OBJECTIVEWernicke's encephalopathy (WE) is an acute neuropsychiatric syndrome resulting from thiamine deficiency, which is associated with significant morbidity and mortality. The disorder is still greatly underdiagnosed in children because of either a relatively non-specific clinical presentation in some cases or unrecognized clinical setting. The aim of this literature review was to provide knowledge of pediatric WE in an effort to assist in early diagnosis, thereby reducing the morbidity and mortality.

METHODSThe clinical manifestations, characteristic magnetic resonance imaging (MRI), diagnosis and treatment of one case and the other 35 cases reported in the last decade in children were summarized.

RESULTSThirty-six cases (22 boys and 14 girls, 2-month to 16-year-old) were analyzed. All the other 35 cases except for our case had underlying diseases: improper feeding in 25/35 cases, long-time vomiting in 5/35 cases, immunosuppressive therapy in 4/35 cases, long-time total parenteral nutrition without multivitamin preparations supplementation in 3/35 cases and anorexia nervosa in 1/35 case. The classic triad (mental-status changes, nystagmus and ophthalmoplegia, and ataxia) was seen in 6/36 cases. The other clinical manifestations included consciousness disturbance in 24/36 cases, infection in 22/36 cases, pathological reflex and muscular tension changes in 18/36 cases, convulsion in 17/36 cases, developmental delay in 4/36 cases and failure to thrive in 2/36 cases. Cerebrospinal fluid examination was performed in 31/36 cases, and a slightly raised protein concentration was seen in 7/31 cases. The cerebrospinal fluid lactate levels were detected in 4/36 cases (all increased), serum lactic acid levels in 7/36 cases (6/7 cases increased), serum pyruvate in 4/36 cases (all increased), thiamine pyrophosphate effect (TPPE) in 9/36 cases (all increased), and serum thiamine in 2/36 cases (increased in 1/2 cases). The brain computed tomography (CT) scan was conducted in 20/36 cases and 16/20 cases showed abnormal hypodensity in bilateral basal ganglia, one case revealed diffuse cortical atrophy. The brain MR scan was conducted in 13/36 cases and all the 13 cases revealed symmetrical abnormal signal in bilateral mamillary body and basal ganglia, and 7/13 cases showed abnormal signals in the tegmentum of midbrain, cerebral aqueduct and white matter around the third and fourth ventricles. The diagnosis of WE was confirmed by MR in 12 cases, triad combined with MR in 3 cases, autopsy in 1 case among the 13 cases who underwent MR scan. The diagnosis of WE was confirmed by the TPPE and/or lactate levels in 9/11 cases. The initial thiamine was given by intravenous or intramuscular infusion in 33/36 cases, unknown method in 1 case, orally in 1 case and no thiamine was used in 1 case. The dosage of thiamine was 100 mg daily in 29/35 cases, unknown in 3/35 cases, 50 mg daily in 2/35 cases, 600 mg daily in 1/35 case. 34/35 patients' clinical symptoms improved during 24 hours to 1 week after initial treatment, and 1 case died due to no response to thiamine. Nineteen patients were followed up for 2-2.5 months and 17 cases recovered completely.

CONCLUSIONWernicke's encephalopathy can be difficult to diagnose because of a relatively non-specific clinical presentation. The characteristic MRI findings and the dramatic response of neurological signs to parenteral thiamine will assist early clinical diagnosis. Early and timely thiamine supplementation could reverse the clinical features and improve the prognosis in most cases.