Table 1 Comparison of demographic and clinical variables between patients who improved (n = 11) and those who did not improve (n = 29) with DBS

From: A human brain network linked to restoration of consciousness after deep brain stimulation

 

DoC improved (n = 11), median (IQR), or proportions

DoC non-improved (n = 29), median (IQR), or proportions

p value uncorrected (FDR-corrected), effect size (95% CI)

Age at injury (years)

19 (16–33)

39 (24.5–54)

p = 0.03 (0.14), Hedges’ g = −0.78 (−1.63, −0.09)

Sex (Male:Female)

8:3

21:8

p = 1.0 (1.0),

OR = 1.0 (0.21, 4.82)

Time from injury to DBS (months)

6 (3–12)

6 (3.5–14)

p = 0.67 (0.94), Hedges’ g = −0.19 (−0.53, 0.56)

C/NC score before DBS#

2 (1–2)

3 (2–3.5)

p = 0.0009 (0.01), Hedges’ g = −1.21

(−2.11, −0.58)

DRS score before DBS#

2.2 (1.8–2.6)

3.2 (2.6–3.5)

p = 0.003 (0.02), Hedges’ g = −1.09

(−2.28, −0.47)

CRS–R score before DBS§

7 (6–9)

4 (4–6)

p = 0.06 (0.21), Hedges’ g = 0.67 (0.06, 2.33)

DoC state prior to DBS (UWS:MCS)

8:3

26:3

p = 0.32 (0.75),

OR = 0.31 (0.05, 1.84)

Implant side (Left:Right)

10:1

27:2

p = 1.0 (1.0),

OR = 0.74 (0.06, 9.10)

Cause of injury (CA:TBI)

8:3

20:9

p = 1.0 (1.0),

OR = 1.2 (0.26, 5.61)

DBS lead model (M3387:M3389:BSCI)

4:2:5

10:10:9

p = 0.6 (0.94)

Stimulation amplitude (V)†

3.25 (3–3.5)

3.25 (2.3–3.7)

p = 0.67 (0.94), Hedges’ g = 0.2 (−0.33, 0.79)

Stimulation amplitude (mA)†

4.5 (4–5)

4.5 (4–5)

p = 0.75 (0.95), Hedges’ g = 0.21 (−1.24, 1.05)

Stimulation frequency (Hz)

40 (25–40)

30 (25–30)

p = 0.13 (0.36), Hedges’ g = 0.57 (−0.22, 1.6)

Stimulation pulse width (μs)

210 (210–210)

210 (180–210)

p = 0.38 (0.76), Hedges’ g = 0.34 (−0.07, 0.8)

  1. Continuous variables were compared using two-sided, non-parametric, permutation-based two-sample t-tests (10,000 permutations); categorical variables were compared using two-sided Fisher’s exact tests. Results are reported as both uncorrected and false discovery rate (FDR)-corrected p values, with FDR correction applied across all 14 clinical and demographic variables tested.
  2. BSCI Boston Scientific Vercise lead model, CA cardiac arrest, CI confidence interval, C/NC coma/near-coma, M3387 medtronic lead model 3387, M3389 medtronic lead model 3389; MCS minimally conscious state, OR Odds ratio, DRS disability rating scale, TBI traumatic brain injury, UWS unresponsive wakefulness syndrome.
  3. #Note: a higher score on the C/NC scale and DRS indicates more severe impairment.
  4. §Note: a higher score on the CRS-R scale indicates less severe impairment.
  5. †Note: comparisons of stimulation amplitude were performed separately in patient sub-groups for whom amplitude was recorded as voltage (V; n = 6 improved vs. n = 20 non-improved) or milliamps (mA; n = 5 improved vs. n = 9 non-improved).
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