Patterns of language impairment in multilingual speakers with post-stroke aphasia are diverse: in some cases the language deficits are parallel, that is, all languages are impaired relatively equally, whereas in other cases deficits are differential, that is, one language is more impaired than the other(s). This diversity stems from the intricate structure of the multilingual language system, which is shaped by a complex interplay of influencing factors, such as age of language acquisition, frequency of language use, premorbid proficiency, and linguistic similarity between one's languages. Previous theoretical reviews and empirical studies shed some light on these factors, however no clear answers have been provided. The goals of this review were to provide a timely update on the increasing number of reported cases in the last decade and to offer a systematic analysis of the potentially influencing variables. One hundred and thirty cases from 65 studies were included in the present systematic review and effect sizes from 119 cases were used in the meta-analysis. Our analysis revealed better performance in L1 compared to L2 in the whole sample of bilingual speakers with post-stroke aphasia. However, the magnitude of this difference was influenced by whether L2 was learned early in childhood or later: those who learned L2 before 7 years of age showed comparable performance in both of their languages contrary to the bilinguals who learned L2 after 7 years of age and showed better performance in L1 compared to L2. These robust findings were moderated mildly by premorbid proficiency and frequency of use. Finally, linguistic similarity did not appear to influence the magnitude of the difference in performance between L1 and L2. Our findings from the early bilingual subgroup were in line with the previous reviews which included mostly balanced early bilinguals performing comparably in both languages. Our findings from the late bilingual subgroup stressed the primacy of L1 and the importance of age of L2 learning. In addition, the evidence from the present review provides support for theories emphasizing the role of premorbid proficiency and language use in language impairment patterns in bilingual aphasia.

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The Oxford Cognitive Screen (OCS) is a screening tool for the assessment of poststroke deficits in attention, memory, praxis, language, and number processing. The goal of the present study was to develop a Russian version of the OCS (Rus-OCS) via translation of the original battery, its cultural and linguistic adaptations, and reporting preliminary findings on its psychometric properties. Method: All parts of OCS were translated by native Russian-speaking neuropsychologists. Russian-speaking stroke patients (N ϭ 205) were assessed with the Rus-OCS. Their performance was compared with performance of 60 healthy Russian-speaking adults aged between the ages of 18 and 91 years. The performance of 15 stroke patients and 42 healthy adults were assessed with a parallel version within 7 days of first testing. Convergent validity of the Rus-OCS was established via correlations with comparable tasks. Performance of three stroke groups with different lesion lateralization (right, left, and bilateral) was compared on language and visual attention subtasks. Preliminary normative data based on 5th to 95th percentile were also reported. Results: Measures of internal consistency and test-retest reliability ranged from acceptable to very good and estimates of convergent validity ranged from moderate to high. Sensitivity and specificity was found to range from .56 to 1 and from .73 to 1, respectively. Significant differences in performance between stroke and healthy groups on all subtasks confirmed the discriminative power of the Rus-OCS was good. Conclusions: Rus-OCS is a promising cognitive screening instrument for Russian-speaking patients. However, further validation is needed. Constraints of socioeconomic differences between Russian speakers in the wider population should be considered.

The Rus-BCoS shows promise as a comprehensive cognitive screening tool that can be used by clinicians working with Russian-speaking persons experiencing poststroke aphasia after much further validation and development of reliable normative standards. Given a lack of quantitative neuropsychological assessment tools in Russia, however, we contend the Rus-BCoS offers potential benefits to clinicians and patients. However, data from research studies with a broader sample of Russian speakers are needed.