Reversible Splenial Lesion Syndrome Induced by Paracetamol and Lithium: A Report of Two Cases and Literature Review

Reversible splenial lesion syndrome (RESLES) is a rare neurological syndrome characterized by a reversible lesion in the splenium of the corpus callosum (SCC). Various etiologies, such as infection, high-altitude cerebral edema, seizures, antiepileptic drug withdrawal, and metabolic abnormalities, are involved in the development of RESLES. However, few studies have reported drug-induced cases of this disorder, especially those induced by paracetamol, which have not been previously documented. Firstly, a 50-year-old man with neuropsychiatric symptoms who was taking an overdose of paracetamol was referred to our hospital. Laboratory tests revealed elevated levels of liver enzymes and creatine kinase, with no signs of infection. The patient fully recovered after eight days of symptomatic treatment. Secondly, a 35-year-old female was taking 1750 mg/day lithium, 500 mg/day quetiapine, and 500 mg/day magnesium valproate for bipolar disorder (BD). She experienced generalized tremors, rigidity, and dysarthria, along with high fever, hypertension, tachycardia, and tachypnea. Her blood lithium level was 1.46 mmol/L, and her valproic acid (VPA) serum concentration was 27.00 mg/L. The patient fulfilled the diagnostic criteria for neuroleptic malignant syndrome (NMS). Symptoms and brain lesions completely resolved two weeks after discontinuing lithium and quetiapine. Both patients' cerebral magnetic resonance imaging (MRI) typically demonstrated a reversible lesion with transiently reduced diffusion in the SCC. RESLES is usually detected incidentally and is easily neglected. Our report suggests that RESLES should be considered in patients exhibiting neuropsychiatric symptoms, particularly those accompanied by taking medicine irregularly.