Differential Diagnosis for a 13-year-old Male Involved in a Motor Vehicle Accident

Single Most Likely Diagnosis

• Concussion or Mild Traumatic Brain Injury (mTBI): Given the mechanism of injury (rear-end collision with a fall and hit to the head), the patient's symptoms of headache and light sensitivity are consistent with a concussion. The fact that he denies loss of consciousness does not rule out this diagnosis, as many concussions occur without a loss of consciousness.

Other Likely Diagnoses

• Cervicogenic Headache: Although musculoskeletal palpation and orthopedic testing did not reproduce the headache, the mechanism of injury could still have caused cervical spine strain leading to referred pain to the head.
• Post-Traumatic Headache: This is a broad category that can include headaches due to various causes following a traumatic event, including but not limited to concussion, musculoskeletal strain, or other injuries sustained during the accident.

Do Not Miss Diagnoses

• Subdural or Epidural Hematoma: Although less likely given the absence of loss of consciousness and worsening symptoms, these conditions can present subtly at first and are potentially life-threatening if not promptly diagnosed and treated.
• Cervical Spine Fracture or Instability: The mechanism of injury could have caused a cervical spine injury, which might not always present with immediate neurological deficits or severe pain.
• Intracranial Hemorrhage: Similar to subdural or epidural hematoma, any form of intracranial bleeding is a medical emergency that requires immediate attention.

Rare Diagnoses

• Vertebral Artery Dissection: This is a rare but serious condition that can occur after a traumatic event, especially one involving a sudden and forceful movement of the neck.
• Chiari Malformation: If the patient has an underlying Chiari malformation, the trauma could potentially exacerbate symptoms or lead to new neurological findings.
• Post-Traumatic Meningitis: Although rare, head trauma can increase the risk of meningitis, especially if there is a breach in the dura mater.

Each of these diagnoses should be considered in the context of the patient's overall clinical presentation, and further evaluation, including imaging studies and possibly neurological consultation, may be necessary to determine the exact cause of the patient's symptoms.