Is the Addenbrooke?s Cognitive Examination effective to detect frontotemporal dementia?

Abstract

We evaluated the Addenbrooke's cognitive examination (ACE), a simple instrument to differentiate frontotemporal dementia (FTD) from Alzheimer's disease (AD), in our dementia patients clinic population. The Verbal-Language/Orientation-Memory (VLOM) ratio, which compares its language and memory scores, determines whether FTD or AD is more likely. The ACE was translated into French with adaptation maintaining the number of words in the name and address learning and delayed recall test, and with cultural adaptation for the semantic memory. The 85 included subjects had no evidence of two or more organic pathologies, after at least six months of follow-up, and an MMSE score>or=20/30. Patients with cognitive impairment due to alcohol intake were excluded. The diagnosis of a specific dementing illness was based on the consensus of the neurologist and neuropsychologists in the team. Thereafter, another neurologist expert in dementia, blinded to the ACE result and to the diagnosis and treatment, reviewed all cases files and proposed a diagnosis. A diagnostic agreement was reached for 79 cases (92.9%) with 40 (50.6%) dementia: 25 AD (62.5 %), 9 FTD (22.5 %). We estimated that the sensitivity for detecting dementia of an ACE score<or=83/100 was 90% with a specificity of 64.1%. When the ACE score was<or=88/100, the sensitivity for diagnosing FTD of a VLOM ratio<2.2 was 11.1% with a specificity of 88 % and the sensitivity for diagnosing AD of a VLOM ratio>3.2 was 72%,with a specificity of 69.4%. We conclude that, when used as originally proposed, ACE is very accurate for the detection of dementia, but much less effective in discriminating the most common frontal variant of FTD.

The Neuropsychological Profile of Alzheimer Disease

“…This conclusion is supported by several other studies using clinically diagnosed patients that found similar levels of discriminability when differentiating FTD from AD on the basis of tests of executive function, visuospatial abilities, and episodic memory (Elfgren et al 1994;Gregory et al 1997;Lipton et al 2005;Libon et al 2007). These differences are robust enough to be detected with relatively brief dementiascreening instruments that tap multiple cognitive functions (Mathuranath et al 2000;Bier et al 2004;Slachevsky et al 2004). …”

Utility and Limitations of Addenbrooke’s Cognitive Examination-Revised for Detecting Mild Cognitive Impairment in Parkinson’s Disease

“…It assesses various cognitive domains, without requiring specialized test equipment or personnel [33]. Studies have shown that ACE can differentiate dementia subtypes, including Alzheimer’s disease, frontotemporal dementia, progressive supranuclear palsy and other atypical parkinsonian syndromes [33,34,35,36,37,38]. The ACE incorporates the MMSE, expanding on memory, language and visuospatial components, and adding a verbal fluency section [33].…”

Distinct cognitive profiles and rates of decline on the Mattis Dementia Rating Scale in autopsy-confirmed frontotemporal dementia and Alzheimer's disease

“…Given that different cognitive deficit profiles are exhibited by patients with FTD and AD on neuropsychological test batteries, it is possible that these differences may be robust enough to be detected with relatively brief dementiascreening instruments that tap multiple cognitive functions (Bier et al, 2004;Kertesz et al, 2003a;Mathuranath et al, 2000;Slachevsky et al, 2004). An instrument that may be particularly effective in this regard is the Mattis Dementia Rating Scale (MDRS; Mattis, 1976Mattis, , 1988.…”