What are the barriers to early neurological prognosis in acute brain injury?

From the Guidelines

Early neurological prognostication in acute brain injury is significantly hindered by various barriers, including the presence of confounding factors, physiological disturbances, and institutional limitations, which necessitate a multimodal approach to prognostication with serial assessments over time. The primary barriers to early neuro prognostication include:

• Confounding factors such as sedative medications, neuromuscular blockade, and metabolic derangements that mask true neurological status, as seen in patients with mild traumatic brain injury (MTBI) who may have normal initial CT scans but later develop persistent neurocognitive sequelae 1
• Physiological disturbances including hypotension, hypoxemia, fever, and electrolyte abnormalities, which can significantly impact outcomes, with studies showing that arterial hypotension and hypoxemia are associated with increased mortality and poor neurological outcome 1
• Institutional limitations, including variable availability of advanced neuroimaging (MRI, PET scans), electrophysiological testing (EEG, somatosensory evoked potentials), and biomarkers (neuron-specific enolase, S100B), which can limit the accuracy of prognostication, as highlighted in the 2021 update of the ACR Appropriateness Criteria for head trauma 1
• Inter-observer variability in clinical examination and interpretation of diagnostic tests, which reduces reliability and underscores the need for a standardized approach to prognostication, as emphasized in the clinical policy for adult mild traumatic brain injury in the acute setting 1 These barriers necessitate a multimodal approach to prognostication, with serial assessments over time, typically waiting at least 72 hours after injury and complete clearance of confounding medications before making definitive prognostic statements about neurological recovery, as supported by the most recent evidence 1.

From the Research

Barriers to Early Neuro Prognostication

Some of the barriers to early neuro prognostication in acute brain injury include:

• Limitations of available predictors and prognostic models 2
• Flawed heuristics and the self-fulfilling prophecy 2
• Influence of surrogate decision-maker bias on end-of-life decisions 2, 3
• Lack of evidence-based guidelines for prognostication 4, 3, 5
• High variability in prognostication among clinicians and institutions 3, 5
• Complexity of neuroprognostication, which draws upon an intricate set of biomedical, probabilistic, psychosocial, and ethical factors 6
• Unsystematic clinical approach to neuroprognostication, which can lead to errors 6

Challenges in Prognostication

The challenges in prognostication after acute brain injury are further complicated by:

• The need for a systematic approach to neuroprognostication, using highly reliable multimodal data and involving experts 2
• The importance of considering patient values and preferences in prognostication and decision-making 2, 3, 6
• The role of shared decision-making between surrogates and clinicians in ensuring that patients receive treatments they would choose 3
• The need for further research to ameliorate variability and focus on scientific and patient-centered approaches to prognostication 5