A 7 year old boy presents with worsening restlessness, and difficulty in concentrating for 18 months. His parents also complain that he is often forgetful of his daily activities.
His year end report reveals significant deterioration of school grades, and difficulty in maintaining attention while playing. On several occasions, his teachers had noticed him to be immobile and staring straight ahead, and apparently unaware of what was happening in class.
He has been attending a new school since the family moved house a year ago. His medical, surgical, developmental and family histories are unremarkable. He is not on any medications.
A complete blood count, serum electrolyte assay, and liver and renal profiles are all within normal parameters.