Conditions Mimicking Cerebral Palsy: Meningitis, Encephalitis, and Other Neurologic Disorders

Several neurologic conditions can produce motor impairments resembling cerebral palsy (CP). Accurate differentiation is critical because many are treatable or have distinct prognoses.

Key Mimics

Infectious/Inflammatory

• Meningitis: Bacterial or viral infection of meninges → seizures, developmental delay, spasticity, cranial nerve palsies. Acute onset with fever, nuchal rigidity.
• Encephalitis: Brain parenchymal infection (e.g., HSV, enterovirus) → similar motor/cognitive deficits. May follow viral prodrome.
• CNS abscess or granuloma: Focal mass effect causing hemiparesis.

Vascular

• Perinatal Stroke: Arterial ischemic stroke or sinovenous thrombosis → hemiplegic CP phenotype. Often diagnosed retrospectively.
• Intracranial hemorrhage: Germinal matrix hemorrhage (preterms) → spastic diplegia/hemiplegia.

Traumatic

• Non-accidental trauma / abusive head trauma: Subdural hemorrhage, diffuse axonal injury → motor delay, spasticity, seizures.

Metabolic/Genetic

• Mitochondrial disorders: Leigh syndrome, MELAS → progressive encephalopathy, dystonia, ataxia.
• Urea cycle disorders, organic acidemias: Episodic hyperammonemia → neurologic regression.
• Leukodystrophies: Metachromatic leukodystrophy, Krabbe disease → progressive spasticity, cognitive decline.
• Hereditary spastic paraplegias (HSP): Pure or complex spasticity, often later onset.
• Dopa-responsive dystonia (Segawa syndrome): Diurnal fluctuation, dramatic response to levodopa.

Genetic Syndromes with CP-like Features

• Rett syndrome (MECP2), Angelman syndrome, Fragile X, chromosomal microdeletions.

Toxic/Environmental

• Kernicterus (bilirubin encephalopathy) → choreoathetosis, hearing loss, gaze palsy.
• Heavy metal poisoning (lead, mercury).

Diagnostic Approach

• Detailed prenatal/perinatal history
• Neuroimaging (MRI brain/spine)
• Metabolic screening (lactate, ammonia, amino acids, acylcarnitines)
• Genetic testing (chromosomal microarray, targeted panels, exome sequencing)
• EEG if seizures suspected

Early distinction enables disease-specific therapy (e.g., levodopa for dopa-responsive dystonia, immunosuppression for autoimmune encephalitis, metabolic diet) and accurate genetic counseling.