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Objective: To determine the most important factors influencing neuropsychological performance in children with intractable epilepsy due to focal cortical dysplasia and the nature of the interaction among significant variables. Methods: Surgical patients with histologically verified focal cortical dysplasia were retrospectively evaluated to determine the impact of histopathology, extent of lobar involvement, hemispheric laterality, age at onset, and duration of epilepsy on cognitive functioning. A composite neuropsychological variable was obtained by transforming data from 5 major cognitive domains using principal components analysis. Multiple regression was used to examine the unique contributions of predictor variables on composite cognition and Full Scale IQ. Data were qualitatively evaluated for nonstatistical trends. Results: Poor cognitive outcomes were associated with early age at onset of epilepsy (AOE) and widespread dysplastic involvement. Extent of dysplasia and AOE together accounted for 35% of Full Scale IQ variance, and 21% of composite cognitive performance. Each factor contributed independently to cognitive dysfunction. Conclusions: Early AOE disrupts critical periods of development and leads to poor cognitive outcome, but children with multilobar dysplasia are likely to have diminished cognitive skills regardless of AOE. Later AOE is not expected to mitigate deficits because of widespread pathology, nor would a localized lesion be likely to mollify the developmental deficits resulting from early AOE.

Aims. To assess the localizing value of ictal SPECT in very young epilepsy surgery candidates when cerebral haemodynamic responses are known to be immature. Methods. We retrospectively studied 13 infants with intractable focal epilepsy caused by focal cortical dysplasia (FCD). Completeness of resection of the (1) ictal SPECT hyperperfusion zone and (2) cerebral cortex with prominent ictal and interictal abnormalities on intracranial EEG (ECoG or long-term invasive monitoring) and the MRI lesion, when present, were correlated with postoperative seizure outcome. Results. All five patients with complete resection of the ictal SPECT hyperperfusion zone were seizure-free compared to only one of eight patients with incomplete or no excision of hyperperfusion zones (p=0.00843). Similar results were noted for the MRI/iEEG-defined epileptogenic region; five of six patients with complete removal were seizure-free, whereas only one of seven incompletely resected patients was seizure-free (p=0.02914). All four patients who underwent complete resection of both regions were seizure-free compared to none of the six with incomplete resection (p=0.01179). Conclusion. Despite age-related differences in cerebral perfusion, ictal SPECT provides useful localization data in infants with FCD. Complete resection of the hyperperfused regions is a strong predictor of favourable outcome. The added information may alleviate the need for invasive EEG evaluations in some patients.

Purpose Anecdotal reports have described cortical malformations in epileptic patients with Sturge-Weber syndrome (SWS). No data are available regarding the prevalence and significance of this association. Methods We reviewed retrospectively the clinical profile, preoperative magnetic resonance imaging (MRI) studies, and pathology reports of all patients with SWS and medically intractable epilepsy evaluated in our epilepsy surgery program between 1979 and 2006. Results Twelve patients (male/female = 7/5) were identified. Mean age at seizure onset was 11.1 +/- 16.7 months. Seizures occurred daily in seven patients and weekly in five patients. A facial port-wine stain was noted in 10 cases. Eleven patients evidenced developmental delay and eight were hemiparetic. Eight patients underwent excisional surgery for epilepsy (mean age 10.3 +/- 6.5 year), including hemispherectomy (n = 4) and focal cortical resection (n = 4). Tissue was available for neuropathology in six operated cases and revealed polymicrogyria (n = 3) and cortical dysplasia (n = 4). Polymicrogyria was associated with cortical dysplasia in one child. Brain MRIs were reviewed in 10 of 12 patients and were consistent with cortical malformations in all cases. Conclusions We conclude that cortical malformations are frequent in patients with medically intractable epilepsy and Sturge-Weber-syndrome and may be the primary cause of epilepsy.

Background: Focal cortical dysplasia (FCD) is recognized as the major cause of focal intractable epilepsy in childhood. Various factors influencing postsurgical seizure outcome in pediatric patients with FCD have been reported. Objective: To analyze different variables in relation to seizure outcome in order to identify prognostic factors for selection of pediatric patients with FCD for epilepsy surgery. Methods: A cohort of 149 patients with histologically confirmed mild malformations of cortical development or FCD with at least 2 years of postoperative follow-up was retrospectively studied; 113 subjects had at least 5 years of postoperative follow-up. Twenty-eight clinical, EEG, MRI, neuropsychological, surgical, and histopathologic parameters were evaluated. Results: The only significant predictor of surgical success was completeness of surgical resection, defined as complete removal of the structural MRI lesion (if present) and the cortical region exhibiting prominent ictal and interictal abnormalities on intracranial EEG. Unfavorable surgical outcomes are mostly caused by overlap of dysplastic and eloquent cortical regions. There were nonsignificant trends toward better outcomes in patients with normal intelligence, after hemispherectomy and with FCD type II. Other factors such as age at seizure onset, duration of epilepsy, seizure frequency, associated pathologies including hippocampal sclerosis, extent of EEG and MRI abnormalities, as well as extent and localization of resections did not influence outcome. Twenty-five percent of patients changed Engel9s class of seizure outcome after the second postoperative year. Conclusions: The ability to define and fully excise the entire region of dysplastic cortex is the most powerful variable influencing outcome in pediatric patients with focal cortical dysplasia.

Objective Focal cortical dysplasia (FCD) is the most frequent pathological finding in pediatric epilepsy surgery patients. Several histopathological types of FCD are distinguished. The aim of the study was to define distinctive features of FCD subtypes. Methods We retrospectively reviewed clinical, electroencephalographic, magnetic resonance imaging, neuropsychological, and surgical variables, and seizure outcome data in 200 children. Cortical malformations were histopathologically confirmed in all patients, including mild malformation of cortical development type II (mMCD) in 36, FCD type Ia in 55, FCD type Ib in 39, FCD type IIa in 35, and FCD type IIb in 35 subjects. Results Perinatal risk factors were more frequent in mMCD/FCD type I than FCD type II. Children with FCD type IIb had more localized ictal electroencephalographic patterns and magnetic resonance imaging changes. Increased cortical thickness, abnormal gyral/sulcal patterns, gray/white matter junction blurring, and gray matter signal abnormality in fluid-attenuated inversion recovery and T2-weighted sequences occurred more often in FCD type II, were infrequent in FCD type I, and rare in mMCD. Lobar hypoplasia/atrophy was common in FCD type I. Hippocampal sclerosis was most frequent in FCD type I. Neuropsychological testing demonstrated no significant differences between the groups. There was a trend toward better surgical outcomes in FCD type II compared with FCD type I patients. Interpretation Different histopathological types of mMCD/FCD have distinct clinical and imaging characteristics. The ability to predict the subtype before surgery could influence surgical planning. Invasive electroencephalographic study should be considered when mMCD/FCD type I is expected based on noninvasive tests. Ann Neurol 2008;63:758–769

Purpose Gliomatosis cerebri (GC) is a rare neoplastic disorder that may present as intractable epilepsy during early life. We report our experience regarding the evaluation and the surgical treatment of epilepsy in this population. Methods All children evaluated between 1990 and 2006 for surgery of epilepsy (n = 741) with pathologically proven GC were selected. Results We identified four male children with age at seizure onset ranging from 4 months to 11 years. Two had hemiparesis and one child with infantile spasms was developmentally delayed. Seizures occurred daily (n = 3) or monthly (n = 1). Ictal semiology was consistent with psychomotor seizures (n = 1), partial motor seizures (n = 2), and asymmetric epileptic spasms (n = 1). Surgery was symptomatic and aimed at debulking and controlling the epilepsy. Procedure was individually tailored based on the presurgical evaluation. Brain MRI revealed widespread hemispheric involvement (n = 3) or infiltration of the temporal lobe and basal ganglia (n = 1). Two patients were initially misdiagnosed as hemispheric cortical dysplasia and hemimegalencephaly. Scalp EEG was nonlocalizing in two cases, showed a right temporal focus in one case, and was not performed in one case. Interictal SPECT in one patient revealed widespread hemispheric hypoperfusion. Three cases were resected under ECoG guidance after a mean delay of 11 months after seizure onset. Following functional hemispherectomy (n = 1) or focal cortical resection (n = 2), all children were alive and seizure free with a mean follow-up of 48 months (2-5 years). No unexpected complication was reported. One nonoperated case was alive but still seizing after 15 months follow-up. Chemotherapy was associated in three cases. Conclusions GC is a rare cause of medically resistant epilepsy that may present in early life. The lack of a discrete lesion may lead to diagnostic uncertainty, especially in infancy. Epilepsy surgery is an effective therapy that can improve quality of life.

Summary Purpose To assess the predictive value of ictal single-photon emission computed tomography (SPECT) for outcome after excisional epilepsy surgery in a large population of children with focal cortical dysplasia (FCD). Methods One hundred seventy-three ictal SPECT studies in 106 children with histologically proven FCD were retrospectively analyzed. The extent and location of ictal hyperperfusion and completeness of surgical removal were assessed. Completeness of resection of epileptogenic regions defined by ictal SPECT, electroencephalography (EEG), and magnetic resonance imaging (MRI) were compared and correlated with postoperative seizure outcome. In addition, subcortical activation of the cerebellum, basal ganglia, and thalamus were analyzed. Key Findings The extent of hyperperfusion was focal or lobar in 58%, whereas multilobar activations occurred in only 32%; hemispheric or bilateral findings were rare. Favorable postsurgical seizure outcome was achieved in 67% patients with nonlocalized SPECT findings, 45% with nonresected ictal hyperperfusion, 36% with partially resected ictal hyperperfusion, and 86% when the zone of ictal hyperperfusion was completely resected (p = 0.000198). The favorable postsurgical outcome after complete removal of the SPECT hyperperfusion zone surpassed the 75% rate of seizure freedom in patients with removal of MRI/EEG-defined epileptogenic region. A similar predictive value of ictal SPECT for seizure outcome was found in nonoperated patients and subjects who were undergoing reoperation. Subcortical activation conferred no predictive value. Significance Ictal SPECT helps to define the epileptogenic zone in a high proportion of children with FCD undergoing surgical evaluation. Complete removal of both SPECT and MRI/EEG-defined regions is a strong predictor of surgical success and has important implications for surgical planning.

The authors report two cases with Horner's syndrome and thalamic lesions documented by CT and MRI. There is evidence of a right posterolateral thalamic hemorrhage in one case and a left anterior thalamic infarction in the other. The possible mechanisms of sympathetic pathway involvement in these cases are discussed. In the first case, Horner's syndrome could be due to compression of the posterior hypothalamic area-where the sympathetic pathway's superior center is supposed to be located-or of the posterior longitudinal fasciculus, by edema resulting from the hemorrhage. In the second case, there is evidence of a small infarction, which appears to be limited to the tuberothalamic territory. In this case, the authors postulate a possible role of the thalamus in the development of a Horner's syndrome, perhaps by way of thalamic projections to the hypothalamic sympathetic center.

Audiogenic seizures in genetically susceptible rodents are provoked by intense acoustic stimulations which result in a tonic seizure associated with a short flattening of the EEG. These seizures have been shown to involve primarily brainstem structures. Daily exposure to sound for 30-40 days produced a permanent change in the evoked seizure with development of facial myoclonias, rearing and falling, or of tonic-clonic seizures accompanied by high amplitude cortical spike-and-wave discharges. Kindled audiogenic seizures appear similar to seizures kindled from amygdala or hippocampus, suggesting that repeated auditory stimulations cause a progressive propagation of the epileptic discharge toward limbic structures. To verify this hypothesis, the behavioral and EEG development of electrical hippocampal kindling has been studied in 7 non epileptic controls (NE), 8 acoustic susceptible (AS), and 8 audiogenic kindled rats (KAS). The behavioral and EEG development of the electrical hippocampal kindling was similar in the AS and the NE rats. However, 2 animals in the AS group but no controls exhibited behavioral running and bouncing during the course of hippocampal kindling. In the KAS group, the hippocampal kindling was clearly facilitated as compared to NE and AS: behavioral stage greater than or equal to 5 was reached in a mean of 4 stimulations in KAS versus 30 and 22 stimulations respectively in NE and AS groups. This positive transfer phenomenon suggests that during kindling of audiogenic seizures, epileptic discharge spreads from the brainstem to the forebrain and progressively involves the hippocampus.

Averaged responses of elbow muscles to action potentials of 37 single motor cortex cells were analyzed in two Macaca fascicularis monkeys during performance of a submaximal but high level isometric contraction. Post-spike facilitations (PSFs) of the rectified electromyographic activity (EMG) were frequently (72%) observed. They consisted of PSFs largely distributed in agonistic (biceps brachii and brachioradialis) and antagonistic (triceps brachii) muscles. Some post-spike inhibitions (7%) were also noted. As compared with distal muscles PSFs, most of the proximal PSFs were of lower amplitude, probably because of the higher level of the contractions. These PSFs were also of longer latency. The data indicate functional connectivity between motor cortical cells and proximal limb muscles. Cortical cells with oligosynaptic and even, for a few of them, with monosynaptic connections to the α-motoneurones may contribute to recruitment of motor units (MUs) involved in proximal limb muscle contraction.

Although benign forms of epilepsies with onset in infancy have recently been recognized, the occurrence of seizures in an infant or very young child is very often an event of great significance and the prognosis concerning both epilepsy and neuropsychological development must be guarded. No reliable clinical or electroencephalographic (EEG) markers that can predict the outcome have been described. In a retrospective series of 10 patients, we found a peculiar EEG pattern seen across sleep stages, but not in the waking state in infants whose first seizures appeared before the age of 1 year, and which were mostly complex focal. In all cases, follow-up showed a favourable outcome with complete seizure remission and no cognitive impairment. The specificity of these EEG changes was 100%, but the sensitivity was lower, since they were not seen in some of the infants with the same favourable outcome. We discuss the clinical similarities between our patients and those cases reported earlier by other authors as benign, non-familial or familial focal epilepsies, in whom, however, no interictal abnormalities had been seen on the EEG. Such EEG changes are probably specific to benign, self-limited, early onset focal epilepsies.

A 42-year-old woman developed eosinophilic meningitis after exposure to cats. Brain magnetic resonance imaging showed numerous areas of abnormal enhancement. A lung nodule contained eosinophilic infiltrates. Toxocara antibodies were present in serum and cerebrospinal fluid. Meningoencephalit

Summary: Purpose: In rodents, specific motor components of generalized convulsive seizures depend on two distinct anatomic substrates: (a) forebrain networks are responsible for facial and forelimb clonus with or without rearing and falling; and (b) brainstem networks are responsible for running-bouncing fits and tonic convulsions. To investigate the requirement of proprioceptive inputs in the generation of these two different types of seizures, we compared the effects of neuromuscular blockade by D-tubocurarine on the EEG expression of brainstem and forebrain-triggered seizures. Methods: Unilateral electrical stimulations were applied for 50 consecutive days in freely moving male adult rats through a bipolar electrode aimed at the dorsal hippocampus (n = S), the occipital cortex (n = 4), the inferior colliculus (n = 6), or the midbrain reticular formation (n = 6). Two days after the last stimulation, rats were paralyzed with d-tubocurarine and stimulated in the same way. Results: In brainstem structures, the first electrical stimulation induced tonic seizures concomitant with low-voltage cortical activity; repetition of daily stimulations progressively induced tonic-clonic seizures associated with high-amplitude cortical spike-wave discharges. After immobilization by d-tubocurarine, brainstem stimulations failed to induce any EEG paroxysm. In forebrain structures, repeated electrical stimulations produced a classic kindling with progressive occurrence of clonic seizures associated with large cortical discharges; d-tubocurarine left unchanged the EEG pattern of these latter seizures. Conclusions: These data suggest that proprioceptive reafferentation resulting from movement is necessary for the generation of self-sustained brainstem seizures but is not implicated in the elaboration of forebrain seizures.

To the Editor: Ifosfamide is a chemotherapeutic agent used in the treatment of cervical carcinoma, soft-tissue sarcomas, and germ-cell tumors. Myelosuppression is common. Hemorrhagic cystitis is prevented by the administration of mesna. Confusion and coma have been associated with the use of ifosfamide, and antiepileptic drugs may be required.1 Ifosfamide may also cause a dose-dependent encephalopathy in the presence of a pelvic mass that obstructs the ureters or intrinsic renal impairment.2 The drug is marketed in the United States as Ifex (Bristol-Myers Oncology Division, Princeton, N.J.). We report the reversal of ifosfamide-associated encephalopathy with methylene blue in a 68-year-old woman . . .

The behavioral and EEC concomitants of kindling produced by daily electrical stimulation of the inferior colliculus have been recorded in three series of Wistar rats: 1.(1) non epileptic controls (NE), 2.(2) rats susceptible to audiogenic seizures (AS), 3.(3) acoustically susceptible rats with prior kindling of audiogenic seizures by repeated sound exposure (KAS). Repeated collicular stimulation produced behavioral and EEG changes which were similar in the AS and the NE rats. The tonic seizure without cortical discharges elicited by the first stimulation progressively changed into tonic-clonic seizures with sustained cortical EEG discharges after more than 20 stimulations. In the KAS group, the electrical collicular kindling was clearly accelerated: kindled tonic-clonic seizures and their EEG discharges already occurred after one to five electrical stimulations. Similarly, after completion of electrical collicular kindling in AS, sound stimulations immediately induced characteristic kindled audiogenic seizures. The immediate reciprocal positive transfer observed between kindling of audiogenic seizures and kindling of seizures induced by electrical stimulation of the inferior colliculus suggests that kindling of these two brain-stem seizures involves similar structures and mechanisms.

We report a girl 3 years and 6 months old with onset of aphasia at age 3 years and 3 months. There was no evidence of brain damage and there were no seizures. The neuropsychological evaluation showed that the girl tended to be right-handed, that aphasia was global and that other higher cortical functions seemed to be preserved. Isolated spikes and spikes-and-wave were recorded during wake over the right temporal region with rare independent contralateral abnormalities. During polysomnography (PSG), the physiological patterns of sleep were preserved and right temporal epileptiform discharges were significantly increased in all sleep stages. Maximal activation was obtained at sleep onset and during rapid eye movement (REM) sleep periods, when focal abnormalities became continuous and spread contralaterally. Repeat PSGs showed that the activation profile retained this particular trait, although subclinical discharges tended to increase during slow wave sleep (SWS). This pattern of subclinical temporal status epilepticus during REM sleep differs from the characteristic activation profile found in the syndrome of continuous spikes-and-waves during SWS. However, this profile was transient and all epileptiform changes disappeared during clinical recovery at 18 months of follow-up.

Electrical stimulations were applied daily for 40 days to the dorsal tegmentum in 9 rats through chronically implanted bipolar electrodes. The intensity of current (2 s trains of 50 Hz, 1 ms monophasic square waves) necessary to trigger a full tonic seizure was determined and applied for all further stimulations. Initial stimulations induced a tonic seizure with a low voltage fast electrocorticographic activity. After repeated stimulations, high amplitude spike and wave discharges developed over the cortex, their duration exceeding 50 s at the 40th stimulation. Simultaneously, the tonic seizures evolved into tonic-clonic fits with bilateral myoclonias following the tonic phase. These EEG and behavioral modifications persisted for 30 days after the last stimulus. These results demonstrate that kindling may be obtained from brainstem structures.