An Overview of Head Injury Management Eldad J. Hadar, M.D. Department of Neurosurgery

Checklist Definitions –Glasgow Coma Scale –Intracranial Pressure Mechanisms of brain injury Evaluation of head injury Management of head injury –Operative –Nonoperative

Head Injury Guidelines 1995 – 1 st edition 2000 – 2 nd edition 2007 – 3 rd edition Level I – Accepted principles reflecting high degree of clinical certainty Level II – Strategies reflecting moderate degree of clinical certainty Level III – Degree of clinical certainty not established

Checklist Definitions –Glasgow Coma Scale –Intracranial Pressure Mechanisms of brain injury Evaluation of head injury Management of head injury –Operative –Nonoperative

Glasgow Coma Scale (GCS) Introduced by Teasdale and Jennett in 1974 Consists of 3 clinical signs that have –Prognostic significance –Good reproducibility between observers Scale range 3-15 GCS < 8 has generally become accepted as representing coma / severe head injury

Glasgow Coma Scale (GCS)

Intracranial Pressure (ICP) Normal CPP > 50 mm Hg Autoregulatory mechanisms maintain CBF at CPP’s down to 40 mm Hg CPP = MAP – ICP

Intracranial Pressure (ICP) In head injury, ICP > mm Hg may be more detrimental than low CPP (increasing CPP may not afford protection from intracranial hypertension). Aggressive attempts to maintain CPP > 70 should be avoided due to ARDS (Level II) CPP<50 should be avoided (Level III)

Checklist Definitions –Glasgow Coma Scale –Intracranial Pressure Mechanisms of brain injury Evaluation of head injury Management of head injury –Operative –Nonoperative

Mechanisms of Traumatic Brain Injury Impact injury Cerebral or brainstem contusions Cerebral lacerations Diffuse axonal injury (DAI) Secondary injury Intracranial hematoma Edema Ischemia

Checklist Statistics Definitions –Glasgow Coma Scale –Intracranial Pressure Mechanisms of brain injury Evaluation of head injury Management of head injury –Operative –Nonoperative

Initial Assessment History –LOC +/- –Intoxicants –Seizure –Posttraumatic amnesia Physical Exam –GCS –Level of consciousness –Cranial nerves –Fundoscopic exam –Motor exam Start with ABC’s

Radiographic Evaluation CT Imaging study of choice for initial work-up MRI More helpful later in hospital course Skull x-rays Arteriography

Indications for CT Presence of any criteria placing patient at moderate or high risk for intracranial injury Assessment prior to general anesthesia for other procedures

Checklist Definitions –Glasgow Coma Scale –Intracranial Pressure Mechanisms of brain injury Evaluation of head injury Management of head injury –Operative –Nonoperative

Head Injury Management Nonoperative Seen in absence of significant intracranial mass lesion. Typically consists of assessment and/or treatment of intracranial pressure (ICP). Operative Typically required when a significant intracranial mass lesion is present. Decompressive craniectomy or brain resection less common.

Head Injury Management Nonoperative Seen in absence of significant intracranial mass lesion. Typically consists of assessment and/or treatment of intracranial pressure (ICP). Operative Typically required when a significant intracranial mass lesion is present. Decompressive craniectomy or brain resection less common.

Nonoperative Management Frequent neuro checks ICP monitoring

Indications for ICP Monitoring No data to support Level I recommendation Severe head injury (GCS 3-8) with abnormal CT (Level II) Severe head injury (GCS 3-8) with normal CT and 2 of the following (Level III): Age > 40 years Unilateral or bilateral motor posturing SBP < 90 mm Hg Mild-moderate head injury at discretion of treating physician

Indications for ICP Monitoring Loss of neurological examination Sedation General anesthesia

Clinical Scenario 20 y.o. male in MVA –Intubated Score 1T –Eyes open to pain Score2 –Briskly localizes Score5 TotalGCS8T

ICP Monitor

Preferred method in Guidelines

Therapy for Intracranial Hypertension First tier Positioning Ventricular drainage Osmotic diuresis Hyperventilation (Level III – temporizing measure) Second tier Sedation Neuromuscular blockade Hypothermia Barbiturate coma Glucocorticoids not recommended (Level I)

Head Injury Management Nonoperative Seen in absence of significant intracranial mass lesion. Typically consists of assessment and/or treatment of intracranial pressure (ICP). Operative Typically required when a significant intracranial mass lesion is present. Decompressive craniectomy or brain resection less common.

Operative Management Types of mass lesions Epidural hematoma Subdural hematoma Cerebral contusion Decompressive craniectomy/brain resection

Epidural Hematoma (EDH) 1% of head trauma admissions Male: Female = 4:1 Source of bleeding is arterial in 85% of cases (middle meningeal artery) Mortality ranges from 5-10% with optimal management Neurological injury caused by secondary mechanisms

Subdural Hematoma (SDH) About twice as common as EDH Mortality 50-90% Impact injury much higher than with EDH Often associated brain injury Two common sources of bleeding Tearing of bridging veins Cortical laceration

Cerebral Contusion Often little mass effect Not often operative

Pre-op Post-op Hemicraniectomy

Key Points 2 mechanisms of brain injury Impact injury Secondary injury GCS < 8 has generally become accepted as representing coma / severe head injury CT is generally the imaging study of choice in the acute assessment of head injury Operative and nonoperative strategies are generally aimed at reducing mass effect and, therefore, reducing ICP Nothing beats a neuro exam.