Differential Diagnosis for 82-year-old Male with Sudden Onset of Headache and Speech Difficulty

The patient's presentation of sudden onset headache, difficulty speaking clearly, and disorientation suggests a neurological cause. The differential diagnosis can be categorized as follows:

• Single most likely diagnosis
  • Acute Ischemic Stroke: The sudden onset of speech difficulties (aphasia) and disorientation in an elderly patient strongly suggests an acute ischemic stroke. The lack of other symptoms such as weakness or numbness does not rule out this diagnosis, as strokes can present with isolated cognitive or speech deficits.
• Other Likely diagnoses
  • Intracranial Hemorrhage: Although less common than ischemic stroke, intracranial hemorrhage can present with sudden headache and neurological deficits, including speech difficulties.
  • Transient Ischemic Attack (TIA): A TIA, often referred to as a "mini-stroke," can present with similar symptoms to an ischemic stroke but typically resolves within 24 hours. However, TIAs are a warning sign for a future stroke and require prompt evaluation.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Meningitis: Although less likely given the absence of fever or neck stiffness, meningitis can present with sudden onset of headache and altered mental status, including disorientation and speech difficulties.
  • Subarachnoid Hemorrhage: This condition, often due to aneurysmal rupture, can present with a sudden, severe headache (often described as "the worst headache of my life") and may be accompanied by neurological deficits.
  • Status Epilepticus (post-ictal state): If the patient had a seizure, the post-ictal state could present with confusion, disorientation, and speech difficulties.
• Rare diagnoses
  • Cerebral Venous Thrombosis: This condition can present with headache, seizures, and neurological deficits, including speech difficulties, but is less common than arterial strokes.
  • Encephalitis: Inflammation of the brain tissue can cause a variety of symptoms including headache, confusion, and speech difficulties, but is relatively rare.

Emergency Department Orders

Given the differential diagnosis, the following should be ordered in the emergency department:

• Immediate Neuroimaging: A non-contrast CT scan of the head to evaluate for hemorrhage, followed by a contrast CT or MRI if no hemorrhage is seen, to evaluate for ischemia or other abnormalities.
• Laboratory Tests: Complete blood count (CBC), basic metabolic panel (BMP), coagulation studies, and cardiac enzymes to evaluate for potential causes or contributors to the patient's condition.
• Electrocardiogram (ECG): To evaluate for cardiac causes of the patient's symptoms, such as atrial fibrillation, which could increase the risk of ischemic stroke.
• Neurological Consultation: Prompt consultation with a neurologist or neurosurgeon, depending on the initial findings, to guide further management and potential intervention.
• Speech and Cognitive Assessment: Formal assessment by a speech therapist or neurologist to better characterize the patient's speech difficulties and cognitive status.