Cognitive Reserve in ALS with Comorbid Frontotemporal Dementia (FTD): A Population-Based Study (P5.081)

Background. ALS is associated with cognitive impairment in 50% of patients, going from frontotemporal dementia (ALS-FTD), to executive cognitive impairment (ALS-ECI), non-executive cognitive impairment (ALS-NECI) and behavioral impairment (ALS-Bi). A protective effect of cognitive reserve has been described in AD and FTD. No data about its role in ALS with comorbid FTD are available. Aim. To assess the impact of cognitive reserve in a population-based series of ALS patients with different degrees of cognitive impairment. Methods. ALS patients incident in Piemonte, Italy, from January 1st 2009 to December 31st 2011 were eligible for the study (n=281). Patients underwent a neuropsychological and genetic testing. 202 (71.9%) patients were evaluated; 19 were excluded because of premorbid cognitive or psychiatric disturbances. Ninety-one (49.7%) were cognitively normal, 23 (12.6%) had ALS-FTD, 36 (19.7%) ALS-ECI, 10 (5.5%) ALS-NECI, 11 (6.0%) ALS-Bi, and 11 (6.0%) non-classifiable cognitive impairment (ALS-NCCI), one comorbid AD. A Reserve Index (range, 2-12) was calculated considering years of education and occupational attainment (Borroni et al, Dement Geriatr Cogn Disord 2009). Results. Reserve Index was significantly lower in patients with ALS-FTD (4.9, SD 1.3), than in other groups (normal cognition 7.0 [SD 1.9], ALS-ECI 6.6 [SD 2.0], ALS-NECI 7.4 [SD 2.0], ALS-Bi 6.8 [SD 2.6], ALS-NCCI 8.5 [SD 2.4]) (p=0.0001). Reserve Index was not correlated with age and site of onset, but was lower in women (p=0.04). Neuropsychological tests significantly related to Reserve Index were Phonemic Fluency (p=0.009), ROCF - Copy (p=0.014), ROCF - recall (p=0.002), TMT B (p=0.0001) and B-A (p=0.001), Stroop CW (p=0.0001), WAIS - Block Design (p=0.0001), Wechsler Memory Scale II - revised (p=0.0001), WCST - number of categories (p=0.0001), Raven’s colored progressive matrices (p=0.0001); and FAB (p=0.0001). Discussion. Our data indicate that cognitive reserve may have a role in ALS with cognitive impairment. Cognitive reserve in ALS-FTD is mainly related to frontal functioning, short term memory and non-verbal intelligence, and, to a lesser extent, to visuospatial and praxic abilities. Disclosure: Dr. Canosa has nothing to disclose. Dr. Montuschi has nothing to disclose. Dr. Iazzolino has nothing to disclose. Dr. Calvo has nothing to disclose. Dr. Moglia has nothing to disclose. Dr. Bertuzzo has nothing to disclose. Dr. Lopiano has nothing to disclose. Dr. Restagno has nothing to disclose. Dr. Brunetti has nothing to disclose. Dr. Ossola has nothing to disclose. Dr. Lo Presti has nothing to disclose. Dr. Cammarosano has nothing to disclose.