We assessed the clinical characteristics and efficacy of
neurotransmitters and
levetiracetam in a patient with hyperphenylalaninemia due to
dihydropteridine reductase (
DHPR) deficiency who developed epileptic
seizures. A boy with
DHPR deficiency, who had been successfully treated with
tetrahydrobiopterin (BH4),
levodopa, and
5-hydroxytryptophan (5-HTP) since he was 2 months old, started having monthly episodes of blurred vision,
loss of consciousness, and falls at the age of 12 years. He was taking BH4 510 mg/day,
levodopa 670 mg/day,
5-HTP 670 mg/day, and
entacapone 300 mg/day. We evaluated the seizure semiology, EEG findings, and efficacy of
levodopa,
5-HTP, and
levetiracetam (LEV). His
seizures were comprised of an abrupt loss of awareness and eye deviation to the right. Interictal EEG showed slightly slow posterior-dominant rhythm in 7-8 Hz; intermittent, irregular slowing in the bilateral parieto-occipital region; and multiregional independent spikes in bilateral hemispheres. Ictal EEG showed a seizure pattern starting at the left temporal region. Brain MRI showed diffuse signal increase of deep white matter on T2-weighted and FLAIR images. Dosage increase of
levodopa to 1340 mg/day, of
5-HTP to 1500 mg/day, or of both did not suppress
seizures.
Levetiracetam 2000 mg/day markedly reduced
seizures without any adverse events. Patients with
DHPR deficiency can develop epileptic
seizures of partial onset which can be successfully and safely treated with LEV.