Magnetic Resonance Imaging “Tigroid Pattern” in Alexander Disease

Abstract

Alexander disease (AD) is a rare white matter disorder resulting from mutations in the gene encoding for the glial fibrillary acidic protein. Diffuse white matter involvement with frontal predominance is typical of infantile AD that is clinically characterized by progressive motor and mental retardation, seizures, and megaloencephaly. We describe the case of a 10-year-old patient harboring a de novo missense mutation c.235C > T (p.R79C) in the GFAP gene, showing a relatively slow clinical and neuroradiologic progression of disease associated with a previously unreported magnetic resonance imaging (MRI) finding consistent with the so-called tigroid pattern. This pattern has been previously described in only a few different neurologic conditions, including Pelizaeus-Merzbacher disease and some lysosomal disorders. This report expands the spectrum of MRI features in AD.

Keywords

Alexander disease - GFAP - tigroid pattern

• References

• 1 Messing A, Brenner M, Feany MB, Nedergaard M, Goldman JE. Alexander disease. J Neurosci 2012; 32 (15) 5017-5023
• 2 Brenner M, Johnson AB, Boespflug-Tanguy O, Rodriguez D, Goldman JE, Messing A. Mutations in GFAP, encoding glial fibrillary acidic protein, are associated with Alexander disease. Nat Genet 2001; 27 (1) 117-120
• 3 van der Knaap MS, Naidu S, Breiter SN , et al. Alexander disease: diagnosis with MR imaging. AJNR Am J Neuroradiol 2001; 22 (3) 541-552
• 4 Caroli F, Biancheri R, Seri M , et al. GFAP mutations and polymorphisms in 13 unrelated Italian patients affected by Alexander disease. Clin Genet 2007; 72 (5) 427-433
• 5 van der Knaap MS, Salomons GS, Li R , et al. Unusual variants of Alexander's disease. Ann Neurol 2005; 57 (3) 327-338
• 6 van der Knaap MS, Ramesh V, Schiffmann R , et al. Alexander disease: ventricular garlands and abnormalities of the medulla and spinal cord. Neurology 2006; 66 (4) 494-498
• 7 Jefferson RJ, Absoud M, Jain R, Livingston JH, , v an der Knaap MS, Jayawant S. Alexander disease with periventricular calcification: a novel mutation of the GFAP gene. Dev Med Child Neurol 2010; 52 (12) 1160-1163
• 8 Caro PA, Marks HG. Magnetic resonance imaging and computed tomography in Pelizaeus-Merzbacher disease. Magn Reson Imaging 1990; 8 (6) 791-796
• 9 van der Voorn JP, Pouwels PJ, Kamphorst W , et al. Histopathologic correlates of radial stripes on MR images in lysosomal storage disorders. AJNR Am J Neuroradiol 2005; 26 (3) 442-446
• 10 Onur MR, Senol U, Mihçi E, Lüleci E. Tigroid pattern on magnetic resonance imaging in Lowe syndrome. J Clin Neurosci 2009; 16 (1) 112-114