John O. Susac

Microangiopathy of the brain and retina

Two, women (26 and 40 years old) developed an unusual microangopathy that affected the brain and retina. Psychiatric symptoms initially overshadowed the subacute features of the progressive neurologic disorder. Ophthalmoscopic findings of multifocal branch retinal artery occlusions provided clinical evidence of vasculopathy. Laboratory data did not reveal evidence of the known vasculitides, including systemic lupus erythematosus (SLE) arid syphilis. Cerebral angiography suggested vasculitis in the younger patient. Brain biopsy in the older patient (after 3 months of steroid therapy) revealed a sclerosis of the small pial and cortical vessels that was consistent with a “healed angiitis”. Both patients seemed to respond to steroid therapy.

MRI findings in Susac’s syndrome

Background: Susac syndrome (SS) is a self-limited syndrome, presumably autoimmune, consisting of a clinical triad of encephalopathy, branch retinal artery occlusions, and hearing loss. All three elements of the triad may not be present or recognized, and MR imaging is often necessary to establish the diagnosis. Objective: To determine the spectrum of abnormalities on MRI in SS. Methods: The authors reviewed the MR images of 27 previously unreported patients with the clinical SS triad, and 51 patients from published articles in which the MR images were depicted or reported. Results: All 27 patients had multifocal supratentorial white matter lesions including the corpus callosum. The deep gray nuclei (basal ganglia and thalamus) were involved in 19 (70%). Nineteen (70%) also had parenchymal enhancement and 9 (33%) had leptomeningeal enhancement. Of the 51 cases from the literature, at least 32 had callosal lesions. The authors could not determine the presence of callosal lesions in 18 of these patients, and only one was reported to have a normal MRI at the onset of encephalopathy. Conclusions: The MR scans in SS show a rather distinctive pattern of supratentorial white matter lesions that always involve the corpus callosum. There is often deep gray matter, posterior fossa involvement, and frequent parenchymal with occasional leptomeningeal enhancement. The central callosal lesions differ from those in demyelinating disease, and should support the diagnosis of SS in patients with at least two of the three features of the clinical triad.

Susac's syndrome: The triad of microangiopathy of the brain and retina with hearing loss in young women

In 1975, I saw a young woman with a previously unreported clinical triad of encephalopathy, branch retinal artery occlusions, and deafness. This patient was presented to me at a conference in Albany, NY. Shortly thereafter, Dr. John Selhorst referred to me a 40-year-old woman with an identical set of clinical findings. With Dr. John Hardimann, Armed Forces Institute of Pathology neuropathologist, who interpreted the brain biopsy findings in the Selhorst case, we reported these cases in 1979 as microangiopathy of the brain and retina.l There have since been 16 additional patients reported, and I have personally cared for two additional patients in my practice. Although the syndrome is considered rare, based upon numerous phone calls and personal communications, I do not believe it is that unusual. Because the syndrome is almost invariably misdiagnosed as multiple sclerosis, the Editor-in-Chief of Neurology asked me to write this brief review for neurologists. There have been many descriptive designations and acronyms for the In 1986, I presented a 26-year-old woman with this syndrome to Dr. William F. Hoyt at the San Francisco Neuroophthalmological Symposium held in his honor. When Dr. Hoyt saw the branch retinal artery occlusions, he announced the diagnosis as “Susac’s syndrome.” Modesty would have prevented me from using this eponymic title, but the Editor-in-Chief insisted that I refer to the disorder as “Susac’s syndrome” and I must comply. The syndrome exclusively affects young women between the ages of 21 and 41, and will be easily recognized if particular attention is paid to the ophthalmoscopic examination of the retina.

Susac's syndrome: 1975–2005 microangiopathy/autoimmune endotheliopathy

Susacs syndrome (SS) consists of the clinical triad of encephalopathy, branch retinal artery occlusions (BRAO) and hearing loss. It is due to a microangiopathy affecting the precapillary arterioles of the brain, retina, and inner ear (cochlea and semicircular canals). Women are more commonly affected than men (3:1); the age of onset ranges from 9 to 58 years; but young women between the ages of 20 and 40 are most vulnerable. The encephalopathy is almost always accompanied by headache which may be the presenting feature. Multifocal neurological signs and symptoms, psychiatric disturbances, cognitive changes, memory loss, and confusion may rapidly progress to dementia. The MRI shows a distinctive white matter disturbance that always affects the corpus callosum. The central callosal fibers are particularly vulnerable and central callosal holes develop as the active lesions resolve. Linear defects (spokes) and rather large round lesions (snowballs) sometime dominate the MRI findings, which include cortical, deep gray (70%) and leptomeningeal involvement (33%). Frequently, the lesions enhance and may be evident on diffusion weighted imaging (DWI). The BRAO are best evaluated with fluorescein angiography, which may show the pathognomonic multifocal fluorescence. Gass plaques are frequently present and reflect endothelial damage. Brain biopsy shows microinfarction to be the basic pathology, but more recent pathological studies have shown endothelial changes that are typical for an antiendothelial cell injury syndrome. Elevated levels of Factor VIII and von Willebrand Factor Antigen reflect the endothelial perturbation. Despite extensive evaluations, a procoagulant state has never been demonstrated. SS is an autoimmune endotheliopathy that requires treatment with immunosuppressants: steroids, cyclophosphamide, and intravenous immunoglobulin, usually in combination. Aspirin is a useful adjunct.

Microangiopathy of the brain, retina and cochlea (Susac syndrome). A Report of five cases and a review of the literature

OBJECTIVE This study reports five new cases of microangiopathy of the brain, retina, and cochlea (Susac syndrome) and reviews the worlds literature. DESIGN Five cases were systematically studied by the authors. The cases in the literature were identified through Medline searches for Susac syndrome; microangiopathy of the brain, retina, or ear; and cross-referencing the indexes of each retrieved article. PARTICIPANTS The number of new patients studied in this report was five. An additional 41 patients were culled from the literature. INTERVENTION Patients were treated with corticosteroids, antineoplastic agents, and other methods in a noncontrolled, nonrandomized fashion. MAIN OUTCOME MEASURES With respect to therapeutic intervention, the main clinical outcome measures were return of vision, improvement of neurologic and psychiatric manifestations, and recovery of auditory function. Alterations of abnormalities observed by cranial magnetic resonance imaging also were monitored. RESULTS Of 46 identified patients, 39 were women. The mean age of the patients was 30 years. Forty-one patients (89%) had arterial occlusions, which were bilateral in 60%. Thirty-one patients (67%) reported hearing loss. Twenty patients (44%) had a global encephalopathy, but other neurologic manifestations were common. The mean duration of the illness was 46.7 months. CONCLUSION This rare syndrome is more common than previously thought, has a strong female preponderance, and often can be identified at an early stage with a careful history and physical examination. Magnetic resonance imaging of the brain often shows lesions suggestive of multiple sclerosis. Fluorescein angiography may show arteriolar wall hyperfluorescence. Early treatment with corticosteroids often is, although not invariably, associated with a good prognosis. The disease appears to be self-limited in most patients.

Susac syndrome: an organ-specific autoimmune endotheliopathy syndrome associated with anti-endothelial cell antibodies.

Susac syndrome (SS) is the triad of encephalopathy, branch retinal artery occlusions (BRAOs), and hearing loss. Migraines may herald and accompany encephalopathy. Little is known about pathogenesis. Based on light microscopic findings in brain biopsy material analogous to anti-endothelial cell antibody (AECA)-mediated microvascular injury, we postulated that SS microangiopathy was attributable to AECAs. We examined serum samples from 11 patients with SS for AECAs; 9 were positive by indirect immunofluorescence and Western blot studies. A highly distinctive band on Western blots corresponding to a 50-kDa protein was observed in 8 positive SS samples; the other positive case exhibited specific reactivity with a protein band at 40 kDa. Of the 2 negative cases, 1 had been inactive since 1988; the other was an abortive variant characterized solely by BRAOs. There was enhanced surface binding of SS serum using live endothelial cell substrates compared with samples from healthy subjects. Additional serum samples from apparently healthy patients, 2 with atypical migraines, and patients with other forms of autoinflammatory disease did not show the distinctive band of immunoreactivity. SS is a distinct autoimmune endotheliopathy syndrome associated with AECAs; the antibody target seems specific in many cases and may be a disease biomarker. The exact role of AECAs in disease propagation remains unanswered.

Retinal arterial wall plaques in Susac syndrome

PURPOSE To demonstrate retinal arterial wall plaques (RAWPs) in patients with Susac syndrome, a disorder that consists of the triad of branch retinal artery occlusion, encephalopathy, and hearing loss. The clinician may misinterpret these RAWPs as emboli. DESIGN Observational case series. METHODS Four patients (one man and three women, aged 21-38 years) were examined and followed. RESULTS Four patients with Susac syndrome had RAWPs in association with branch retinal artery occlusions. They were present in six of eight eyes. The plaques were yellow to yellow-white and located usually away from retinal bifurcations. Retinal arterial wall plaques occur at the midarteriolar segments, whereas Hollenhorst plaques occur at vascular bifurcations. Four of six eyes had resolution of the plaques. CONCLUSIONS Retinal arterial wall plaques may occur with branch retinal artery occlusions in Susac syndrome. This finding should help the clinician who is struggling to make a diagnosis in a patient with an enigmatic encephalopathy and/or hearing loss. These plaques may resolve over time.

Hoquet diabolique Intractable hiccups as a manifestation of multiple sclerosis

In three patients, intractable hiccups occurred as part of the symptomatology of multiple sclerosis. In one patient intractable hiccups were the presenting complaint, and in another patient exacerbations of symptoms were almost always heralded by intractable hiccups. Intractable hiccups occur in a variety of diseases, including many that affect the brainstem and cervical cord, but have not been reported in multiple sclerosis. The hiccup may be a ‘primitive” gastrointestinal reflex that is disinhibited by lesions such as multiple sclerosis plaques. Carbamazepine was successful in arresting the hiccups in one of the cases presented.

Gass plaques and fluorescein leakage in Susac Syndrome

INTRODUCTION Susac Syndrome (SS) consists of the triad of encephalopathy, branch retinal artery occlusion, and hearing loss. It is an autoimmune endotheliopathy that primarily affects young women. Two funduscopic findings, Gass plaques (GP) and arteriolar wall hyperfluorescence (AWH), have recently been described and are not only useful in making the SS diagnosis but also point to the endothelium as the site of autoimmune injury. In this report we wish to raise awareness of GP and AWH with this disorder. METHODS Four selected SS cases are presented with fundus photographs revealing GP. Fluorescein angiographic photographs are shown describing AWH. RESULTS GP are shown in several cases. These GP are unique in that they are yellow, sometimes refractile, and located distant from retinal arteriolar bifurcations unlike Hollenhorst plaques which are orange and located at retinal arteriolar bifurcations. Fluorescein angiography displays AWH of the retinal arterioles of patients with SS distant from affected vessels which has not been demonstrated in other retinal vasculitides. CONCLUSION Small punctuate yellow GP are almost unique to this disorder and their characteristic location and color should assist in confirming the diagnosis. Fluorescein angiography should be performed in all patients with an unexplained encephalopathy to look for the characteristic AWH pattern that occurs in this illness.

Retinal and optic nerve head pathology in Susac's Syndrome

PURPOSE This article describes the first retinal histopathologic findings in a patient with Susacs syndrome (SS). DESIGN Observational case report. PARTICIPANT A 51-year-old white woman diagnosed with SS. METHODS Eyes from a 51-year-old white woman diagnosed with SS were obtained at autopsy. One retina was dissected and processed for adenosine diphosphatase (ADPase) flat embedding. Selected areas were processed further for transmission electron microscopy. MAIN OUTCOME MEASURES Histopathologic examination using ADPase flat-embedding technique. RESULTS There were vaso-occlusive changes in the retinal periphery resulting in small areas of capillary dropout. Cross-sections demonstrated serous filled spaces between the retinal blood vessels and the internal limiting membrane. Lumens adjacent to these spaces appeared compressed and sometimes closed, but without thrombosis. Decreased ADPase activity in some peripheral blood vessels suggested endothelial cell dysfunction and vaso-occlusion. In the optic nerve head, numerous corpora amylacea were observed in the vicinity of capillaries with thickened walls and narrow lumens. Transmission electron microscopy demonstrated thickened and amorphous vascular basal lamina and open endothelial cell junctions in some retinal blood vessels. CONCLUSIONS The serous deposits with compression of retinal vessel lumens observed histologically probably represent the so-called string of pearls described clinically in SS. Chronic extension of these serous deposits along the vessel wall possibly are the cause of retinal arterial wall plaques as described by Gass and other investigators. In the optic nerve head, corpora amylacea are probably a result of microinfarcts resulting from optic nerve head capillary angiopathy. Accumulation of amorphous material in the basal lamina, loss of viable endothelial cells, and capillary dropout suggest that SS may be an endotheliopathy.