Bilingualism delays the onset of behavioral but not aphasic forms of frontotemporal dementia

Bilingualism has been found to delay onset of dementia and this has been attributed to an advantage in executive control in bilinguals. However, the relationship between bilingualism and cognition is complex, with costs as well as benefits to language functions. To further explore the cognitive consequences of bilingualism, the study used Frontotemporal dementia (FTD) syndromes, to examine whether bilingualism modifies the age at onset of behavioural and language variants of Frontotemporal dementia (FTD) differently. Case records of 193 patients presenting with FTD (121 of them bilingual) were examined and the age at onset of the first symptoms were compared between monolinguals and bilinguals. A significant effect of bilingualism delaying the age at onset of dementia was found in behavioural variant FTD (5.7 years) but not in progressive nonfluent aphasia (0.7 years), semantic dementia (0.5 years), corticobasal syndrome (0.4 years), progressive supranuclear palsy (4.3 years) and FTD-motor neuron disease (3 years). On dividing all patients predominantly behavioral and predominantly aphasic groups, age at onset in the bilingual behavioural group (62.6) was over 6 years higher than in the monolingual patients (56.5, p=0.006), while there was no difference in the aphasic FTD group (60.9 vs. 60.6 years, p=0.851). The bilingual effect on age of bvFTD onset was shown independently of other potential confounding factors such as education, gender, occupation, and urban vs rural dwelling of subjects. To conclude, bilingualism delays the age at onset in the behavioral but not in the aphasic variants of FTD. The results are in line with similar findings based on research in stroke and with the current views of the interaction between bilingualism and cognition, pointing to advantages in executive functions and disadvantages in lexical tasks

Dementia diagnosis in seven languages: the Addenbrooke’s Cognitive Examination-III in India

OBJECTIVE: With the rising burden of dementia globally, there is a need to harmonize dementia research across diverse populations. The Addenbrooke's Cognitive Examination-III (ACE-III) is a well-established cognitive screening tool to diagnose dementia. But there have been few efforts to standardize the use of ACE-III across cohorts speaking different languages. The present study aimed to standardize and validate ACE-III across seven Indian languages and to assess the diagnostic accuracy of the test to detect dementia and mild cognitive impairment (MCI) in the context of language heterogeneity.  METHODS: The original ACE-III was adapted to Indian languages: Hindi, Telugu, Kannada, Malayalam, Urdu, Tamil, and Indian English by a multidisciplinary expert group. The ACE-III was standardized for use across all seven languages. In total, 757 controls, 242 dementia, and 204 MCI patients were recruited across five cities in India for the validation study. Psychometric properties of adapted versions were examined and their sensitivity and specificity were established.  RESULTS: The sensitivity and specificity of ACE-III in identifying dementia ranged from 0.90 to 1, sensitivity for MCI ranged from 0.86 to 1, and specificity from 0.83 to 0.93. Education but not language was found to have an independent effect on ACE-III scores. Optimum cut-off scores were established separately for low education (≤10 years of education) and high education (>10 years of education) groups.  CONCLUSIONS: The adapted versions of ACE-III have been standardized and validated for use across seven Indian languages, with high diagnostic accuracy in identifying dementia and MCI in a linguistically diverse context

Impact of bilingualism on cognitive outcome after stroke

Background and Purpose:  Bilingualism has been associated with slower cognitive aging and a later onset of dementia. In this study, we aimed to determine whether bilingualism also influences cognitive outcome after stroke.  Methods:  We examined 608 patients with ischemic stroke from a large stroke registry and studied the role of bilingualism in predicting poststroke cognitive impairment in the absence of dementia.  Results: A larger proportion of bilinguals had normal cognition compared with monolinguals (40.5% versus 19.6%; P<0.0001), whereas the reverse was noted in patients with cognitive impairment, including vascular dementia and vascular mild cognitive impairment (monolinguals 77.7% versus bilinguals 49.0%; P<0.0009). There were no differences in the frequency of aphasia (monolinguals 11.8% versus bilinguals 10.5%; P=0.354). Bilingualism was found to be an independent predictor of poststroke cognitive impairment.  Conclusions  Our results suggest that bilingualism leads to a better cognitive outcome after stroke, possibly by enhancing cognitive reserve

Dementia in developing countries: Does education play the same role in India as in the West?

ABSTRACT Evidence suggests that education protects from dementia by enhancing cognitive reserve. However, this may be influenced by several socio-demographic factors. Rising numbers of dementia in India, high levels of illiteracy and heterogeneity in socio-demographic factors provide an opportunity to explore this relationship. Objective: To study the association between education and age at dementia onset, in relation to socio-demographic factors. Methods: Association between age at dementia onset and literacy was studied in relationship to potential confounding factors such as gender, bilingualism, place of dwelling, occupation, vascular risk factors, stroke, family history of dementia and dementia subtypes. Results: Case records of 648 dementia patients diagnosed in a specialist clinic in a University hospital in Hyderabad, India were examined. All patients were prospectively enrolled as part of an ongoing longitudinal project that aims to evaluate dementia subjects with detailed clinical, etiological, imaging, and follow-up studies. Of the 648 patients, 98 (15.1%) were illiterate. More than half of illiterate skilled workers were engaged in crafts and skilled agriculture unlike literates who were in trade or clerical jobs. Mean age at onset in illiterates was 60.1 years and in literates 64.5 years (p=0.0002). Factors independently associated with age at dementia onset were bilingualism, rural dwelling and stroke, but not education. Conclusion: Our study demonstrates that in India, rural dwelling, bilingualism, stroke and occupation modify the relationship between education and dementia

Contraceptive vaccines based on zona pellucida glycoproteins for dogs and other wildlife population management

Zona pellucida (ZP) glycoproteins, by virtue of their critical role in fertilization, have been proposed as candidate antigens for the development of contraceptive vaccines. In this review, the potential of a ZP-based contraceptive vaccine for the management of wildlife population, with special reference to street dogs, is discussed. Immunization of various animal species, including female dogs, with native porcine ZP led to inhibition of fertility, which was associated with the ovarian dysfunction. Immunization of female dogs with Escherichia coli-expressed recombinant dog ZP glycoprotein-3 (ZP3) either coupled to diphtheria toxoid or expressed as fusion protein with 'promiscuous' T non-B-cell epitope of tetanus toxoid also led to inhibition of fertility. To improve the contraceptive efficacy of ZP-based contraceptive vaccine, various groups are working on improving the immunogen, use of DNA vaccine as prime-boost strategy, and delivering the zona proteins/peptides presented on either virus-like particles or entrapped in microsphere. Host-specific live vectors such as ectromelia virus and cytomegalovirus have also been used to deliver mouse ZP3 in mice. Various studies show the enormous potential of the ZP-based vaccine for the management of wildlife population, where permanent sterilization may be desirable