COMA 2003, Version 1 Christopher C. Luzzio, MD

Consciousness An active process with multiple components. Wakefulness or alertness is a precondition. Self-awareness of one’s own cognition and mental processes. Processing of internal and external stimuli. Working memory and attention. Spatial and temporal ordering of long-term memory. Decision making. Deductive reasoning, planning, or synthesis of above.

“Cogito, ergo sum” (I think, therefore, I am.) Rene Descartes

Altered Consciousness Delirium or acute confusional state. mostly awake to easily aroused level of consciousness fluctuates Stuporous. difficult to arouse medical emergency Coma (unresponsive). no speech, no eye opening, no motor response

Encephalopathy Delirium –Acute onset –Inattention –Disorganized thinking –Altered alertness –Fluctuating course –Metabolic or structural –MMS test not useful Dementia –Chronic –Attentive (early) –Progressive loss of cognitive abilities –Little fluctuation –Structural –MMS test useful

Glasgow Coma Scale Monitoring level of consciousness (score 3-15) Eyes open 1.Never 2.To pain 3.To verbal stimuli 4.spontaneously Best verbal response 1.No response 2.Incomprehensible sounds 3.Inappropriate words 4.Disoriented and converses 5.Oriented and converses Best motor response 1.No response 2.Extension (decerebrate rigidity) 3.Abnormal flexion (decorticate rigidity) 4.Flexion-withdrawal to pain 5.Localizes pain 6.Obeys commands

E.R. Pitfall #1 Acute Parietal lobe infarcts: –Aphasia –Visual Sensory Neglect –Often treated as metabolic delirium –Thrombolytic window missed –CT scan often does not show acute CVA

Physiology of Coma and Acute Delirium Pathologic processes that impair: –Globally cortical neurons or –Bilateral thalamic nuclei or –Brainstem Ascending reticular activating system

The Coma Exam Rapidly determine level of injury. –Diffuse (metabolic) –Focal Supratentorial (hemispheres) Infratentorial (brainstem) Likely more serious

Resuscitation First Neurological ABCs Avoid worsening neck injuries Airway Breathing Circulation Diabetes-check blood sugar Drugs-nalaxone for opiate overdose Epilepsy-control seizures (bitten tongue) Fever-meningitis-antibiotics Glasgow Coma Scale Herniation syndromes

Herniation Syndromes Uncal Herniation –Unilateral mass forces the ipsilateral temporal lobe through the tentorium. Contralateral upper motor neuron signs. –Ipsilateral third nerve compression. Dilated pupil –Contralateral upper brainstem. Ipsilateral hemiplegia –CSF flow interrupted –Abnormal respirations Cheyne-Stokes Erratic

Herniation Syndromes Central Herniation –Supratentorial lesion forces the diencephalon centrally through the tentorium. –Compresses upper midbrain, later pons and medulla. –Early Erratic respirations Small reactive pupils Increased limb tone Babinsky sign Decorticate rigidity Decerebrate posturing (later) Fixed and dilated pupils

Herniation Syndromes Bad prognosis Avoid if possible –Recognize possibility (strokes) –Treat edema (masses) –Evacuate blood –Hyperventilate –Raise head of bed –Osmotic agents (Mannitol) Neurosurgical emergency Craniotomy

More on Exam Observe body position and movement of limbs. Posturing –Decorticate (a) Above red nucleus –Decerebrate (b) Level of red nucleus Hemiparesis Hemiposturing Myoclonus

More on Exam Best verbal response –Don’t miss aphasia Head and neck –Fractures –Stiffness –Otitis media Eyelids –Ptosis –Facial weakness

More on Exam Pupils equal –Pinpoint…………………opiates or pontine lesion –Small and reactive…….metabolic encephalopathy –Mid-sized fixed…………midbrain lesion –Mid-sized reactive……..metabolic lesion Pupils unequal –Dilated and unreactive...3 rd nerve palsy –Small and reactive……..Horner syndrome

More on Exam Examine the fundi, eye position and eye movements. Papilloedema : –Absence does not exclude raised ICP –Hypertension –Masses –Hydrocephalus –CVT –Meningitis –Hemorrhage

More on Exam Doll’s eye maneuver (oculocephalic testing) –Not to done unless cervical injury is excluded. –Both eyes move (normal). –One eye moves (unilateral lesion). –Eyes fail to move any direction (bilateral brainstem lesions). Caloric testing Corneal reflex Gag reflex

More on Exam Motor system –Tone –Movements –Symmetry Tendon Reflexes Plantar response Response to painful stimuli

More on Exam Vitals –BP, respirations, temperature, pulse –Cushing’s response hypertension, bradycardia, irregular respirations General exam

Causes of Coma and Delirium

Investigations

Other Conditions Locked-in state Persistent vegetative Brain death –EEG