Semantic memory impairment in dementia: A cross-cultural adaptation study.

BACKGROUND: Semantic memory deficits are frequently encountered in dementia and distinct patterns of semantic impairment characterize the subtypes of dementia. Life course and cultural experiences significantly influence semantic memory. Hence, there is a need to assess semantic memory using culturally appropriate tests, to aid accurate diagnosis of dementia and facilitate cross-cultural collaborative research. AIMS: In this prospective study, we adapted and validated the Cambridge Semantic Memory (CSM) test battery to the Indian cultural context and studied the patterns of semantic memory impairment across dementia subtypes. METHODS: The CSM battery was modified using standard methods and by incorporating culturally appropriate changes and new semantic categories relevant to India. The adapted Indian Semantic Memory (ISM) test battery was administered to a cohort of 121 subjects, consisting of controls and dementia: Alzheimer's disease (AD), progressive non-fluent aphasia (PNFA), semantic dementia (SD), and behavioral variant fronto-temporal dementia (BvFTD). Profile of semantic memory performance across groups was examined. RESULTS: The ISM battery was found to be a valid measure of semantic memory. The novel semantic categories of gods/religious icons, vegetables, and food items added value to the diagnostic process. Distinct semantic memory profiles in SD, PNFA, AD, and BvFTD were demonstrated. CONCLUSIONS: The cultural adaptation of a semantic memory battery for the Indian context provided sensitive evidence of semantic memory impairment in dementia and its subtypes. The clinical and research application of the ISM battery will enhance diagnostic evaluation that can aid in early and accurate identification of deficits and devising intervention strategies and enable research across cultures.

Picture-naming test for a linguistically diverse population with cognitive impairment and dementia.

BACKGROUND: Picture-naming tests (PNTs) evaluate linguistic impairment in dementia due to semantic memory impairment, impaired lexical retrieval or perceptual deficits. They also assess the decline in naming impairment at various stages of dementia and mild cognitive impairment (MCI) that occurs due to progressive cognitive impairment. With the increasing numbers of people with dementia globally, it is necessary to have validated naming tests and norms that are culturally and linguistically appropriate. AIMS: In this cross-sectional study we harmonized a set of 30 images applicable to the Indian context across five languages and investigated the picture-naming performance in patients with MCI and dementia. METHODS & PROCEDURES: A multidisciplinary expert group formed by the Indian Council of Medical Research (ICMR) collaborated towards developing and adapting a picture naming test (PNT) known as the ICMR-PNT in five Indian languages: Hindi, Bengali, Telugu, Kannada and Malayalam. Based on cross-cultural adaptation guidelines and item-wise factor analysis and correlations established separately across five languages, the final version of the ICMR-PNT test was developed. A total of 368 controls, 123 dementia and 128 MCI patients were recruited for the study. Psychometric properties of the adapted version of the ICMR-PNT were examined, and sensitivity and specificity were examined. OUTCOMES & RESULTS: The ICMR-PNT scores in all languages combined were higher in controls compared with patients with dementia and MCI (F2, 615 = 139.85; p < 0.001). Furthermore, PNT scores for MCI was higher in comparison with patients with dementia in all languages combined (p < 0.001). The area under the curve across the five languages ranged from 0.81 to 1.00 for detecting dementia. There was a negative correlation between Clinical Dementia Rating (CDR) and ICMR-PNT scores and a positive correlation between Addenbrooke's Cognitive Examination-III (ACE-III) and ICMR-PNT scores in control and patient groups. CONCLUSIONS & IMPLICATIONS: The ICMR-PNT was developed by following cross-cultural adaptation guidelines and establishing correlations using item-wise factor analysis across five languages. This adapted PNT was found to be a reliable tool when assessing naming abilities effectively in mild to moderate dementia in a linguistically diverse context. WHAT THIS PAPER ADDS: What is already known on this subject Picture-naming evaluates language impairment linked to naming difficulties due to semantic memory, lexical retrieval or perceptual disturbances. As a result, picture naming tests (PNTs) play an important role in the diagnosis of dementia. In a heterogeneous population such as India, there is a need for a common PNT that can be used across the wide range of languages. What this study adds to existing knowledge PNTs such as the Boston Naming Test (BNT) were developed for the educated, mostly English-speaking, Western populations and are not appropriate for use in an Indian context. To overcome this challenge, a PNT was harmonized in five Indian languages (Hindi, Bengali, Telugu, Kannada and Malayalam) and we report the patterns of naming difficulty in patients with MCI and dementia. The ICMR-PNT demonstrated good diagnostic accuracy when distinguishing patients with mild to moderate dementia from cognitively normal individuals. What are the potential or actual clinical implications of this work? With the growing number of persons suffering from Alzheimer's disease and other forms of dementia around the world, its critical to have culturally and linguistically relevant naming tests and diagnosis. This validated ICMR-PNT can be used widely as a clinical tool to diagnose dementia and harmonize research efforts across diverse populations.

Identification and functional characterization of two novel mutations in KCNJ10 and PI4KB in SeSAME syndrome without electrolyte imbalance.

BACKGROUND: Dysfunction in inwardly rectifying potassium channel Kir4.1 has been implicated in SeSAME syndrome, an autosomal-recessive (AR), rare, multi-systemic disorder. However, not all neurological, intellectual disability, and comorbid phenotypes in SeSAME syndrome can be mechanistically linked solely to Kir4.1 dysfunction. METHODS: We therefore performed whole-exome sequencing and identified additional genetic risk-elements that might exert causative effects either alone or in concert with Kir4.1 in a family diagnosed with SeSAME syndrome. RESULTS: Two variant prioritization pipelines based on AR inheritance and runs of homozygosity (ROH), identified two novel homozygous variants in KCNJ10 and PI4KB and five rare homozygous variants in PVRL4, RORC, FLG2, FCRL1, NIT1 and one common homozygous variant in HSPA6 segregating in all four patients. The novel mutation in KCNJ10 resides in the cytoplasmic domain of Kir4.1, a seat of phosphatidylinositol bisphosphate (PIP2) binding. The mutation altered the subcellular localization and stability of Kir4.1 in patient-specific lymphoblastoid cells (LCLs) compared to parental controls. Barium-sensitive endogenous K+ currents in patient-specific LCLs using whole-cell patch-clamp electrophysiology revealed membrane depolarization and defects in inward K+ ion conductance across the membrane, thereby suggesting a loss-of-function effect of KCNJ10 variant. CONCLUSION: Altogether, our findings implicate the role of new genes in SeSAME syndrome without electrolyte imbalance and thereby speculate the regulation of Kir4.1 channel activity by PIP2 and integrin-mediated adhesion signaling mechanisms.

Communication partner training for healthcare workers engaging with people with aphasia: Enacting Sustainable Development Goal 17 in Austria, Egypt, Greece, India and Serbia.

PURPOSE: This commentary describes how a grassroot-led partnership initiated by members of the organisations World Federation of NeuroRehabilitation and Collaboration of Aphasia Trialists is addressing the marginalisation of people with aphasia, through education and knowledge exchange related to communication partner training of health professionals. RESULT: A partnership between academics and healthcare professionals across Austria, Denmark, Egypt, Ireland, Greece, India, Serbia and the United Kingdom was established in 2020. Through bimonthly online sessions in 2021-2022 a Danish communication partner training program was introduced while six teams adapted and translated the training and its materials to their local contexts. CONCLUSION: A collaborative partnership enabled multiple translations of an existing communication partner training program for healthcare professionals working with people with aphasia to support a sustainable delivery model that is linguistic and culturally sensitive. This commentary paper focusses on Sustainable Development Goal (SDG) 17 and also addresses SDG 10.

Outcome of epilepsy in patients with mitochondrial disorders: Phenotype genotype and magnetic resonance imaging correlations.

OBJECTIVES: Studies exploring the outcome of epilepsy in patients with mitochondrial disorders are limited. This study examined the outcome of epilepsy in patients with mitochondrial disorders and its relation with the clinical phenotype, genotype and magnetic resonance imaging findings. PATIENTS AND METHODS: The cohort was derived from the database of 67 patients with definite genetic diagnosis of mitochondrial disorders evaluated over a period of 11years (2006-2016). Among this, 27 had epilepsy and were included in final analysis. Data were analyzed with special reference to clinical phenotypes, genotypes, epilepsy characteristics, EEG findings, anti epileptic drugs used, therapeutic response, and magnetic resonance imaging findings. Patients were divided into three groups according to the seizure frequency at the time of last follow up: Group I- Seizure free; Group II- Infrequent seizures; Group III- uncontrolled seizures. For each group the clinical phenotype, genotype, magnetic resonance imaging and duration of epilepsy were compared. RESULTS: The phenotypes & genotypes included Mitochondrial Encephalopathy Lactic Acidosis and Stroke like episodes (MELAS) & m.3243A>G mutation (n = 10), Myoclonic Epilepsy Ragged Red Fiber syndrome (MERRF) & m.8344A>G mutation (n = 4), Chronic Progressive External Ophthalmoplegia plus &POLG1 mutation (CPEO, n = 6), episodic neuroregression due to nuclear mutations (n = 6; NDUFV1 (n = 3), NDUFA1, NDUFS2, MPV17-1 one each), and one patient with infantile basal ganglia stroke syndrome, mineralizing angiopathy &MT-ND5 mutations. Seven patients (25.9%) were seizure free; seven had infrequent seizures (25.9%), while thirteen (48.1%) had frequent uncontrolled seizures. Majority of the subjects in seizure free group had episodic neuroregression & leukoencephalopathy due to nuclear mutations (85.7%). Patients in group II with infrequent seizures had CPEO, POLG1 mutation and a normal MRI (71%) while 62% of the subjects in group III had MELAS, m.3243A>G mutation and stroke like lesions on MRI. CONCLUSIONS: A fair correlation exists between the outcome of epilepsy, clinical phenotypes, genotypes and magnetic resonance imaging findings in patients with mitochondrial disorders. The recognition of these patterns is important clinically because of the therapeutic and prognostic implications.

Audiological manifestations in mitochondrial encephalomyopathy lactic acidosis and stroke like episodes (MELAS) syndrome.

OBJECTIVES: Reports of audiological manifestations in specific subgroups of mitochondrial disorders are limited. This study aims to describe the audiological findings in patients with MELAS syndrome and m.3243A>G mutation. PATIENTS & METHODS: Audiological evaluation was carried out in eight patients with confirmed MELAS syndrome and m.3243A>G mutation. The evaluation included a complete neurological evaluation, pure tone audiometry (n=8), otoacoustic emissions (n=8) and brainstem evoked response audiometry (n=6), magnetic resonance imaging (n=8) and muscle biospy (n=6). RESULTS: Eight patients (Age range: 5-45 years; M:F-1:3) including six children and two adults underwent formal audiological evaluation. Five patients had hearing loss; of these two had "subclinical hearing loss", one had moderate and two had severe hearing loss. The abnormalities included abnormal audiometry (n=5), otoacoustic emission testing (n=7) and absent brainstem auditory evoked responses (n=1). The findings were suggestive of cochlear involvement in four and retrocochlear in one. CONCLUSIONS: This study shows that hearing loss of both cochlear and retrocochlear origin occurs in patients with MELAS and may be subclinical. Early referrals for audiological evaluation is warranted to recognize the subclinical hearing loss in these patients. The therapeutic implications include early interventions in the form of hearing aids, cochlear implants and cautioning the physicians for avoidance of aminoglycosides.

Evaluating the effect of risperidone on speech: A cross-sectional study.

Speech subsystems are susceptible to the effects of several factors including medications. The atypical antipsychotics can also adversely affect the speech because of its action on serotonin and dopamine neurotransmitters. The present study aims to analyze the speech characteristics associated with atypical antipsychotic risperidone. Speech of 92 patients on risperidone with or without trihexyphenidyl and/or clonazepam were compared with that of 31 persons who were not on any psychotropic medicines. Compared to control group, maximum phonation duration, sequential motion rate of diadochokinesia was reduced by about 3s and 1syllable/s respectively and s/z ratio was increased by 0.16 in patients with risperidone. Performance of larynx, lips and tongue sub-system and intelligibility of speech were also significantly reduced in risperidone group. Risperidone did impact the phonation and articulation sub-systems of speech mildly, which was independent of tardive dyskinesia and extrapyramidal symptoms. Randomized controlled prospective study looking into impact on speech and related effect on drug adherence, functioning and quality of life needs to be conducted with risperidone and other atypical antipsychotics.

Audiological findings in Infantile Refsum disease.

Audiological manifestations in a four-year-old child with Infantile Refsum disease are reported. He was born to non-consanguineous parents and had normal birth history and mildly delayed milestones prior to presentation. Clinical features were characterized by neuroregression, retinitis pigmentosa, hearing loss, peripheral neuropathy and white matter signal changes on magnetic resonance imaging. Biochemical evaluation showed elevated serum levels of long chain fatty acid and phytanic acid confirming the diagnosis. The audiological profile was characterized by absent auditory brainstem responses with robust otocoustic emissions, which indicated auditory neuropathy as the possible cause of hearing loss.

Speech-Language and swallowing manifestations and rehabilitation in an 11-year-old girl with MELAS syndrome.

Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a rare mitochondrial disease. The available studies on MELAS syndrome are limited to evaluation of radiological, audiological, genetic, and neurological findings. Among the various neurological manifestations, speech-language and swallowing manifestations are less discussed in the literature. This report describes the speech-language and swallowing function in an 11-year-old girl with MELAS syndrome. The intervention over a period of 6 months is discussed.