Understanding Coma

• Definition: Coma is a deep state of unconsciousness. Patients don’t respond to stimuli, eyes closed, may show reflex actions but no purposeful movements.
• Disorders of Consciousness: Terms like lethargy, obtundation, stupor, delirium, etc., describe varying levels of responsiveness and awareness.

Evaluating Coma

• Glasgow Coma Scale (GCS): A tool to objectively describe consciousness level; rates eye, verbal, and motor responses.
• Full Outline of UnResponsiveness (FOUR) Score: Includes eye and motor responses, brainstem reflexes, and respiration pattern.

Anatomy & Physiology

• ARAS: Ascending Reticular Activating System plays a key role in arousal and consciousness, stretching from the brainstem to the cortex.

Causes of Coma

• Nonstructural Causes: Systemic issues like metabolic disorders, toxins, endocrine issues, etc.
• Structural Causes: Physical brain damage due to injury, stroke, tumors, etc.

Diagnosis

• Differential Diagnosis: Distinguishing coma from other states like locked-in syndrome, brain death, and vegetative states requires a careful exam and history.
• Diagnostic Tools: Imaging (CT, MRI), EEG, and lab tests (blood, CSF analysis).

Treatment & Management

• Initial Steps: Ensure airway, breathing, and circulation. Look into history for clues.
• Neurological Exam: Check for motor response, pupillary reaction, eye movements, and respiratory pattern.
• Imaging and Labs: CT scans for trauma or stroke, blood tests for systemic issues.

Prognosis

• Depends on the cause and severity of the coma. Persistent vegetative states are rare.