Table 1.
Amyotrophic lateral sclerosis-frontotemporal spectrum disorder (ALS-FTSD) criteria for the diagnosis of cognitive and behavioral symptoms associated with ALS, modified following Strong et al. [2].
| ALS-FTSD Variant | Acronym | Definition |
|---|---|---|
| ALS with behavioral impairment | ALSbi | Apathy with or without other behavioral changes or Presence of two or more behavioral/cognitive changes associated with bvFTD * |
| ALS with cognitive impairment | ALSci | Evidence of either executive dysfunction/social cognition or language dysfunction or a combination of the two Executive impairment criteria: impaired letter fluency OR impairment on 2 non-overlapping tests of executive dysfunction (may include social cognition) Language impairment: impairment on 2 non-overlapping tests in which language impairment is not explained by a decrease in verbal fluency |
| ALS with combined cognitive and behavioral impairment |
ALS-cbi | Criteria fulfilled for both ALSci and ALSbi |
| ALS with frontotemporal dementia | ALS-FTD | Progressive deterioration of behavior and/or cognition (observation or history) and Presence of at least three behavioral/cognitive changes associated with bvFTD * or At least two behavioral/cognitive changes associated with bvFTD * together with loss of insight and/or psychotic symptoms or Fulfilled criteria for primary progressive aphasia (non-fluent/agrammatical variant or semantic variant) |
| ALS with comorbid dementia |
ALS-dementia | Comorbid ALS and Alzheimer’s disease/other dementia than FTD Mixed dementia (ALS and vascular dementia) |
| FTLD-MND-like | Neuropathological evidence of FTLD and neuropathological hallmarks of ALS but the clinical diagnostic criteria of ALS are not met |
* Behavioral/cognitive manifestations of bvFTD: Early behavioral disinhibition; Early apathy; Early loss of sympathy and empathy; Early perseverative, stereotyped, or compulsive behavior; Hyperorality/dietary change; Neuropsychological profile: executive deficits with relative sparing of memory and visuospatial functions. For abbreviations, see the list at the end of this article.