B26.2 Mumps encephalitis

Name of the Condition

• Mumps encephalitis

Summary

Mumps encephalitis is a rare but serious complication of mumps, involving inflammation of the brain tissue. It typically occurs as a result of the mumps virus spreading to the central nervous system. The condition may present with neurological symptoms and requires prompt medical evaluation.

Causes

Mumps encephalitis is caused by the mumps virus, an RNA virus from the Paramyxoviridae family. The virus infects the brain, leading to inflammation. This complication arises when the virus crosses the blood-brain barrier during a mumps infection.

Risk Factors

• Lack of vaccination against mumps.
• Close contact with an infected individual.
• Immunocompromised states, such as HIV/AIDS or chemotherapy.
• Age, with adolescents and young adults at higher risk for complications.

Symptoms

• Altered mental status, such as confusion or disorientation.
• Seizures.
• Headache.
• Fever.
• Nausea or vomiting.
• Stiff neck (less common than in meningitis).

Diagnosis

Diagnosis is based on clinical presentation and confirmed through laboratory tests. Cerebrospinal fluid analysis may show elevated white blood cells or viral presence. Imaging, such as MRI or CT scans, can help assess brain inflammation. Serology tests for mumps antibodies may also be used.

Treatment Options

• Supportive care, including rest, hydration, and fever management.
• Anticonvulsants if seizures occur.
• Hospitalization for monitoring and management of neurological symptoms.
• No specific antiviral treatment is available for mumps encephalitis.

Prognosis and Follow-Up

Prognosis varies depending on the severity of inflammation and promptness of treatment. Most patients recover with appropriate care, though some may experience residual neurological effects. Follow-up includes monitoring for long-term complications and neurological function.

Complications

• Permanent neurological damage.
• Cognitive impairment.
• Seizure disorders.
• In rare cases, coma or death.

Lifestyle & Prevention

• Ensure vaccination against mumps, as it is the most effective preventive measure.
• Avoid close contact with individuals showing mumps symptoms.
• Practice good hygiene, such as handwashing, to reduce transmission risk.

When to Seek Professional Help

Seek immediate medical attention if experiencing severe headache, confusion, seizures, or other neurological symptoms during or after a mumps infection. Early intervention is critical to manage complications.

Tips for Medical Coders

When coding for mumps encephalitis, use the ICD-10-CM code B26.2. Document the clinical correlation between mumps infection and encephalitis, including any laboratory or imaging results that confirm the diagnosis. Ensure the code is supported by clear medical record documentation of neurological involvement.