Subarachnoid hemorrhage

• Disease description (causes and symptoms)

  • Definition summary: Subarachnoid hemorrhage (SAH) is a condition in which blood enters the space beneath the arachnoid membrane and on the surface of the brain. It is mainly caused by rupture of a cerebral aneurysm (a sac-like bulge). In rare cases, it may result from rupture of a cerebral arteriovenous malformation (AVM), trauma, bleeding disorders, or use of anticoagulants.
  • Pathophysiology: When acute bleeding caused by rupture of an arterial wall introduces blood into the subarachnoid space, it can cause increased intracranial pressure, vasoconstriction (vasospasm), hydrocephalus due to impaired cerebrospinal fluid absorption, inflammation, and electrolyte abnormalities, resulting in neurological damage.
  • Main symptoms
    • Sudden, extremely severe headache (“thunderclap headache”)
    • Vomiting, neck stiffness (nuchal rigidity), decreased consciousness, or coma
    • Focal neurological deficits (hemiplegia, sensory abnormalities, speech impairment)
    • Seizures (convulsions), difficulty breathing, syncope (including cardiac arrest)
    • Drooping eyelids, visual disturbances, etc.
  • Key diagnostic points (briefly): Non-contrast brain CT is performed first. If CT is negative but SAH is strongly suspected, lumbar puncture (cerebrospinal fluid examination) is performed, and CT/MR angiography (CTA/MRA) or digital subtraction angiography (DSA; catheter-based cerebral angiography) is performed to investigate vascular lesions.

• Treatment methods and precautions

  • Emergency care (initial management)
    • Stabilization of the airway, breathing, and circulation; correction of blood pressure, fluid status, and electrolytes
    • Consider reversal of anticoagulants or antiplatelet agents, if possible
    • Symptomatic treatment for pain, vomiting, and seizures
  • Early hemorrhage management and securing the bleeding source
    • If aneurysmal bleeding is suspected, the aneurysm should be secured as quickly as possible (surgical clipping or endovascular coiling) to reduce the risk of rebleeding. This is usually decided as early as possible (within several days, or within 24 hours depending on the patient's condition).
  • Prevention and treatment of vasospasm and delayed cerebral ischemia
    • Oral administration of nimodipine (e.g., 60 mg every 4 hours, usually for 21 days) — recommended for prevention of delayed ischemic neurological deficits.
    • If vasospasm occurs, induced blood pressure elevation to increase blood flow and pressure (hypertensive therapy), and, if necessary, endovascular balloon angioplasty or infusion of a local vasodilator.
  • Management of intracranial pressure and hydrocephalus
    • Drainage of cerebrospinal fluid through an external ventricular drain (EVD); decompressive surgery may be considered in severe cases.
  • Other
    • If seizures occur, administer anticonvulsants; preventive long-term use of anticonvulsants in asymptomatic patients is generally limited.
    • Prevention of complications such as infection and venous thromboembolism, and rehabilitation therapy (to promote neurological recovery).
  • Lifestyle management and precautions
    • During the early and intermediate stages after hemorrhage, avoid strenuous activity and lifting heavy objects, and limit activities that cause a sudden rise in blood pressure.
    • Do not smoke or drink excessively; manage blood pressure and lipid levels; consult the treating physician about the use of anticoagulants or antiplatelet agents.
    • Because the risk of early rebleeding after hemorrhage exists, maintain strict bed rest during outpatient or inpatient care and monitor for signs of bleeding.
  • Complications (important)
    • Rebleeding, ischemic cerebral infarction due to delayed vasospasm, acute or chronic hydrocephalus, seizures, electrolyte abnormalities (especially hyponatremia), infection, etc.
  • Prognostic factors
    • The amount of hemorrhage, level of consciousness (GCS at diagnosis), the patient's overall condition, the cause of the hemorrhage (aneurysm location and size), and whether appropriate treatment was provided early all affect the prognosis.

• Outpatient visit checklist (including recommended items to bring and sample questions)

  • Recommended items to bring
    • A list of all medications currently being taken (including prescription drugs, over-the-counter drugs, herbal medicines, and supplements), particularly whether anticoagulants or antiplatelet agents are being taken
    • Records of previous tests and imaging (CT, MRI, CTA, and DSA images and reports)
    • The time of onset and course of recent symptoms (time the headache began, pattern of changes, whether seizures occurred, etc.)
    • Blood pressure records and records of chronic diseases (hypertension, diabetes, hyperlipidemia)
    • Allergy history and records of previous surgeries and hospitalizations
    • Smoking cessation and alcohol-use status, and family history (cerebral aneurysms or cerebral hemorrhage)
  • Examples of questions to prepare for an outpatient visit (things to ask the doctor directly)
    • The onset and pattern of symptoms (when they began, how often they occur, and factors that relieve or worsen them)
    • Whether any of the medications currently being taken should be stopped or adjusted
    • Bringing copies of imaging or test results, if available, is recommended

• Examples of general questions to ask the doctor

  • What are the main side effects of this medication (e.g., nimodipine or an antihypertensive), and how should I respond if side effects occur?
  • How high is the risk of rebleeding, and what measures do you recommend to reduce it?
  • When can I return to daily activities (driving, work, exercise, etc.)? What activities should I avoid?
  • What is the schedule and duration of future follow-up examinations (imaging and neurological examinations)?

• Examples of disease-specific questions (1–2)

  • Regarding my aneurysm (if present): Considering its location, size, and shape, which is more appropriate—surgical clipping or endovascular coiling? Please explain the advantages and disadvantages of each method and the risks of recurrence and rebleeding.
  • I am currently taking an anticoagulant (or antiplatelet agent). How should it be managed before and after the future treatment plan (surgery/procedure)? (For example, the timing of discontinuation or reversal and assessment of bleeding risk.)

(Note: The information above is general and educational. Individual diagnosis and treatment should be determined according to the patient's condition in consultation with the treating medical team.)