Glasgow Coma Scale in Traumatic Brain Injury: Universality and Limitations

Abstract

Traumatic brain injury (TBI) is a leading cause of mortality and neurological disability, and its critical initial assessment relies on standardized tools. The Glasgow Coma Scale (GCS) is the universal tool for quantifying the level of consciousness, assessing motor and verbal responses, as well as eye opening, allowing for the classification of TBI severity and guiding immediate decisions. However, the authors highlight its inherent limitations. The main limitation is its purely physiological-functional nature, which provides an overall score but lacks topographic or etiological specificity, failing to inform about the location, extent, or type of brain injury. This can lead to an underestimation of damage in cases such as diffuse axonal injury. Furthermore, the assessment is compromised in "blind spots" such as intubation (which invalidates the verbal component), aphasia, sedation, or muscle relaxation, where it is not possible to distinguish between the primary neurological deficit and iatrogenic limitations. Therefore, the authors emphasize that the GCS should never be used in isolation. Its optimal value is achieved by integrating it within a comprehensive assessment paradigm that combines a complete serial neurological examination and, crucially, neuroimaging techniques. Computed tomography (CT) is essential in the acute phase to identify lesions requiring surgery, while magnetic resonance imaging (MRI) is superior in the subacute stage for characterizing parenchymal damage and predicting outcomes. Only this clinical-imaging synergy allows for a precise anatomical-functional understanding, optimizing therapeutic management and prognosis for the neurotrauma patient.