Acta Neurol Belg DOI 10.1007/s13760-014-0337-4
NEURO-IMAGES
Characteristic callosal involvement in Susac’s syndrome Alexandra Seghers • Joachim Van Calster Guido Wilms • Be´ne´dicte Dubois
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Received: 12 June 2014 / Accepted: 14 July 2014 Ó Belgian Neurological Society 2014
Keywords Susac’s syndrome Magnetic resonance imaging Fluorescein angiography After experiencing paresthesia in the right hand and increasing headache, instability and black spots in the left visual field since 2 weeks, a 30-year-old female presented with an episode of irresponsiveness with prolonged confusion. There was some spontaneous improvement of the cognitive impairment but short-term memory difficulties remained. We found a decreased vision of the right eye (best corrected ETDRS visual acuity 20/32 compared 20/40 on the left), an instable gait, and a right-sided hyperreflexia. Subsequently, she developed auditory loss and tinnitus. She became increasingly apathetic and somnolent, culminating in another episode of loss of consciousness, now with myoclonic jerking of the right half of the face. Analysis of the cerebrospinal fluid showed a normal white cell count, a moderately elevated protein level with a normal IgG index, and no oligoclonal bands. A. Seghers (&) B. Dubois Department of Neurology, University Hospitals Leuven, Herestraat 49, 3000 Louvain, Belgium e-mail: [email protected] B. Dubois e-mail: [email protected] J. Van Calster Department of Ophthalmology, University Hospitals Leuven, Louvain, Belgium e-mail: [email protected] G. Wilms Department of Radiology, University Hospitals Leuven, Louvain, Belgium e-mail: [email protected]
Brain magnetic resonance imaging (MRI) revealed multiple T2 hyperintensities, most of which showed diffusion restriction. The most prominent lesions were found in the corpus callosum (Fig. 1). On ophthalmological evaluation, occlusions of branch retinal arteries were seen (Fig. 2). Our patient was diagnosed with Susac’s syndrome (SS) and treated with corticosteroids and intravenous cyclophosphamide monthly, which, with exception of one initial episode of cognitive deterioration with a new gadolinium enhancing callosal lesion on MRI, has led to an improvement of the clinical picture over the last year with stabilization of MRI findings ever since. Treatment with corticosteroids is slowly being tapered. Susac’s syndrome is characterized by the clinical triad of encephalopathy, branch retinal artery occlusions (BRAOs), and hearing loss (HL). The true incidence is unknown; 304 cases have been reported worldwide. The condition is most commonly seen in women from 20 to 40 years [1, 2]. Susac et al. [3] state that in its encephalopathic form, pathognomonic MRI lesions of the corpus callosum permit an immediate diagnosis, even in the absence of BRAO and HL. Characteristic findings are microinfarcts of its central portion (‘‘snowballs’’, eventually evolving into pathognomonic central callosal ‘‘holes’’). The callosal roof is also frequently affected by microinfarcts in ‘‘icicle’’ and ‘‘spoke’’ configurations. Moreover, the ‘‘string of pearls’’ MRI finding—the studding of the internal capsules with microinfarcts, most dramatically shown on diffusionweighted images (DWI)—is found to be pathognomonic when associated with the typical central callosal lesions. Diffusion tensor imaging (DTI) reveals microstructural degeneration of cerebral fibers appearing normal on conventional MRI. Involvement of the callosal genu is characteristic and correlates with functional deficits [4].
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Acta Neurol Belg Fig. 1 Sagittal T2 showing central callosal demyelinisation: ‘‘snowballs’’ (black arrows), ‘‘spokes’’ (white arrows), and an ‘‘icicle’’ (arrowhead)
Fig. 2 Color fundus photography (a) of the right eye with BRAO and ischemic retinal edema; early (b, c) and late (d) fluorescein angiography pictures showing arteriolar nonperfusion and arteriolar wall hyperfluorescence, respectively
SS is considered an autoimmune-mediated microangiopathy of precapillary arterioles affecting the brain, retina, and inner ear [4]. Standardized treatment guidelines are lacking. First-line therapy consists of high-dose corticosteroids. Early, aggressive, sustained immunosuppressive treatment improves the outcome but dosage and duration of treatment remain undetermined [3].
Conflict of interest
123
No conflict of interest was reported.
References 1. Do¨rr J, Krautwald S, Wildemann B et al (2013) Characteristics of Susac syndrome: a review of all reported cases. Nat Rev Neurol 9(6):307–316 2. Garcı´a-Carrasco M, Mendoza-Pinto C, Cervera R (2014) Diagnosis and classification of Susac syndrome. Autoimmun Rev 13(4–5):347–350 3. Rennebohm R, Susac JO, Egan RA, Daroff RB (2010) Susac’s syndrome—update. J Neurol Sci 299(1–2):86–91 4. Kleffner I, Duning T, Lohmann H et al (2012) A brief review of Susac syndrome. J Neurol Sci 322(1–2):35–40
NEURO-IMAGES
Characteristic callosal involvement in Susac’s syndrome Alexandra Seghers • Joachim Van Calster Guido Wilms • Be´ne´dicte Dubois
•
Received: 12 June 2014 / Accepted: 14 July 2014 Ó Belgian Neurological Society 2014
Keywords Susac’s syndrome Magnetic resonance imaging Fluorescein angiography After experiencing paresthesia in the right hand and increasing headache, instability and black spots in the left visual field since 2 weeks, a 30-year-old female presented with an episode of irresponsiveness with prolonged confusion. There was some spontaneous improvement of the cognitive impairment but short-term memory difficulties remained. We found a decreased vision of the right eye (best corrected ETDRS visual acuity 20/32 compared 20/40 on the left), an instable gait, and a right-sided hyperreflexia. Subsequently, she developed auditory loss and tinnitus. She became increasingly apathetic and somnolent, culminating in another episode of loss of consciousness, now with myoclonic jerking of the right half of the face. Analysis of the cerebrospinal fluid showed a normal white cell count, a moderately elevated protein level with a normal IgG index, and no oligoclonal bands. A. Seghers (&) B. Dubois Department of Neurology, University Hospitals Leuven, Herestraat 49, 3000 Louvain, Belgium e-mail: [email protected] B. Dubois e-mail: [email protected] J. Van Calster Department of Ophthalmology, University Hospitals Leuven, Louvain, Belgium e-mail: [email protected] G. Wilms Department of Radiology, University Hospitals Leuven, Louvain, Belgium e-mail: [email protected]
Brain magnetic resonance imaging (MRI) revealed multiple T2 hyperintensities, most of which showed diffusion restriction. The most prominent lesions were found in the corpus callosum (Fig. 1). On ophthalmological evaluation, occlusions of branch retinal arteries were seen (Fig. 2). Our patient was diagnosed with Susac’s syndrome (SS) and treated with corticosteroids and intravenous cyclophosphamide monthly, which, with exception of one initial episode of cognitive deterioration with a new gadolinium enhancing callosal lesion on MRI, has led to an improvement of the clinical picture over the last year with stabilization of MRI findings ever since. Treatment with corticosteroids is slowly being tapered. Susac’s syndrome is characterized by the clinical triad of encephalopathy, branch retinal artery occlusions (BRAOs), and hearing loss (HL). The true incidence is unknown; 304 cases have been reported worldwide. The condition is most commonly seen in women from 20 to 40 years [1, 2]. Susac et al. [3] state that in its encephalopathic form, pathognomonic MRI lesions of the corpus callosum permit an immediate diagnosis, even in the absence of BRAO and HL. Characteristic findings are microinfarcts of its central portion (‘‘snowballs’’, eventually evolving into pathognomonic central callosal ‘‘holes’’). The callosal roof is also frequently affected by microinfarcts in ‘‘icicle’’ and ‘‘spoke’’ configurations. Moreover, the ‘‘string of pearls’’ MRI finding—the studding of the internal capsules with microinfarcts, most dramatically shown on diffusionweighted images (DWI)—is found to be pathognomonic when associated with the typical central callosal lesions. Diffusion tensor imaging (DTI) reveals microstructural degeneration of cerebral fibers appearing normal on conventional MRI. Involvement of the callosal genu is characteristic and correlates with functional deficits [4].
123
Acta Neurol Belg Fig. 1 Sagittal T2 showing central callosal demyelinisation: ‘‘snowballs’’ (black arrows), ‘‘spokes’’ (white arrows), and an ‘‘icicle’’ (arrowhead)
Fig. 2 Color fundus photography (a) of the right eye with BRAO and ischemic retinal edema; early (b, c) and late (d) fluorescein angiography pictures showing arteriolar nonperfusion and arteriolar wall hyperfluorescence, respectively
SS is considered an autoimmune-mediated microangiopathy of precapillary arterioles affecting the brain, retina, and inner ear [4]. Standardized treatment guidelines are lacking. First-line therapy consists of high-dose corticosteroids. Early, aggressive, sustained immunosuppressive treatment improves the outcome but dosage and duration of treatment remain undetermined [3].
Conflict of interest
123
No conflict of interest was reported.
References 1. Do¨rr J, Krautwald S, Wildemann B et al (2013) Characteristics of Susac syndrome: a review of all reported cases. Nat Rev Neurol 9(6):307–316 2. Garcı´a-Carrasco M, Mendoza-Pinto C, Cervera R (2014) Diagnosis and classification of Susac syndrome. Autoimmun Rev 13(4–5):347–350 3. Rennebohm R, Susac JO, Egan RA, Daroff RB (2010) Susac’s syndrome—update. J Neurol Sci 299(1–2):86–91 4. Kleffner I, Duning T, Lohmann H et al (2012) A brief review of Susac syndrome. J Neurol Sci 322(1–2):35–40
