Differential Diagnosis for the 55-year-old Female Patient
Single Most Likely Diagnosis
- Subarachnoid Hemorrhage (SAH): The patient's sudden onset of severe headache (worst headache of life), stiffening of hands, and loss of consciousness after a stressful event (arguing on the phone) are classic symptoms of SAH. Although the initial CT scan did not show bleeding, SAH can sometimes be missed on initial imaging, especially if the bleed is small or the scan is done very early after the event.
Other Likely Diagnoses
- Seizure Disorder: The patient's initial presentation with stiffening of hands and loss of consciousness could be indicative of a seizure. The improvement in her condition and the presence of frontal and occipital headache could be post-ictal.
- Hypertensive Encephalopathy: The patient's high blood pressure (150/100) and severe headache could suggest hypertensive encephalopathy, especially if there is evidence of cerebral edema or posterior reversible encephalopathy syndrome (PRES) on imaging.
- Acute Stroke (Ischemic or Hemorrhagic): Although the initial CT scan did not show infarct or bleeding, acute stroke cannot be completely ruled out without further imaging (e.g., MRI) or repeat CT scans.
Do Not Miss Diagnoses
- Intracranial Aneurysm or Arteriovenous Malformation (AVM): These conditions can cause SAH or other types of intracranial bleeding and are critical to diagnose due to their high morbidity and mortality if ruptured.
- Meningitis or Encephalitis: Infection can cause severe headache, altered mental status, and focal neurological deficits, making it crucial to consider and rule out with appropriate tests (e.g., lumbar puncture).
- Cervical Spine Injury: The patient's loss of consciousness and current neurological deficits (weakness in lower extremities) could be indicative of a cervical spine injury, especially if there was trauma involved (e.g., car accident).
Rare Diagnoses
- Reversible Cerebral Vasoconstriction Syndrome (RCVS): This condition can cause severe headache and is often associated with vasoconstriction of cerebral arteries, which can lead to ischemic or hemorrhagic strokes.
- Cerebral Venous Sinus Thrombosis: This rare condition can cause headache, altered mental status, and focal neurological deficits due to thrombosis of the cerebral venous sinuses.
- Pituitary Apoplexy: Sudden hemorrhage or infarction of the pituitary gland can cause severe headache, altered mental status, and neurological deficits, although it is a rare condition.