OVERVIEW

What is cerebral edema?

Cerebral edema is a pathophysiological process caused by various factors such as physical injuries (e.g., mechanical trauma, pressure damage) and biochemical changes, leading to secondary alterations in brain tissue ^[1].

Common symptoms include headache, nausea, vomiting, visual disturbances, impaired consciousness, speech difficulties, and paralysis. With active drug therapy and surgical intervention, symptoms can be alleviated, improving the patient's quality of life. Without timely or effective treatment, it may lead to brain herniation or even death.

Is cerebral edema common?

Cerebral edema is a clinically common neurological disorder caused by brain tissue damage, but specific epidemiological data are currently unavailable.

What are the classifications of cerebral edema?

1. Internationally, cerebral edema is classified into the following four types:

   • Cytotoxic cerebral edema: Water retention within cells causes swelling, but the blood-brain barrier remains intact ^[1].
   • Vasogenic cerebral edema: Disruption of the blood-brain barrier increases capillary permeability, allowing fluid leakage into the extracellular space ^[1].
   • Interstitial cerebral edema: Caused by impaired cerebrospinal fluid drainage.
   • Osmotic cerebral edema: Intracellular swelling due to changes in blood osmotic pressure and fluid shifts between intra- and extracellular spaces.

2. Based on the timing of onset, it can be divided into:

   • Early-onset cerebral edema: Refers to acute-onset cerebral edema ^[2].
   • Delayed cerebral edema: Refers to worsening edema occurring some time after hemorrhage ^[2].

SYMPTOMS

What are the symptoms and manifestations of cerebral edema?

• Headache: Pain in the head that worsens when lying flat, coughing, or sneezing.
• Vomiting: Projectile vomiting accompanied by nausea.
• Visual disturbances: Impaired vision, decreased visual acuity, etc.
• Consciousness disorders: Drowsiness (can be awakened), restlessness, lethargy (cannot be awakened by light tapping, only by painful stimuli), coma, etc.
• Language disorders: Slurred speech, difficulty expressing oneself clearly, and in severe cases, inability to speak.
• Triad of intracranial hypertension: Increased blood pressure, slowed heart rate, and slowed, deepened breathing.
• Paralysis: Limb movement disorders, numbness, and in severe cases, limb paralysis.
• Symptoms in infants and young children: Feeding difficulties, restlessness, head banging, bulging fontanelle, enlarged fontanelle, separation of cranial sutures, seizures (e.g., eye muscle twitching, drooling, repeated sucking, rowing-like limb movements, etc.).

What complications can cerebral edema cause?

Brain herniation: If cerebral edema is not treated promptly, it can compress normal tissue, causing displacement and leading to brain herniation. Symptoms include severe headache, frequent vomiting, and restlessness ^[1].

CAUSES

What are the common causes of cerebral edema?

• Brain diseases: Such as encephalitis, congenital cerebrovascular malformations, cerebral hemorrhage, etc., can all cause cerebral edema.
• Traumatic brain injury: Injuries such as blunt force trauma can lead to cerebrovascular damage and infection, resulting in cerebral edema.
• Brain tumors: Brain tumors compress surrounding tissues, causing brain tissue swelling and leading to cerebral edema.
• Poisoning: Conditions like organophosphate poisoning can reduce cerebral oxygen metabolism and blood flow, resulting in cerebral edema.
• Perinatal asphyxia and hypoxia: Fetal or neonatal asphyxia increases cerebral blood flow, leading to cerebral edema.

Who is commonly affected by cerebral edema?

• Patients with brain diseases: Those with conditions like encephalitis or cerebral hemorrhage are prone to cerebral edema.
• Brain tumor patients: Tumors compressing surrounding brain tissues cause swelling, making these individuals susceptible to cerebral edema.
• Patients with traumatic brain injury: Such individuals are at risk due to cerebrovascular damage and infection.

Is cerebral edema hereditary?

Cerebral edema is not hereditary ^[2].

DIAGNOSIS

How is cerebral edema diagnosed?

Doctors can diagnose cerebral edema through physical examination, blood tests, liver and kidney function tests, intracranial pressure monitoring, CT scans, and MRI scans.

What tests are needed to diagnose cerebral edema?

• Physical examination: Observe symptoms such as headache, nausea, and vomiting; use an ophthalmoscope to check for increased intracranial pressure; monitor infants for feeding difficulties or persistent crying to preliminarily diagnose cerebral edema.
• Blood tests: Measure white blood cell and platelet counts to detect infections or anemia, aiding in diagnosis and treatment planning.
• Liver and kidney function tests: Assess liver and kidney health to determine the cause and progression of cerebral edema.
• Intracranial pressure monitoring: Evaluates the severity of cerebral edema and treatment effectiveness.
• CT scan: Identifies the location and extent of cerebral edema and detects other brain abnormalities to support diagnosis.
• MRI scan: Determines the size, location, and tissue damage of cerebral edema, aiding in diagnosis and identifying underlying causes.

How to recognize cerebral edema in oneself or others?

Sudden unconsciousness, severe headache, vomiting, agitation, slurred speech, or paralysis on one side of the body may indicate cerebral edema. The most accurate clinical method is a head CT scan. Cerebral edema is complex and difficult to self-diagnose. If such symptoms occur, call emergency services immediately.

What diseases are easily confused with cerebral edema? How to differentiate them?

Cerebral hemorrhage: Both conditions share symptoms like headache, nausea, vomiting, and paralysis. However, cerebral hemorrhage may also cause irregular breathing, unstable pulse, and blood pressure. Cerebral hemorrhage can lead to cerebral edema. A CT scan can differentiate between the two.

TREATMENT

When should you seek medical attention for cerebral edema?

• If symptoms such as headache, nausea, or vomiting occur, further examination under a doctor's guidance is necessary;

• If vision declines, vision loss, or drowsiness occurs, prompt medical attention is required;

• If symptoms like lethargy or coma appear, immediate medical care is needed.

Which department should you visit for cerebral edema?

Cerebral edema can be treated in the neurology department; if surgical intervention is required, neurosurgery may be consulted; for consciousness disorders such as bleeding-induced coma, emergency care is necessary.

What are the treatment methods for cerebral edema?

The treatment principle is to promptly eliminate the cause of cerebral edema and hematoma after cerebral hemorrhage to relieve compression; effectively inhibit water infiltration into brain tissue and promote its expulsion, repair damaged brain function as soon as possible; and maintain stable vital signs and water-electrolyte balance.

1. General treatment:

   • Elevate the head of the bed to keep the head in a midline position, maximizing cerebral venous outflow and controlling increased intracranial pressure ^[1].

   • Hyperventilation can reduce carbon dioxide partial pressure in the blood, decreasing cerebral blood flow and alleviating cerebral edema symptoms ^[1].

2. Medication:

   • Hyperosmotic dehydrating agents: Such as mannitol, which can shift fluid from interstitial spaces into blood vessels, relieving symptoms. Suitable for cerebral edema patients but may cause adverse effects like heart failure, chills, or fever ^[1].
   • Bumetanide: Can reduce blood-brain barrier damage, cytotoxic edema, and neuronal necrosis. Suitable for cerebral edema patients but may cause fatigue, diarrhea, muscle cramps, or vomiting ^[1].
   • Dexamethasone: Can improve brain tissue and alleviate cerebral edema symptoms. Suitable for cerebral edema patients but may cause weight gain, lower limb edema, or muscle weakness ^[3].
   • Barbiturates: Such as diazepam, with sedative effects, suitable for infant cerebral edema patients but may cause drowsiness, mild headache, or fatigue ^[4].
   • Corticosteroids: Such as prednisone or methylprednisolone, which reduce capillary permeability and alleviate cerebral edema symptoms. Suitable for cerebral edema patients but may cause acne, hirsutism, or edema ^[4].
   • Calcium channel blockers: Such as nimodipine, which inhibit vasospasm and improve cerebral blood flow, alleviating cerebral edema symptoms. Suitable for cerebral edema patients but may cause bleeding, headache, or palpitations ^[5].

3. Surgical treatment:

   Decompressive craniectomy: Can relieve intracranial hypertension and brain compression, suitable for refractory cerebral edema but may cause bleeding or infection ^[6].

4. Mild hypothermia therapy: Reduces cerebral blood flow, decreasing water infiltration into brain tissue after hemorrhage, enhancing hypoxia tolerance, and alleviating cerebral edema while ensuring oxygen supply to hypoxic brain tissue and promoting recovery. Mild hypothermia typically maintains a temperature of 34–35°C but may cause shivering, hypertension, tachycardia, or tachypnea ^[1].

How long is the treatment cycle for cerebral edema?

Cerebral edema develops rapidly, appearing within 1–2 hours after cerebral hemorrhage and progressively worsening, peaking at 24 hours and subsiding after 4–5 days; or peaking around 3–4 days post-hemorrhage before gradually resolving ^[7].

Can cerebral edema be cured?

Yes, it can be cured. The cure rate varies depending on the cause. For example, cerebral edema caused by brain trauma can be cured after the trauma is resolved ^[8].

What happens if cerebral edema is not treated promptly?

If cerebral edema is not treated promptly, the condition may worsen, potentially leading to brain herniation or even death, severely impacting the patient's quality of life and endangering their life.

DIET & LIFESTYLE

What should patients with cerebral edema pay attention to in their diet?

• Eat more fresh vegetables and fruits rich in fiber, such as leeks, celery, bananas, and kiwis, to supplement vitamins and strengthen physical fitness.

• Consume high-protein foods, such as eggs and lean meat, to promote recovery.

What should patients with cerebral edema pay attention to in daily life?

• Take medication as prescribed: Follow the doctor's instructions strictly, and do not increase, reduce, or stop medication without authorization.
• Maintain a regular routine: Keep a consistent sleep schedule, wake up early, eat meals on time, rest adequately, and avoid overexertion and emotional stress.
• Sleep in a lateral position: Patients in the acute phase of cerebral hemorrhage may vomit at any time. Sleeping on the side can prevent choking caused by vomit.
• Engage in moderate exercise: Patients with functional impairments should perform daily limb exercises. For those with aphasia, language rehabilitation training should be conducted alongside physical exercises.
• Maintain a positive mindset: Control emotions to avoid excessive fluctuations. Listening to light music can help relax the body and mind.
• Patients with cerebral edema may experience coma or paralysis and require long-term bed rest. Keep the room clean and tidy, and caregivers should turn the patient regularly and perform limb exercises to prevent bedsores and venous thrombosis.

Does cerebral edema require follow-up examinations? How are they conducted?

Yes, follow-up examinations are necessary. Typically, they are conducted once a month initially, and once every three months after the condition stabilizes. A head CT scan is required during follow-ups to monitor intracranial pressure and assess disease progression and treatment effectiveness.

PREVENTION

Can Cerebral Edema Be Prevented? How to Prevent It?

• Enhance safety awareness. High-risk workers should take protective measures, follow traffic rules, avoid running red lights, wear seat belts while driving, and prevent head injuries.
• Actively treat diseases that may cause cerebral edema, such as encephalitis and meningitis, to avoid their progression.
• Schedule regular health check-ups to detect potential illnesses early and ensure timely treatment.
• Engage in moderate physical exercise to strengthen the body and improve resistance to viruses and diseases.