Stimulant Refractory ADHD Linked to Frontal Lobe Epilepsy and Nicotinic Acetylcholine Receptors : A Case Study

Background: Recent epidemiological and clinical studies have shown that children with frontal lobe epilepsy exhibit a high incidence of ADHD as well as a higher lifetime prevalence of ADHD compared to children without epilepsy. Genetic components linked to Alpha7 Nicotinic Acetylcholine Receptor Subunit (CHRNA7) abnormalities may be involved in conferring susceptibility to both ADHD and epilepsy.

Objectives : To present two siblings exhibiting stimulant refractory ADHD due to underlying comorbid frontal lobe epilepsy confirmed through EEG and associated with 15q13.3 microdeletion.

Case Presentation : A pair of siblings were diagnosed with stimulants refractory ADHD presenting with increased eye blinking, facial contracture, chewing and swallowing behaviors, microabsences mistaken for day dreaming. A maternal history of epilepsy (grandmother) combined with the symptoms described above, led us to suspect frontal lobe seizures, confirmed with basic Electroencephalogram. In depth genetic analyses conducted with CGH microarray confirmed a 15q13.3 microdeletion encompassing CHRNA7 gene in the mother and two out of her three siblings all showing ADHD and/or frontal lobe epilepsy. Adequate antiepileptic drugs controlling the seizures lead then to successfully treat the ADHD symptoms with psychostimulants.

Conclusion : In this case study, decreasing the seizure threshold while treating ADHD with psychostimulants uncovered an underlying epileptic comorbidity. Treating the underlying epilepsy did not eliminate the ADHD but gave us access to better control. The disclosure of the CHRNA7 abnormality associated with the epilepsy and ADHD emphasizes the increasingly recognized importance in the scientific literature of nicotinic acetylcholine receptors in neuropsychiatric disorders.