Differential Diagnosis for Worsening Headache and Cranial Pressure

The patient's presentation of a worsening headache and sensation of cranial pressure, accompanied by visual disturbances such as "shooting lights," following a recent diagnosis of kidney infection and treatment with IV antibiotics, necessitates a broad differential diagnosis. The categories below outline potential causes, prioritized by likelihood and urgency.

• Single Most Likely Diagnosis

  • Idiopathic Intracranial Hypertension (IIH): Given the patient's symptoms of worsening headache, visual disturbances (including "shooting lights" which could be indicative of photopsia), and the absence of focal neurological deficits, IIH is a plausible diagnosis. The recent use of antibiotics, particularly those with potential side effects on intracranial pressure, could be a contributing factor, although the direct link is less clear.

• Other Likely Diagnoses

  • Viral Meningitis: Although the patient has been treated with antibiotics for a kidney infection, the possibility of a viral meningitis, which would not respond to amoxicillin, should be considered, especially given the headache and visual disturbances.
  • Sinusitis or Other Local Infections: Given the recent history of infection and the symptoms of headache and visual disturbances, sinusitis or other local infections spreading to involve the intracranial structures could be a consideration.
  • Medication-Induced Headache: The use of Tylenol and Advil for symptom relief could potentially contribute to medication-overuse headache, although this would be less likely given the acute onset and severity of symptoms.

• Do Not Miss Diagnoses

  • Subarachnoid Hemorrhage (SAH): Although the headache did not reach its maximum intensity immediately, SAH is a critical diagnosis that must be ruled out due to its high morbidity and mortality. The presence of "the worst headache" of the patient's life is a red flag.
  • Meningitis (Bacterial): Despite recent antibiotic treatment, bacterial meningitis could still be a consideration, especially if the treatment did not adequately cover the causative organism or if the infection has spread to the meninges.
  • Cerebral Venous Thrombosis (CVT): This condition can present with headache, visual disturbances, and can be associated with infections, dehydration, or other prothrombotic states. It is crucial to consider CVT due to its potential for severe outcomes if not promptly treated.

• Rare Diagnoses

  • Intracranial Abscess: As a complication of the recent infection, an intracranial abscess could present with headache, fever, and focal neurological signs, although the latter are not mentioned in this case.
  • Systemic Lupus Erythematosus (SLE) or Other Vasculitides: These conditions can cause a wide range of neurological symptoms, including headache and visual disturbances, but would be less likely without other systemic symptoms or a known history of autoimmune disease.

Workup in the ED

• Immediate Imaging: A non-contrast CT scan of the head to rule out hemorrhage, followed by an MRI if the CT is negative but clinical suspicion remains high for conditions like CVT or intracranial abscess.
• Lumbar Puncture (LP): If imaging does not show a contraindication, LP can help diagnose meningitis, subarachnoid hemorrhage (if CT is negative but suspicion remains), and measure opening pressures to assess for IIH.
• Blood Work: Complete blood count (CBC), blood cultures, and electrolyte panel to assess for signs of infection or other systemic abnormalities.
• Visual Field Examination: Formal visual field testing if possible, to further evaluate the visual disturbances.
• Neurological Examination: Repeated and detailed neurological examinations to monitor for any changes or development of focal deficits.