Soru

A $6$-month-old boy is brought to the clinic by his parents due to abnormal movements. Over the past $2$ weeks, he has had multiple episodes daily where he suddenly bends his head and trunk forward while stiffening his arms. These episodes occur in clusters, most often just after waking up from a nap. The parents are also highly concerned about his development because he has not yet begun to crawl or pull himself to a stand, though he rolls over in both directions and babbles. Vital signs are within normal limits. Neurologic examination shows a slightly hypotonic infant. Skin examination reveals three $2\text{-cm}$, elliptical, hypopigmented macules on his trunk that are accentuated under a Wood lamp. Laboratory studies show a thyroid-stimulating hormone (TSH) level of $2.5\ \mu\text{U/mL}$ and a free T4 of $1.2\ \text{ng/dL}$. An electroencephalogram demonstrates a high-voltage, chaotic, slow-wave background with multifocal spikes. Which of the following is the most appropriate next step in management?