Differential Diagnosis for Worsening Headaches in an 18-year-old Man
- Single most likely diagnosis:
- Idiopathic Intracranial Hypertension (IIH): The patient's symptoms of intermittent, dull, occipital headaches triggered by physical activity, cough, or straining, accompanied by nausea and dizziness, are suggestive of increased intracranial pressure. The absence of fever, photophobia, vision disturbances, or focal neurological deficits also points towards IIH, although the lack of papilledema on examination might seem contradictory, it's not universally present.
- Other Likely diagnoses:
- Tension-type headaches: These are common in young adults and can be triggered by stress, physical activity, or other factors. The description of dull, occipital headaches could fit this diagnosis, although the presence of nausea and dizziness is less typical.
- Exertional headaches: These are headaches brought on by physical activity and could explain the patient's symptoms. However, they are usually more severe and shorter-lived.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Subarachnoid hemorrhage: Although the patient's symptoms do not strongly suggest a hemorrhagic stroke (e.g., no sudden, severe headache, no focal neurological deficits), this diagnosis must always be considered due to its high morbidity and mortality.
- Brain tumor: Any new or worsening headache pattern, especially if accompanied by other symptoms like nausea and dizziness, warrants consideration of a space-occupying lesion, despite the lack of focal neurological signs.
- Arteriovenous malformation (AVM): Similar to subarachnoid hemorrhage and brain tumors, AVMs can present with headaches and would be catastrophic if missed.
- Rare diagnoses:
- Chiari malformation: This condition involves a structural defect in the cerebellum that can cause increased intracranial pressure and symptoms similar to those described, especially with coughing or straining.
- Pseudotumor cerebri syndrome (PTCS) secondary to another condition: While IIH is considered, other causes of increased intracranial pressure without a mass lesion (e.g., due to certain medications, vitamin deficiencies) should also be entertained, though they are less common.