Mental status changes in children with systemic cancer

Mental status changes are second only to headaches as a cause of neurologic consultation in children with systemic cancer, but the literature on these patients is sparse. This study consisted of a review of the consultations because of changes in mental status in patients with pediatric cancer, with analysis of clinical presentation, etiology, underlying cancer, and neuroradiologic findings. Hematologic cancers were the underlying disorder in slightly more than one half of the patients. The majority of children suffered from iatrogenically induced encephalopathy, predominantly opioid-related. Several drugs were associated with depressed sensorium, but a pure metabolic deficit was rare. One third of the patients had multiple causative factors. Neuroimaging studies were particularly helpful in children with unexplained somnolence but were less useful if the patient had hallucinations. The absence of localizing signs in children with unexplained somnolence or stupor did not exclude the presence of structural disease. Altered mental status is frequently observed in children being actively treated for systemic cancer. The majority of children suffer from iatrogenically induced encephalopathy, predominantly opioid-related. The presence of hallucinations favors a toxic-metabolic dysfunction, especially if associated with myoclonus. Under those circumstances a neuroimaging study is usually unrewarding. If the main complaint is unexplained somnolence without hallucinations or delusions, the performance of a brain imaging study is mandatory, even in the absence of localizing signs.