18.1 Concussion, Moderate-to-Severe TBI & Intracranial Injury

ABFM Family Medicine Certification Study Guide Exam

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1 Chapter 1: Exam Structure, Blueprint & Clinical Decision-Making

1.1 Exam Blueprint, FMCLA vs. One-Day Exam & Board Scoring 1.2 Clinical Reasoning, Test-Taking Strategy & Ambiguity Management 1.3 Evidence-Based Medicine & Clinical Practice Guidelines in Primary Care

2 Chapter 2: Healthcare Systems, Practice Management & Quality

2.1 Practice Management, Billing, Coding & Documentation 2.2 Quality Improvement, Patient Safety & Diagnostic Stewardship 2.3 Interprofessional Team-Based Care & Care Coordination

3 Chapter 3: Ethics, Law, Biostatistics & Health Equity

3.1 Medical Ethics, Informed Consent & Surrogate Decision-Making 3.2 Biostatistics, Clinical Epidemiology & Diagnostic Test Interpretation 3.3 Social Determinants of Health, Health Equity & Cultural Humility 3.4 Physician Wellness, Burnout Prevention & Professionalism

4 Chapter 4: Lifestyle Counseling & Behavior Change

4.1 Alcohol Use Screening & Brief Intervention 4.2 Illicit Drug & Cannabis Counseling 4.3 Tobacco & Vaping Cessation Counseling

5 Chapter 5: Nutrition, Physical Activity & Chronic Disease Prevention

5.1 Dietary Counseling for Obesity & Chronic Disease Prevention 5.2 Exercise Prescription & Physical Activity Counseling 5.3 Genetic Risk Assessment & Family History Counseling

6 Chapter 6: Routine Adult Immunizations

6.1 ACIP Adult Respiratory Vaccines: Influenza, COVID-19, RSV & Pneumococcal 6.2 ACIP Adult Non-Respiratory Vaccines: Tdap, Shingrix, HPV & Hep B 6.3 Immunizations in Special Populations: Pregnancy, Asplenia & Immunocompromise

7 Chapter 7: Pediatric Health Maintenance & Surveillance

7.1 Newborn Examination & Early Postnatal Care 7.2 Well-Child Care, Developmental Surveillance & Milestones 7.3 Pediatric & Adolescent Screening: Vision, Hearing, Anemia & Lead 7.4 Pediatric Oral Health, Dental Screening & Fluoride

8 Chapter 8: Behavioral Health & Safety Screening

8.1 Primary Care Depression, Anxiety & Behavioral Health Screening 8.2 Domestic Violence, Intimate Partner Violence & Firearm Safety 8.3 Occupational Health & Recreational Safety Counseling

9 Chapter 9: Adult Preventive Screening: Cardiovascular & Metabolic

9.1 Cardiovascular Disease & Hypertension Screening 9.2 Type 2 Diabetes Screening & Prediabetes Risk Stratification 9.3 Abdominal Aortic Aneurysm & Osteoporosis Screening

10 Chapter 10: Adult Cancer Screening: Breast & Gynecologic

10.1 Breast Cancer Screening & Risk-Assessment 10.2 Cervical Cancer Screening & ASCCP Algorithms 10.3 Skin Cancer Clinical Assessment & Counseling

11 Chapter 11: Adult Cancer Screening: Colorectal, Lung & Prostate

11.1 Colorectal Cancer Screening Modalities & Intervals 11.2 Lung Cancer Screening with Low-Dose CT 11.3 Prostate Cancer Screening & Shared Decision-Making

12 Chapter 12: Sexual Health, Infectious Disease Screening & Contraception

12.1 Sexual Health Counseling & Risk-Reduction Strategies 12.2 STI Screening: Chlamydia, Gonorrhea, Syphilis & Trichomoniasis 12.3 Bloodborne Infectious Disease Screening: HIV & Hepatitis C

13 Chapter 13: Reproductive Life Planning, Lactation & Preoperative Care

13.1 Preconception Planning & Comprehensive Contraception Management 13.2 Lactation Support & Breastfeeding Counseling 13.3 Preoperative Medical Evaluation & Pre-Participation Sports Exam

14 Chapter 14: Emergent Cardiovascular Conditions

14.1 Acute Coronary Syndromes & Myocardial Infarction 14.2 Acute Chest Pain Risk Stratification & Triage 14.3 Acute or Critical Valvular Heart Emergencies

15 Chapter 15: Cardiac Arrhythmias, Heart Failure & Hypertensive Crises

15.1 Acute Atrial & Ventricular Arrhythmias 15.2 Acute Decompensated Heart Failure & Cardiogenic Shock 15.3 Hypertensive Emergency & Urgency Management

16 Chapter 16: Vascular & Thromboembolic Emergencies

16.1 Pulmonary Embolism & Deep Vein Thrombosis 16.2 Acute Aortic Syndromes & Peripheral Vascular Emergencies 16.3 Critical Limb Ischemia & Acute Arterial Occlusion

17 Chapter 17: Neurologic Emergencies: Stroke & Altered Consciousness

17.1 Acute Ischemic Stroke & Intracranial Hemorrhage 17.2 Syncope Evaluation & Status Epilepticus 17.3 Acute Delirium, Encephalopathy & Severe Confusion

18 Chapter 18: Neurologic Trauma & Acute Cranial Emergencies

18.1 Concussion, Moderate-to-Severe TBI & Intracranial Injury 18.2 Thunderclap & Acute Severe Secondary Headaches 18.3 Acute Ophthalmologic Emergencies

19 Chapter 19: Acute Abdominal, Pelvic & Gastrointestinal Emergencies

19.1 Acute Abdominal & Pelvic Pain Triage 19.2 Upper & Lower Gastrointestinal Bleeding 19.3 Acute Hepatic Failure, Cholangitis & Severe Jaundice

20 Chapter 20: Acute Pulmonary & Airway Emergencies

20.1 Acute Hypoxic Respiratory Failure & ARDS 20.2 Severe Community-Acquired Pneumonia & Empyema 20.3 Acute Severe Epistaxis & Airway Obstruction

21 Chapter 21: Acute Traumatic Injuries & Wound Care

21.1 Major Trauma Resuscitation & Initial Assessment 21.2 Burn Assessment, Inhalation Injury & Resuscitation 21.3 Laceration Management, Complex Wounds & Animal Bites

22 Chapter 22: Acute Orthopedic & Musculoskeletal Emergencies

22.1 Acute Ambulatory Fractures & Initial Splinting 22.2 Compartment Syndrome & Major Orthopedic Trauma 22.3 Septic Arthritis & Acute Microcrystalline Crises

23 Chapter 23: Severe Infections, Sepsis & Systemic Emergencies

23.1 Sepsis, Septic Shock & Initial Fluid Resuscitation 23.2 Necrotizing Soft Tissue Infections & Severe CNS Infections 23.3 Anaphylaxis Diagnosis, Epinephrine Dosing & Airway Protection

24 Chapter 24: Metabolic, Endocrine & Electrolyte Emergencies

24.1 Diabetic Ketoacidosis & Hyperosmolar Hyperglycemic State 24.2 Critical Electrolyte Emergencies: Dyskalemias & Dysnatremias 24.3 Severe Calcium Abnormalities & Acute Adrenal Crisis

25 Chapter 25: Hematologic, Urologic & Dental Emergencies

25.1 Severe Symptomatic Anemias & Coagulopathic Emergencies 25.2 Testicular Torsion, Priapism & Acute Urinary Retention 25.3 Urgent Odontogenic Infections & Dental Trauma

26 Chapter 26: Psychiatric, Behavioral & Obstetric/Gynecologic Emergencies

26.1 Suicidal Ideation, Acute Agitation & Behavioral Emergencies 26.2 Acute Physical & Sexual Assault Care 26.3 Life-Threatening Vaginal Bleeding & Ectopic Pregnancy 26.4 Environmental Heat Stroke & Severe Hypothermia

27 Chapter 27: Acute Head, Neck & Neurologic Symptoms

27.1 Primary Acute Headaches: Migraine, Tension & Cluster 27.2 Concussion & Minor Closed Head Injury Evaluation 27.3 Transient Ischemic Attack Evaluation & ABCD2 Risk Scoring

28 Chapter 28: Acute Cranial Nerves, Hearing & Sensory Symptoms

28.1 Peripheral Neuropathies: Bell's Palsy, Carpal Tunnel & Radiculopathy 28.2 Acute Tinnitus, Sudden Sensorineural Hearing Loss & Cerumen Impaction 28.3 Acute Dizziness, Benign Paroxysmal Positional Vertigo & Vestibular Neuritis

29 Chapter 29: Acute Upper Respiratory Tract Infections

29.1 Acute Viral Rhinosinusitis vs. Bacterial Rhinosinusitis 29.2 Acute Pharyngitis: Group A Streptococcus & Centor Criteria 29.3 Acute Otitis Media, Otitis Externa & Serous Effusion

30 Chapter 30: Acute Lower Respiratory Infections & Cough

30.1 Influenza, COVID-19 & Viral Respiratory Syndromes 30.2 Acute Bronchitis & Lower Respiratory Tract Infections 30.3 Ambulatory Community-Acquired Pneumonia

31 Chapter 31: Allergic, Nasal & Non-Infectious Pulmonary Conditions

31.1 Allergic Rhinitis & Acute Non-Anaphylactic Allergic Reactions 31.2 Acute Dyspnea in Ambulatory Care 31.3 Interstitial Lung Diseases & Sarcoidosis Presentation

32 Chapter 32: Acute Chest, Cardiac & Vascular Symptoms

32.1 Palpitations Evaluation & Arrhythmia Triage in Primary Care 32.2 Deep Vein Thrombosis & Superficial Thrombophlebitis 32.3 Ambulatory Hypotension & Orthostasis Evaluation

33 Chapter 33: Acute Upper Gastrointestinal Conditions

33.1 Peptic Ulcer Disease & Gastritis 33.2 Dysphagia, Esophagitis & Acute Esophageal Disorders 33.3 Acute Nausea, Vomiting & Foodborne Illness

34 Chapter 34: Acute Lower Gastrointestinal Conditions

34.1 Acute Infectious Diarrhea & Gastroenteritis 34.2 Acute Constipation & Functional Bowel Changes 34.3 Ano-Rectal Disorders: Hemorrhoids, Fissures, Abscesses & Pruritus Ani

35 Chapter 35: Inflammatory, Functional & Malabsorptive GI Disorders

35.1 Acute Flares of Inflammatory Bowel Disease 35.2 Irritable Bowel Syndrome: Diagnosis, Subtyping & Management 35.3 Celiac Disease & Malabsorption Syndromes

36 Chapter 36: Acute Abdominal, Hepatic & Biliary Disorders

36.1 Ambulatory Abdominal & Pelvic Pain Triage 36.2 Acute Cholecystitis, Biliary Colic & Pancreatitis 36.3 Acute Liver Injury & Viral Hepatitis

37 Chapter 37: Acute Abdominal Wall, Hernias & Dental Conditions

37.1 Abdominal Wall, Inguinal & Ventral Hernias 37.2 Acute Dental Pain, Odontogenic Abscess & Aphthous Ulcers 37.3 Acute Edema: Unilateral vs. Bilateral Diagnostic Evaluation

38 Chapter 38: Acute Infectious Dermatoses

38.1 Bacterial Skin Infections: Impetigo, Cellulitis & Cutaneous Abscesses 38.2 Fungal Skin Infections: Tinea Corporis, Cruris, Pedis & Onychomycosis 38.3 Viral Cutaneous Infections: Herpes Simplex, Zoster & Molluscum Contagiosum

39 Chapter 39: Inflammatory, Allergic & Autoimmune Dermatoses

39.1 Atopic Dermatitis, Contact Dermatitis & Eczematous Flares 39.2 Non-Infectious Rashes: Urticaria, Drug Eruptions & Erythema Multiforme 39.3 Cutaneous Malignancies & Premalignant Lesions: AK, BCC, SCC & Melanoma

40 Chapter 40: Acute Shoulder, Elbow & Upper Extremity Injuries

40.1 Rotator Cuff Pathology, Tendinopathy & Shoulder Impingement 40.2 Lateral & Medial Epicondylitis, Olecranon Bursitis & Elbow Sprains 40.3 Wrist & Hand Soft-Tissue Injuries: De Quervain, TFCC & Finger Sprains

41 Chapter 41: Acute Knee, Ankle & Lower Extremity Injuries

41.1 Meniscal Tears, Ligamentous Knee Injuries & Patellofemoral Pain 41.2 Ankle Sprains, Ottawa Ankle Rules & Achilles Tendinopathy 41.3 Plantar Fasciitis, Shin Splints & Overuse Syndromes

42 Chapter 42: Acute Ambulatory Fractures & Dislocations

42.1 Distal Radius, Scaphoid & Common Upper Extremity Fractures 42.2 Metatarsal, Clavicle & Common Lower Extremity Fractures 42.3 Joint Dislocation Management: Nursemaid's Elbow & Shoulder Subluxation

43 Chapter 43: Acute Axial Musculoskeletal Pain & Falls

43.1 Acute Low Back Pain: Red Flags, Strain & Disc Herniation 43.2 Acute Cervical Strain, Whiplash & Axial Neck Pain 43.3 Evaluation of Falls in Ambulatory & Older Patients

44 Chapter 44: Acute Inflammatory Arthropathies & Generalized Pain

44.1 Acute Inflammatory Arthritis & Spondyloarthropathies 44.2 Myalgias, Rhabdomyolysis & Post-Viral Pain Syndromes 44.3 Acute Non-Headache Pain Management Strategies

45 Chapter 45: Acute Renal, Urinary & Genitourinary Conditions

45.1 Uncomplicated UTI, Pyelonephritis & Acute Urethritis 45.2 Hematuria Workup & Glomerulonephritis 45.3 Nephrolithiasis & Acute Urinary Tract Obstruction

46 Chapter 46: Acute Male Genitourinary & Prostatic Conditions

46.1 Acute Prostatitis, Epididymitis & Orchitis 46.2 Acute Scrotal Pain: Torsion vs Appendage, BPH & Male Genital Emergencies 46.3 Acute Urinary Retention & Incontinence Evaluation

47 Chapter 47: Acute Women's Health & Early Pregnancy Care

47.1 Early Pregnancy Diagnosis, Dating & Initial Complications 47.2 Abnormal Uterine Bleeding & Acute Menstrual Disorders 47.3 Premenstrual Syndrome & Premenstrual Dysphoric Disorder

48 Chapter 48: Breast Disorders, STIs & Pediatric Elimination

48.1 Palpable Breast Mass, Mastitis & Nipple Discharge 48.2 Sexually Transmitted Infections: Diagnosis, Staging & CDC Guidelines 48.3 Pediatric Enuresis & Encopresis

49 Chapter 49: Systemic Signs, Metabolic Dysregulation & Miscellaneous Infections

49.1 Acute Fever, Sepsis Screening & FUO in Primary Care 49.2 Acute Hyperglycemia & Symptomatic Hypoglycemia 49.3 Electrolyte Abnormalities: Mild-to-Moderate Disturbances 49.4 Vector-Borne, Tick-Borne & Rickettsial Illnesses

50 Chapter 50: Chronic Cardiovascular Diseases: Hypertension & Ischemia

50.1 Essential Hypertension Management: 2025 AHA/ACC Guideline & JNC Strategies 50.2 Chronic Coronary Artery Disease & Post-MI Secondary Prevention 50.3 Chronic Heart Failure: HFrEF, HFpEF & Quadruple GDMT

51 Chapter 51: Chronic Vascular, Valvular & Dyslipidemic Diseases

51.1 Peripheral Arterial Disease & Claudication 51.2 Chronic Valvular Heart Disease & Murmur Evaluation 51.3 Lipid Disorders & ASCVD Risk-Based Statin Therapy

52 Chapter 52: Chronic Respiratory Diseases: Asthma & COPD

52.1 Chronic Asthma Management: GINA Stepwise SMART Therapy 52.2 Chronic Obstructive Pulmonary Disease: GOLD Recommendations 52.3 Solitary Pulmonary Nodule Evaluation & Fleischner Society Criteria

53 Chapter 53: Chronic Metabolic Diseases: Diabetes Mellitus

53.1 Type 2 Diabetes Management: ADA Pharmacotherapy Algorithms 53.2 Type 1 Diabetes: Basal-Bolus Insulin, CGMs & Diabetic Complications 53.3 Diabetic Microvascular & Macrovascular Disease Surveillance

54 Chapter 54: Obesity, Nutrition & Metabolic Bone Diseases

54.1 Medical & Behavioral Management of Obesity & Incretin Mimetics 54.2 Osteoporosis & Metabolic Bone Disease: DEXA, FRAX & Antiresorptives 54.3 Nutritional Deficiencies: Vitamin D, B12, Iron & Malnutrition

55 Chapter 55: Chronic Endocrine Disorders

55.1 Primary & Subclinical Hypothyroidism, Hyperthyroidism & Nodules 55.2 Adrenal Disorders: Addison's Disease & Cushing's Syndrome 55.3 Hypercalcemia, Hyperparathyroidism & Pituitary Disorders

56 Chapter 56: Chronic Kidney Disease & Venous Disorders

56.1 Chronic Kidney Disease: KDIGO Staging & Renoprotective Therapy 56.2 Chronic Venous Insufficiency, Stasis Dermatitis & Lymphedema 56.3 Chronic Electrolyte & Acid-Base Management in CKD

57 Chapter 57: Chronic Gastrointestinal & Hepatic Diseases

57.1 Gastroesophageal Reflux Disease, Barrett's Esophagus & Dyspepsia 57.2 Chronic Liver Disease: MASLD/NAFLD, Cirrhosis & Portal Hypertension 57.3 Viral Hepatitis B & C: Long-Term Monitoring & DAA Therapy

58 Chapter 58: Colorectal Surveillance & Chronic Pancreaticobiliary Care

58.1 Post-Polypectomy Colorectal Polyp Surveillance Guidelines 58.2 Chronic Pancreatitis & Exocrine Pancreatic Insufficiency 58.3 Chronic Nausea, Gastroparesis & Functional GI Disorders

59 Chapter 59: Chronic Musculoskeletal & Rheumatologic Disorders

59.1 Osteoarthritis: Hip, Knee & Hand Management 59.2 Spinal Conditions: Spinal Stenosis, Spondylolisthesis & Compression Fractures 59.3 Chronic Myopathies & Fibromyalgia Syndrome

60 Chapter 60: Chronic Neurologic & Neurodegenerative Disorders

60.1 Dementia: Alzheimer's, Vascular & Lewy Body Disease 60.2 Parkinson's Disease & Essential Tremor 60.3 Epilepsy: Chronic Antiseizure Medications & Post-Stroke Care

61 Chapter 61: Chronic Peripheral Nerves, Pain & Sensory Disorders

61.1 Diabetic & Chronic Peripheral Neuropathies 61.2 Chronic Pain Syndromes & Chronic Daily Headaches 61.3 Chronic Tinnitus, Presbycusis & Persistent Dizziness

62 Chapter 62: Chronic Psychiatric Disorders

62.1 Major Depressive Disorder & Generalized Anxiety Disorder 62.2 Bipolar Disorder: Maintenance Pharmacotherapy & Lithium Monitoring 62.3 Adult & Pediatric Attention-Deficit/Hyperactivity Disorder

63 Chapter 63: Chronic Behavioral Health & Neurodevelopmental Conditions

63.1 Chronic Behavioral Conditions: PTSD, OCD & Somatization 63.2 Autism Spectrum Disorder & Intellectual Disabilities 63.3 Eating Disorders: Anorexia Nervosa, Bulimia & Binge Eating

64 Chapter 64: Chronic Substance Use Disorders & Tobacco Cessation

64.1 Alcohol Use Disorder: Pharmacotherapy & Relapse Prevention 64.2 Opioid & Stimulant Use Disorders: MOUD & Harm Reduction 64.3 Longitudinal Tobacco Cessation Pharmacotherapy

65 Chapter 65: Chronic Dermatologic Conditions

65.1 Acne Vulgaris, Rosacea & Seborrheic Dermatitis 65.2 Chronic Plaque Psoriasis & Biologic Therapies 65.3 Chronic Eczema, Hidradenitis Suppurativa & Cutaneous Lupus

66 Chapter 66: Chronic Reproductive, Infectious & Geriatric Special Care

66.1 Chronic Menstrual Disorders, Infertility & Sexual Dysfunction 66.2 Menopause Management & Hormone Replacement Therapy 66.3 Chronic HIV Infection Management & Primary Care Integration 66.4 Gender-Affirming Primary Care & Hormone Therapy 66.5 Advance Care Planning, Palliative Care & End-of-Life Symptom Control

67 Chapter 67: Continuity Care: Sleep, Fatigue, Cancer, Pregnancy & the Adult Preventive Visit

67.1 Chronic Insomnia & Obstructive Sleep Apnea 67.2 Chronic Malaise, Fatigue & ME/CFS 67.3 Primary Care During Cancer Treatment & Survivorship 67.4 Routine Prenatal Care & Longitudinal Pregnancy Management 67.5 The Periodic Adult Health Examination & Medicare Annual Wellness Visit

18.1 Concussion, Moderate-to-Severe TBI & Intracranial Injury

Key Takeaways Explain This Topic AI

Traumatic Brain Injury (TBI) is classified by Glasgow Coma Scale (GCS) score: Mild TBI/Concussion corresponds to GCS 13–15, Moderate TBI to GCS 9–12, and Severe TBI to GCS 3–8, which mandates early endotracheal intubation for definitive airway protection ('GCS 8 or less, intubate').

The Canadian CT Head Rule (CCHR) guides non-contrast head CT in adults with minor head injury; high-risk criteria for neurosurgical intervention include GCS <15 at 2 hours post-injury, suspected open or depressed skull fracture, signs of basilar skull fracture (hemotympanum, Battle sign, raccoon eyes, CSF leak), ≥2 episodes of vomiting, or age ≥65 years.

Pediatric PECARN rules safely stratify clinically important traumatic brain injury (ciTBI <0.05% risk in low-risk groups); high-risk criteria warranting immediate CT include GCS <15, altered mental status, or palpable skull fracture (<2 years) / signs of basilar skull fracture (≥2 years), while isolated vomiting or headache permits clinical observation.

Epidural hematoma results from middle meningeal artery rupture beneath a temporal bone fracture at the pterion, classically presenting with transient loss of consciousness, a lucid interval, and rapid uncal herniation (ipsilateral blown pupil, contralateral hemiparesis) with a biconvex lenticular hyperdensity that does not cross suture lines; subdural hematoma results from sheared bridging cortical veins, yielding a crescentic collection crossing suture lines common in elderly and alcoholic patients.

Sports-related concussion management requires relative physical and cognitive rest for the initial 24 to 48 hours only, followed by symptom-limited resumption of daily activities and light aerobic exercise; return to sport requires completing a 6-stage graduated protocol (minimum 24 hours per stage without symptom recurrence) to prevent lethal Second Impact Syndrome.

Last updated: September 2026

Glasgow Coma Scale & Traumatic Brain Injury Classification

Traumatic Brain Injury (TBI) is a major cause of death and lifelong disability globally. Clinical triage, monitoring, and therapeutic interventions are anchored to the Glasgow Coma Scale (GCS) , which evaluates motor, verbal, and eye-opening responses. The GCS provides an objective measure of the depth of impaired consciousness, with scores ranging from 3 (deep coma or death) to 15 (fully awake, alert, and oriented).

Glasgow Coma Scale Components

Assessment Category Patient Response Score
Eye Opening (E) Spontaneous eye opening 4
Opens eyes in response to verbal command/speech 3
Opens eyes in response to central pressure / pain 2
No eye opening to any stimulus 1
Verbal Response (V) Oriented to person, place, and time 5
Confused conversation, but able to answer questions 4
Inappropriate words (random, exclamatory, disorganized speech) 3
Incomprehensible sounds (moaning, groaning, no recognizable words) 2
No verbalization 1
Motor Response (M) Obeys commands fully 6
Localizes to painful stimulus (moves hand toward site of pain) 5
Normal flexion withdrawal (rapid pull away from painful stimulus) 4

Abnormal flexion ( Decorticate posturing : arms flexed/adducted, wrists flexed, legs extended; reflects corticospinal disruption above the red nucleus) 3

Abnormal extension ( Decerebrate posturing : arms extended/adducted/pronated, teeth clenched, legs extended; reflects midbrain/pontine disruption below the red nucleus; carries worse prognosis) 2

Flaccid, no motor response 1

Clinical Note : If an endotracheal tube is in place, the verbal score is designated as "1T" (e.g., GCS E3V1TM5 = GCS 9T).

Severity Stratification of TBI

Mild TBI / Concussion (GCS 13–15) :

Represents ~80% of all traumatic brain injuries.

Patients are typically conscious upon presentation but may report transient loss of consciousness (LOC), retrograde or anterograde amnesia, confusion, dizziness, headache, or visual disturbances.

The primary diagnostic priority is identifying the small subset (5–10%) harboring acute neurosurgical intracranial hemorrhage requiring emergent intervention.

Moderate TBI (GCS 9–12) :

Represents ~10% of presentations.

Characterized by marked confusion, somnolence, lethargy, or focal neurologic deficits.

Requires mandatory non-contrast head CT, trauma surgery/neurosurgical consultation, and admission to a high-acuity monitored setting or intensive care unit (ICU).

Severe TBI (GCS 3–8) :

Represents ~10% of presentations and carries significant mortality (30–40%).

Patients are comatose and unable to protect their airway.

Cardinal Airway Mandate: "GCS 8 or less, intubate." Early definitive endotracheal intubation via Rapid Sequence Intubation (RSI) is critical to prevent fatal secondary hypoxemia and hypercapnic cerebral vasodilation.

Critical Resuscitation Goals in Severe TBI

Secondary brain injury occurs in the hours to days following the primary biomechanical insult. Clinical management focuses on maintaining adequate Cerebral Perfusion Pressure (CPP) , calculated as: CPP = MAP − ICP \text{CPP} = \text{MAP} - \text{ICP} CPP = MAP − ICP

Normal intracranial pressure (ICP) is <15 mm Hg. In severe TBI, sustained ICP >20–22 mm Hg compromises cerebral perfusion and drives fatal brainstem herniation.

Avoid Secondary Insults (The "H-Bombs" of TBI) :

Hypotension : A single episode of Systolic Blood Pressure (SBP) <90 mm Hg doubles mortality. Target SBP ≥100 mm Hg for patients aged 50–69 years, or ≥110 mm Hg for patients aged 15–49 or ≥70 years, utilizing isotonic crystalloids and IV vasopressors (e.g., norepinephrine) if necessary.

Hypoxia : A single documented episode of PaO2 <60 mm Hg or SpO2 <90% dramatically worsens functional outcome. Maintain SpO2 ≥95%.

Hyperventilation / Hypocapnia : Routine aggressive hyperventilation is strictly contraindicated. Hypocapnia (PaCO2 <35 mm Hg) induces profound cerebral vasoconstriction, causing severe secondary ischemic cerebral infarction. Normocapnia (PaCO2 target 35–40 mm Hg) is maintained. Brief, temporary hyperventilation (PaCO2 target 30–35 mm Hg) is reserved exclusively as a temporary bridge during active uncal herniation while definitive osmotic therapy or craniotomy is prepared.

Hyperpyrexia : Maintain normothermia; elevated core temperature accelerates cerebral metabolic demand.

Hyperglycemia : Target blood glucose 140–180 mg/dL; avoid extremes of hypo- and hyperglycemia.

Clinical Decision Rules for Urgent Head CT in Adults: CCHR & NOC

Liberal imaging of every minor head bump causes unnecessary ionizing radiation exposure, emergency department overcrowding, and financial cost. Validated clinical decision algorithms identify patients who can be safely discharged without neuroimaging.

The Canadian CT Head Rule (CCHR)

The CCHR applies to adult patients (age ≥16 years) with blunt minor head trauma who experienced witnessed loss of consciousness, definite amnesia, or witnessed disorientation, and present with a baseline GCS score of 13 to 15. CANADIAN CT HEAD RULE (CCHR) ALGORITHM

┌────────────────────────────────────────────────────────────────────────┐
│ Inclusion: Minor Head Injury + (LOC, Amnesia, or Witnessed Confusion) │
│ Exclusions: Age <16, GCS <13, Anticoagulant use, Penetrating trauma │
└───────────────────────────────────┬────────────────────────────────────┘
│
▼
┌────────────────────────────────────────────────────────────────────────┐
│ HIGH-RISK CRITERIA (Need for Neurosurgical Intervention: ~100% Sens) │
│ 1. GCS <15 at 2 hours post-injury │
│ 2. Suspected open or depressed skull fracture │
│ 3. Any clinical sign of basilar skull fracture: │
│ • Hemotympanum (blood behind tympanic membrane) │
│ • Battle sign (retroauricular/mastoid ecchymosis) │
│ • Raccoon eyes (periorbital ecchymosis without facial trauma) │
│ • CSF otorrhea or CSF rhinorrhea │
│ 4. ≥2 episodes of vomiting │
│ 5. Age ≥65 years │
└───────────────────────────────────┬────────────────────────────────────┘
│
┌──────────────────┴──────────────────┐
│ ANY High-Risk Present? │
├─────────────────┬───────────────────┤
│ YES │ NO │
▼ ▼ │
┌─────────────────────────┐ ┌─────────────────────────────────────┐
│ URGENT NON-CONTRAST │ │ MEDIUM-RISK CRITERIA │
│ HEAD CT MANDATED │ │ (Brain Injury on CT: ~98-100% Sens) │
└─────────────────────────┘ │ 1. Retrograde amnesia ≥30 minutes │
│ 2. Dangerous mechanism of injury: │
│ • Pedestrian struck by vehicle │
│ • Occupant ejected from vehicle │
│ • Fall from height >3 ft (>5 sts)│
└──────────────────┬──────────────────┘
│
┌──────────────────┴──────────────────┐
│ ANY Medium-Risk Present? │
├─────────────────┬───────────────────┤
│ YES │ NO (All Negative) │
▼ ▼ │
┌─────────────────────────┐ ┌─────────────────────┐
│ URGENT NON-CONTRAST │ │ HEAD CT NOT │
│ HEAD CT MANDATED │ │ INDICATED │
└─────────────────────────┘ │ Safe for Discharge │
└─────────────────────┘

High-Risk Criteria (Predicting Need for Neurosurgical Intervention) :

GCS score <15 at 2 hours post-injury
Suspected open or depressed skull fracture (e.g., scalp laceration over palpable bone step-off)

Any clinical sign of basilar skull fracture :

Hemotympanum (violaceous blood pooling behind the intact tympanic membrane)
Battle's sign (ecchymosis over the mastoid process behind the ear; delayed appearance 12–36 hours)
"Raccoon eyes" (bilateral periorbital ecchymosis sparing the tarsal plate, without direct orbital trauma)

CSF rhinorrhea or otorrhea (clear fluid leak; positive "halo test" on filter paper, positive beta-2 transferrin)

Two or more discrete episodes of vomiting
Age ≥65 years (cerebral atrophy stretches bridging veins, predisposing to hemorrhage with minimal trauma)

Medium-Risk Criteria (Predicting Clinically Important Brain Injury on CT) :

6. Retrograde amnesia to the event of ≥30 minutes (inability to recall events immediately preceding impact)

7. Dangerous injury mechanism : Pedestrian struck by motor vehicle; occupant ejected from motor vehicle; fall from an elevation >3 feet (or >5 stairs)

CCHR Exclusion Criteria : Patients with GCS <13, age <16 years, open penetrating injuries, bleeding diathesis, or therapeutic anticoagulation (warfarin, DOACs, LMWH) . Exam Pearl : Any blunt head trauma patient on therapeutic anticoagulants or antiplatelet therapy requires an immediate non-contrast head CT regardless of a normal GCS or negative decision rules.

The New Orleans Criteria (NOC)

The New Orleans Criteria apply strictly to blunt head injury patients with a baseline GCS of 15. A non-contrast head CT is indicated if any of the following 7 criteria are present:

Headache
Vomiting
Age >60 years
Drug or alcohol intoxication
Deficits in short-term memory (persistent anterograde amnesia)
Physical evidence of trauma above the clavicles

Post-traumatic seizure Comparison : The CCHR has higher specificity than NOC, leading to lower imaging rates while maintaining near 100% sensitivity for neurosurgical lesions.

Pediatric Head Trauma: The PECARN Decision Rules

Children have thinner cranial bones, larger head-to-body ratios, and developing brains that are particularly vulnerable both to traumatic shearing and to the carcinogenic risks of ionizing radiation. The Pediatric Emergency Care Applied Research Network (PECARN) criteria represent the most rigorously validated tool for ruling out clinically important traumatic brain injury (ciTBI) —defined as intracranial injury resulting in death, neurosurgery, intubation for >24 hours, or hospital admission for ≥2 nights.

PECARN Rule Structure (<2 Years vs ≥2 Years)

Age Cohort High-Risk Criteria (~4.3–4.4% ciTBI Risk); CT Scan Recommended Intermediate-Risk Criteria (~0.8–0.9% ciTBI Risk); Observation vs CT (Shared Decision-Making) Low-Risk Criteria (<0.05% ciTBI Risk); No CT Recommended

Children <2 Years • GCS score <15; • Altered mental status (agitation, lethargy, repetitive questions, slow response); • Palpable skull fracture • Non-frontal scalp hematoma (occipital, parietal, or temporal); • History of loss of consciousness ≥5 seconds; • Severe injury mechanism (MVC with rollover/ejection/fatality; pedestrian/bicyclist struck; fall >3 feet; head struck by high-impact projectile); • Acting abnormally per parent / primary caregiver • Normal mental status (GCS 15); • No palpable fracture; • Frontal scalp hematoma only or none; • No LOC or <5 seconds; • Non-severe mechanism; • Acting completely normal per parent

Children ≥2 Years • GCS score <15; • Altered mental status; • Clinical signs of basilar skull fracture (hemotympanum, Battle sign, raccoon eyes, CSF leak) • History of any documented loss of consciousness; • History of vomiting; • Severe injury mechanism (fall >5 feet; high-speed MVC; bicycle vs motor vehicle without helmet); • Severe headache • Normal mental status (GCS 15); • No signs of basilar skull fracture; • No loss of consciousness; • No vomiting; • Non-severe mechanism; • Mild or absent headache

Clinical Application of the Intermediate Group : In intermediate-risk children, observational monitoring for 4 to 6 hours in the emergency department is preferred over reflex CT. If symptoms (e.g., headache, vomiting, or behavior) improve, imaging can be safely omitted. CT is favored if intermediate features are multiple, symptoms worsen during observation, or the child is <3 months old.

Extra-Axial Intracranial Hemorrhages: Epidural vs Subdural Hematoma

Extra-axial hemorrhages collect within the anatomical compartments surrounding the brain parenchyma. Differentiating epidural from subdural hematoma on clinical and radiological grounds is an essential board-exam competency.

Clinical and Radiographic Distinctions

Clinical Characteristic Epidural Hematoma (EDH) Subdural Hematoma (SDH)

Vascular Source Middle Meningeal Artery (85%; arterial bleed) or middle meningeal vein Bridging Cortical Veins (tearing as they cross the subdural space to the superior sagittal sinus; venous bleed)

Anatomical Space Potential space between the inner table of the calvarium and the outer periosteal layer of the dura mater Potential space between the dura mater and the arachnoid mater

Classic Mechanism Direct blunt lateral head trauma to the temporal bone / pterion (thinnest skull region) Rotational acceleration-deceleration or shear forces; common in falls, motor vehicle crashes, or shaken baby syndrome

Predisposed Populations Young adults, adolescents, athletes participating in contact sports Elderly individuals , chronic alcohol use disorder (due to cerebral brain atrophy stretching bridging veins), patients on anticoagulants

Classic Clinical Presentation The "Lucid Interval" : Initial transient concussion/LOC → temporary regaining of full consciousness and orientation → rapid catastrophic secondary neurological collapse Acute: Immediate coma or fluctuating depressed consciousness; Chronic: Insidious presentation over weeks with progressive dull headache, apathy, cognitive slowing, dementia mimicry, mild hemiparesis, gait ataxia

CT Brain Appearance Hyperdense, biconvex (lenticular / lens-shaped) extra-axial collection Crescent-shaped (concave) extra-axial collection along the cerebral convexity

Suture Line Boundary Does NOT cross cranial suture lines (dura is tightly adherent to sutures); CAN cross dural reflections (falx, tentorium) CROSSES cranial suture lines (subdural space is continuous across sutures); bounded by and does NOT cross dural reflections (falx, tentorium)

Emergency Management Neurosurgical emergency : Emergent craniotomy with hematoma evacuation and vessel ligation (or bedside burr-hole decompression if herniating) Acute symptomatic: Emergent craniotomy evacuation; Chronic symptomatic: Burr-hole trephination or middle meningeal artery (MMA) embolization EPIDURAL HEMATOMA SUBDURAL HEMATOMA

Outer Skull Outer Skull
┌─────────────────┐ ┌─────────────────┐
│ Calvarium │ │ Calvarium │
├─────────────────┤ ├─────────────────┤
│ │ │ DURA MATER │
│ (Arterial) │ ├─────────────────┤
│ BICONVEX / │ Dura │ │
│ LENTICULAR │ │ (Venous) │
│ COLLECTION │ │ CRESCENTIC │ Arachnoid
│ │ │ COLLECTION │
├─────────────────┤ │ │
│ DURA MATER │ ├─────────────────┤
├─────────────────┤ │ ARACHNOID MATER │
│ Brain Tissue │ │ Brain Tissue │
└─────────────────┘ └─────────────────┘
Does NOT cross suture lines • CROSSES cranial suture lines
Middle Meningeal Artery • Bridging Cortical Veins
Uncal Herniation Syndrome

When an expanding extra-axial hematoma (most acutely an epidural hematoma) expands in the temporal fossa, it displaces the medial temporal lobe—specifically the uncus —inferomedially over the free edge of the tentorium cerebelli:

Ipsilateral CN III Compression : The uncus directly compresses the ipsilateral oculomotor nerve (CN III). Parasympathetic pupillary constrictor fibers run on the outer surface of CN III; their disruption causes an unreactive, fixed, and dilated pupil ( "blown pupil" ), followed by ptosis and a "down-and-out" eye.

Ipsilateral Cerebral Peduncle Compression : Compression of the descending corticospinal fibers in the ipsilateral crus cerebri produces contralateral hemiparesis or hemiplegia .

Kernohan's Notch Phenomenon (False Localizing Sign) : Occasionally, the expanding mass shifts the midbrain laterally against the opposite tentorial edge, compressing the contralateral cerebral peduncle, resulting in hemiparesis ipsilateral to the hematoma.

Brainstem Compression : Downward displacement compresses the reticular activating system, precipitating deep coma, decerebrate posturing, and respiratory arrest.

Concussion Diagnosis & Modern Active Recovery Protocols

A concussion is a traumatic brain injury induced by biomechanical forces that cause functional neurological disturbance rather than gross structural neuropathology. Standard structural neuroimaging (CT and routine MRI) is normal.

Pathophysiology: The Neurometabolic Cascade

Biomechanical shearing forces stretch neuronal membranes, initiating a complex cascade:

Indiscriminate Depolarization : Massive efflux of intracellular potassium ( K + K^+ K + ) and influx of sodium and calcium ( C a 2 + Ca^{2+} C a 2 + ), triggering non-specific release of excitatory amino acids (glutamate).

Energy Crisis : Membrane ion pumps (Na+/K+-ATPase) consume excessive ATP to restore ionic equilibrium, driving a period of acute hyperglycolysis.

Cerebral Hypoperfusion : Concurrently, cerebral blood flow drops by up to 50%. This creates a critical mismatch between cellular metabolic demand and vascular energy supply.

Mitochondrial Dysfunction : Intracellular calcium sequestration impairs oxidative phosphorylation, leaving neurons highly vulnerable to secondary injury for 7 to 14 days.

Diagnosis & Clinical Assessment

Diagnosis is clinical and relies on recognizing symptoms across four clinical domains:

Somatic : Headache (most common, >80%), dizziness, nausea, photophobia, phonophobia, balance difficulty.

Cognitive : Feeling "in a fog," slowed processing speed, difficulty concentrating, memory impairment.

Affective / Emotional : Irritability, sadness, emotional lability, anxiety.

Sleep : Drowsiness, insomnia, sleeping more or less than usual.

Sideline Tools : The Sport Concussion Assessment Tool 6 (SCAT-6) or Standardized Assessment of Concussion (SAC) evaluates orientation, immediate memory, concentration (digits backward, months in reverse), and balance via the Modified Balance Error Scoring System (mBESS).

Amsterdam 2023 / Berlin Consensus Guidelines: The Shift to Active Recovery

Historical practice enforced strict, prolonged sensory deprivation in a dark room until all symptoms completely resolved ("cocoon therapy"). Landmark clinical trials and the 6th International Consensus Conference on Concussion in Sport (Amsterdam 2023) have proven that prolonged rest is harmful, predisposing patients to deconditioning, social isolation, depression, and persistent symptoms.

The Modern Paradigm :

Initial 24 to 48 Hours : Relative physical and cognitive rest (limiting screens, avoiding intense physical exertion).

After 48 Hours : Early, gradual resumption of light physical activity (e.g., brisk walking, stationary cycling) that does not bring on or worsen symptoms, even if the patient is not yet fully asymptomatic. Sub-symptom aerobic exercise accelerates autonomic recovery and shortens time to full clinical resolution.

The 6-Stage Graduated Return-to-Sport (RTS) Strategy

Athletes must never return to contact sport on the day of injury ("when in doubt, sit them out"). Progression through the following 6-stage protocol begins once the initial 24–48 hours of rest are complete: GRADUATED 6-STAGE RETURN-TO-SPORT (RTS) PROTOCOL

┌────────────────────────────────────────────────────────────────────────┐
│ Stage 1: Symptom-Limited Activity │
│ • Daily activities that do not provoke symptoms (walking, light tasks) │
│ • Goal: Gradual reintroduction of work/school activities │
└───────────────────────────────────┬────────────────────────────────────┘
│ (≥24 hours without symptom exacerbation)
▼
┌────────────────────────────────────────────────────────────────────────┐
│ Stage 2: Light Aerobic Exercise │
│ • Walking or stationary cycling at slow-to-medium pace (<70% HRmax) │
│ • NO resistance training; NO head impact activities │
│ • Goal: Increase heart rate without provoking symptoms │
└───────────────────────────────────┬────────────────────────────────────┘
│ (≥24 hours without symptom exacerbation)
▼
┌────────────────────────────────────────────────────────────────────────┐
│ Stage 3: Sport-Specific Exercise │
│ • Running drills in soccer, skating drills in hockey │
│ • NO head impact activities; NO contact │
│ • Goal: Add movement and dynamic coordination │
└───────────────────────────────────┬────────────────────────────────────┘
│ (≥24 hours without symptom exacerbation)
▼
┌────────────────────────────────────────────────────────────────────────┐
│ Stage 4: Non-Contact Training Drills │
│ • Harder training drills (passing, agility); progressive resistance │
│ • Goal: Exercise, coordination, and increased cognitive load │
└───────────────────────────────────┬────────────────────────────────────┘
│ (≥24 hours without symptom exacerbation)
▼
┌────────────────────────────────────────────────────────────────────────┐
│ Stage 5: Full-Contact Practice │
│ • MANDATORY: Prior formal medical clearance from licensed clinician │
│ • Normal training activities, live scrimmages, checking │
│ • Goal: Restore confidence and assess functional skills by coaching │
└───────────────────────────────────┬────────────────────────────────────┘
│ (≥24 hours without symptom exacerbation)
▼
┌────────────────────────────────────────────────────────────────────────┐
│ Stage 6: Return to Sport │
│ • Unrestricted competition, normal game play │
└────────────────────────────────────────────────────────────────────────┘

Progression Rule : Each stage requires a minimum of 24 hours . If any concussive symptoms recur during or after a stage, the athlete must stop activity, rest for 24 hours until asymptomatic, and then drop back to the previously tolerated asymptomatic stage.

Return-to-Learn (RTL) : Cognitive recovery must precede full return to sport. Accommodations include partial school days, frequent rest breaks, extended time for assignments, and postponement of standardized testing.

Second Impact Syndrome & Persistent Post-Concussive Symptoms
Second Impact Syndrome (SIS)

Second Impact Syndrome is a catastrophic complication that occurs when an athlete sustains a second head impact before symptoms from an initial concussion have completely resolved (typically within days to weeks).

Pathophysiology : During the post-concussive vulnerable window, cellular autoregulation of cerebral blood flow is disrupted. A second impact—even minor, such as a routine tackle or blow to the chest that transmits rotational force to the head—triggers sudden, irreversible loss of cerebrovascular autoregulation . This causes massive cerebral engorgement, severe diffuse brain edema, intracranial hypertension, and fatal brainstem herniation within 2 to 5 minutes.

Prognosis : Mortality approaches 50%, and permanent catastrophic neurological disability occurs in nearly 100% of survivors. It occurs predominantly in children, adolescents, and young adults under age 25.

Prevention : Absolute adherence to concussion return-to-play protocols and medical clearance.

Persistent Post-Concussive Symptoms (PPCS)

Historically termed "post-concussion syndrome," PPCS is defined as concussion-related symptoms persisting beyond expected recovery windows (>4 weeks in adults, >12 weeks in children). Management requires targeted multidimensional active rehabilitation:

Vestibular and ocular physical therapy (for vestibulo-ocular reflex [VOR] dysfunction and convergence insufficiency);

Cervical spine manual therapy (for cervicogenic headache and neck spasm);
Sub-symptom-threshold aerobic exercise prescription;

Cognitive Behavioral Therapy (CBT) and sleep hygiene for associated affective disturbances.