Type 1 lissencephaly and multiple afebrile seizures in a 2-month-old baby.

Case Report

A 2-month-old baby boy was brought to the Neurology Department following an abnormally high number of generalized seizures he experienced, both when awake and in his sleep (over 10 times per 24 h for 10 days). Each seizure lasted for 1–2 min. Upon admission, he was administered 0.25 mg/kg of intravenous (IV) diazepam. Electroencephalography test showed that this patient had an abnormal wave brain pattern (epilepsy). Five days later, we started 1.30 mg/kg/day Topamax because IV diazepam was unable to effectively control the seizures. He was a term baby from nonconsanguineous parents (father 34 and mother 32 years old) and was healthy at birth (Apgar scores of 8 and 9). None of the parents has neurological disorders. This is a good case of lissencephaly type 1 (classic type) as revealed by the patient's brain magnetic resonance imaging (MRI) [Figure 1a–c]. Besides, the diagnosis of lissencephaly was detected on antenatal ultrasound at 34 weeks of gestation.

Figure 1

T2-weighted magnetic resonance imaging (MRIs) of patient. Sagittal MRI (a) and axial MRI (b) showing a smooth maldeveloped, greatly thickened brain and broad distribution of gray matter throughout. Extremely diminished volume of white matter can be noticed with enlargement of lateral ventricles in c, (arrows - right 14.39 mm and left 15 mm)

Discussion

Lissencephaly is a rare severe congenital cortical disorder in which abnormal organization of cortical layers occurs during embryogenesis.[1] There are two types of lissencephaly: Type 1 and type 2. Type 2 presents with the clinical features described as epileptic seizures, mental retardation, and developmental delay. This case report, however, is about type 1. To our knowledge, few cases of lissencephaly have been reported in China. Diagnosis is based on radiological images of the brain (MRI, computed tomography) or a more specialized genetic test known as fluorescence in situ hybridization for chromosomal testing.[1] Pinard et al. found that lissencephaly is genetically X-linked (recurrence in siblings within the same family) or chromosome 17-linked.[12] In a study by Saillour et al., conducted on a group of 63 patients, median life expectancy was found to be 6 years.[3] Prognosis of such patients is based on the severity of the brain malformation.[1] Previous researches showed that babies suffering from lissencephaly, in addition to seizures, also display mild to moderate retardation, failure to thrive, muscle spasticity, developmental delay, and slight to profound cognitive impairment.[12] Other symptoms may include unusual facial appearance, hands or toes malformation and difficulty in swallowing.[12] No cure exists for lissencephaly, but supportive care like anti seizures and gastrostomy tube insertion for feeding difficulties may be provided if such complications are encountered. MRI should be performed in parents or siblings who present with epilepsy or mental retardation because it provides detailed cortical anatomy, superb gray-white matter distinction, and thereby clearly reveals detailed structural changes of the brain.[2]