Memantine as Adjunctive Therapy in Lennox–Gastaut Syndrome With Neuropsychiatric Comorbidity: A Case Report
Lennox–Gastaut Syndrome (LGS) is a severe childhood-onset epileptic encephalopathy characterised by multiple daily seizures of varying semiology, intellectual disability, and a characteristic electroencephalographic pattern. Neuropsychiatric comorbidities - including attention-deficit/hyperactivity disorder (ADHD), autistic spectrum manifestations, and learning difficulties - are well documented in this population. Management is challenging owing to poor seizure response to conventional antiepileptic medications and the complexity introduced by co-occurring psychiatric disorders. We report the case of a patient with LGS severely resistant to antiepileptic therapy and complicated by worsening ADHD symptoms. Following years of trialling multiple antiseizure medications with limited benefit, memantine was initiated alongside other medications and was associated with meaningful improvement in seizure frequency, cognition, and behavioural manifestations. ADHD medications were subsequently reintroduced, were well tolerated, and further improved the patient’s attention and behaviour. This case highlights a novel application of memantine - an agent most commonly used in the management of Alzheimer’s disease - and suggests its potential utility as adjunctive therapy for improving both seizure control and neuropsychiatric symptoms in patients with LGS. Further research is warranted to evaluate this therapeutic approach systematically.