Omphalitis

Disease Description (Causes and Symptoms)

Encephalitis is an acute or subacute inflammatory disease of the brain parenchyma. Depending on the cause, it is classified as primary (mainly direct invasion by viruses) or secondary (spread to the brain following an infection in another area). Its pathophysiology involves pathogens (viruses, bacteria, fungi, etc.) or an immune-mediated response causing inflammation in brain tissue, resulting in neuronal damage, cerebral edema, and focal neurological deficits.

Major Causes

• Viruses: herpes simplex virus (HSV), varicella-zoster virus, arboviruses (including JE), enteroviruses, Epstein-Barr virus (EBV), cytomegalovirus (CMV), etc.
• Bacterial causes (mainly in the form of meningoencephalitis or secondary infection): Streptococcus pneumoniae, Neisseria, Escherichia coli, Listeria, etc.
• Others: Mycobacterium tuberculosis, fungi, parasites, HIV, immune-mediated causes (autoimmune encephalitis)
• Risk factors: older age, immunocompromised status, recent head trauma or brain surgery, neonates

Major Symptoms

• Acute fever, headache, chills, vomiting, lack of energy
• Altered consciousness (stupor or coma), mental confusion, behavioral changes, disorientation
• Seizures, focal neurological deficits (hemiplegia, speech impairment), neck stiffness (meningeal irritation symptoms may also occur)
• Children: bulging fontanelle, etc.
  Important diagnostic tests include brain MRI (to identify the location of lesions), cerebrospinal fluid testing (LP; cell count, protein, glucose, PCR, and culture), blood tests, and electroencephalography (EEG).

Treatment Methods and Precautions

The goals of treatment are to eliminate the cause, control cerebral edema, seizures, and systemic complications, and minimize neurological sequelae.

General Treatment Principles

• Immediate supportive care: fluid and electrolyte correction, respiratory and hemodynamic monitoring (ICU admission in severe cases)
• Empirical antiviral therapy: when HSV is suspected, administer intravenous acyclovir immediately (start without waiting for test results)
• Antibiotics: administer broad-spectrum antibiotics when a bacterial cause is suspected (e.g., ceftriaxone + vancomycin ± ampicillin [considering Listeria])
• Antiseizure medication: administer when seizures occur or when there is a risk of recurrent seizures (e.g., levetiracetam)
• Steroids: considered for certain immune-mediated or vasculitic encephalitis cases. They are generally not used routinely in viral encephalitis (the decision depends on the cause).
• Surgery: drainage or surgery is required if a brain abscess is present
• Rehabilitation: early rehabilitation, including physical and speech therapy, is important for neurological recovery

Precautions and Self-Care

• If fever, headache, vomiting, clouding of consciousness, or other symptoms worsen, visit the emergency room immediately
• Do not use aspirin in children (risk of Reye syndrome)—acetaminophen is preferred for reducing fever
• Complete the prescribed course of antiviral or antibiotic treatment as directed by the doctor
• During recovery, fatigue, reduced concentration, and cognitive impairment may persist for a long time; follow the doctor's instructions regarding strenuous activities, driving, and operating important machinery

Complications (Possible)

• Respiratory failure, coma, death
• Cognitive impairment (memory), speech impairment, ataxia or hemiplegia, visual or hearing impairment, chronic epilepsy (seizures)

Prognosis

• The prognosis varies depending on the cause (e.g., the prognosis of HSV encephalitis is poorer when treatment is delayed), age, level of consciousness at the initial examination, and whether treatment was started early. Some people recover completely, while others are left with permanent neurological sequelae.

Prevention

• Vaccination (MMR, varicella, Japanese encephalitis, etc.), mosquito avoidance (for arboviruses), prevention of neonatal infection (maternal care), hand hygiene

Checklist Before an Outpatient Visit (Examples of Items to Bring and Questions)

Items to Bring

• A list of currently used medications (including prescription drugs, nonprescription drugs, and supplements)
• Medical history (recent infections, head trauma, brain surgery, immunocompromised status, vaccination history)
• Recent test results (copies of CT/MRI, blood tests, and cerebrospinal fluid test results, if available)
• The time symptoms began and their progression (temperature changes, whether seizures occurred, changes in consciousness, etc.)
• Recent travel history (epidemic areas, history of mosquito bites), contact with animals, etc.

Key Information to Tell the Doctor at the Outpatient Visit (Example Questions)

• The time symptoms began and how they progressed (suddenly/gradually)
• Whether fever, seizures, or decreased consciousness are present, and their frequency
• Whether antibiotics or antiviral drugs were recently taken
• Whether the patient is pregnant (for women); for children, birth history and vaccination status

Examples of General Questions to Ask the Doctor

• What additional tests should be performed for this cause? (MRI, LP, PCR, etc.)
• What medications are you planning to start as part of the current treatment? What are the expected effects and side effects?
• How do you determine whether hospitalization or ICU treatment is necessary?
• After recovery, when can normal activities (driving, returning to school or work, exercise) be resumed?
• Is there a risk of recurrence, and what measures should be taken for prevention?

Examples of Disease-Specific Questions

• If HSV encephalitis is suspected: "The HSV PCR result is negative. Can acyclovir be discontinued, and how is the treatment duration (e.g., 14–21 days) determined?"
• Regarding the recovery period and sequelae: "I had one seizure. How long should I continue taking antiseizure medication? What are the criteria for discontinuing it?"