Fluorescein Angiography Findings in Susac Syndrome: A Multicenter Retrospective Case Series.

BACKGROUND: Susac syndrome is a vasculopathy, resulting in the classic triad of branch retinal artery occlusion (BRAO), inner ear ischemia, and brain ischemia. In this retrospective chart review, we characterize fluorescein angiography (FA) findings and other ancillary studies in Susac syndrome, including the appearance of persistent disease activity and the occurrence of new subclinical disease on FA. METHODS: This multicenter, retrospective case series was institutional review board-approved and included patients with the complete triad of Susac syndrome evaluated with FA, contrasted MRI of the brain, and audiometry from 2010 to 2020. The medical records were reviewed for these ancillary tests, along with demographics, symptoms, visual acuity, visual field defects, and findings on fundoscopy. Clinical relapse was defined as any objective evidence of disease activity during the follow-up period after initial induction of clinical quiescence. The main outcome measure was the sensitivity of ancillary testing, including FA, MRI, and audiometry, to detect relapse. RESULTS: Twenty of the 31 (64%) patients had the complete triad of brain, retinal, and vestibulocochlear involvement from Susac syndrome and were included. Median age at diagnosis was 43.5 years (range 21-63), and 14 (70%) were women. Hearing loss occurred in 20 (100%), encephalopathy in 13 (65%), vertigo in 15 (75%), and headaches in 19 (95%) throughout the course of follow-up. Median visual acuity at both onset and final visit was 20/20 in both eyes. Seventeen (85%) had BRAO at baseline, and 10 (50%) experienced subsequent BRAO during follow-up. FA revealed nonspecific leakage from previous arteriolar damage in 20 (100%), including in patients who were otherwise in remission. Of the 11 episodes of disease activity in which all testing modalities were performed, visual field testing/fundoscopy was abnormal in 4 (36.4%), MRI brain in 2 (18.2%), audiogram in 8 (72.7%), and FA in 9 (81.8%). CONCLUSIONS: New leakage on FA is the most sensitive marker of active disease. Persistent leakage represents previous damage, whereas new areas of leakage suggest ongoing disease activity that requires consideration of modifying immunosuppressive therapy.

Elevated Intracranial Pressure Associated With Exogenous Hormonal Therapy Used for Gender Affirmation.

BACKGROUND: Addison disease, corticosteroid withdrawal, and taking synthetic growth hormone have been linked with development of intracranial hypertension, but there is still debate on whether administration of other exogenous hormones plays a role in precipitating elevated pressure. The growing use of hormonal therapy for gender affirmation provides an opportunity to explore this possibility. METHODS: All transgender patients taking exogenous hormones for female-to-male (FTM) and male-to-female (MTF) transitions who were diagnosed with intracranial hypertension at Massachusetts Eye and Ear Infirmary, Massachusetts General Hospital and Beth Israel Deaconess Medical Center between August 2014 and November 2018 were included in a retrospective review. Visual acuity, type, and dose of exogenous hormone, visual field testing, clinical exam, results of neuroimaging and lumbar puncture, and treatment modalities were catalogued and analyzed. RESULTS: Six transgender individuals were identified. Five were FTM, with an average hormone treatment time of 18.4 months, and one was MTF who had been treated with hormones for 4 years. The average age of all patients was 23.5 years. The average time between onset of symptoms and presentation was 5 months. Fifty percent of the patients reported pulse-synchronous tinnitus, 83% reported positional headache, 33% reported transient visual obscurations, and 16% reported diplopia. Lumbar punctures performed on 4 of the patients revealed elevated opening pressures and normal cerebrospinal fluid constituents. MRI findings consistent with elevated intracranial pressure (ICP) were present in the other 2 patients in whom lumbar puncture was unsuccessful. Four patients were treated with acetazolamide and one was treated with topiramate, with an average follow-up time of 15.7 months. All patients demonstrated bilateral optic disc swelling, and all maintained normal acuity and color vision. Performance on visual field testing was not significantly affected in any patient. CONCLUSIONS: This is the largest reported series to date of gender-transitioning patients with intracranial hypertension, including one novel MTF conversion. These observations warrant further investigation into the possible link of exogenous hormonal therapy and elevated ICP and any mechanisms or confounders underlying this potential association.

Ophthalmic manifestations of giant cell arteritis.

GCA, the most common systemic arteritis, affects medium-sized and larger extradural arteries that have the internal elastic lamina. Involvement of the ophthalmic artery and its branches results in visual loss, which is often complete but is usually painless. Visual loss may be monocular or binocular developing simultaneously or sequentially. Rarely, it stems from occipital lobe infarct that result in homonymous hemianopia, a visual field defect involving the two identical halves (right or left) of the visual fields of both eyes. Visual hallucinations and diplopia are less common. All visual symptoms, including those that are transient, require urgent ophthalmological evaluation and treatment with high-dose glucocorticoids to avoid permanent visual loss.

Autoimmune Neurologic Disorders.

The practice of autoimmune neurology focuses on the diagnosis and treatment of a wide spectrum of neurological conditions driven by abnormal immune responses directed against neural tissues. These include autoimmune, paraneoplastic, postinfectious, and iatrogenic conditions. Symptoms of autoimmune neurologic disorders can be diverse and often difficult to recognize in their early stages, complicating the diagnosis. This review discusses the classification and management of common autoimmune neurological conditions, placing an emphasis on the rapid identification of autoimmune etiology and mechanism of immune dysfunction to allow for the timely institution of appropriate treatment.

Autoimmune Encephalitis in Critical Care: Optimizing Immunosuppression.

Autoimmune diseases affecting the nervous systems are a common cause of admission to the intensive care unit (ICU). Although there exist several well-described clinical syndromes, patients more commonly present with progressive neurologic dysfunction and laboratory and radiographic evidence of central nervous system (CNS) inflammation. In the critical care setting, the urgency to intervene to prevent permanent damage to the nervous system and secondary injury from the systemic manifestations of these syndromes often conflicts with diagnostic uncertainty. Furthermore, treatment is limited by current therapeutic agents that remain non-specific for individual diseases, especially for those whose pathophysiology remains unclear. Primary autoimmune, paraneoplastic, parainfectious, and iatrogenic neurologic disorders all share the common underlying pathophysiology of an adaptive immune response directed against an antigen within the nervous system. Several different mechanisms of immune dysfunction are responsible for pathogenesis within each of these categories of disease, and it is at this level of pathophysiology that the most effective and appropriate therapeutic decisions are made. In this review, we outline the basic diagnostic and therapeutic principles in the management of autoimmune diseases of the nervous system in the ICU. We approach these disorders not as lists of distinct clinical syndromes or molecular targets of autoimmunity but rather as clusters of syndromes based on these common underlying mechanisms of immune dysfunction. This approach emphasizes early intervention over precise diagnosis. As our understanding of the immune system continues to grow, this framework will allow for a more sophisticated approach to the management of patients with these complex, often devastating but frequently reversible, neurologic illnesses.

The Neurology of Immune-Mediated Disorders in Women.

Many neuroinflammatory disorders have a predilection for women; even if there is no female predominance, neuroinflammatory conditions in women pose a management challenge for several reasons. Disease activity of these conditions may change during pregnancy and commonly increases in the postpartum period. Uncontrolled disease activity may affect pregnancy outcomes. Moreover, immunomodulating agents that are used to suppress the disease activity may have a negative impact on fertility, pregnancy, and fetal outcomes, and on infants who are breastfed. Adverse effects of immunosuppressants extend beyond the reproductive issues and may include bone loss, increased risk of cancers, and infectious complications. The successful management of women with these disorders requires that not only practitioners understand and recognize the adverse effects of immunosuppressants, but also seek to prevent adverse outcomes through counseling about contraceptive choices, safety monitoring, risk surveillance, and other strategies.

Short Follow-up Bias Confounds Estimates of the "Typical" Clinical Course of Susac Syndrome.

BACKGROUND: To evaluate the validity of the prevailing concept that Susac syndrome (SS), a rare microvasculopathy of the brain, retina, and inner ear, is a self-limiting disease. METHODS: We performed a literature search to identify all cases of SS reported between 1973 and October 2015. If available, we determined their demographics, duration of follow-up, and the clinical course that was labeled as monocyclic or polycyclic. We attempted to determine the number of relapses and the relapse rate in patients with polycyclic disease. RESULTS: Our literature search yielded 185 relevant publications reporting 405 cases of SS. The duration of follow-up could be determined in 247/405 cases, with a range 0.5-312 months. The mean was 41 months but the distribution was skewed, with a median of 24 months. Defining the clinical course as monocyclic or polycyclic was possible in 102 patients who were followed for greater than 24 months; 53 were identified as having a polycyclic course. Patients labeled polycyclic were followed longer than those labeled monocyclic (median 62 vs 42 months, P < 0.001). The number or frequency of attacks per patient could not be determined. CONCLUSIONS: The follow-up of published cases of SS is short, creating an inherent bias toward the impression that the disease is self-limiting. Our findings suggest that stratification of SS into monocyclic, polycyclic, and chronic continuous courses may oversimplify the phenotype of SS; instead, the possibility of a relapsing-remitting course must be considered in all patients with this disorder.

Management of Transient Monocular Vision Loss and Retinal Artery Occlusions.

Acute transient or permanent retinal occlusive disease requires prompt medical attention and can be an ophthalmological emergency. Central retinal artery occlusion leads to permanent and severe monocular visual loss in the majority of patients. Transient monocular vision loss leaves no permanent deficits, but requires the same level of clinical vigilance, as it portends possible future adverse events, including loss of vision and stroke. Acute treatment options remain limited, and secondary prevention of cerebral ischemic events is the mainstay of management. This article reviews the current evidence for managing patients with retinal ischemia.

Mitochondrial Encephalopathy and Optic Neuropathy Due to m.10158 MT-ND3 Complex I Mutation Presenting in an Adult Patient: Case Report and Review of the Literature.

INTRODUCTION: Establishing a diagnosis of mitochondrial disease in adults remains a clinician's challenge. We report a case of syndrome reminiscent of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) in an adult patient who carries m.10158T>C mutation in complex I respiratory chain gene MT-ND3 (mitochondrially encoded NADH dehydrogenase 3). CASE REPORT: This 26-year-old man from Thailand presented with new-onset headaches, seizures, stroke-like episodes, and poor vision due to optic neuropathy and cortical blindness. Instead of expected mutations in the mitochondrial tRNA gene that are frequently associated with MELAS, the mutation in MT-ND3 with variable tissue heteroplasmy (blood 5.3%, muscle 89.5%) was demonstrated. The patient's clinical features, blood biomarkers, neuroimaging findings, muscle biopsy with histochemical and functional in vitro analysis, and genetic studies were analyzed and compared with all previously reported ND3 disease cases. CONCLUSIONS: ND3 disease due to m.10158T>C mutation was previously described only in patients with Leigh or Leigh-like syndrome. Our findings thus indicate that ND3 disease can manifest with atypical phenotype in adults. The diagnosis of mitochondrial disease caused by other than typical MELAS-associated mutations in adults with stroke-like episodes, headaches, and seizures should be considered. An analysis of tissue other than blood, which is more likely to harbor a tissue-specific mitochondrial DNA mutation at a measurable level, may be necessary for diagnosis.

Treatment of Susac Syndrome.

OPINION STATEMENT: Susac syndrome is a microangiopathy of the brain, retina, and cochlea. Several lines of evidence support the concept that this disease is an acquired autoimmune disorder. Prospective, randomized, controlled studies of treatments are not available because the disease is rare. Furthermore, the average period of follow-up in reported cases is short, limiting a complete understanding of the natural history of the disease. Empirical treatment strategies are therefore based upon expert recommendations and anecdotal reports of response to various immunomodulators, and the appropriate duration of therapy is not known. In our opinion, the encephalopathic form of Susac syndrome should be treated early and aggressively to avoid cognitive dysfunction and disability. Induction therapy with pulse methylprednisolone frequently proves to be inadequate. Additional agents, including intravenous immunoglobulins, intravenous cyclophosphamide, or rituximab are often necessary to induce a sustained remission. Maintenance therapy with oral glucocorticoids combined with intravenous immunoglobulins, mycophenolate mofetil, methotrexate, azathioprine, cyclophosphamide, or rituximab is typically necessary to achieve a sustained remission. Aspirin may be used as an adjunctive agent, although evidence showing efficacy is scant. The response to treatment should be closely monitored by frequent clinical examinations, brain MRI, and fluorescein angiography. Once disease remission has been established, it appears prudent to continue maintenance treatment for at least two additional years, although the real long-term risk of future relapses remains unknown. Establishing a multicenter patient registry and biorepository is essential to study the pathogenesis of the disease, further define the duration of disease, identify reliable biomarkers that aid early diagnosis and assess risk of relapse, and develop effective disease-specific therapies.

A 44-year-old man with eye, kidney, and brain dysfunction.

Retinal vasculopathy with cerebral leukodystrophy (RVCL) is a rare, autosomal dominant condition caused by mutations of TREX1 (3-prime repair exonuclease-1). The phenotypic expressions range from isolated retinal involvement to varying degrees of retinopathy, cerebral infarction with calcium depositions, nephropathy, and hepatopathy. We report a case of RVCL caused by a novel TREX1 mutation. This patient's multisystem presentation, retinal involvement interpreted as "retinal vasculitis," and improvement of neuroimaging abnormalities with dexamethasone led to the accepted diagnosis of a rheumatologic disorder resembling Behçet disease. Clinicians should consider RVCL in any patient with retinal capillary obliterations associated with tumefactive brain lesions or nephropathy.

Treatment of neuromyelitis optica.

PURPOSE OF REVIEW: Neuromyelitis optica (NMO) is an antibody-mediated inflammatory disease of the central nervous system with a predilection for the optic nerves, spinal cord and certain brain regions. It has a distinct pathogenesis relating to aquaporin-4 autoimmunity and complement-mediated injury. This knowledge has translated into targeted efforts to develop novel, disease-specific treatments. In this review, we discuss evidence supporting the use of currently available treatments for acute exacerbations and for long-term disease modification. We also discuss the risks and benefits of available and emerging immunotherapies. RECENT FINDINGS: Early, accurate diagnosis of NMO with appropriate acute and long-term immunosuppressive treatment is of prime importance for the prevention of disability associated with this disease. Standard measures for the management of acute exacerbations include intravenous methylprednisolone and plasmapheresis. First-line, long-term immunotherapies for NMO include azathioprine, mycophenolate mofetil and rituximab. Three randomized controlled treatment trials evaluating these agents are currently being conducted. In addition, there are numerous emerging therapies that are based upon current understanding of the disease immunopathogenesis. SUMMARY: NMO is an autoimmune disease that is separate from multiple sclerosis. Better understanding of its antibody and complement-dependent pathophysiology has proven to be critical for the formulation of current and future treatment strategies.

A Cluster of CNS Infections Due to B. cereus in the Setting of Acute Myeloid Leukemia: Neuropathology in 5 Patients.

Bacillus cereus typically causes a self-limited foodborne gastrointestinal (GI) illness. Severe invasive infection occurs rarely, mainly among immunocompromised hosts. We describe a cluster of B. cereus infections among 5 patients with acute myeloid leukemia and chemotherapy-induced neutropenia. The initial case presented with occipital lobe abscess and was found on biopsy to have organisms consistent with Bacillus species. Within 1 week, a second patient died of fulminant brain swelling and hemorrhage. Neuropathologic autopsy and culture revealed B. cereus; hospital infection control and public health officials were notified. Three more patients died within the subsequent 9 months (2 patients had rapid massive hemorrhage and many bacilli reminiscent of Bacillus anthracis infection, and 1 patient had sparse bacilli, petechial hemorrhages, and border zone infarcts). Blood cultures yielded positive results in 3 of 5 cases. A possible route of infection was hematogenous dissemination via GI mucosal breaches (GI symptoms occurred in 3 of 5 cases, and postmortem GI ulceration was found in 3 of 4 cases). Bacilli were seen in 2 of 3 GI ulcerations. Epidemiologic work-up, including a site visit conducted by the Centers for Disease Control and Prevention, did not identify a clear common source but suggested the possibility of bananas as a food source. Bacillus cereus causes a rapidly progressive, hemorrhagic meningoencephalitis with high mortality among patients with neutropenia. Neuropathologists can play a key role in the detection of outbreaks.

Clinical features, diagnostic findings, and treatment of Susac syndrome: a case series.

BACKGROUND: Susac syndrome (SS) is a rare, presumed autoimmune condition characterized by the clinical triad of branch retinal artery occlusions (BRAOs), encephalopathy, and sensorineural hearing loss. The aim of this study was to evaluate clinical features, diagnostic results, treatment, and outcomes in SS. METHODS: Five patients with SS were referred to three tertiary care centers in Boston. The observation period across these patients was 7-57months. RESULTS: At initial presentation, none of the patients demonstrated the complete triad of BRAO, sensorineural hearing loss, and encephalopathy. The interval between symptom onset and diagnosis of SS was 4-30weeks. Brain MRI findings thought to be characteristic of SS (including callosal fluid-attenuated inversion recovery (FLAIR) hyperintense and T1 hypointense lesions) were frequently absent. Microinfarcts noted on diffusion-weighted imaging (DWI), BRAOs and vessel wall hyperfluorescence on fluorescein angiography (FA) were present in all cases in the acute encephalopathic phase. All patients treated with glucocorticoids and intravenous immunoglobulins (IVIg) alone experienced further clinical progression until additional immunosuppressive therapy was instituted. CONCLUSIONS: The rarity of SS, its incomplete and variable presentation, and the nonspecific imaging findings invariably led to delayed diagnosis. DWI and FA should be used to identify the acute microvascular injury and monitor treatment response. Immunomodulatory agents more potent than glucocorticoids and IVIg might be required to control the disease.

Ocular inflammation in neurorheumatic disease.

Neuroimmunologic and systemic rheumatic diseases are frequently accompanied by inflammation of the eye, ocular adnexa, and orbital tissues. An understanding of the diverse forms of ophthalmic pathology in these conditions aids the clinician in making appropriate preventative, diagnostic, therapeutic, and prognostic decisions. In this review, the authors address ocular inflammation in neurorheumatic disease in three sections: first, they highlight current perspectives on immune mechanisms in the development of these disorders; next, they provide a framework for the recognition and evaluation of ophthalmologic inflammatory entities; finally, they discuss in detail several inflammatory conditions that affect the nervous system and the eye, emphasizing the features that should alert neurologists to initiate ophthalmologic evaluation. The conditions discussed include multiple sclerosis, neuromyelitis optica, chronic relapsing inflammatory optic neuropathy, Susac syndrome, Cogan syndrome, acute posterior multifocal placoid pigment epitheliopathy, Vogt-Koyanagi-Harada disease, Behçet disease, sarcoidosis, systemic lupus erythematosus, granulomatosis with polyangiitis (Wegener granulomatosis), polyarteritis nodosa, giant cell arteritis, IgG4-related disease, and Sjögren syndrome.

A neurologist's guide to safe use of immunomodulatory therapies.

Increased understanding of the pathogenesis of immune-mediated neurologic conditions with concomitant development of new therapeutic agents modulating various aspects of the immune system has resulted in the use of innovative therapies in the treatment of these diseases. These novel immunomodulatory therapeutic regimens also augment the potential for complications, including severe adverse effects.In this review, the authors address practical issues regarding management of patients with neuroimmunological conditions treated with immunomodulatory therapies, including glucocorticoids, methotrexate, azathioprine, mycophenolate, cyclophosphamide, rituximab, tumor necrosis factor-α inhibitors, and intravenous immunoglobulins. Particular focus is placed on their infectious and noninfectious adverse effects, contraindications, safety monitoring, risk surveillance, and preventive strategies in clinical practice.