 5% to 16% of patients, neurosarcoidosis is one of the more serious manifestations of the disease. Cranial neuropathies are common, but involvement of the mininges or the brain or spinal cord parenchyma causes more severe morbidity. MR imaging of affected portions of the neuraxis is a very sensitive diagnostic technique. Treatment with corticosteroids is the mainstay of therapy.

Bipolar disorder and cerebral sarcoidosis

A 40-year-old man suffered both a short-term memory defect and bipolar mood disorder. It is postulated that both conditions are due to progressive cerebral sarcoidosis affecting the limbic system. The need for early detection and treatment is emphasised.

Progression of hydrocephalus during corticosteroid therapy for neurosarcoidosis

We describe a patient with sarcoid meningitis and hydrocephalus who improved rapidly after initiation of oral prednisone therapy, but who later decompensated acutely and required an emergency ventriculoperitoneal shunt. Hydrocephalus associated with neurosarcoidosis may progress despite steroid treatment, even when symptoms have improved. If hydrocephalus associated with neurosarcoidosis is treated with corticosteroids and without a shunt procedure we suggest that the corticosteroids should be continued at high doses for a prolonged period.

A case of hypothalamic sarcoidosis with hypopituitarism and prolonged remission of hypogonadism

A 21-year-old man developed hypopituitarism, with symptomatic hypogonadism and diabetes insipidus (DI), as well as uveitis, retinal vasculitis, and papilledema in association with systemic sarcoidosis. A suprasellar tumor was demonstrated by computed tomography (CT). Although ophthalmic symptoms disappeared with prednisone and the DI was controlled with Desmopressin (DDAVP), the hypogonadism did not improve with human menopausal gonadotropin (HMG) and human chorionic gonadotropin (HCG). In long-term follow-up, the hypogonadism unexpectedly resolved.

Intrathecal production of oligoclonal IgM and IgG in CNS sarcoidosis

A longitudinal study of multiple paired CSF and serum specimens from a patient with CNS sarcoidosis revealed high CSF IgM and IgG indices as well as oligoclonal IgM and IgG bands in CSF reflecting intrathecal IgM and IgG production. The antibody specificity of intrathecally-produced IgM and IgG remained undefined despite analysis for antibodies against mycobacterium tuberculosis and Kveim suspension. Steroid treatment induced rapid and complete clinical remission, and also decrease of CSF IgM and IgG antibodies, while oligoclonal IgM and IgG persisted in CSF. Repeated determinations of these CSF variables together with cell count and CSF/serum albumin ratio as a variable of blood-brain barrier function, might be useful in assessing effect of therapy in CNS sarcoidosis.

Central nervous system sarcoidosis

Sarcoidosis may involve the central nervous system (CNS) in approximately 5% of cases. Three levels of neurological involvement are possible and include cranial nerve abnormalities, peripheral neuropathies, and lesions of the brain, spinal cord, and meninges. In addition to abnormal neurological findings, psychiatric presentations of CNS sarcoidosis include symptoms of delirium, dementia, depression, personality changes, and psychosis. The diagnosis usually rests on neurological, psychiatry, and cerebrospinal fluid (CSF) abnormalities with a history of sarcoidosis in other organ systems. The CSF, however, may be normal in as many as 30% of cases. The complexities of the illness and the difficulties that may be encountered in making the diagnosis are illustrated with a case of suspected CNS sarcoidosis that presented with delirium and choreoathetosis. The use of steroids as the mainstay of treatment is also discussed.

A case of subcortical dementia due to sarcoidosis of the hypothalamus and fornices

A patient with sarcoidosis involving predominantly the hypothalamus and fornices was evaluated for dementia. He showed a relative sparing of fund of knowledge and orientation. Memory skills, particularly short-term memory, were severely impaired. Behavioral changes included apathy and a lack of spontaneity. Insight was relatively preserved. The pattern of his deficits showed some similarities to the pattern reported in patients with Huntington's disease and was different from that described in Alzheimer's disease. The dementia caused by subcortical pathology may differ in important respects from that caused by diffuse cortical dysfunction.

An electron microscopic study of central nervous system sarcoidosis

Although the fine structure of extraneural sarcoidosis is well documented, ultrastructural study of central nervous system (CNS) sarcoidosis has been limited. Electron microscopic (EM) examination of 3 biopsy cases of CNS sarcoid revealed a mixed cellular population of lymphocytes, epitheloid cells, and multinucleated giant cells. The epitheloid and multinucleated giant cells shared common ultrastructural features of nuclei and cytoplasm. In addition, they displayed similar specializations of the cell surface, including subplasmalemmal linear densities (SLD) and villous projections. These findings recapitulate those described in extraneural sarcoidosis and other granulomatous disorders. This supports the contention that the macrophages or epitheloid cells present in CNS lesions are derived from the same mononuclear phagocytic system as their systemic counterparts.