Covert hepatic encephalopathy: Agreement and predictive validity of different indices

Table 1 Number of subjects with varying combinations of electroencephalographic and psychometric/psychophysic abnormalities

	PHES		CFFo		CFFm
	Normal	Abnormal	Normal	Abnormal	Normal	Abnormal
EEG normal	58	18	57	19	64	12
EEG abnormal	30	26	34	22	40	16
Association	χ2 = 7.5, P = 0.006		χ2 = 3.0, P = 0.08		χ2 = 3.1, P = 0.08
Cohen ĸ	0.23		0.15		0.14

EEG: Electroencephalography; PHES: Psychometric hepatic encephalopathy score; CFFo/m: Critical flicker frequency original/modified.

Table 2 Number of subjects with varying combinations of psychometric and psychophysic abnormalities

	CFFo		CFFm
	Normal	Abnormal	Normal	Abnormal
PHES normal	69	19	75	13
PHES abnormal	22	22	29	15
Association	χ2 = 11.0, P = 0.001		χ2 = 6.5, P = 0.01
Cohen ĸ	0.3		0.21

PHES: Psychometric hepatic encephalopathy score; CFFo/m: Critical flicker frequency original/modified.

Table 3 Electroencephalographic, psychometric and psychophysic indices in relation to the presence of grade I hepatic encephalopathy, portal-systemic shunt and a history of hepatic encephalopathy

	EEG					Psychometry		CFF
	MDF (Hz)	δ	θ	α	β	PHES	MPZS
No grade I HE	10.3 ± 1.8	7% ± 6%	26% ± 17%	45% ± 17%	21% ± 13%	-0.9 ± 2.9	-0.2 ± 0.9	41.9 ± 5.4
(n = 85)
Grade I HE	8.2 ± 1.9b	15% ± 16%b	43% ± 17%b	29% ± 18%b	12% ± 8%b	-5.3 ± 4.0b	-1.5 ± 1.1b	39.9 ± 5.3a
(n = 47)
No portal-systemic shunt	10.1 ± 1.8	5% ± 3%	29% ± 23%	44% ± 18%	21% ± 13%	-1.3 ± 2.8	-0.3 ± 0.8	42.8 ± 5.1
(n = 24)
Portal-systemic shunt	9.3 ± 2.2	11% ± 12%d	35% ± 19%	36% ± 19%	18% ± 13%	-2.6 ± 3.8	-0.7 ± 1.1	41.2 ± 5.7
(n = 60)
No HE history	10.2 ± 1.7	6% ± 7%	25% ± 17%	48% ± 18%	21% ± 12%	-1.5 ± 3.6	-0.3 ± 1.1	41.9 ± 5.9
(n = 44)
HE history	9.1 ± 2.1f	12% ± 12%f	37% ± 19%f	35% ± 19%f	17% ± 12%	-2.9 ± 4.0	-0.8 ± 1.1e	40.6 ± 5.3
(n = 76)

^aP < 0.05,

^bP < 0.01 vs no grade I hepatic encephalopathy (HE);

^dP < 0.01 vs no portal-systemic shunt;

^eP < 0.05,

^fP < 0.01 vs no HE history. EEG: Electroencephalography; CFF: Critical flicker frequency; MDF: Mean dominant frequency; PHES: Psychometric hepatic encephalopathy score; MPZS: Mean psychometric Z score.

Table 4 Electroencephalographic, psychometric and psychophysic indices in four patients who were studied in different conditions over time

Patient	Condition	Time	EEG					Psychometry		CFF
			MDF (Hz)	δ	θ	α	β	PHES	MPZS	(Hz)
1 male 55, B7, MELD 11	Baseline	0	10.8	8%	19%	49%	24%	5	1.6	41
1	Post-TIPS, overt grade I	+ 11 mo	9.6	3%	34%	49%	14%	5	1.6	49
1	Post-TIPS, treated	+ 19 mo	10.5	3%	15%	64%	18%	2	0.9	46
1	Post-TIPS, treated	+ 23 mo	11.5	4%	11%	59%	27%	4	1.2	46
2 male 70, A6, MELD 9	Post-TIPS, overt grade I	0	7.9	7%	64%	20%	9%	0	-0.2	46
2	Post-TIPS, treated	+ 18 wk	10.7	10%	18%	44%	28%	-1	-0.1	39
3 male 63, B9, MELD 14	Overt grade II	0	4.8	42%	50%	6%	2%	-6	-1.8	42
3	Treated	+ 11 wk	8.2	4%	67%	21%	7%	-1	-0.5	57
4 male 69, B7, MELD 9	Overt grade II	0	5.4	45%	38%	10%	7%	-9	-2.4	37
4	Treated	+ 6 wk	10.8	4%	21%	51%	24%	-3	-0.7	39

HE: Hepatic encephalopathy; EEG: Electroencephalography; CFF: Critical flicker frequency; MDF: Mean dominant frequency; PHES: Psychometric hepatic encephalopathy score; MPZS: Mean psychometric Z score; TIPS: Transjugular intrahepatic portosystemic shunt.