A-256 A Unique Bilingual Phenotype in the Context of Late Onset MELAS

Abstract

Abstract Objective Mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) is a progressive disease with typical onset before age 40 characterized by eventual neurocognitive deterioration. This case study highlights bilingual-bicultural neuropsychological principles within the Socially Responsible Neuropsychology (SRN) model to illustrate the phenotypic presentation of bilingual late-onset MELAS. Method The case is a 56-year-old, right-handed, bilingual Latino male (L1 Spanish, L2 English) with 16 years of education in his country of origin and 22 years as an industrial engineer in the U.S. At age 52, he was diagnosed with MELAS after an abrupt episode of olfactory hallucinations and dysgraphia in both languages. MRI revealed acute infarcts in the right parietal lobe and left cerebellum. He was referred for neuropsychological assessment 4 years later to evaluate reported neurocognitive decline and deterioration of L2, and to assist in targeted treatment planning. Results The clinical interview revealed significant decline in both receptive and expressive L2 English language capabilities, particularly relative to baseline as an industrial engineer, with relative sparing of L1 Spanish. Consistent with prior acute right hemisphere strokes, the neurocognitive profile also revealed lateralized impairment in visuospatial skills and memory. Notably verbal learning and memory in the mesial temporal system was preserved. Conclusions This case study illustrates how late L2 acquisition can lead to bilateral language representation, altering the phenotype of late-onset MELAS. Application of the SRN model highlights the importance of including background information regarding language acquisition and current language use to illustrate a unique bilingual MELAS phenotype and its impact on language loss and recovery.