Is the Glasgow Coma Scale (GCS) used to assess patients with seizures, particularly those with significant post-ictal impairment?

You're Right—GCS Was Designed for Coma, Not Seizures

The Glasgow Coma Scale was specifically developed in 1974 to assess comatose patients with head injury and was never intended for evaluating seizures or post-ictal states. 1

Original Purpose and Design

The GCS was created by Teasdale and Jennett as a standardized tool to facilitate reliable neurological assessments of comatose patients, with the original validation studies requiring that coma be present for at least 6 hours. 1 The scale was designed to:

• Provide serial evaluations by relatively inexperienced care providers in the pre-CT era 1
• Facilitate communication between rotating healthcare providers 1
• Assess patients with traumatic brain injury who were unconscious 1

The scale was explicitly not designed to diagnose patients with mild or even moderate TBI, nor was it intended to replace a complete neurological examination. 1

Why GCS Gets Misapplied to Seizures

In clinical practice, the GCS is sometimes used to assess post-ictal patients because:

• It provides a standardized numerical assessment of altered consciousness 1
• Many emergency departments use it as a default consciousness assessment tool 2
• Post-ictal patients may have significantly depressed consciousness requiring monitoring 1

However, this represents an off-label application of a tool designed for a different clinical scenario. 1

Important Limitations When Applied to Seizures

The GCS has significant confounding factors that make it particularly problematic for post-ictal assessment:

• Sedation effects from benzodiazepines or other anti-seizure medications cannot be distinguished from neurological impairment 1, 3
• Intubation (common after status epilepticus) eliminates the verbal component entirely 1, 2
• Metabolic disturbances that may have triggered the seizure affect the score 3
• A single GCS determination is insufficient to determine the extent of brain injury or predict outcome 1, 4

What GCS Actually Tells You in Post-Ictal Patients

If you do use GCS after a seizure, understand what you're actually measuring:

• Serial assessments showing improvement suggest recovery from the post-ictal state rather than structural injury 1, 4
• Declining scores (≥2 point drop) warrant immediate imaging to rule out intracranial hemorrhage or other complications 3
• Persistently low scores beyond the expected post-ictal period suggest alternative pathology requiring investigation 3

Better Approaches for Seizure Patients

Rather than relying on GCS alone for post-ictal patients:

• Document specific neurological findings: focal deficits, pupillary responses, and level of arousal 1, 3
• Use serial examinations to track recovery trajectory rather than a single numerical score 1, 4
• Consider the FOUR score if you need a structured assessment, as it evaluates brainstem reflexes and doesn't require verbal responses 1
• Focus on clinical deterioration rather than absolute GCS values when making management decisions 1, 3

The Bottom Line

You're correct to question using GCS for seizures. The scale was designed for traumatic coma, not post-ictal states. 1 While it may provide some standardized documentation of consciousness level, it was never validated for this purpose and has significant limitations in this context. 1, 2 Clinical judgment based on serial neurological examinations remains superior to relying on a single GCS score in seizure patients. 1, 4