Epileptic seizures associated with lactose intolerance in a child: A causal relationship?

In this paper, we report a case of a 5-year-old girl whose intractable seizures ceased after introduction of a lactose free diet. Because of epileptic seizures, antepileptic agents and vagal nerve stimulation treatment were applied to the patient, who had mental and motor retardation, over a period of 4 years. Despite treatments, seizures were refractory. An electroencephalogram showed a continuous pattern of generalized discharges briefly attenuated by short periods of suppression. A lactose tolerance test was performed and lactose intolerance was diagnosed. A lactose-free diet was given and after this diet was applied, no further seizures were seen. Galactose deficiency due to lactose intolerance might have been the cause of motor and mental retardation in this patient. We speculate that lactose intolerance should be considered in the differential diagnosis of intractable seizures. Early diagnosis of lactose intolerance may prevent motor and mental retardation.