Table 2 Patient characteristics at the time of COVID-19 onset and COVID-19 acute encephalopathy

General examination and parameter at COVID-19 onset

 dyspnea

54 (55.7%)

42 (53.2%)

12 (66.7%)

0.431¹

 cough

60 (63.2%)

50 (64.9%)

10 (55.6%)

0.588¹

 fever

80 (82.5%)

67 (84.8%)

13 (72.2%)

0.299¹

 FiO2

32.31 (± 17.30)

33.35 (± 18.31)

27.84 (± 11.38)

0.113²

Percentage of lung parenchyma with COVID-19 lesions (pulmonary CT scan)

0.583²

 0–30%

13 (20.0%)

11 (20.4%)

2 (18.2%)

 30–50%

22 (33.8%)

19 (35.2%)

3 (27.3%)

 50–70%

17 (26.2%)

14 (25.9%)

3 (27.3%)

  > 70%

13 (20.0%)

10 (18.5%)

3 (27.3%)

Neurological signs at COVID-19 acute encephalopathy

 fluctuation

87 (89.7%)

73 (92.4%)

14 (77.8%)

0.085¹

 inattention

86 (88.7%)

74 (93.7%)

12 (66.7%)

0.005¹

 thought disturbance

68 (74.7%)

61 (82.4%)

7 (41.2%)

0.001¹

 alertness trouble

48 (48.5%)

44 (54.4%)

4 (22.2%)

0.026¹

 drowsiness

51 (52.6%)

42 (53.2%)

9 (50.0%)

0.999¹

 agitation

33 (34.0%)

29 (36.7%)

4 (22.2%)

0.283¹

 psychomotor slowdown

63 (65.6%)

55 (70.5%)

8 (44.4%)

0.053¹

 obnubilation

32 (34.4%)

28 (36.8%)

4 (23.5%)

0.401¹

 perseveration

53 (58.2%)

47 (64.4%)

6 (33.3%)

0.031¹

 disorientation

48 (54.5%)

43 (60.6%)

5 (29.4%)

0.030¹

 hallucination

17 (19.3%)

14 (19.4%)

3 (18.8%)

0.999¹

 focal neurological sign

27 (27.8%)

23 (29.1%)

4 (22.2%)

0.772¹

COVID-19 acute encephalopathy features

 CAM

2.97 (± 1.05)

3.18 (± 0.89)

2.06 (± 1.21)

0.001³

 RASS ≤ -3

8 (8.2%)

7 (8.9%)

1 (5.6%)

0.168¹

 mutism

14 (14.4%)

12 (15.2%)

2 (11.1%)

0.999¹

 severe encephalopathy^a

72 (74.2%)

67 (84.8%)

5 (27.8%)

 < 0.001¹

 duration of encephalopathy (days)

25.8 (± 59.3)

27.9 (± 65.5)

16.9 (± 12.4)

0.018³

Biological results in the blood

 C-reactive protein (mg/l)

89.85 (39.2–163.4)

89.6 (41.9—163.6)

90.1 (9.7—159.3)

0,504²

 leucocytes (/mm3)

9.88 (7.3–12.2)

9.84 (7.2—12)

11.35 (8.5—14.2)

0,215²

 lymphocytes (/mm3)

0.82 (0.5–1.1)

0.79 (0.5—1)

0.97 (0.7—1.2)

0,230²

 segmented neutrophils (/mm3)

7.47 (5.5–10.4)

7.35 (5.1—10)

9.09 (6.4—11.7)

0,272²

 monocytes (/mm3)

0.53 (0.3–0.8)

0.52 (0.3—0.8)

0.58 (0.4—0.7)

0,998²

 thrombocytes (/mm3)

298 (232–354.5)

307 (241—356.8)

264 (167—319)

0,345²

Brain MRI

 missing values^b

35

27

8

 leucoencephalopathy

0.050¹

  0

23 (31.5%)

17 (28.3%)

6 (46.2%)

  1

32 (43.8%)

30 (50.0%)

2 (15.4%)

  2

7 (9.6%)

6 (10.0%)

1 (7.7%)

  3

11 (15.1%)

7 (11.7%)

4 (30.8%)

 stroke (DWI lesion)

34 (47.2%)

26 (44.1%)

8 (61.5%)

0.359¹

 hyperT2 lesion (number)

7.12 (± 6.22%)

7.3 (± 6.2)

6.31 (± 6.54)

0.623³

 microbleed (number)

3.03 (± 7.43%)

2.9 (± 7.75)

3.62 (± 5.92)

0.714³

 number of vessels with endotheliitis^c

 < 0.001¹

  0

9 (14.5%)

1 (1.9%)

8 (80.0%)

  1

18 (29.0%)

16 (30.8%)

2 (20.0%)

  2

16 (25.8%)

16 (30.8%)

0

  3

19 (30.6%)

19 (36.5%)

0

 circumferential endotheliitis^c

48 (77.4%)

48 (92.3%)

0

 < 0.001¹

 endotheliitis^c

 < 0.001¹

  unilateral

26 (41.9%)

24 (46.2%)

2 (20.0%)

  bilateral

27 (43.5%)

27 (51.9%)

0

 stenosis

3 (4.1%)

3 (5.0%)

0

EEG slowing

47 (53.4%)

40 (55.6%)

7 (43.8%)

0.420¹

Epidemiological features

 intensive care unit

62 (63.9%)

50 (63.3%)

12 (66.7%)

0.999³

 hospitalization time

43.5 [25.0–61.5]

43.5 [25.0–61.0]

42.5 [28.0–66.0]

0.796²

 mRS at discharge

0.008¹

  0

9 (9.3%)

8 (10.1%)

1 (5.6%)

  1

23 (23.7%)

13 (16.5%)

10 (55.6%)

  2

16 (16.5%)

12 (15.2%)

4 (22.2%)

  3

22 (22.7%)

21 (26.6%)

1 (5.6%)

  4

14 (14.4%)

13 (16.5%)

1 (5.6%)

  5

1 (1.0%)

1 (1.3%)

0 (0.0%)

  6 (death)

12 (12.4%)

11 (13.9%)

1 (5.6%)

 mRS at discharge ≥ 3

49 (50.5%)

46 (58.2%)

3 (16.7%)

0.002¹