Cognitive dysfunction and brain atrophy in Susac syndrome

Long-term cognitive outcomes in Susac syndrome: A case series

Susac syndrome (SuS) presents with encephalopathy, visual disturbances, and hearing loss from immune-mediated microvascular occlusion. While acute SuS is well-described, long-term cognitive outcomes with current treatments are underknown. We assessed ten SuS patients treated in accordance with evidence-based guidelines using immunotherapies targeting humoral and cell-mediated pathways. Patients were followed for a median 3.6 years. Initially, cognition inversely correlated with corpus callosum lesions on MRI. All reported cognitive improvement; 5/10 patients had residual deficits in visual attention and executive function. Early, aggressive treatment was associated with good outcomes; extensive early corpus callosum lesions may identify patients at-risk of persistent cognitive deficits.

The neurocognitive and neuropsychiatric manifestations of Susac syndrome: a brief review of the literature and future directions

Encephalopathy is part of the clinical triad of Susac syndrome, but a detailed understanding of the neurocognitive and neuropsychiatric profile of this condition is lacking. Existing literature indicates that cognitive deficits range in severity from subtle to profound. Executive function and short-term recall are affected frequently. Psychiatric manifestations may be absent or may include anxiety, mood disorders or psychosis. If psychiatric phenomena develop during the disease course, it can be hard to disentangle whether symptoms directly relate to the pathology of Susac syndrome or are secondary to treatment-related side effects. In this article, we review what is known about the cognitive and psychiatric morbidity of Susac syndrome and identify areas where knowledge is deficient. Importantly, we also provide a framework for future research, arguing that better phenotyping, understanding of pathophysiology, evaluation of treatments on cognitive and psychiatric outcomes, and longitudinal data capture are vital to improving patient outcomes.

Cognitive profile in a young woman with Susac syndrome: a case report

Susac syndrome is a rare immune-mediated endotheliopathy affecting the microvasculature. It presents three main symptoms: encephalopathy, branch retinal artery occlusions, and hearing loss . Here we present a new case report focusing on the evolution of the cognitive profile. The patient underwent two neuropsychological examinations. The first, one month after the onset of the symptomatology, highlighted a prevalent involvement of verbal executive functions. The second, conducted six months later, revealed a global improvement in most previously deficient areas, although with the persistence of a difficulty in cognitive estimation. . This case illustrates the importance of a comprehensive analysis of patients with Susac syndrome to appreciate the whole range of cognitive deficits and reliably evaluate symptom evolution.

Cognitive outcomes in Susac syndrome: A 2-year neuropsychological follow-up study

BACKGROUND AND PURPOSE

Susac syndrome (SuS) is a rare, autoimmune, neurological disease characterized by a clinical triad of branch retinal artery occlusion, sensorineural hearing loss and encephalopathy. Neuropsychological functioning in SuS is little researched and the prevalence, nature, and evolution over time of cognitive deficits in SuS remain unclear. This study aimed to better understand the long-term neuropsychological outcomes of patients with SuS.

METHODS

Thirteen patients with SuS (mean [SD] age 39.5 [11.1] years) were enrolled at the Ghent University Hospital by their treating neurologist. The cognitive functioning and emotional well-being of each patient was evaluated by means of a thorough neuropsychological test battery at baseline and after 2 years. Follow-up testing after 2 years was performed in 11 patients (mean [SD] age 42.2 [11.5] years).

RESULTS

Patients showed normal neuropsychological test results at a group level, both at baseline and follow-up testing. Significant improvements over time were found for information processing speed, verbal recognition, and semantic and phonological fluency. Individual test results showed interindividual variability at baseline, with most impairments being in attention, executive functioning and language, which improved after a 2-year period. In addition, patients reported significantly lower mental and physical well-being, both at baseline and follow-up testing.

CONCLUSIONS

Our results suggest that neuropsychological dysfunction in SuS is limited at a group level and improves over time. Nonetheless, individual test results reveal interindividual variability, making cognitive screening essential. Furthermore, a high psycho-emotional burden of the disease was reported, for which screening and follow-up are necessary.

Susac syndrome: neurological update (clinical features, long-term observational follow-up and management of sixteen patients)

Susac syndrome is a likely autoimmune microangiopathy affecting the brain, retina and inner ear. Due to the rarity of this condition, diagnosis and treatment can be challenging. Diagnosis is based on the presence of the clinical triad of central nervous system dysfunction, branch retinal artery occlusions and sensorineural hearing loss. Typical MRI findings of callosal and peri-callosal lesions may assist in diagnosis. Clinical course can be monophasic, polycyclic or chronic continuous. It is important to look out for red flags to attain an accurate diagnosis and follow a therapeutic algorithm based on severity of the disease and response to treatment. Patients are treated with steroids and immunosuppressive agents with a variable response. Early aggressive treatment especially in severe cases, may help in preventing relapses and morbidity/disability. This study highlights important diagnostic features and proposes a treatment algorithm based on clinical experience from management of 16 patients from 2 neuroscience centres in the UK since 2007, who were followed up over a long period of 3-15 years.

Olfactory function in Susac syndrome

OBJECTIVES

Susac syndrome is a rare autoimmune endotheliopathy involving the brain, retina, and inner ear. Olfactory dysfunction is a common early manifestation of several central nervous system diseases, including neurodegenerative diseases and autoimmune-mediated diseases such as Multiple Sclerosis. While the literature is abundant about the Susac syndrome classic triad of encephalopathy, branch retinal artery occlusion, and low-frequency sensorineural hearing loss, little is known about the extent of olfactory sense involvement.

METHODS

Using the Sniffin' Sticks test, this study evaluated olfactory function (identification and threshold) in ten recovering Susac syndrome patients under our clinic surveillance with a median of 3.1 (SD=1.53) years post-disease onset.

RESULTS

olfactory assessment by threshold and odor identification were within the normal range. No differences between recovering Susac syndrome patients to standard norms of odor identification and threshold were found.

CONCLUSIONS

Our findings do not support olfactory dysfunction in Susac syndrome and thereby, do not support olfactory assessment as a reliable biomarker for this condition.

Atypical clinical and novel radiological findings in Susac syndrome: Experience from a large monocentric cohort

Susac syndrome (SuS) is a rare immune-mediated endotheliopathy that affects the brain, retina and inner ear and is characterised by the variable clinical triad of encephalopathy, visual and vestibulocochlear dysfunction. Here, we present clinical and paraclinical data of 19 SuS patients followed at Ghent University Hospital and highlight some atypical clinical and novel radiological findings. Our findings suggest that spinal involvement expands the clinical phenotype of SuS. We further introduce dark blood sequences as a more sensitive technique to detect radiological disease activity in SuS. Our data add to the current understanding of the diagnosis, monitoring and treatment of SuS.

Susac syndrome with cognitive impairment - case report of 31-year-old woman

Introduction: Susac syndrome (SuS) is a rare immune-mediated disease caused by occlusions of microvessels in the brain, retina and inner ear. It is characterized by the clinical triad of encephalopathy, visual disturbances and hearing loss. The diagnosis of SuS is based mainly on the clinical symptoms and the supporting tests in which characteristic changes occur in the MRI.

Case report: Here, we present a case of a patient with possible SuS with psychiatric symptoms. A 31-year-old woman was admitted to the Department of Psychiatry due to deteriorating mental health for several weeks manifested as a negative mood and suicidal thoughts. During hospitalization, a neurological consultation was conducted, in which the patient was identified as conscious, psychomotor sluggish, with impaired verbal contact and persistent hearing and vision impairment. Cross-sectional assessment of cognitive functions revealed that the patient had a generalized syndrome of neuropsychological deficits, which confirms the diagnosis of dementia.

Discussion: This case summary provides an example of a woman diagnosed with SuS manifested as a cognitive impairment with associated vision and hearing deterioration. It is worth emphasizing the fact that such presentation of the triad of at disease onset is rare. The characteristics of the organic changes in the brain described in the MRI probably explain the symptoms described in that case. The prognosis of SuS depends on early diagnosis and treatment.

Conclusions: A diagnosis of SuS should always be considered in the presence of nonspecific neuropsychiatric symptoms and progressive multifocal neurological symptoms, hearing loss, and visual impairment. An important fact is that the typical triad of SuS symptoms in most cases does not occur simultaneously, which makes the diagnostic process very difficult and may lead to misdiagnosis.

Brain magnetic resonance imaging lesion load at diagnosis, severity at onset and outcomes in Susac syndrome: A prospective cohort study

BACKGROUND

Susac syndrome (SuS) is a rare occlusive microvessel disease of the brain, retina and inner ear. We aimed to determine whether brain lesion load at the acute phase predicts poor outcomes in SuS.

METHODS

A prospective national cohort study was conducted from December 2012 to December 2019 in 20 centres in France. Patients included at the principal investigator's center with available brain magnetic resonance imaging (MRI) at diagnosis were analyzed. MRI was reviewed by an experienced neuroradiologist blinded to clinical status. The size, topography and number of hyperintense lesions on diffusion-weighted imaging (DWI-HL) were analyzed at diagnosis and during follow-up. Outcomes involved descriptive characteristics of patients at onset and last follow-up.

RESULTS

Twenty-three patients (38.1 [18.8-56.5] years, 16 females) were prospectively studied. The triad (i.e., brain, eye and ear involvement) was complete at onset in 17 patients. Brain MRI was performed 1.1 (0.1-3.4) months after the first symptom. All patients had DWI-HL at the acute phase. Patients were separated into two groups according to the number of DWI-HL on first MRI: a first group of patients (n=15) displaying low brain lesion load (<50 DWI-HL per patient) and a second group of patients (n=8) displaying high brain lesion load (≥100 DWI-HL). The median follow-up was 57.9 (9.7-98) months. Clinical features, treatment, relapse rate, time to disappearance of DWI-HL, disabilities and professional outcome did not differ according to brain lesion load.

CONCLUSION

Brain lesion load assessed by DWI at the acute phase is not associated with risks of disability in SuS.

[Update on Susac syndrome]

Susac syndrome is a rare disease affecting mainly young women, characterized by a microangiopathy limited to the cerebral, retinal, and cochlear vessels. Although the pathophysiology of Susac syndrome is not yet fully elucidated, recent advances favour a primitive vasculitis affecting the cerebral, retinal and cochlear small vessels. Susac syndrome must be recognized in the presence of the pathognomonic clinical triad associating: 1/subacute encephalopathy with unusual headache and pseudopsychiatric features associated with diffuse white matter, grey matter nuclei and specifically corpus callosum lesions on brain MRI; 2/eye involvement that may be pauci-symptomatic, with occlusions of the branches of the central artery of the retina at fundoscopy and arterial wall hyperfluorescence on fluorescein angiography; and 3/cochleo-vestibular damage with hearing loss predominating at low frequencies on the audiogram. Relapses are frequent during an active period lasting approximately 2 years. Eventually, the disease resolves but isolated retinal arterial wall hyperfluorescence without new occlusions may recur, which should not lead to treatment intensification. First-line treatment consists of a combination of anti-aggregants and high dose corticosteroids. In refractory patients or in case of relapse, immunomodulatory molecules such as intravenous immunoglobulins or immunosuppressive drugs such as mycophenolate mofetil, cyclophosphamide or rituximab should be started. Unfortunately, sequelae-mostly hearing loss- remain frequent in these young patients.