Encephalitis

• Meningoencephalitis
• Acute disseminated encephalomyelitis

• 323.9 Unspecified cause of encephalitis, myelitis, encephalomyelitis

• G04.90 Encephalitis and encephalomyelitis, unspecified

• 5A: Primary Prevention/Risk Reduction for Loss of Balance and Falling
• 5C: Impaired Motor Function and Sensory Integrity Associated with Nonprogressive Disorders of the Central Nervous System – congenital origin or acquired in infancy or childhood
• 5D: Impaired Motor Function and Sensory Integrity Associated with Nonprogressive Disorders of the Central Nervous System – acquired in adolescence or adulthood
• 5I: Impaired Arousal, Range of Motion and Motor Control Associated with Coma, Near Coma, or Vegetative State

Description

• Infection of the brain parenchyma
• Most commonly results in infection of the entire brain, but some viruses attack specific nervous system structures

Essentials of Diagnosis

• May occur with meningitis; some overlap of signs and symptoms
• Two primary forms: viral and bacterial
• Post-infectious encephalitis: autoimmune reaction to systemic viral infection
• Causative factor must be identified to initiate appropriate medical treatment prior to physical therapy involvement
• Common forms include
  • Herpes simplex encephalitis (most common in adults: sporadic encephalitis)
  • Arboviral encephalitis
    • Most common epidemic forms: West Nile virus, Eastern and Western equine encephalitis, rabies

General Considerations

• Rapid differential diagnosis of encephalitis vs. meningitis should be made due to similarities of initial symptoms and response to medication
• Severity may progress over a period of 1 week; PT should monitor for changing neurologic signs and symptoms, refer accordingly

Demographics

• Approximately 20,000 cases of acute viral encephalitis are reported annually in the United States
• Death occurs in 5 to 20%
• All ages and genders susceptible; some forms more common in specific geographic locations

Signs and Symptoms

• Fever
• Headache
• Nuchal rigidity
• Vomiting
• General malaise
• Coma
• Cranial nerve palsy
• Hemiplegia
• Involuntary movements
• Ataxia

Functional Implications

• Inability to perform ADLs independently
• Loss of independent functional mobility
• Inability to perform age and education appropriate cognitive tasks
• Inability to execute fine and gross motor tasks independently

Possible Contributing Causes

• Increased risk to individuals who are
  • Immunosuppressed
  • Perinatal to early childhood period
• Prior meningitis

Differential Diagnosis

• Stroke
• Subdural empyema
• Cerebral abscess
• Cerebral venous thrombosis
• Septic embolism
• Meningitis

Laboratory Tests

• Cerebral spinal fluid testing
• Intracranial pressure

Imaging

• CT scan for detailed imaging
• MRI with gadolinium enhancement

Medications

• Antiviral agents
• Corticosteroids if cerebral edema present

• To ER if encephalitis suspected
• To neurologist during infection and for follow-up
• To physician for respiratory therapy if source of infection is pulmonary in origin
• To occupational therapist for ADL- and cognitive-retraining
• To social ...