Differential Diagnosis for Headache or Bump on the Head

When evaluating a patient with a headache or a bump on the head, it's crucial to consider various potential diagnoses to ensure appropriate management and to avoid missing critical conditions. The differential diagnosis can be organized into the following categories:

• Single Most Likely Diagnosis

  • Concussion: This is often the most likely diagnosis in the context of a recent head injury, especially if there are symptoms such as confusion, disorientation, memory loss, or loss of consciousness, even if brief. A concussion is a type of traumatic brain injury caused by a blow to the head or body, a fall, or another injury that jars or shakes the brain inside the skull.

• Other Likely Diagnoses

  • Tension Headache: Could be exacerbated by or mistaken for a concussion, especially if the headache is severe and follows a head injury. However, tension headaches typically do not involve loss of consciousness or severe confusion.
  • Subcutaneous Hematoma or Contusion: A bump on the head can result in a collection of blood under the skin (hematoma) or bruising (contusion), which might be painful and could be mistaken for a more serious condition if not properly evaluated.
  • Migraine: Although migraines can be severe and debilitating, they are typically distinguished from concussions by the presence of other migraine symptoms such as aura, photophobia, phonophobia, and nausea, without a history of recent trauma.

• Do Not Miss Diagnoses

  • Epidural Hematoma: A potentially life-threatening condition where bleeding occurs between the skull and the dura mater, the outermost membrane covering the brain. It often presents with a loss of consciousness, severe headache, and sometimes a period of lucidity after initial unconsciousness, followed by rapid deterioration.
  • Subdural Hematoma: Similar to an epidural hematoma but the bleeding occurs beneath the dura mater. It can present with headache, confusion, and in severe cases, loss of consciousness.
  • Subarachnoid Hemorrhage: Bleeding into the space surrounding the brain (subarachnoid space), often due to an aneurysm rupture. It presents with a sudden, severe headache (often described as "the worst headache of my life"), and can be accompanied by vomiting, confusion, and loss of consciousness.
  • Skull Fracture: A break in one or more of the bones that form the skull, which can be associated with a severe headache and may require immediate medical attention, especially if there are signs of depression of the fracture or cerebrospinal fluid leakage.

• Rare Diagnoses

  • Arteriovenous Malformation (AVM): An abnormal connection between arteries and veins, which can rupture and cause bleeding in the brain, presenting with sudden onset of headache, seizures, or other neurological deficits.
  • Cerebral Venous Sinus Thrombosis: A blood clot in the venous sinuses of the brain, which can cause headache, confusion, and seizures, often in patients with predisposing factors such as hypercoagulability or dehydration.

Each of these diagnoses requires careful consideration based on the patient's history, physical examination, and sometimes additional diagnostic tests like imaging studies (CT or MRI scans). The key to distinguishing between them lies in a thorough evaluation of the onset, characteristics, and associated symptoms of the headache or bump on the head, as well as the presence of any neurological deficits or signs of increased intracranial pressure.