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

Intraoperative electrocorticography-guided resection of the epileptogenic zone in an unusual porencephalic cyst: case report and literature review

Introduction

Porencephalic cysts resulting from perinatal artery infarctions typically manifest as large cysts accompanied by pre-existing neurological deficits. A small porencephalic cyst without any neurological deficit is a rare cause of medically refractory epilepsy.

Case presentation

A 23-year-old female presented with a history of medically refractory epilepsy secondary to a small right parieto-temporal porencephalic cyst. Despite optimal anti-seizure medications, seizures persisted. Surgical intervention was planned, and intraoperative electrocorticography (ioECoG) was used to delineate the epileptogenic zone (EZ), which was found to be two gyri posterior to the cyst.

Discussion

Very focal ischaemia resulting in a small porencephalic cyst from perinatal artery infarction exhibits a distinct organization of the EZ involving wider area posteriorly indicating involvement of arterial territory distal to the cyst. This contrasts with the typical perilesional EZ observed in other lesional epilepsy causes.

Conclusion

Our findings emphasize the need to consider aetiology during interpretation of ioECoG to better define the electrophysiological border between the normal and epileptogenic brain, aiding in achieving a better surgical outcome.

Surgical treatment for drug-resistant epilepsy due to early brain injury in children

BACKGROUND

The study aimed to summarize the indications and clinical features of pediatric drug-resistant epilepsy associated with early brain injury, surgical outcomes, and prognostic factors.

METHODS

We retrospectively analyzed children diagnosed with drug-resistant epilepsy due to early brain injury, who had undergone surgery at the Pediatric Epilepsy Center of Peking University First Hospital from May 2014 to May 2021. Clinical data of vasculogenic and non-vasculogenic injuries from early brain damage were compared and analyzed. The surgical outcomes were assessed using the Engel grading system.

RESULTS

The median ages at acquiring injury, seizure onset, and surgery among 65 children were 19.0 (0-120) days, 8.6 (0-136.5) months, and 62.9 (13.5-234) months, respectively. Of the 14 children with non-vasculogenic injuries, 12 had posterior ulegyria. Unilateral or bilateral synchronous interictal epileptiform discharges were located mainly in the posterior quadrant in 10 children (71 %), and unilateral posterior quadrant or non-lateralized ictal region in eight children (57 %). The surgical approach was mainly temporo-parieto-occipital or parieto-occipital disconnection in nine children. Of 49 children with vasculogenic injuries, magnetic resonance imaging revealed hemispheric abnormalities in 38. Unilaterally hemispheric or bilateral interictal epileptiform discharges were observed in 36 children (73 %), whereas 42 (86 %) had unilateral hemispheric or non-lateralized ictal onset. The surgical procedure involved hemispherotomy in 38 children (78 %) and lobectomy or disconnection, multilobectomy or disconnection and hemispherotomy in 5, 20, and 40 children, respectively. Fifty-five patients (84.6 %) achieved remission from seizure during follow-up at 5.4 years. Age at surgery (odds ratio = 1.022, 95 % confidence interval = 1.003-1.042, P = 0.023) and etiology (odds ratio = 17.25, 95 % confidence interval = 2.778-107.108, P = 0.002) affected the seizure outcomes.

CONCLUSION

Children with drug-resistant epilepsy due to early brain injury can successfully be treated with surgery after rigorous preoperative screening. Good surgical outcomes are associated with an early age at surgery and an etiology of vasculogenic injury.

Surgery for Intractable Epilepsy in Pediatrics, a Systematic Review of Outcomes other than Seizure Freedom

To perform a systematic review evaluating reported outcomes for epilepsy surgery in pediatric patients with pharmacoresistant epilepsy beyond seizure control, including impact on quality of life, behavioral, neurocognitive outcomes as well as complications, and death. We reviewed articles from both EMBASE and MEDLINE/PubMed articles that met formal criteria (patients ≤18 years, those with intractable epilepsy, at least 5 patients in the case series, published in peer-reviewed journal). Each reviewer independently reviewed the articles and those with discrepancies were discussed and consensus was reached. Out of a total of 536 abstracts obtained from EMBASE and MEDLINE/PubMed searches combined with additional cross-referencing, a total of 98 manuscripts ultimately met all inclusion criteria. The manuscripts were divided into 3 outcomes categories: Quality of Life (16), Cognitive Outcomes (60), and Deficits and Complications (50). Several papers fell into more than 1 category. These were separated by surgical types and evaluated. We found that overall reporting in all domains was variable and inconsistent amongst the different studies. This systematic review highlights the lack of completeness in reporting outcomes and complications involving pediatric epilepsy surgery and discordant results. This underscores the importance of multicenter systematic prospective data collection in pediatric patients who undergo pediatric epilepsy surgery.

Surgical strategy for refractory epilepsy secondary to porencephaly: ictal SPECT may obviate the need for intracranial electroencephalography. Patient series

BACKGROUND

Surgical treatment of intractable epilepsy caused by porencephaly can be difficult because of poorly localizing or lateralizing electroclinical findings. The authors aimed to determine whether noninvasive evaluations are sufficient in these patients.

OBSERVATIONS

Eleven patients were included in this study. The porencephalic cyst was in the left middle cerebral artery (MCA) area in 9 patients, the left posterior cerebral artery area in 1 patient, and the bilateral MCA area in 1 patient. Interictal electroencephalography (EEG) revealed multiregional, bilateral, interictal epileptiform discharges in 5 of 11 patients. In 6 of 10 patients whose seizures were recorded, the ictal EEG was nonlateralizing. Nine patients underwent ictal single-photon emission computed tomography (SPECT), which revealed lateralized hyperperfusion in 8 of 9 cases. Fluorodeoxyglucose positron emission tomography (FDG-PET) was useful for identifying the functional deficit zone. No patient had intracranial EEG. The procedure performed was hemispherotomy in 7 patients, posterior quadrant disconnection in 3 patients, and occipital disconnection in 1 patient. A favorable seizure outcome was achieved in 10 of 11 patients without the onset of new neurological deficits.

LESSONS

Ictal SPECT was useful for confirming the side of seizure origin when electroclinical findings were inconclusive. Thorough noninvasive evaluations, including FDG-PET and ictal SPECT, enabled curative surgery without intracranial EEG. Seizure and functional outcomes were favorable.

Epilepsy surgery for Rasmussen encephalitis: the UCLA experience

OBJECTIVE

Rasmussen encephalitis (RE) is a rare inflammatory neurological disorder typically involving one hemisphere and resulting in drug-resistant epilepsy and progressive neurological decline. Here, the authors present seizure outcomes in children who underwent epilepsy surgery for RE at a single institution.

METHODS

The records of consecutive patients who had undergone epilepsy surgery for RE at the UCLA Mattel Children's Hospital between 1982 and 2018 were retrospectively reviewed. Basic demographic information, seizure history, procedural notes, and postoperative seizure and functional outcome data were analyzed.

RESULTS

The cohort included 44 patients, 41 of whom had sufficient data for analysis. Seizure freedom was achieved in 68%, 48%, and 22% of the patients at 1, 5, and 10 years, respectively. The median time to the first seizure for those who experienced seizure recurrence after surgery was 39 weeks (IQR 11-355 weeks). Anatomical hemispherectomy, as compared to functional hemispherectomy, was independently associated with a longer time to postoperative seizure recurrence (HR 0.078, p = 0.03). There was no statistically significant difference in postoperative seizure recurrence between patients with complete hemispherectomy and those who had less-than-hemispheric surgery. Following surgery, 68% of the patients could ambulate and 84% could speak regardless of operative intervention.

CONCLUSIONS

A large proportion of RE patients will have seizure relapse after surgery, though patients with anatomical hemispherectomies may have a longer time to postoperative seizure recurrence. Overall, the long-term data in this study suggest that hemispheric surgery can be seen as palliative treatment for seizures rather than a cure for RE.

Dramatic response after functional hemispherectomy in a patient with epileptic encephalopathy carrying a de novo COL4A1 mutation

We describe the first case of a successful functional hemispherectomy in a patient with epileptic encephalopathy and a de novo collagen type IV alpha 1 (COL4A1) mutation. A 4-year-old girl was COL4A1 mutation-positive and suffered from drug-resistant epilepsy, hemiplegia, and developmental delay. Magnetic resonance imaging detected no porencephaly, and she had no cataract or renal abnormality. Following a presurgical evaluation for epilepsy, she underwent a functional hemispherectomy. She has been seizure free with no intracranial hemorrhage or other perioperative complications. Patients with a COL4A1 mutation have an increased risk for intracranial hemorrhage because of disrupted integrity in the vascular basement membrane due to the mutation. After weighing the risks and benefits to these patients, epilepsy surgery may not be absolutely contraindicated. Furthermore, pediatric neurologists should be aware of an undiagnosed COL4A1 mutation when a patient presents with an unexplained neurological phenotype, such as mild hemiparesis, even in the absence of porencephaly.

Five-Year Long-Term Prognosis of Epileptic Children After Hemispheric Surgery: A Systematic Review and Meta-analysis

To estimate children's long-term seizure outcomes after hemispheric surgery and the associated predictors.A systematic review of 4 databases and a meta-analysis were performed from January 1, 1995 to August 31, 2015. The databases included PubMed, Embase, Science Direct, and Web of Science; patients were classified into the Engel Class I group and the Engel Class II to IV group, according to their seizure outcomes. Nine potential predictors were then stratified across the groups and estimated using the Wilcoxon rank-sum test for continuous variables and the Chi-squared test for categorical variables.The search yielded 15 retrospective studies, with a total sample size of 380. Five years after surgery, 268 (0.71, 95% confidence interval [CI]: 0.64-0.78) children were seizure free; the seizure onset age in the Engel Class I group was significantly higher than that of the Engel Class II to IV group (standardized mean difference [SMD] = 0.26, 95% CI: 0.03-0.49, P = 0.028); specifically, when predicting the positive long-term outcomes, the odds ratio for late onset age (≥3.6 months, median value of the Engel Class II-IV group) versus early onset age was 2.65 (95% CI: 1.454-4.836, z = 3.18, P = 0.001). The abnormal magnetic resonance imaging (MRI) findings were more predictive for positive seizure outcomes than the normal findings (odds ratio [OR] = 4.60, 95% CI: 1.27-16.62, P = 0.02).Following hemispheric surgery, the long-term prognosis of children with epilepsy was good. Late seizure onset (age ≥ 3.6 months) and abnormal MRI findings were positive predictors for long-term seizure control in children.

Neuroepidemiology of Porencephaly, Schizencephaly, and Hydranencephaly in Miyagi Prefecture, Japan

BACKGROUND

No population-based surveys of porencephaly, schizencephaly, and hydranencephaly have been conducted in Japan or other Asian countries. We performed a neuroepidemiologic analysis to elucidate the incidence of porencephaly, schizencephaly, and hydranencephaly in Miyagi prefecture, Japan, during 2007-2011.

METHODS

We sent inquiry forms in February 2012 to three neonatal intensive care units, 25 divisions of orthopedic surgery in municipal hospitals, 33 divisions of pediatrics including one university hospital, municipal hospitals, pediatric practitioners, and institutions for physically handicapped children located in Miyagi prefecture. These covered all clinics related to pediatric neurology and orthopedic surgery in Miyagi prefecture. In the inquiry, diagnostic criteria for porencephaly, schizencephaly, and hydranencephaly were described and representative images of magnetic resonance imaging were shown. We obtained an 82% (27 of 33) response rate from the divisions of pediatrics, a 100% (3 of 3) response rate from the neonatal intensive care units, and a 68% (17 of 25) response rate from orthopedic surgery clinics. The magnetic resonance imaging scans of each patient were retrieved and inspected.

RESULTS

Five, one, and two individuals developed porencephaly, schizencephaly, and hydranencephaly, respectively. The estimated incidence rates of porencephaly, schizencephaly, and hydranencephaly were 5.2 (95% confidence interval [CI], 0.6-9.8), 1.0 (95% CI, 0.0-3.1), and 2.1 (95% CI, 0.0-5.0) per 100,000 live births, respectively.

CONCLUSIONS

The prevalence rates of porencephaly, schizencephaly, and hydranencephaly at birth reported herein are compatible with results reported previously in the United States and European countries. The overall prevalence rate of these three diseases was 8.3 (95% CI, 2.6-14.1) per 100,000 live births.

Temporal lobe epilepsy in infants and children

Clinical expression of temporal lobe seizures is different with a more diverse and more extensive etiology in infants and children than it is in adults. It is dominated by cortical dysplasia, low-grade tumors and perinatal damage. Hippocampal sclerosis, although less frequent, exists in children usually as a dual pathology associated with ipsilateral neocortical lesions. The clinical semiology of temporal seizures is more varied, and sometimes misleading. Motor features including tonic, clonic or myoclonic behaviors, and infantile spasms predominate in infants. Classical complex partial seizures with behavioral arrest and automatisms, as well as lateralizing signs are rare and occur mostly with onset after the age of two years. Interestingly, aura, emotional, and autonomic signs seem to be independent on the brain maturation process. Moreover, the neuropsychological profile varies according to age of onset and duration, lateralization of the focus and etiology. Quality of care benefits from individual cognitive assessment for memory and emotional processes.

Surgical management of medically refractory epilepsy due to early childhood stroke

OBJECT.: The risk of developing epilepsy after perinatal stroke, hypoxic/ischemic injury, and intracerebral hemorrhage is significant, and seizures may become medically refractory in approximately 25% of these patients. Surgical management can be difficult due to multilobar or bilateral cortical injury, nonfocal or poorly lateralizing video electroencephalography (EEG) findings, and limited functional reserve. In this study the authors describe the surgical approaches, seizure outcomes, and complications in patients with epilepsy due to vascular etiologies in the perinatal period and early infancy.

METHODS

The records were analyzed of 19 consecutive children and adults with medically refractory epilepsy and evidence of perinatal arterial branch occlusions, hypoxic/ischemic insult, or hemorrhagic strokes, who underwent surgery at the Comprehensive Epilepsy Center of Beth Israel Medical Center and St. Luke's-Roosevelt Hospital Center. Preoperative findings including MRI, video EEG, functional MRI, and neuropsychological testing were analyzed. The majority of patients underwent staged operations with invasive mapping, and all patients had either extra- or intraoperative functional mapping.

RESULTS

In 7 patients with large porencephalic cysts due to major arterial branch occlusions, periinsular functional hemispherotomy was performed in 4 children, and in 3 patients, multilobar resections/disconnections were performed, with 1 patient undergoing additional resections 3 years after initial surgery due to recurrence of seizures. All of these patients have been seizure free (Engel Class IA) after a mean 4.5-year follow-up (range 15-77 months). Another 8 patients had intervascular border-zone ischemic infarcts and encephalomalacia, and in this cohort 2 hemispherotomies, 5 multilobar resections/disconnections, and 1 focal cortical resection were performed. Seven of these patients remain seizure free (Engel Class IA) after a mean 4.5-year follow-up (range 9-94 months), and 1 patient suffered a single seizure after 2.5 years of seizure freedom (Engel Class IB, 33-month follow-up). In the final 4 patients with vascular malformation-associated hemorrhagic or ischemic infarction in the perinatal period, a hemispherotomy was performed in 1 case, multilobar resections in 2 cases, and in 1 patient a partial temporal lobectomy was performed, followed 6 months later by a complete temporal and occipital lobectomy due to ongoing seizures. All of these patients have had seizure freedom (Engel Class IA) with a mean follow-up of 4.5 years (range 10-80 months). Complications included transient monoparesis or hemiparesis in 3 patients, transient mutism in 1 patient, infection in 1 patient, and a single case of permanent distal lower-extremity weakness. Transient mood disorders (depression and anxiety) were observed in 2 patients and required medical/therapeutic intervention.

CONCLUSIONS

Epilepsy surgery is effective in controlling medically intractable seizures after perinatal vascular insults. Seizure foci tend to be widespread and rarely limited to the area of injury identified through neuroimaging, with invasive monitoring directing multilobar resections in many cases. Long-term functional outcomes have been good in these patients, with significant improvements in independence, quality of life, cognitive development, and motor skills, despite transient postoperative monoparesis or hemiparesis and occasional mood disorders.

Surgical treatment of pediatric epileptic encephalopathies

Pediatric epileptiform encephalopathies are a group of neurologically devastating disorders related to uncontrolled ictal and interictal epileptic activity, with a poor prognosis. Despite the number of pharmacological options for treatment of epilepsy, many of these patients are drug resistant. For these patients with uncontrolled epilepsy, motor and/or neuropsychological deterioration is common. To prevent these secondary consequences, surgery is often considered as either a curative or a palliative option. Magnetic resonance imaging to look for epileptic lesions that may be surgically treated is an essential part of the workup for these patients. Many surgical procedures for the treatment of epileptiform encephalopathies have been reported in the literature. In this paper the evidence for these procedures for the treatment of pediatric epileptiform encephalopathies is reviewed.

Role of MRI in patient selection for surgical treatment of intractable epilepsy in infancy

Epilepsy surgery is an effective treatment in selected patients with localization-related intractable epilepsy. The success of epilepsy surgery is in part dependent upon identification of a lesion on MRI. In infants, the surgical epileptogenic substrates include focal cortical dysplasia (FCD), hemimegalencephaly, tuberous sclerosis complex, Sturge Weber syndrome, hypoxic-ischemic or cerebrovascular injury and low-grade tumor. The sensitivity of MRI in identifying the epileptogenic substrate is influenced by the nature of the epileptogenic substrate, MRI technique and expertise of the interpreting physician. The MRI features of some lesions such as FCD may differ in infants compared to children and adults; the white matter adjacent to FCD may demonstrate lower T2 and higher T1 signal in some infants due to premature myelination, while in others, the white matter demonstrates higher T2 or lower T1 signal due to demyelination, dysmyelination or gliosis, similar to children and adults. The appearances of some lesions, such as FCD, may change with time, due to brain maturation or seizure related changes. MRI for patients with localization-related intractable epilepsy should have high-resolution, multiplanar and multisequence. In infants, volumetric T1 and high-resolution T2 imaging are recommended. FLAIR and proton density sequences are less helpful in infants due to lack of myelin in the white matter. The physician interpreting the scan should be familiar with the imaging appearances of epileptogenic substrates and may need to review the scan more than once if a lesion is not seen on initial inspection.

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.

Focal epileptogenic lesions

The spectrum of focal epileptogenic lesions and their clinical manifestations in children differ substantially from those seen in adults. In adults, mesial temporal sclerosis is the common lesion in surgical series; but in children, MTS is uncommon, and when it does occur, it exists frequently as dual pathology. The most common lesions in pediatric epilepsy surgery candidates are malformations of cortical development, developmental tumors, or encephalomalacia from infarction, hypoxia, trauma, or infection. Careful analysis of the lesion characteristics on brain MRI is sufficiently predictive of pathology in most cases. Histopathological evaluation remains the gold standard for diagnosis of mass lesions. The electroclinical phenotype of epilepsy in adults is largely determined by the anatomical location of the lesion and its connectivity. In children, in addition to the location of the lesion, the age at onset of the lesion and the age at onset of epilepsy have a major impact on the electroclinical phenotype. Children with congenital or early acquired lesions may manifest with generalized features on EEG and seizure semiology. Experience from various centers has demonstrated that a subset of these children benefit from epilepsy surgery despite a generalized epilepsy phenotype. All children with medically refractory epilepsy and a focal lesion should undergo evaluation for potential epilepsy surgery irrespective of the EEG findings and seizure semiology.

Levetiracetam in children and adolescents with epilepsy and hemiplegic cerebral palsy

AIM

To monitor the effect of adding levetiracetam in paediatric patients with hemiplegic cerebral palsy and uncontrolled epilepsy.

METHODS

A case series of eight patients with hemiplegic cerebral palsy whose focal seizures were not adequately controlled by their current anticonvulsants were monitored after levetiracetam was added to their medications. If there was a 50% reduction in seizure frequency, then the other anticonvulsants were discontinued. Prolonged follow-up occurred for a minimum of 2 years.

RESULTS

There were seven males and one female whose ages ranged from 4 years to 17 years. All had focal onset seizures, while seven also had secondarily generalised tonic clonic seizures. Levetiracetam resulted in at least a 50% reduction in seizure frequency in seven, with no change in one. Three were able to wean successfully to monotherapy and remained seizure free for over 2 years. They had a prior history of infrequent seizures, one to six per year. Those who continued to require multiple anticonvulsants had a prior history of more frequent seizures, 6-50/year. Levetiracetam was well tolerated, and none ceased this because of side effects.

CONCLUSION

Levetiracetam is likely to be an effective anticonvulsant in children and adolescents with hemiplegic cerebral palsy and infrequent but persistent focal seizures.

Low-grade focal cortical dysplasia is associated with prenatal and perinatal brain injury

PURPOSE

Prenatal and perinatal adverse events are reported to have a pathogenetic role in focal cortical dysplasia (FCD). However, no data are available regarding the prevalence and significance of this association. A cohort of children with significant prenatal and perinatal brain injury and histologically proven mild malformations of cortical development (mMCD) or FCD was analyzed.

METHODS

We retrospectively evaluated a surgical series of 200 patients with histologically confirmed mMCD/FCD. Combined historical and radiologic inclusion criteria were used to identify patients with prenatal and perinatal risk factors. Electroclinical, imaging, neuropsychological, surgical, histopathologic, and seizure outcome data were reviewed.

RESULTS

Prenatal and perinatal insults including severe prematurity, asphyxia, bleeding, hydrocephalus, and stroke occurred in 12.5% of children with mMCD/FCD (n = 25). Their epilepsy was characterized by early seizure onset, high seizure frequency, and absence of seizure control. Patients with significant prenatal and perinatal risk factors had more abnormal neurologic findings, lower intelligence quotient (IQ) scores, and slower background EEG activity than mMCD/FCD subjects without prenatal or perinatal brain injury. MRI evidence of cortical malformations was identified in 74% of patients. Most patients underwent large multilobar resections or hemispherectomies; 54% were seizure-free 2 years after surgery. Histologically "milder" forms of cortical malformations (mMCD and FCD type I) were observed most commonly in our series.

CONCLUSIONS

Surgically remediable low-grade cortical malformations may occur in children with significant prenatally and perinatally acquired encephalopathies and play an important role in the pathogenesis of their epilepsy. Presurgical detection of dysplastic cortex has important practical consequences for surgical planning.

Prenatal stroke

The main focus of this chapter is the comprehensive description of the neuropathology, the imaging correlates and underlying mechanisms of prenatal stroke. We describe established prenatal stroke in subgroups similar to postnatal stroke: arterial (forebrain or hindbrain) infarction, venous thrombosis, primary lobar haemorrhage. This longitudinal classification should facilitate the study of risk factors and mechanisms. Forebrain lesions of arterial type present as porencephaly, (hemi)hydranencephaly, multicystic encephalopathy or schizencephaly. Venous prenatal forebrain stroke presents as simple porencephaly (in some of genetic nature) and sinus thrombosis. A list of rare porencephaly-like conditions is added for differentiation from arterial and venous porencephaly. Hindbrain infarctions (so far the only reported variants seem to be of arterial nature) present as brainstem disconnection, focal brainstem destruction, uni- or bilateral cerebellar destruction and focal spinal cord ischaemia. Prenatal intracranial haemorrhage and congenital brain infection should be considered in the differential diagnosis of prenatal stroke.

Outcomes of perinatal arterial ischemic stroke and cerebral sinovenous thrombosis

Perinatal stroke can result in cerebral palsy, cognitive impairment, epilepsy, and sensory deficits. While some children only experience one type of disability, severe disabilities often cluster together. Death associated with perinatal stroke is rare, and often associated with other comorbidities. Clinical and radiographic factors can help predict outcome, but additional as-yet unknown factors appear to contribute to outcome as well. Rehabilitation can ameliorate deficits, and advances in rehabilitation technology and in adult stroke rehabilitation offer promise to pediatric perinatal stroke patients.

Neuropathogical features of a rat model for perinatal hypoxic-ischemic encephalopathy with associated epilepsy

Hypoxic-ischemic (HI) encephalopathy is an important neurological problem of the perinatal period. Little is known of the long-term progression of HI insults or the maladaptive changes that lead to epilepsy. Using rats with unilateral carotid occlusion followed by hypoxia at postnatal day 7, this study provides an initial analysis of the epilepsy caused by a perinatal HI insult with chronic and continuous behavioral monitoring. The histopathology was investigated at postnatal day 30 and later at > or =6 months of age using cresyl violet, Timm, and rapid Golgi staining and immunocytochemistry. The resultant epilepsy showed an increase in seizure frequency over time, with a preponderance for seizure clusters and behavioral features of an ipsilateral cerebral syndrome. In addition to parasagittal infarcts and porencephalic cysts in severe lesions, columnar neuronal death was found with cytomegaly in isolated groups of dysmorphic cortical neurons. Cortical dysgenesis was seen in the form of deep laminar cell loss, microgyri, white matter hypercellularity, and blurring of the white and gray matter junction. Mossy fiber sprouting was not only detected in the atrophied ipsilateral dorsal hippocampus of HI rats with chronic epilepsy, but was also found in comparable grades in spared ipsi- and contralateral ventral hippocampi. The cortical lesions in this animal model show histological similarities with those found in humans after perinatal HI. The occurrence of cortical abnormalities that are associated with epilepsy in humans correlates with the consequent detection of spontaneous recurrent seizures.

Neuropsychological features of lesion-related epilepsy in adults: an overview

Lesional epilepsy is thought to be a direct consequence of focal brain lesions of dysgenetic, neoplastic, vascular, or traumatic origin. It has been estimated that at least half of all epilepsies are the result of such lesions. The current discussion includes an overview of the cognitive and behavioral presentations in adults with epilepsy secondary to focal pathology. The neuropsychological presentation in this population is influenced by many factors, including the location and nature of the underlying lesion, seizure characteristics, the effects of treatment, and patient variables. Few studies attempt to disentangle the specific contributions of these variables to cognitive performance. However, where available studies examining the separable effects of seizure-related variables on cognitive functioning in individuals with lesional epilepsy are also reviewed. This overview includes a discussion of focal malformations of cortical and vascular development and select foreign tissue and acquired lesions.