Table 1. Mean (+S.D.) Demographic and Cognitive Performance.

	ALS	ALS-FTD	ALS Total	Control
n	47	9	56	29
Age (years)	58.19 (13.04)	62.44 (9.81)	58.88 (12.59)*	67.76 (7.67)
Education (years)	15.09 (2.80)	14.11 (3.41)	14.93 (2.89)	16.07 (2.67)
Gender (M/F)	29/18	6/3	35/21	13/16
Disease Duration (months)	6.85 (8.66)	5.40 (6.62)	6.71 (8.44)
Functional Rating Scale (n=52)	34.13 (8.48)	38.57 (3.05)	34.73 (8.10)
MMSE (n=56)	27.85 (3.23)	24.89 (6.33)*	27.38 (4.00)*	29.25 (1.11)
Visual Verbal Test (VVT)
Initial Categorization Failures	0.04 (0.20)	0.22 (0.67)	0.07 (0.32)	0.00 (0.00)
Cognitive Flexibility (max=10)	8.55 (2.40)*	6.67 (4.03)*	8.25 (2.77)*	9.41 (1.15)
Letter Fluency (n=47)1
Words/minute Total	11.63 (5.31)*	6.81 (1.26)ˆ*	10.91 (5.21)*	14.31 (5.20)
Digit Span (n=45)2
Digits Forward	6.72 (1.24)	6.80 (0.84)	6.69 (1.10)	6.95 (1.17)
Digits Backwards	4.24 (1.763)	4.20 (1.30)	4.33 (1.49)	5.09 (1.74)

Notes

¹We combined the number of F words/minute obtained from a generation task (FAS task, n=30) where subjects are required to provide as many words that begin with the letters F, A, or S as possible within sixty seconds (Spreen & Struss, 1990) and a similar measure task is used where subjects only provide words that begin with the letter F (F words generation task, n=17). This was necessitated by having changed our procedure for collecting letter fluency, and we maximized available data by focusing on category letter fluency for F words.

²In digit span forward, subjects are required to repeat a series of number sequences that become progressively longer; backward digit span requires subjects to repeat the number sequences in the reverse order of which they are presented.

^*ALS differs from controls p<0.05;

^ˆALS differs from ALS-FTD p<0.05