Case report review suggests LAI paliperidone stabilizes behavior in a 9-year-old with TBI over two years

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Frontiers in Medicine Published April 29, 2026 Medically reviewed April 29, 2026 DOI ↗ By Dr. Ji-eun Park, MD · Brain, Mind & Pain

Key Takeaway

Consider LAI paliperidone for severe PTCS behavioral dysregulation when oral adherence fails in pediatric TBI.

This source is a case report review focusing on a single 9-year-old boy with severe traumatic brain injury and posttraumatic confusional state. The patient received long-acting injectable paliperidone palmitate with adjunct nightly risperidone after failing multiple oral agents including risperidone, methylphenidate, olanzapine, and aripiprazole. Follow-up lasted two years. The authors synthesize findings showing aggression markedly decreased and functional status improved from Rancho Los Amigos Level IV to Level VIII. Secondary outcomes included intellectual ability and executive dysfunction. Safety data indicate weight gain and asymptomatic hyperprolactinemia occurred, but no extrapyramidal or cardiac events were observed. Tolerability was characterized by limited adverse effects. The authors state that discontinuations were not reported. The review highlights that spontaneous recovery and developmental maturation cannot be excluded as potential contributors to the observed improvements. The authors emphasize that larger, controlled studies are needed to clarify the efficacy, safety, and long-term neurocognitive impact of LAI antipsychotics in pediatric TBI. Practice relevance is limited to the suggestion that LAI paliperidone can be a practical option to stabilize severe PTCS-related behavioral dysregulation when oral adherence fails. The certainty of these findings is constrained by the single-case nature of the evidence.

Study Details

Study typeSystematic review

EvidenceLevel 1

PublishedApr 2026

View Original Abstract ↓

Post-traumatic confusional state (PTCS) is a disabling sequel of pediatric traumatic brain injury (TBI), with little guidance on pharmacologic management when aggression and poor impulse control dominate and adherence is poor. We describe a 9-year-old boy with severe TBI who evolved from coma to a prolonged PTCS characterized by agitation, externalizing behaviors, and dysexecutive symptoms. Multiple oral agents—risperidone, methylphenidate, olanzapine, and aripiprazole—were trialed over several years with minimal benefit and poor adherence. Following an acute agitation episode in 2022, long-acting injectable (LAI) paliperidone palmitate was initiated (100 mg then 150 mg monthly) with adjunct nightly risperidone 2 mg. Over two years, aggression markedly decreased and functional status improved from Rancho Los Amigos Level IV (“confused–agitated”) to Level VIII (“purposeful–appropriate”). Cognitive testing at age 19 showed average intellectual ability but persistent executive dysfunction. Adverse effects were limited to weight gain and asymptomatic hyperprolactinemia; no extrapyramidal or cardiac events occurred. While spontaneous recovery and developmental maturation cannot be excluded, this case suggests LAI paliperidone can be a practical option to stabilize severe PTCS-related behavioral dysregulation when oral adherence fails. Larger, controlled studies are needed to clarify efficacy, safety, and long-term neurocognitive impact of LAI antipsychotics in pediatric TBI.