Periventricular heterotopia

The condition is first noticed when seizures appear, often during the teenage years. Characteristic nodules around the ventricles of the brain are then typically discovered when magnetic resonance imaging (MRI) studies are done. Patients usually have normal intelligence, although some have mild intellectual disability. Difficulty with reading and spelling has been reported in some girls with periventricular heterotopia. Less commonly, people with periventricular heterotopia may have more severe brain malformations, small head size (microcephaly), developmental delays, recurrent infections, blood vessel abnormalities, or other problems.^[1][2]

The X-linked form of periventricular heterotopia usually affects females because in males, the severity may cause death before birth. Additional features that have been reported in this form include heart anomalies, stomach immobility, strabismus, short fingers, and dyslexia.^[1]

The autosomal recessive form is severe and may cause severe developmental delay and seizures beginning in infancy.^[2] 

Periventricular heterotopia may also occur in association with other conditions such as Ehlers-Danlos syndrome (Ehlers-Danlos with periventricular heterotopia), which also results in extremely flexible joints, skin that stretches easily, and fragile blood vessels.^[1]

The following evaluations are recommended:^[1]

• Imaging exams of the brain to establish the diagnosis
• Evaluation by a neurologist
• Evaluation by a doctor specialized in epilepsy if seizures are present
• Psychiatric evaluation if necessary
• Magnetic resonance angiography (MRA) of the brain vessels, carotid arteries, and aorta because of the risk for stroke
• Evaluation by a cardiologist and either echocardiogram or a heart magnetic resonance imaging (MRI) because of the risk for aortic aneurysm
• Evaluation by a hematologist if findings suggest a bleeding diathesis.

Treatment of epilepsy generally follows principles for a seizure disorder caused by a known structural brain abnormality. Carbamezipine is most often used, because most people with this condition have focal seizures. However, the choice of antiepileptic drug may be selected based on side effects, tolerability, and efficacy.^[1]

It is recommended that people with the X-linked form of the condition have studies evaluating the carotid artery and an abdominal ultrasound, due to the risk for aortic or carotid dissection or other vascular anomalies.^[1]

Treatment may also include surgery for removal of the lesion and more recently, laser ablation guided with magnetic resonance.^[3][4]