Table 5. PSD^a on EEG^b and mean disease duration by disease subtype in fatal cases.

PSD on EEG	Allc (months) (n = 840)	Subtyped
		sCJD (months) (n = 665)	fCJD (months) (n = 90)	dCJD (months) (n = 62)	GSS (months) (n = 18)	FFI (months) (n = 3)
Positive	15.9 (n = 705)	15.5e (n = 611)	14.5e (n = 51)	22.9e (n = 39)	29.5 (n = 2)	—
Negative	23.6 (n = 135)	16.1e (n = 54)	25.6e (n = 39)	14.1e (n = 23)	60.5 (n = 16)	10.6 (n = 3)

^aPeriodic synchronous discharge.

^bElectroencephalograms.

^cVariant CJD and undetermined CJD were included.

^dThe legend for abbreviations of subtype is in Table 1.

^eDifferences in mean disease duration among 3 types of CJD (sCJD, fCJD, and dCJD) and between positive and negative PSD findings were tested by using 2-way analysis of variance. The probabilities were 0.756 for subtype and 0.864 for PSD finding.