Neurodevelopmental Regression

Neurodevelopmental regression is loss of previously acquired skills. Unlike developmental delay, regression strongly suggests acquired neurological disease, neurodegeneration, metabolic disease, epileptic encephalopathy or severe psychosocial pathology and warrants urgent evaluation.

Loss may involve:

• Language
• Motor abilities
• Social interaction
• Continence
• Feeding skills
• Cognitive performance

Associated seizures, movement disorder, ataxia, visual loss or progressive weakness help localize the process.

• Confirm true loss of previously mastered skills.

• Obtain detailed developmental timeline and family history.

• EEG is required when epileptic encephalopathy is possible.

• MRI brain is often appropriate.

• Consider metabolic testing including lactate, ammonia, plasma amino acids and urine organic acids when metabolic disease is suspected.

• Genetic testing is increasingly central in unexplained regression.

Management is cause specific.

Treat reversible causes urgently, including seizures, metabolic decompensation, hypothyroidism, vitamin deficiency or CNS infection.

Provide multidisciplinary developmental support while diagnosis proceeds.

Progressive regression requires paediatric neurology involvement.