Letter to the Editor: Management of Psychiatric Manifestations in a Case of Pediatric Posterior Reversible Encephalopathy Syndrome Due to Chemotherapy

To the Editor:

Posterior reversible encephalopathy syndrome (PRES) is a rare encephalopathic subtype with significant morbidity and mortality, yet much about its pathophysiology, diagnostics, and treatment remains unclear. PRES commonly presents with hypertension, seizures, and altered mental status, with MRI findings of edema in the parietal and occipital lobes. Distinct psychiatric manifestations of PRES include confusion, agitation, and visual disturbances. Case reports have linked PRES to pediatric cancers and use of cytotoxic agents, including intrathecal methotrexate and vincristine (Mittal et al. 2017). Lack of early intervention in PRES can lead to long-term neurologic deficits and even death (Tambasco et al. 2016).

In this study, we discuss a case of PRES successfully managed in a 10-year-old male with recently diagnosed acute lymphoblastic leukemia (ALL). The patient presented to the local university hospital emergency department with status epilepticus. Of note, he was diagnosed with ALL 5 weeks before admission and completed induction chemotherapy that included vincristine, daunomycin, polyethylene glycol-L-asparaginase, prednisone, intrathecal cytarabine, and intrathecal methotrexate. Hematologic remission was subsequently confirmed and he received another dose of intrathecal methotrexate. Two days later, the patient experienced a witnessed episode of status epilepticus. Seizure was aborted with midazolam 5 mg followed by lorazepam 5 mg and he was admitted to the pediatric intensive care unit for observation.

The patient continued to experience seizure events including intermittent staring episodes. He was initiated on levetiracetam and lorazepam 2 mg. Upon administration of lorazepam, the patient's seizure-like activity ceased and he responded appropriately to verbal stimuli. A routine electroencephalogram demonstrated continuous bilateral slowing with frequent spikes in multiple lobes, consistent with encephalopathy. Furthermore, MRI revealed edema and diffusion hyperintensity in the bilateral medial parietal–occipital lobes, supporting a diagnosis of PRES. He was started on lisinopril 5 mg to treat hypertension (BP 140/90). He also experienced intermittent anxiety and complained of worsening headaches, visual disturbances consisting of lines in his field of view, diplopia, blurred vision, and visual hallucinations.

Psychiatry was consulted to address new-onset delirium, irritability, and intermittent anxiety. Sublingual risperidone 0.125 mg every 8 hours as needed was initiated for periods of delirium, along with lorazepam 0.25 mg every 6 hours as needed for anxiety, agitation, and visual disturbances, and melatonin 3 mg at 8 pm to improve circadian rhythm. The patient significantly improved on this regimen, requiring only one dose of risperidone. He steadily improved over the following 6 days and was seizure free and neuropsychiatrically stable upon discharge. The patient was alert and oriented; his agitation resolved and he no longer experienced visual disturbances.

This case highlights PRES as a rare but potential complication of chemotherapeutics and the value of psychiatric intervention in minimizing morbidity. Some literature supports use of low-dose mixed dopamine serotonin receptor antagonists, particularly risperidone (due to its safety and efficacy in children), in children with cancer presenting with PRES or other CNS insults (Abrams et al. 2016). As demonstrated by this case, prompt use of antipsychotic at the onset of visual disturbances in pediatric PRES likely reduces patient morbidity of irreversible neurologic damage (de Laat et al. 2010). Further research must be done to clarify the role that mixed dopamine serotonin receptor antagonists should play in future cases of PRES in pediatric patients.