Insight in ALS: awareness of behavioral change in patients with and without FTD

Although impaired insight is a core diagnostic criterion for establishing the diagnosis of frontotemporal dementia (FTD), insight has rarely been studied in amyotrophic lateral sclerosis (ALS).

To determine differences between patient and informant (caregiver) reports of behavior and behavioral change in amyotrophic lateral sclerosis.

Behavioral data for 17 patients with ALS and 4 patients with ALS-FTD were analyzed. Behavioral changes were evaluated using the Frontal Systems Behavior Scale (FrSBe). We compared premorbid to current behavioral profiles and patient self-reports with those of their informants to determine the level of awareness regarding behavioral changes since the onset of ALS.

ALS patients without FTD had normal insight, as defined by this study, although self-reports suggested mild behavioral abnormalities. In contrast, patients with ALS-FTD revealed a marked loss of insight regarding profound changes in behavior.

Patients with ALS-FTD exhibit a profound lack of insight, which is not found in non-demented ALS patients. Patients without dementia have normal insight, although they report mild behavioral changes that might reflect a psychological response to the disease.