Microangiopathy of the brain and retina

Vasospasm, its role in the pathogenesis of diseases with particular reference to the eye

Vasospasm can have many different causes and can occur in a variety of diseases, including infectious, autoimmune, and ophthalmic diseases, as well as in otherwise healthy subjects. We distinguish between the primary vasospastic syndrome and secondary vasospasm. The term "vasospastic syndrome" summarizes the symptoms of patients having such a diathesis as responding with spasm to stimuli like cold or emotional stress. Secondary vasospasm can occur in a number of autoimmune diseases, such as multiple sclerosis, lupus erythematosus, antiphospholipid syndrome, rheumatoid polyarthritis, giant cell arteritis, Behcet's disease, Buerger's disease and preeclampsia, and also in infectious diseases such as AIDS. Other potential causes for vasospasm are hemorrhages, homocysteinemia, head injury, acute intermittent porphyria, sickle cell disease, anorexia nervosa, Susac syndrome, mitochondriopathies, tumors, colitis ulcerosa, Crohn's disease, arteriosclerosis and drugs. Patients with primary vasospastic syndrome tend to suffer from cold hands, low blood pressure, and even migraine and silent myocardial ischemia. Valuable diagnostic tools for vasospastic diathesis are nailfold capillary microscopy and angiography, but probably the best indicator is an increased plasma level of endothelin-1. The eye is frequently involved in the vasospastic syndrome, and ocular manifestations of vasospasm include alteration of conjunctival vessels, corneal edema, retinal arterial and venous occlusions, choroidal ischemia, amaurosis fugax, AION, and glaucoma. Since the clinical impact of vascular dysregulation has only really been appreciated in the last few years, there has been little research in the according therapeutic field. The role of calcium channel blockers, magnesium, endothelin and glutamate antagonists, and gene therapy are discussed.

Susac syndrome: a vasospastic disorder?

PURPOSE

The Susac syndrome is a microangiopathy that leads to visual symptoms, hearing loss and neurological symptoms.

CASE REPORT

We report on a young woman suffering from this syndrome who also presented the following signs and symptoms typical of a vasospastic syndrome; 1) a history of cold hands, low blood pressure and migraine; 2) a typical alteration of conjunctival vessels; 3) prolonged flow arrest time after cooling in nailfold capillaromicroscopy; 4) increased resistivity in the orbital vessels measured by color Doppler imaging; and 5) an increased plasma level of endothelin-1.

CONCLUSIONS

We postulate that the Susac syndrome is a manifestation of the vasospastic syndrome.

[Susacs syndrome: case report]

We present the case of a 34-year-old woman with clinical picture suggestive of Susacs syndrome, or retinocochlear vasculopathy. This syndrome, which was described for the first time in 1979, is characterized by a clinical triad of encephalopathy, neurosensorial deafness and visual deficit. Its pathogenesis and treatment are still disputed. We have called special attention to differential diagnosis, since this entity has not yet been described in Brazil, and is probably underdiagnosed.

Susac syndrome: microangiopathy of the retina, cochlea and brain

BACKGROUND

Susac syndrome is characterized by the triad of branch retinal arterial occlusions, encephalopathy and cochlear microangiopathy. The underlying process is believed to be a small vessel vasculitis causing microinfarcts in the retina, brain and cochlea.

METHODS

Analysis of two male and two female cases of Susac syndrome recognized in Australia.

RESULTS

In this series the epidemiology, mode of presentation, ophthalmologic features, neurologic and cochleo-vestibular features, radiologic characteristics, cerebrospinal fluid findings, therapeutic interventions, clinical course and outcome of Susac syndrome is examined. Key ophthalmologic differential diagnoses include systemic lupus erythematosis (SLE), Behçet's syndrome and other vasculitides such as sarcoidosis, tuberculosis, syphilis and lymphoma. Neuro-otologic features are most frequently misdiagnosed as multiple sclerosis.

CONCLUSION

Susac syndrome, first described in 1979, is becoming an increasingly recognized condition. Early recognition of the syndrome is important because treatment with systemic immunosuppression may minimize permanent cognitive, audiologic and visual sequelae.

Susac syndrome

PURPOSE

To report the first Japanese case of the Susac syndrome characterized by microangiopathy of the brain, retina, and cochlea.

METHODS

Case report. A 36-year-old Japanese man underwent extensive clinical and laboratory examination for encephalopathy, bilateral recurrent branch retinal arterial occlusion, and hearing loss.

RESULTS

This case was initially diagnosed as acute disseminated encephalomyelitis. Despite exhaustive clinical and laboratory examination of the patient, no evidence of a known systemic disease was found. The bilateral recurrent branch retinal arterial occlusions were widely disseminated. Remission occurred 1 year after symptom onset. This patient demonstrated all of the clinical features associated with the Susac syndrome.

CONCLUSION

Susac syndrome has been considered rare, but it is probably more common than previously thought and seems to occur in any race. This disorder usually occurs in young women, but it can affect men.

Susac's syndrome or retinocochleocerebral vasculopathy: a misdiagnosed and overlooked disorder

We report a case of Susac's syndrome (retinocochleocerebral vasculopathy) that was initially successfully treated with steroids. The patient had a recurrence of the disorder 2 years after the onset of the first clinical manifestations; this was treated with steroids and both calcium channel blockers and aspirin. Our findings underline the importance of recognizing patients with retinocochleocerebral vasculopathy at an early stage so that it may be accurately managed and, therefore, result in both decreased morbidity and disability related to severe sequelae. We also stress the need for patients with Susac's syndrome to have both close and long-term follow-up in order to disclose both symptomatic and asymptomatic recurrences of the disorder.

Encephalopathy, hearing loss and retinal occlusions (Susac's syndrome): a new case

We describe a young woman with retinal arteriolar occlusions, encephalopathy, and hearing loss. At present this disorder is known as Susac's syndrome, a microangiopathy of the brain and retina whose pathogenesis is, however, unknown. The article reviews the clinical features of this rare, but not unusual, syndrome that can easily be misdiagnosed as multiple sclerosis.

Central nervous system vasculitis

Vasculitis is inflammation of blood vessel walls, which produces dysfunction in both the peripheral and central nervous system (CNS). Cerebral ischemia is the major cause for neurological manifestations of CNS vasculitis. Unfortunately, a universally accepted classification of vasculitis has not emerged. Vasculitis affecting the CNS alone is referred to as primary angiitis of the CNS; secondary vasculitis occurs in association with a variety of conditions, including infections, drug abuse, lymphoproliferative disease and connective tissue diseases. The pathogenesis of vasculitis includes different immunological mechanisms. Recently, anti-neutrophil cytoplasmatic antibody (ANCA) has been demonstrated to play an active role in the immunopathogenesis of the vasculitis. Diagnosis of vasculitis depends on a combination of clinical, radiographic and pathologic features. A wide spectrum of clinical features may occur. The most typical clinical picture of CNS vasculitis is troke, encephalopathy or seizures. Assays for ANCA, serum cytokines, antibodies to endothelial cell antigens have been reported to be useful in diagnosing or monitoring the disease activity. The gold standard in diagnosis is confirmation of vasculitis in a biopsy specimen. Angiography may suggest the diagnosis but no abnormalities are pathognomonic. Ideally, the therapy of each vasculitis would focus on the specific immunologic mechanism causing the disease. Such specific interventions are not yet available. In general the most important approaches induce global immunosuppression. The goal of therapy, however, is to prevent recurrence of disease.

Susac syndrome

Susac syndrome is an occlusive arteriolar disease that provokes infarcts in the cochlea, retina, and brain of young subjects, mostly women. Its cause is unknown. Some infarcts may be asymptomatic and only revealed by ancillary investigation: 1) audiogram that shows bilateral sensorineural hearing loss predominating on low frequencies, 2) funduscopy and fluorescein retinal angiography demonstrating bilateral distal branch retinal artery occlusions, and 3) brain MRI T2-weighted images disclosing small multifocal hyperintensities in white and gray matter. Treatment options are not codified, ranging from antithrombotic drugs to immunomodulatory therapy. Course is self-limited after an active fluctuating phase. Dementia, blindness, and deafness are rare late sequelae, and half of patients return to normal life.

Retinocochleocerebral vasculopathy

We report 10 patients with retinocochleocerebral vasculopathy and review the clinical and diagnostic considerations in previously reported patients with this uncommonly recognized disease. The clinical manifestations include acute and subacute multifocal and diffuse encephalopathic symptoms, hearing loss, and visual loss attributable to microangiopathy affecting the arterioles of the brain, retina, and cochlea. Diagnosis is facilitated by demonstration of retinal arteriolar occlusions without uveitis or keratoconjunctivitis, mid- to low-frequency unilateral or bilateral sensorineural hearing loss, and numerous small foci of increased signal in the white and gray matter on T2 weighted brain magnetic resonance imaging. Because many conditions may produce any combination of strokelike cerebral symptoms, encephalopathy, hearing loss, and visual loss, the differential diagnosis for retinocochleocerebral vasculopathy includes connective tissue disease, demyelinating disease, procoagulant state, infection, neoplasm, and more routine mechanisms of cerebral and retinal ischemia. Brain biopsy specimens demonstrate only minimal nonspecific periarteriolar chronic inflammatory cell infiltration with or without microinfarcts. The demonstration of subclinical arteriolar microangiopathy in muscle biopsy specimens, documented in 3 of our patients may assist in making the diagnosis. The clinical course appears to be monophasic. In addition to corticosteroids, treatment options include immunosuppressant agents (cyclophosphamide or azathioprine) aspirin, calcium channel blockers (nimodipine), intravenous immunoglobulin, and plasmapheresis. The etiology of the disease is unknown, but histopathologic and laboratory evidence suggests that an immune-mediated mechanism may be involved.

Susac's syndrome: a rare cause of fluctuating sensorineural hearing loss

Susac's syndrome is extremely rare and is characterized by the clinical triad of encephalopathy, retinal artery occlusion and deafness. A case of this rare syndrome is presented and for the first time the fluctuating nature of the hearing loss is demonstrated. The site and nature of the hearing loss has been investigated. The value of neural hearing loss as a method of monitoring the clinical severity is discussed.

Reversal of visual loss with hyperbaric oxygen treatment in a patient with Susac syndrome

PURPOSE

The purpose of the study is to report on a 34-year-old woman with Susac syndrome who presented on two separate occasions with visual acuity loss from a recurrent branch retinal artery occlusion and underwent hyperbaric oxygen treatment with favorable outcome.

METHODS

Visual acuity was 20/400 in the left eye and count fingers in the right eye after separate occlusive events. The patient underwent hyperbaric oxygen treatment on each occasion of visual acuity loss. The patient subsequently was diagnosed with Susac syndrome (microangiopathy of the retina, brain, and middle ear). The authors present visual fields, photographs, angiograms, and ancillary tests documenting diagnosis and course of treatment.

RESULTS

On each occasion, visual acuity improved to 20/25 during and was maintained after hyperbaric oxygen treatment. Visual fields showed improvement immediately after treatment.

CONCLUSION

This is the first report of hyperbaric oxygen treatment for Susac syndrome. Dramatic post-treatment visual field and acuity changes suggest benefit of treatment. Hyperbaric oxygen treatment can be considered a treatment option for visual complications of this syndrome. Susac syndrome should be included in the differential diagnosis of recurrent branch retinal artery occlusion.

Idiopathic recurrent branch retinal arterial occlusion. Natural history and laboratory evaluation

PURPOSE

To investigate the long-term visual and systemic prognosis of patients with idiopathic recurrent branch retinal artery occlusions, and to test recent hypotheses regarding possible causes of this syndrome.

METHODS

The authors retrospectively reviewed the medical and photographic records of 16 eligible patients. Each of 15 living patients was interviewed by one of the authors, then underwent follow-up ophthalmic examination, formal visual field testing, and a battery of clinical laboratory tests.

RESULTS

Over a mean follow-up of 9 years, only three eyes (9%) lost visual acuity from foveal ischemia, although nine eyes (28%) had central and/or extensive peripheral visual field loss at final examination. Ocular neovascular complications developed in eight eyes (25%). Eight patients (50%) had associated vestibuloauditory and/or transient sensorimotor symptoms, but serious permanent neurologic deficits or recurrent systemic thromboembolic events did not develop. Although most patients had one or more vaso-occlusive risk factors, extensive laboratory testing failed to define the etiology of the arterial occlusions.

CONCLUSIONS

On long-term follow-up, the visual, neurologic, and systemic prognosis for most patients with idiopathic recurrent branch retinal arterial occlusions remains favorable. Although it is probable that such patients are etiologically heterogeneous, the authors theorize that many have mild or partial manifestations of the microangiopathic syndrome of encephalopathy, hearing loss, and retinal arteriolar occlusions.

Small infarctions of cochlear, retinal, and encephalic tissue in young women

BACKGROUND AND PURPOSE

Recently, a rare syndrome that involves uniformly the brain, inner ear, and retina in previously healthy young women has been described. Brain biopsies and ophthalmologic examinations disclosed small infarcts as a pathoanatomical substrate of the disease. In previous reports, an autoimmune disorder or a coagulopathy have been suggested as possible etiologies.

CASE DESCRIPTIONS

Both patients (aged 22 and 20 years) had brain involvement with neurological and neuropsychological deficits. Multifocal small hyperintensities were shown in magnetic resonance imaging of the brain. Findings of cerebrospinal fluid examination and electroencephalography were pathological in case 1 and of cerebral angiography in case 2. Both patients had a neurosensory hearing loss and multiple retinal branch arteriolar occlusions. Both women were on fenfluramine before onset of the disease. In case 1, attacks recurred during a follow-up of 34 months. At onset of the disease the 5-hydroxyindoleacetic acid and homovanillic acid levels of the cerebrospinal fluid were reduced; 13 months later the 5-hydroxyindoleacetic acid level was still reduced and the homovanillic acid level was low-normal. In case 2, with the longest follow-up of 13 years, the disease was active during only the initial 2 1/4 years. During this period a combination of oral anticoagulant and antiplatelet agents was ineffective.

CONCLUSIONS

Our findings could not support current etiologic hypotheses. Whether changes in 5-hydroxyindoleacetic acid and homovanillic acid levels in the cerebrospinal fluid and/or fenfluramine intake play a role in the pathogenesis of the disease remains to be elucidated.

Microangiopathy with retinopathy, encephalopathy, and deafness (RED-M) and systemic features

The case of a young woman with a rare syndrome of acute encephalopathy followed by deafness and retinopathy developing over 1 year is reported. Unlike previously described similar cases, she had considerable systemic symptoms and signs including polyarthralgia-arthritis, diffuse myalgia, malar rash, livedo reticularis, night sweats, and fatigue suggestive of systemic lupus erythematosus. However, results of most immunological investigations were repeatedly normal, including antinuclear antibodies. Anticardiolipin antibodies were elevated on one occasion. Cyclophosphamide has been the most effective treatment for exacerbations of the disease, which have continued to occur over 6 years. This microangiopathic syndrome more likely relates to an immunologically mediated vasculitis of small blood vessels than to a thromboembolic etiology.

Microangiopathy of the brain, retina, and ear: improvement without immunosuppressive therapy

We describe a pregnant young woman with branch retinal arteriolar occlusions, encephalopathy, and hearing loss in whom we demonstrated a patent foramen ovale. She improved while receiving anticoagulants and no immunosuppressive therapy. The microangiopathic syndrome of retinopathy, encephalopathy, and deafness may be due to a disturbance of coagulation and/or microembolism.

Bilateral retinopathy and encephalopathy

A 22-year-old woman presenting with recurrent transient episodes of vertebro-basilar artery syndrome and blurred vision was initially diagnosed as suffering from a collagen disease affecting the retina and CNS. Treatment with systemic steroids induced an apparent remission. However, a rapid deterioration of her condition prompted a reevaluation of the diagnosis and treatment. Ophthalmoscopic examination disclosed numerous ischemic foci in both eyes, scattered superficial hemorrhages, and neovascular tufts on the optic nerves. The possibility that both the cerebral and ocular phenomena were the results of systemic showering of emboli was raised. Careful two-dimensional echo cardiography revealed a mitral mass compatible with myxoma of the left atrium. The difficult differential diagnosis of combined encephalopathy and retinopathy is discussed.

Encephalopathy, deafness and blindness in young women: a distinct retinocochleocerebral arteriolopathy?

Three young women (aged 18 years, 19 years and 19 years) who developed progressive neuropsychic and neurologic disturbances with hearing loss and multifocal retinal artery branch occlusions are reported. This retinocochleocerebral syndrome has been reported previously only in 12 young North American women. Its pathogenesis is unknown, but an atypical viral infection of the vessel walls has been suggested. Abnormalities of T lymphocytes subsets in blood in one of the patients suggested an immunological dysfunction, but all other tests, including immunological reactions on brain and skin biopsies, were negative or non-specific. Steroids and immunosuppressive agents have been advocated on an empirical basis, but the second patient showed a substantial recovery without any therapy and the third gradually deteriorated despite azathioprine, cyclophosphamide, prednisone and plasma exchanges. This retinocochleocerebral syndrome probably corresponds to an arteriolopathy of unknown nature.

Microangiopathy with encephalopathy, hearing loss and retinal arteriolar occlusions: two new cases

Two young women developed encephalopathy, hearing loss and retinal arteriolar occlusions. Their behaviour became immature and cognitive functions were severely impaired. One of the patients underwent brain biopsy, which showed several microinfarcts in both white and grey matter and microangiopathic changes, with thickened arteriolar segments staining intensely for laminin and fibronectin. These findings support the concept of a new type of microangiopathy involving the brain, inner ear and retina.

Treatment of sagittal sinus thrombosis associated with cerebral hemorrhage and intracranial hypertension

Two cases of complete sagittal sinus occlusion with multiple brain hemorrhages, elevated intracranial pressure, and disseminated intravascular coagulation are described. These patients were successfully managed using pentobarbital-induced coma to ameliorate intracranial pressure elevation. This therapy was combined with monitoring of intracranial pressure and intermittent drainage of cerebrospinal fluid to further control intracranial pressure elevations. Thrombus and coagulopathy resolved with pentobarbital alone in one patient and after pentobarbital plus heparin therapy in the second patient. It is suggested that cases of severe distal sagittal sinus thrombosis with brain hemorrhage and intracranial hypertension may benefit from combined pentobarbital coma and intraventricular drainage. This allows for stabilization of bleeding tendencies before instituting heparin therapy when necessary. Management of sagittal sinus thrombosis with barbiturates or ventricular drainage is best performed in an intensive care unit environment with continuous monitoring of intracranial pressure and substantial electrophysiologic and neuroradiologic support.

Retinal vasculitis

Evidence is now accumulating on both clinical and experimental grounds that the retina is an a priori source of inflammatory activity. Reactive inflammation in the retina may produce many of the clinical signs previously ascribed to uveal inflammation. Autoimmune mechanisms are probably responsible for the majority of cases of retinal vasculitis. Autoimmune retinal vasculitis occurs without other classical signs of inflammatory response in any other parts of the body. When associated systemic manifestations occur they may reflect different underlying immunopathogenic abnormalities. Thus in diseases with predominantly arterial involvement (e.g. systemic lupus erythematosus, polyarteritis nodosa) the retinal arteries bear the brunt of this disease. In Behçet's disease the systemic involvement is usually venous and ocular involvement produces diffuse capillary and venous inflammation with areas of retinal necrosis and major vascular occlusion. The retinal appearances differ from sarcoidosis in which a granulomatous response produces characteristic periphlebitis. Finally, autoimmune retinal vasculitis produces diffuse capillary and venous damage, without any systemic signs. In the next decade the search will be for the identification of the specific antigens initiating these disparate retinal features. Retinal S antigen is a potent antigen, but rhodopsin, interphotoreceptor binding protein, and transducin all need further experimental investigation. Precise documentation will herald the dawn of new therapeutic measures based on a sound immunological fabric.

A syndrome of brain, inner ear and retinal microangiopathy

We report the seventh case of a self-limiting syndrome of brain, inner ear and retinal microangiopathy which affects adult women producing mild to moderate mental status and personality changes, mild pyramidal and cerebellar dysfunction, patchy and asymmetrical visual loss secondary to non-inflammatory retinal infarctions, and asymmetrical neurosensory hearing loss. There is no clinical or laboratory evidence of involvement beyond the brain, the eyes and the ears. Magnetic resonance imaging or brain biopsy in previously reported cases best outline the brain pathology: multiple microinfarcts. All cases have been treated with steroids or cyclophosphamide. The etiology is unknown but may be related to systemic lupus erythematosus.

Idiopathic recurrent branch retinal arterial occlusion

Recurrent multiple branch retinal arterial occlusions of unknown cause occurred in nine apparently healthy individuals. With the exception of three patients who developed associated auditory symptoms, none developed other signs or symptoms of systemic vascular disease. Ophthalmoscopic and fluorescein angiographic findings suggested focal arteritis and arteriolitis as the cause of the obstructions. Most patients retained good visual acuity.

Retinal vasculitis associated with autoantibodies to Sjögren's syndrome A antigen

Severe retinal vasculitis caused by a systemic lupus-like illness developed in two patients with distinctive clinical and immunologic characteristics. Both patients were young women with mild systemic disease and autoantibodies directed against a protein-ribonucleic acid complex termed the Sjögren's syndrome A antigen (SSA). One patient had no antibodies to nuclear antigens on conventional testing, and the other had a low-titer antinuclear antibody test. At the time of onset of retinal arteriolitis, neither patient had an exacerbation of multisystem disease or serologic activity. Despite oral and parenteral corticosteroids, cytotoxic agents, and panretinal photocoagulation, both patients suffered progressive irreversible retinal ischemia, optic disk and retinal neovascularization, vitreous hemorrhage traction retinal detachment, and anterior segment neovascularization.

A syndrome of arterial-occlusive retinopathy and encephalopathy

An analysis of two new cases and four previously reported cases produced evidence for a syndrome of arterial-occlusive retinopathy and encephalopathy. All six patients were women; they ranged in age from 21 to 40 years. The clinical features of this condition include multiple branch retinal arterial occlusions and encephalopathy in which behavioral and memory disturbances predominate early. Hearing loss is frequent. Except for cerebrospinal fluid pleocytosis and an increased cerebrospinal fluid protein level, there are few laboratory or radiographic abnormalities. The disease may be responsive to corticosteroid therapy. There are some similarities between this syndrome and systemic lupus erythematosus but it appears to be a distinct disease entity. A comparison of the retinal findings with those described in experimental allergic encephalitis suggests that this may be a virally induced immune-mediated disease. Although only four clearly documented examples of this syndrome have been reported, we suspect that cases may have been overlooked because of failure to recognize arterial branch occlusions in the peripheral retina.