Table 2.
Neurophysiologic measure studies: study characteristics and patient demographics
| Reference | Number of patients | Study type | Article location | Mean age (years) | Patient characteristics | Primary and secondary goal of study |
|---|---|---|---|---|---|---|
| ICP/CPP positive association studies | ||||||
| Adamides et al. [1] | 14 | Prospective observational | Manuscript | 40 years (range, 19–66) | Severe TBI |
Primary: To evaluate the temporal relationship between CMD measures and ICP/CPP Secondary: None mentioned |
| Belli et al. [7] | 25 | Prospective observational | Manuscript | 41.8 years (range, 16–78) | Severe TBI |
Primary: To evaluate the relationship between CMD measures and ICP Secondary: None mentioned |
| Bolcha et al. [10] | 20 | Prospective observational | Meeting abstract | Unknown | Severe TBI |
Primary: Determine association between ICP/PbtO2 and CMD to patient outcome Secondary: None mentioned |
| Bullock et al. [12] | 80 | Prospective observational | Manuscript | Unknown | Severe TBI |
Primary: Determine association of EAA and clinical outcomes (i.e., ischemic events, ICP/CPP, patient outcome) Secondary: None mentioned |
| Clausen et al. [17] | 76 | Prospective observational | Manuscript | Unknown | Severe TBI |
Primary: Determine association between CMD glycerol and patient outcome Secondary: Determine association between CMD glycerol and monitoring (CPP/PbtO2) |
| Clausen et al. [18] | 151 | Prospective observational | Manuscript | 35.5 years (range, unknown) | Severe TBI |
Primary: Determine the association of brain pH, PCO2, lactate to patient outcome Secondary: Determine the association of above to CPP, PbtO2 |
| Goodman et al. [26] | 7 | Retrospective case series | Manuscript | 34.6 years (range, 19–48) | Severe TBI on barbiturate therapy |
Primary: To evaluate the impact of barbiturate sedation on CMD measures and ICP in severe TBI Secondary: None mentioned |
| Goodman et al. [25] | 126 | Prospective observational | Manuscript | 34.4 years (range, unknown) | Severe TBI |
Primary: Determine association between CMD lactate and glucose to ICP/CPP/PbtO2/SjvO2/rCBF Secondary: Clinical outcome |
| Gupta et al. [28] | 41 | Unknown | Meeting abstract | Unknown (over 18) | Severe TBI |
Primary: Determine association between CMD glycerol and LPR with CPP and patient outcome Secondary: None mentioned |
| Hejcl et al. [34] | 20 | Prospective observational | Meeting abstract | Unknown | Severe TBI |
Primary: Determine association between CMD/ICP/CPP/PbtO2 and patient outcome Secondary: None mentioned |
| Koura et al. [47] | 83 | Unknown | Meeting abstract | Unknown | Severe TBI |
Primary: Determine association between CMD measures and CPP/ICP/patient outcome Secondary: None mentioned |
| Kurtz et al. [48] | 46 | Retrospective case series | Manuscript | 55 years (range, unknown) | Severe TBI |
Primary: Determine association between CMD/serum glucose and patient outcome Secondary: Association with CMD markers of metabolic stress (CPP and PbtO2) |
| Li et al. [51] | 53 | Retrospective case series | Manuscript | 42 years (range, 15–60) | Severe TBI |
Primary: Determine association between CMD glycerol and ICP/CPP and patient outcome Secondary: None mentioned |
| Meixensberger et al. [56] | 9 | Prospective observational | Manuscript | 33.3 years (range, 14–60) | Severe TBI |
Primary: To determine the correlation between CMD measures and ICP/CPP and PbtO2
Secondary: None mentioned |
| Nelson et al. [61] | 90 | Retrospective case series | Manuscript | 48.9 years (range, 17–77) | Severe TBI |
Primary: To determine the relationship between CMD measures and ICP/CPP Secondary: Determine association to outcome |
| Nordstrom et al. [62] | 213 | Retrospective case series | Manuscript | 40 years (range, 19–63) | Severe TBI |
Primary: Determine correlation between CMD markers and injury patterns/patient outcome Secondary: None mentioned |
| Papanikolaou et al. [68] | 30 | Unknown | Meeting abstract | Unknown | Severe TBI |
Primary: To determine the correlation between glycerol and other CMD measures to outcome and ICP/CPP Secondary: None mentioned |
| Paraforou et al. [69] | 34 | Prospective observational | Manuscript | 43.6 years (range, unknown) | Severe TBI |
Primary: Determine relationship between CPP/ICP/CMD and patient outcome Secondary: None mentioned |
| Richards et al. [75] | 9 | Prospective observational | Manuscript | 8 years (range, 3–14) | Severe TBI |
Primary: Determine the association between glutamate and clinical outcome; also determine if an “excitotoxic index” (glutamate:glutamine) correlated to outcome Secondary: Correlation of CMD markers to ICP |
| Salci et al. [79] | 10 | Unclear | Manuscript | 45.1 years (range, 19–63) | Severe TBI |
Primary: To determine the relationship between CMD measures and ICP/compliance Secondary: None mentioned |
| Sarrafzadeh et al. [82] | 18 | Unclear | Meeting abstract | 36 years (range, unknown) | Severe TBI |
Primary: To determine the relationship between CMD measures and ICP/SjvO2/PbtO2
Secondary: None mentioned |
| Singla et al. [86] | 41 | Unknown | Meeting abstract | Unknown | Severe TBI |
Primary: Determine relationship between CPP/CMD to patient outcome Secondary: None mentioned |
| Stahl et al. [87] | 7 | Retrospective case series | Manuscript | 55.4 years (range, 27–74) | Severe TBI whom died |
Primary: To document CMD measure responses to ICP during end of life Secondary: None mentioned |
| Stein et al. [89] | 117 | Unclear | Meeting abstract | Unknown | Severe TBI |
Primary: To determine the relationship between CMD measured metabolic crisis (LPR > 40) and ICP Secondary: None mentioned |
| Stiefel et al. [91] | 27 | Retrospective case series | Meeting abstract | Unknown | Severe TBI |
Primary: Determine relationship between ICP/CPP/PbtO2/CMD and outcome Secondary: Determine is “metabolic compromise” (LPR > 25) or “metabolic crisis” (LPR > 40) is associated to outcome |
| Timofeev et al. [93] | 223 | Retrospective case series | Manuscript | Unknown | Severe TBI |
Primary: Determine the relationship between CMD markers and neurological outcome Secondary: Association between CMD markers and ICP/PRx |
| Timofeev et al. [94] | 97 | Prospective observational | Manuscript | Unknown | Severe TBI |
Primary: To determine the relationship between CMD measures and PRx, ICP/CPP, PbtO2
Secondary: None mentioned |
| Vespa et al. [98] | 17 | Prospective observational | Manuscript | 39.4 years (range, unknown) | Severe TBI |
Primary: To determine the extent and duration of CMD glutamate changes post-TBI Secondary: To determine the correlation between glutamate and CPP |
| PbtO2/SjvO2 positive association studies | ||||||
| Chan et al. [15] | 25 | Unknown | Meeting abstract | Unknown | Severe TBI |
Primary: To determine SjvO2 correlated to CMD measures in TBI Secondary: None mentioned |
| Figaji et al. [21] | 5 | Prospective observational | Meeting abstract | Unknown (children) | Severe TBI |
Primary: Determine association of inflammatory cytokines and other CMD markers/patient outcome Secondary: None mentioned |
| Menzel et al. [57] | 24 | Prospective Non-randomized | Manuscript | 34.4 years (range, 20–74) | Severe TBI Non-randomized to high FiO2 |
Primary: To determine the impact of increased FiO2 on CMD measures and PbtO2
Secondary: None mentioned |
| Menzel et al. [58] | 14 | Prospective single arm | Manuscript | Unknown (adults) | Severe TBI |
Primary: To determine the change in CMD markers, CBF, and PbtO2 to induced hyperoxia Secondary: None mentioned |
| Nortje et al. [63] | 11 | Prospective single arm | Manuscript | 42 years (range, 17–64) | Severe TBI |
Primary: To determine if normobaric hyperoxia leads to changes in 15O PET, CMD and PbtO2
Secondary: None mentioned |
| Purins et al. [72] | 23 | Prospective observational | Manuscript | Unknown | Severe TBI |
Primary: To determine the relationship between PbtO2 and CMD measures Secondary: None mentioned |
| Robertson et al. [76] | 79 | Unknown | Meeting abstract | Unknown | Severe TBI |
Primary: Determine the association between CMD glutamine/aspartate and patient outcome and PbtO2/CBF (TCD) Secondary: None mentioned |
| Sarrafzadeh et al. [83] | 35 | Retrospective case series | Manuscript | Unknown | Severe TBI |
Primary: To determine the relationship between CMD and PbtO2
Secondary: None mentioned |
| Sarrafzadeh et al. [84] | 24 | Unknown | Meeting abstract | Unknown | Severe TBI |
Primary: To determine the relationship between CMD and PbtO2
Secondary: None mentioned |
| Timofeev et al. [95] | 56 | Prospective observational | Manuscript | 38.5 years (range, 25–52) | Severe TBI |
Primary: To compare brain pH to disturbances in PbtO2 and CMD Secondary: None mentioned |
| Valdaka et al. [96] | 5 | Prospective observational | Manuscript | Unknown | Severe TBI during herniation and death |
Primary: To evaluate the correlation between CMD and PbtO2 in fatal TBI Secondary: None mentioned |
| Vilalta et al. [101] | 30 | Prospective single arm | Manuscript | 27 years (range, 17–59) | Severe TBI - Normobaric hyperoxic challenge |
Primary: To determine the impact of normbaric hyperoxia on CMD and PbtO2 in TBI Secondary: Determine the impact on outcome |
| Autoregulation - positive association studies | ||||||
| Asgari et al. [4] | 19 | Prospective observational | Manuscript | 41.9 years (range, unknown) | Severe TBI |
Primary: To evaluate the relationship between MOCAIP ICP waveform-based autoregulation measurements and CMD measures Secondary: None mentioned |
| Asgari et al. [5] | 30 | Prospective observational | Manuscript | 46 years (unknown) | Severe TBI |
Primary: To determine the relationship between CMD measures and PMTM ICP waveform analysis of vasoconstriction/vasodilation Secondary: None mentioned |
| Yokobori et al. [105] | 25 | Prospective observational | Manuscript | 58.2 years (range, unknown) | Severe TBI |
Primary: To determine the association between CMD markers and PRx within the first 7 days of injury Secondary: Determine association between CMD markers and patient outcome |
| Imaging-based positive association studies | ||||||
| Bouzat et al. [11] | 27 | Prospective observational | Manuscript | 39 years (range, 24–54) | Severe TBI |
Primary: To determine the relationship between CMD, PbtO2 and ICP measures to CBF as measured via CTP Secondary: None mentioned |
| Hutchinson et al. [39] | 13 | Prospective observational | Manuscript | 34 years (range, 16–66) | Severe TBI |
Primary: To determine relationship between CMD measures and H2
15O PET Secondary: None mentioned |
| Hutchinson et al. [40] | 17 | Prospective observational | Manuscript | 43.4 years (range, 17–66) | Severe TBI |
Primary: To determine the relationship between CMD measures and FDG PET Secondary: None mentioned |
| Reinert et al. [74] | 85 | Prospective observational | Manuscript | Unknown | Severe TBI |
Primary: Determine the relationship between CMD potassium and ICP/CBF/other CMD substrates and patient outcome Secondary: None mentioned |
| Sala et al. [78] | 24 | Prospective observational | Manuscript | 36 years (range, unknown) | Severe TBI |
Primary: To determine the relationship between CMD measures and CBF post-TBI Secondary: None mentioned |
| Vespa et al. [97] | 19 | Prospective observational | Manuscript | 32.3 years (range, 16–57) | Severe TBI |
Primary: To evaluation the presence of CMD measures during changes in CMRO2 and CMRglu Secondary: None mentioned |
| Vespa et al. [99] | 30 | Prospective observational | Manuscript | 34.4 years (range, unknown) | Severe TBI |
Primary: To describe the trend of CMD glucose after TBI Secondary: Evaluate the lactate response to low CMD glucose; also assess FDG-PET and Xe CT CBF response |
| Zauner et al. [109] | 25 | Unknown | Meeting abstract | Unknown | Severe TBI |
Primary: To evaluate the relationship between CMD glutamate and CBF as measured by Xe CT Secondary: None mentioned |
| Negative association studies | ||||||
| Alessandri et al. [3] | 34 | Unknown | Meeting abstract | Unknown | Severe TBI |
Primary: To determine the association between CMD sodium and glutamate to outcome and ICP Secondary: None mentioned |
| Chamoun et al. [13] | 135 | Prospective observational | Manuscript | 36.6 years (range, 16–91) | Severe TBI |
Primary: Determine the association between CMD glutamate and prognosis Secondary: Correlation between glutamate and MABP/ICP/PbtO2/SjvO2 |
| Johnston et al. [44] | 11 | Prospective single arm | Manuscript | 32 years (range, unknown | Severe TBI |
Primary: To evaluate the relationship between 15O PET, PbtO2 and CMD to CPP augmentation in TBI Secondary: Determine association to outcome |
| Nelson et al. [60] | 26 | Retrospective case series | Manuscript | 52.2 years (range, 15–77) | Severe TBI |
Primary: To determine patterns between CMD measures and ICP/CPP Secondary: Determine association between CMD markers and outcome |
| Peerdeman et al. [70] | 15 | Prospective observational | Manuscript | 39.5 years (range, 18–69) | Severe TBI |
Primary: Determine the association between secondary events (elevated ICP, low CPP, elevated temp) to CMD and outcome Secondary: None mentioned |
| Petzold et al. [71] | 10 | Prospective observational | Manuscript | 39 years (range, 20–68) | Severe TBI |
Primary: To correlate CMD measured neurofilament protein to injury pattern, physiologic measures, and outcome Secondary: Assess other CMD measures relation to outcome |
| Sanchez-Porras et al. [81] | 29 | Retrospective case series | Manuscript | 37.2 years (range, unknown) | Severe TBI |
Primary: To evaluate long PRx and its relationship to patient outcome Secondary: To correlated PRx to other monitoring (i.e., CMD) |
| Vespa et al. [100] | 21 | Retrospective case series | Manuscript | 31.4 years (range, 18–58) | Severe TBI |
Primary: To determine the relationship between CPP and LPR Secondary: None mentioned |
TBI traumatic brain injury, GOS Glasgow outcome scale, GOSE Glasgow outcome scale extended, CMD cerebral microdialysis, RCT randomized control trial, ICP intracranial pressure, CPP cerebral perfusion pressure, NAA N-acetyl acetate, CSF cerebrospinal fluid, LPR lactate:pyruvate ratio, CBF cerebral blood flow, rCBF regional cerebral blood flow, SjvO 2 jugular venous oxygen saturation, MABP mean arterial blood pressure, PbtO 2 partial pressure of oxygen in brain tissue, Mx autoregulation, PRx pressure reactivity monitoring, TCD transcranial Doppler, PET positron emission tomography, FDG fluorodeoxyglucose, OEF oxygen extraction fraction, ROI region of interest, CMRglc cerebral metabolic rate of glucose consumption, CMRO 2 cerebral metabolic rate of oxygen consumption, Xe CT xenon-enhanced computed tomography, CTP compute tomographic perfusion imaging, NIRS near-infrared spectroscopy, MMM multi-modal monitoring, DC decompressive craniectomy