Temporal lobectomy in congenital porencephaly associated with hippocampal sclerosis

Ventriculoperitoneal shunt for giant porencephaly: a case report and literature review

Porencephaly (POR) is an exceedingly rare neurological disorder characterized by the presence of solitary or multiple regressive cerebrospinal fluid (CSF) cavities within the brain parenchyma. Currently, there is a limited understanding of the pathogenesis and treatment options for this condition, and clinical presentations can vary significantly. However, imaging plays a crucial role in diagnosis and determining the optimal treatment strategy, necessitating individualized comprehensive treatment upon detection. We reported a 25-year-old male case with persistent head pain that did not resolve with rest. Magnetic resonance imaging (MRI) confirmed the giant POR, and we finally performed a ventriculoperitoneal shunt, and the symptoms of intracranial hypertension were relieved after surgery.

Epilepsy syndromes in cerebral palsy: varied, evolving and mostly self-limited

Seizures occur in approximately one-third of children with cerebral palsy. This study aimed to determine epilepsy syndromes in children with seizures and cerebral palsy due to vascular injury, anticipating that this would inform treatment and prognosis. We studied a population-based cohort of children with cerebral palsy due to prenatal or perinatal vascular injuries, born 1999-2006. Each child's MRI was reviewed to characterize patterns of grey and white matter injury. Children with syndromic or likely genetic causes of cerebral palsy were excluded, given their inherent association with epilepsy and our aim to study a homogeneous cohort of classical cerebral palsy. Chart review, parent interview and EEGs were used to determine epilepsy syndromes and seizure outcomes. Of 256 children, 93 (36%) had one or more febrile or afebrile seizures beyond the neonatal period and 87 (34%) had epilepsy. Children with seizures were more likely to have had neonatal seizures, have spastic quadriplegic cerebral palsy and function within Gross Motor Function Classification System level IV or V. Fifty-six (60%) children with seizures had electroclinical features of a self-limited focal epilepsy of childhood; we diagnosed these children with a self-limited focal epilepsy-variant given the current International League Against Epilepsy classification precludes a diagnosis of self-limited focal epilepsy in children with a brain lesion. Other epilepsy syndromes were focal epilepsy-not otherwise specified in 28, infantile spasms syndrome in 11, Lennox-Gastaut syndrome in three, genetic generalized epilepsies in two and febrile seizures in nine. No epilepsy syndrome could be assigned in seven children with no EEG. Twenty-one changed syndrome classification during childhood. Self-limited focal epilepsy-variant usually manifested with a mix of autonomic and brachio-facial motor features, and occipital and/or centro-temporal spikes on EEG. Of those with self-limited focal epilepsy-variant, 42/56 (75%) had not had a seizure for >2 years. Favourable seizure outcomes were also seen in some children with infantile spasms syndrome and focal epilepsy-not otherwise specified. Of the 93 children with seizures, at last follow-up (mean age 15 years), 61/91 (67%) had not had a seizure in >2 years. Children with cerebral palsy and seizures can be assigned specific epilepsy syndrome diagnoses typically reserved for normally developing children, those syndromes commonly being age-dependent and self-limited. Compared to typically developing children with epilepsy, self-limited focal epilepsy-variant occurs much more commonly in children with cerebral palsy and epilepsy. These findings have important implications for treatment and prognosis of epilepsy in cerebral palsy, and research into pathogenesis of self-limited focal epilepsy.

Neuropsychological presentation of colpocephaly and porencephaly with symptom onset in adulthood

Colpocephaly is a form of congenital ventriculomegaly while porencephaly describes any full-thickness defect within the brain which usually presents as a cystic structure. Postulated aetologies include intrauterine/perinatal injuries, genetic disorders, and morphogenesis error. Colopocephaly and porencephaly is typically diagnosed in infancy while diagnosis in adulthood is exceptionally rare. We report a case of co-existence of colpocephaly with porencephaly diagnosed incidentally in a 54-year-old male presenting with subtle cognitive and neurologic abnormalities. Neuropsychological assessment revealed weaknesses in executive functions, processing speed, and language.To our knowledge, this is the only reported case of dual incidental findings of porencephaly and colpocephaly in an adult.

Magnetoencephalography helps delineate the extent of the epileptogenic zone for surgical planning in children with intractable epilepsy due to porencephalic cyst/encephalomalacia

OBJECT

Porencephalic cyst/encephalomalacia (PC/E) is a brain lesion caused by ischemic insult or hemorrhage. The authors evaluated magnetoencephalography (MEG) spike sources (MEGSS) to localize the epileptogenic zone in children with intractable epilepsy secondary to PC/E.

METHODS

The authors retrospectively studied 13 children with intractable epilepsy secondary to PC/E (5 girls and 8 boys, age range 1.8-15 years), who underwent prolonged scalp video-electroencephalography (EEG), MRI, and MEG. Interictal MEGSS locations were compared with the ictal and interictal zones as determined from scalp video-EEG.

RESULTS

Magnetic resonance imaging showed PC/E in extratemporal lobes in 3 patients, within the temporal lobe in 2 patients, and in both temporal and extratemporal lobes in 8 patients. Magnetoencephalographic spike sources were asymmetrically clustered at the margin of PC/E in all 13 patients. One cluster of MEGSS was observed in 11 patients, 2 clusters in 1 patient, and 3 clusters in 1 patient. Ictal EEG discharges were lateralized and concordant with MEGSS in 8 patients (62%). Interictal EEG discharges were lateralized and concordant with MEGSS hemisphere in 9 patients (69%). Seven patients underwent lesionectomy in addition to MEGSS clusterectomy with (2 patients) and without (5 patients) intracranial video-EEG. Temporal lobectomy was performed in 1 patient and hemispherectomy in another. Eight of 9 patients achieved seizure freedom following surgery.

CONCLUSIONS

Magnetoencephalography delineated the extent of the epileptogenic zone adjacent to PC/E in patients with intractable epilepsy. Complete resection of the MEGSS cluster along with PC/E can provide favorable seizure outcomes.

Towards early diagnosis and treatment to save children from catastrophic epilepsy -- focus on epilepsy surgery

OBJECTIVE

To analyze and to discuss whether by paying attention to the many recent advancements in the field of pediatric epilepsy surgery catastrophic childhood epilepsies caused by definitive or suspected structural lesions can be prevented more often these days in comparison to the past.

METHODS

Based on data from the literature and supplemented by the authors own experience, risks for children suffering from structural focal epilepsies that the epilepsy becomes catastrophic and ways how such evolutions can possibly be prevented are discussed for the different lesion-types separately - in the order of their frequency as they are seen at pediatric epilepsy surgery centers. Special emphasis is put on data regarding attempts to prevent permanent severe mental retardations.

RESULTS

There are common factors predisposing to catastrophic courses in all structural focal epilepsies, such as early onset and a longer duration of epilepsy (with respect to cognitive outcome not with respect to seizure outcome), but there are also differences. Moreover the better perspectives now in comparison to the past for children with conditions like MRI-negative focal epilepsies, subtle focal cortical dysplasias, epilepsies post hypoxic-ischemic events, tuberous sclerosis etc. are not well recognized yet. While there is agreement that "early" (and successful) surgery is essential in many instances to prevent permanent mental retardations there is insufficient data regarding the issue that "early surgery "might not be early enough under certain circumstances and there is also only little data regarding variables which would allow to keep calm when a child is presenting with early onset difficult to control seizures. One of the biggest changes seen over the last decade is the fact that children with very severe epilepsies, who have unilateral lesions, but "generalized" seizures and/or "generalized" EEGs, are not excluded anymore from considerations for epilepsy surgery. Even children with bilateral lesions can be surgical candidates.

CONCLUSION

The gradually widening spectrum of indications for epilepsy surgery in children is resulting in an increasing number of preventions of catastrophic epilepsies. Insufficient data regarding timing of surgery in order to prevent permanent mental retardations are calling for prospective multi-center studies.

Surgical outcome in neocortical resections of type IIId focal cortical dysplasia with accompanying medial temporal pathology

Focal cortical dysplasia (FCD) type IIId is a newly proposed type associated with early-life brain insults. Such patients are often considered unsuitable for resective epilepsy surgery, given the usually wide extent of the lesion and the poor correlation of MRI to the epileptogenic pathology. Two patients with intractable epilepsy, early-life ischemic/traumatic injury and MRI findings of extensive unilateral cystic-gliotic and ipsilateral medial temporal sclerotic-malformative lesions were subjected to presurgical evaluation revealing well-localized neocortical ictal onsets. They underwent tailored neocortical resections sparing medial temporal areas and achieved Engel class I postsurgical outcomes. Histopathology was consistent with type IIId focal cortical dysplasia. Successful outcomes with tailored resections may be achieved in cases with this subtype of focal cortical dysplasia, in the presence of converging and well-localized semiological, EEG and functional imaging data, even on a background of complex and extensive MRI abnormalities. Medial temporal pathology, although often present in this setting, is not necessarily the site of ictal onsets, and its resection may not be always mandatory for a favorable outcome.

The patient had a normal magnetic resonance imaging and temporal lobe epilepsy secondary to a porencephalic cyst but showed structural lesions (hippocampal sclerosis)

Patients with a porencephalic cyst frequently develop intractable temporal lobe epilepsy (TLE). We report a surgically-treated male patient with intractable mesial TLE (mTLE) secondary to a porencephalic cyst. Although magnetic resonance imaging showed no hippocampal abnormalities, long-term video-electrocorticography revealed seizure onset discharges in the hippocampus. Temporal lobectomy brought an end to the patient's seizures. Hippocampal sclerosis was histopathologically confirmed (dual pathology). Careful evaluation of hippocampal epileptogenicity is required, and temporal lobectomy, which is less invasive than hemispherectomy, can be a treatment of choice for patients with mTLE secondary to a porencephalic cyst.

Neonatal stroke in mice causes long-term changes in neuronal Notch-2 expression that may contribute to prolonged injury

BACKGROUND AND PURPOSE

Notch receptors (1-4) are membrane proteins that, on ligand stilumation, release their cytoplasmic domains to serve as transcription factors. Notch-2 promotes proliferation both during development and cancer, but its role in response to ischemic injury is less well understood. The purpose of this study was to understand whether Notch-2 is induced after neonatal stroke and to investigate its functional relevance.

METHODS

P12 CD1 mice were subjected to permanent unilateral (right-sided) double ligation of the common carotid artery.

RESULTS

Neonatal ischemia induces a progressive brain injury with prolonged apoptosis and Notch-2 up-regulation. Notch-2 expression was induced shortly after injury in hippocampal areas with elevated c-fos activation and increased cell death. Long-term induction of Notch-2 also occurred in CA1 and CA3 in and around areas of cell death, and had a distinct pattern of expression as compared to Notch-1. In vitro oxygen glucose deprivation treatment showed a similar increase in Notch-2 in apoptotic cells. In vitro gain of function experiments, using an active form of Notch-2, show that Notch-2 induction is neurotoxic to a comparable extent as oxygen glucose deprivation treatment.

CONCLUSIONS

These results suggest that Notch-2 up-regulation after neonatal ischemia is detrimental to neuronal survival.

Functional integration of new neurons into hippocampal networks and poststroke comorbidities following neonatal stroke in mice

Stroke in the developing brain is an important cause of chronic neurological morbidities including neurobehavioral dysfunction and epilepsy. Here, we describe a mouse model of neonatal stroke resulting from unilateral carotid ligation that results in acute seizures, long-term hyperactivity, spontaneous lateralized circling behavior, impaired cognitive function, and epilepsy. Exploration-dependent induction of the immediate early gene Arc (activity-regulated cytoskeleton associated protein) in hippocampal neurons was examined in the general population of neurons versus neurons that were generated approximately 1 week after the ischemic insult and labeled with bromodeoxyuridine. Although Arc was inducible in a network-specific manner after severe neonatal stroke, it was impaired, not only in the ipsilateral injured but also in the contralateral uninjured hippocampi when examined 6 months after the neonatal stroke. Severity of both the stroke injury and the acquired poststroke epilepsy negatively correlated with Arc induction and new neuron integration into functional circuits in the injured hippocampi.

Symptomatic epilepsy in children with poroencephalic cysts secondary to perinatal middle cerebral artery occlusion

BACKGROUND

Perinatal cerebral artery occlusion is responsible for ischemic cerebral infarction leading to brain cavitation and gliosis; the territory of the middle cerebral artery is most frequently involved. The resulting poroencephalic cysts are frequently associated with hemiplegia and epilepsy; that can be managed medically in most cases, only 6-7% of them being refractory to medical treatment. This particular subset of congenitally hemiplegic children will be possible candidates for electrophysiological investigation and eventually for resective surgery. Whatever the kind of surgical treatment, surgery should be performed as soon as possible to optimize functional brain reorganization.

CLINICAL MATERIAL

Twelve children with poroencephalic cysts and refractory epilepsy were studied and operated on at the Divisions of Child Neurology and Pediatric Neurosurgery, the Catholic University Medical School, Rome. The hemiparesis ranged from mild to moderate; the developmental delay was of mild degree in three cases, moderate in four cases and severe in the remaining five. Behavioral disorders were observed in patients with mental retardation; two of them also manifested autistic features. All the children presented with a severe epileptic syndrome (starting almost invariably during the first year of life); six patients presented with a West syndrome followed by symptomatic partial epilepsy; the other six presented with partial epilepsy, followed in two cases by continuous spike-waves during sleep. The electroencephalograph (EEG) recordings disclosed focal unilateral interictal epileptiform abnormalities that usually corresponded to the side of the cystic lesion; however, paroxysmal activity often spread synchronously over the contralateral hemisphere. The selection of candidates for surgical treatment was based on neuroimaging and video-EEG monitoring; in particular, we did not use invasive intraoperative neurophysiologic techniques. The convergence of neuroimaging and neurophysiologic findings guided us in performing a limited cortical excision corresponding to the malacic cortex (cyst "membrane").

RESULTS

All the patients underwent excision of the cyst wall. Careful attention was paid not to enter the body of the lateral ventricle to avoid ventriculo-subarachnoid fistulas, eventually responsible for subdural hygroma or cerebrospinal fluid leak. There was one surgery-related death secondary to disseminated intravascular coagulation, following an otherwise uneventful surgical procedure. An elevated systemic blood pressure, secondary to repeated adrenocorticotropic hormone therapy, can represent a possible concurrent factor for this event. No major complications were recorded among the remaining 11 children. Seizure control was excellent in all the 11 survivors in the early postoperative period. Two children presented a relapse of seizures, after an initial improvement, respectively 3 and 4 years after the operation. These two children underwent subsequently a functional hemispherectomy. Overall, seizure outcome was excellent in all the cases. Seven patients (including the two who underwent functional hemispherectomy) are seizure-free (Engel's class Ia), and in one of them antiepileptic therapy has been weaned. In the remaining five children, seizures are sporadic and definitely improved (Engel's class II). An improvement of developmental delay, in particular of cognitive competence, was registered in 8 out of the 11 patients. Two of the four severely retarded children, who also presented behavioral abnormalities, did not show any cognitive improvement, whereas some mild improvement of their basal abilities was demonstrated in the other two. All the remaining children, even though maintaining a moderate retardation, definitely improved their abilities; in particular, one of them reached an almost borderline level. The three patients with unchanged neurodevelopmental delay presented also persistent seizures. On the other hand, two children with persistent seizures presented neurodevelopmental improvement.

CONCLUSIONS

Simple surgical excision of the cyst "membrane" of epileptogenic poroencephalic cysts can represent an excellent means to control epilepsy in affected children. However, postoperative seizure persistence and late recurrences, although rare, do not allow to exclude that hemispherectomy or partial resections (based on electrocorticography findings) might represent the good answer at least in some cases.

Presurgical evaluations of patients with intractable epilepsy

Neuroimaging is helpful, but not definitive, when deciding whether to perform a surgical resection to treat intractable epilepsy

Qualitative and quantitative imaging of the hippocampus in mesial temporal lobe epilepsy with hippocampal sclerosis

MR imaging allows the in vivo detection of hippocampal sclerosis (HS) and has been instrumental in the delineation of the syndrome of mesial temporal lobe epilepsy with HS (mTLE-HS). MR features of HS include hippocampal atrophy with an increased T2 signal. Quantitative MR imaging accurately reflects the degree of hippocampal damage.Ictal single photon emission computed tomography (SPECT) in mTLE-HS shows typical perfusion patterns of ipsilateral temporal lobe hyperperfusion, and ipsilateral frontoparietal and contralateral cerebellar hypoperfusion. Interictal 18fluoro-2-deoxyglucose positron emission tomography (PET) shows multiregional hypometabolism, involving predominantly the ipsilateral temporal lobe. 11C-flumazenil PET shows hippocampal decreases in central benzodiazepine receptor density. Future strategies to study the etiology and pathogenesis of HS should include longitudinal MR imaging studies,MR studies in families with epilepsy and febrile seizures, stratification for genetic background, coregistration with SPECT and PET, partial volume correction and statistical parametric mapping analysis of SPECT and PET images.