Using the Revised Diagnostic Criteria for Frontotemporal Dementia in India: Evidence of an Advanced and Florid Disease

Abstract

BackgroundThe International Consortium (FTDC) that revised the diagnostic criteria for behavioural variant frontotemporal dementia (bvFTD) did not have an Asian representation. Whether the revised criteria are equally useful in the early detection of Asian bvFTD patients therefore remains largely unexplored. Earlier studies have indicated differences in clinical manifestations in Indian and other Asian bvFTD patients when compared to western groups. There is an urgent need for clarification, given the projected exponential rise in dementia in these countries and the imminent clinical trials on bvFTD.ObjectiveTo assess how Indian bvFTD patients fulfil the FTDC criteria, hypothesizing that our patients might present differently early in the illness.MethodIn a hospital-based retrospective observational study, we assessed 48 probable bvFTD patients, diagnosed according to the FTDC criteria, for the speed with which these criteria were fulfilled, the frequency of individual symptoms and their order of appearance during the illness.ResultsMost of our patients presented with moderate to severe dementia, in spite of having relatively short onset to diagnosis times. Patients on average took 1.4 years from onset to meet the FTDC criteria, with 90% of them presenting with four or more symptoms at diagnosis. Disinhibition was the commonest symptom and the first symptom in most patients.ConclusionWith most patients presenting with advanced and florid disease, the FTDC criteria have little additional impact in early identification of bvFTD in India. Modifying the criteria further could allow detection of Indian patients early enough for their inclusion in future clinical trials.

The Phenotype of the C9ORF72 Expansion Carriers According to Revised Criteria for bvFTD

“…without data on their C9ORF72 status), while the number of diagnostic criteria seems to be lower in patients with the C9ORF72 expansion. This argument is supported by the finding that in neuropathological and clinical cohorts, the sensitivity of each possible feature is on average very high (over 50%) except for hyperorality [ 7 , 9 , 10 , 17 , 18 ] while Devenney and colleagues found the mean number of possible bvFTD features to be 4.2/6 in patients with the C9ORF72 expansion which is slightly higher compared to our results (3.19/6 features). Executive dysfunction in the neuropsychological profile was detected in all of the patients and this was found even in the early stages of the disease or in cases that did not fulfill the criteria for bvFTD.…”

Survival in Frontotemporal Dementia Phenotypes: A Meta-Analysis

“…Eleven studies were North American [3,7,19,31,32,33,34,35,36,37,38], eleven were Western European [8,10,39,40,41,42,43,44,45,46,47] and four were from Southeast and East Asia [5,48,49,50]. One was multi-continental [4].…”

“…Furthermore, complex FTD phenotypes that cross syndrome boundaries are not uncommon [34]. It is worth noting that we directly adopted the diagnoses specified by the studies, which were sometimes those made at presentation [4,8,41,50,56,61], sometimes the most recent [10,32,33,36,46], and often had unspecified timing.…”

“…Since our data derive largely from Caucasian subjects living in the United States and Western Europe, the generalizability of our findings to other regions might be at issue. The cross-cultural problem was raised in a report from India [50] that described florid presentations and called for modified criteria to accommodate cultural modes and facilitate earlier case identification, but there is also a report from Nigeria about a case presenting 2 years into the illness with features that matched contemporary diagnostic criteria [69]. …”

Family history of frontotemporal lobar degeneration in Asia – an international multi-center research

“…Relevant data from Asia are sparse (Ikeda et al, Table 3. Family history data in each diagnostic group 2004; Ghosh et al, 2013). Our study is one of the largest reports of FTLD in an Asian population.…”