Focal cortical dysplasia as the cause of refractery symptomatic epilepsy

The development of the brain is an extremely complex process and it is to be expected that it may be disturbed at any stage by a series of factors. Malformations are one of the most common problems in child neurology: they are the cause of 25% of miscarriages, 40% of deaths in the infant period and are a frequent cause of perinatal and later neurological disorders (cerebral palsy, epilepsy, mental retardation). Today’s classification of malformations of the central nervous system are based on the integration of descriptive morphology with data from molecular genetics, in order to make an aetiological classification possible, which is useful to clinicians, radiologists and pathologists. Development disturbances of the brain cortex are an extremely frequent cause of neurodevelopmental deviations. Recognition of them has been improved by imaging examinations of the brain, especially MR. In general developmental disturbances of the cortex are classified according to three events in the development of the cortex: 1. a proliferation of neurons and glia in the ventricular and subventricular zones from the 2nd to the 5th months of pregnancy; 2. multidirectional migration of immature or postmitotic neurons in the developing cortex, up to 6 months pregnancy and 3. cortical organization from the third trimester to 2-3 years of life. The result of these events is gyrification of the cortex, and this disturbance results in disturbance of the development of the brain cortex. Disturbances of proliferation and/or differentiation are characterized by an increase or reduction in the number of neurons and glia, or a proliferation of abnormal cells and they may be diffuse or focal. Focal cortical dysplasia is frequent, and accounts for 25% of stubborn epilepsy in children and 15% in adults. In pathoanatomical terms there is a range of mild disruptions to severe with cortical dyslamination and large bizarre cells. After migration of the neurons the laminating organization of post-migration cells takes place, with the differentiation of the dendrites and axons, synaptogenesis, then reduction of the synapses, retraction of excessive axons and dendrites and the programmed death of cells. So, in focal cortical dysplasia it is not only a matter of a disturbance of organization, but also of proliferation and migration. After clinically establishing a suspicion, MR of the brain makes it possible to discover pathological substrate with great precision. The test should be planned according to clinical findings since routine MR protocols are not always sufficient to discover discrete malformations, but high resolution images are necessary. For this reason we decided to present our patient with the clinical picture of medication refractory symptomatic epilepsy and focal cortical dysplasia. The boy, now 11 years old, was born from a risky, maintained pregnancy, and during the pregnancy IUGR was registered. The birth took place at 42 weeks by Caesarean section due to threatened asphyxia of the baby, AS 6/9, BW 2200 g/BL 47 cm, HC 33 cm. His psychological and motor development continued without disturbance until six months of age, when epileptic seizures began to occur of the infantile spasm type. On the basis of the clinical picture and EEG findings, the diagnosis of West syndrome was made. He was treated with phenobarbital and valproate, with corticosteroid therapy. He was examined and treated regularly, with gradual improvement, to the complete end of the seizures and normal EEG. His psychomotor development continued normally, he was monitored by a psychologist, a CT scan of the brain was performed at 4 years of age and it was within the limits normal. At six years his AET was completely halted. At seven years the epileptic attacks returned with nausea, redness of the face and then hemiconvulsions of the right side, with pallor and hypersalivation, every day up to 5 times a day. An MR of the brain was then performed: the findings showed a subcortical left small zone of heightened intensity of signal in T2 and FLAIR measured image, and hypointensity in T1. The changes were taken to be the sequel to perinatal haemorrhage, and AET was reintroduced. He was hospitalized several times due to worsening epileptic seizures, or the need for correction of his AET. The EEG findings throughout showed convincing focal changes on the left T.P.O – spike wave complex 1-2 Hz, sometimes with generalization. In the finding of the computerized allnight polysomnography there was also a clear focus in REM of left T-O. From that time to the present several forms of antiepileptics have been used in various dosages and combinations. The longest period without an attack was 3 months. He attends school with the regular programme and he is an excellent pupil. In the clinical findings his somatic status is unremarkable, and right MTR more lively with positive Babinski to the right; in Romberg the right hand sinks discretely. He is still having epileptic attacks despite therapy with oxcarbazepine and levetiracetam and the attacks are more frequent in the morning after waking up when he does not react to calling for 30 or so seconds, then describes paresthesia in his legs, and flashing before his eyes. In view of the refractory nature of the attacks MR -3T of the brain was performed in March 2009 (at the age of 10 years and seven months) and the findings showed focal cortical dysplasia, left occipitally. So due to the finding of focal cortical dysplasia or the pharmacoresistant symptomatic epilepsy, a neurosurgeon was consulted who proposed neurosurgical assessment and surgical treatment of the epilepsy. After consultation and examination in the relevant institutions, the boy was sent for surgical treatment to a foreign neurosurgical centre. We conclude that the recognition of focal cortical dysplasia is important because alongside consistent clinical, electrophysiological, radiological, and neuropsychological findings, pharmacoresistant epilepsy may also be treated surgically.

Read more