The current classification of traumatic brain injury (TBI) primarily uses the Glasgow Coma Scale (GCS) to categorize injuries as mild (GCS 13-15), moderate (GCS 9-12), or severe (GCS ≤8). However, this system is unsatisfactory, as it overlooks variations in injury severity, clinical needs, and prognosis. A recent report by the National Academies of Sciences, Engineering, and Medicine (USA) recommended updating the classification system, leading to a workshop in 2024 by the National Institute of Neurological Disorders and Stroke. This resulted in the development of a new clinical, biomarker, imaging, and modifier (CBI-M) framework, with input from six working groups, including the Clinical/Symptoms Working Group (CSWG). The CSWG included both clinical and non-clinical experts and was informed by individuals with lived experience of TBI and public consultation. The CSWG primarily focused on acute clinical assessment of TBI in hospital settings, with discussion and recommendations based on pragmatic expert reviews of literature. Key areas reviewed included: assessment of neurological status; performance-based assessment tools; age and frailty, pre-existing comorbidities, and prior medication; extracranial injuries; neuroworsening; early physiological insults; and physiological monitoring in critical care. This article reports their discussions and recommendations. The CSWG concluded that the GCS remains central to TBI characterization but must include detailed scoring of eye, verbal, and motor components, with identification of confounding factors and clear documentation of non-assessable components. Pupillary reactivity should be documented in all patients, but recorded separately from the GCS, rather than as an integrated GCS-Pupils score. At ceiling scores on the GCS (14/15), history of loss of consciousness (LoC) and the presence and duration of post-traumatic amnesia should be recorded using validated tools, and acute symptoms documented in patients with a GCS verbal score of 4/5 using standardized rating scales. Additional variables to consider for a more complete characterization of TBI include injury mechanism, acute physiological insults and seizures; and biopsychosocial-environmental factors (comorbidities, age, frailty, socioeconomic status, education, and employment). The CSWG recommended that, for a complete characterization of TBI, disease progression/resolution should be monitored over 14 days. While there was a good basis for the recommendations listed above, evidence for the use of other variables is still emerging. These include: detailed documentation of neurological deficits, vestibulo-oculomotor dysfunction, cognition, mental health symptoms, and (for hospitalized patients) data-driven integrated measures of physiological status and therapy intensity. These recommendations are based on expert consensus due to limited high-quality evidence. Further research is needed to validate and refine these guidelines, ensuring they can be effectively integrated into the CBI-M framework and clinical practice.
Keywords: CBI-M framework; Glasgow Coma Scale; NIH NINDS; classification and characterization; craniocerebral trauma; diagnostic techniques and procedures; prognosis; pupil disorders; traumatic brain injury.