In October 2013, a 3-year-old female presented to the Children’s Hospital of Orange County (CHOC Children’s) with seizures. Her seizures were characterized by behavioral arrest, with her right arm and leg extending straight and stiffening. Seizures lasted up to 20 seconds and occurred several times daily.
Nearly 2 years prior at 13 months of age, the patient had a spontaneous intraparenchymal intracranial hemorrhage due to cerebral arteriovenous malformation (AVM). She was treated with sodium valproate despite having no clinically-overt seizures, and was weaned off the medication after several months. The hemorrhage led to right-sided hemiparesis, but she responded well to therapy.
After experiencing seizures 2 years later, the patient was diagnosed with symptomatic localization-related epilepsy characterized by complex partial seizures. Antiepileptic medication, divalproex sodium, was started.
An initial electroencephalogram (EEG) revealed left hemisphere slowing and epileptiform discharges in and near the left temporal head region. In addition, a brain MRI revealed extensive cystic encephalomalacia of the left cerebral hemisphere with associated Wallerian degeneration, as well as multifocal areas of old hemorrhage that were most extensive in the left frontal lobe.
Image: The EEG demonstrates an active interictal pattern, with prominent interictal epileptiform discharges in the left hemisphere, maximum in the left temporal region. It also demonstrates attenuation and slowing of the background activities over the entire left hemisphere.
A cerebral MRA and MRV both showed mild attenuation of the left middle cerebral artery with fewer left middle cerebral artery branch vessels, and no focal stenosis or evidence for residual arteriovenous malformation (AVM).
With breakthrough seizures continuing even with antiepileptic medication, the patient underwent 2, 6-day, long-term EEG video monitoring sessions in October and November 2013, respectively. Several clinical seizures were captured during these sessions, all with similar semiology: sudden stiffening with dystonic posturing of the right leg and foot, and extension of the right hand with claw-like dystonic posturing, often followed by subtle rhythmic clonic activity of the right upper arm, along with altered responsiveness.