Hippocampal damage after prolonged febrile seizure: One case in a consecutive prospective series
ABSTRACT The factors that contribute to hippocampal damage as a sequela, and its frequency, in patients experiencing febrile status epilepticus, remain unknown. Of the 472 patients with febrile seizures admitted to our hospital between February 2004 and August 2008, 77 had prolonged seizures. Among them, 59 underwent magnetic resonance imaging (MRI). A 21-month-old girl showed hippocampal changes after her first episode of febrile status epilepticus. The seizure lasted about 35 min, with eye deviation to the right and ictal rhythmic discharges in the left hemisphere. MRI at 72 h after the seizure revealed high-signal intensities in T(2) and fluid-attenuated inversion recovery (FLAIR) images of the left hippocampus. Left hippocampal volume diminished over the next several months suggesting the occurrence of neuronal cell death. In no other cases, not even those with longer seizure durations, did significant hippocampal changes develop. The frequency of hippocampal damage was 1.7% in this case series. The involvement of factors other than seizure duration merits further study.
Full-textDOI: · Available from: Shuichi Shimakawa, Nov 18, 2014
- SourceAvailable from: Junya Tanaka
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- "Although excessive glutamate stimulation during seizures may lead to neuronal death, hyperthermia-induced seizures themselves do not cause neuronal death in rat hippocampus . However, retrospective studies have demonstrated a significant relationship between a history of prolonged FS during early childhood and TLE-HS as sequel to hippocampal neuronal death . In the current study, PF suppressed cell death induced by glutamate in cultured hippocampal neurons. "
ABSTRACT: Febrile seizures (FS) is the most common convulsive disorder in children, but there have been no clinical and experimental studies of the possible treatment of FS with herbal medicines, which are widely used in Asian countries. Paeoniflorin (PF) is a major bioactive component of Radix Paeoniae alba, and PF-containing herbal medicines have been used for neuromuscular, neuropsychiatric, and neurodegenerative disorders. In this study, we analyzed the anticonvulsive effect of PF and Keishikashakuyaku-to (KS; a PF-containing herbal medicine) for hyperthermia-induced seizures in immature rats as a model of human FS. When immature (P5) male rats were administered PF or KS for 10 days, hyperthermia-induced seizures were significantly suppressed compared to control rats. In cultured hippocampal neurons, PF suppressed glutamate-induced elevation of intracellular Ca(2+) ([Ca(2+)](i)), glutamate receptor-mediated membrane depolarization, and glutamate-induced neuronal death. In addition, PF partially suppressed the elevation in [Ca(2+)](i) induced by activation of the metabotropic glutamate receptor 5 (mGluR5), but not that mediated by α-amino-3-hydroxy-5-methyl-4-isoxazolpropionic acid (AMPA) or N-methyl-D-aspartate (NMDA) receptors. However, PF did not affect production or release of γ-aminobutyric acid (GABA) in hippocampal neurons. These results suggest that PF or PF-containing herbal medicines exert anticonvulsive effects at least in part by preventing mGluR5-dependent [Ca(2+)](i) elevations. Thus, it could be a possible candidate for the treatment of FS in children.PLoS ONE 08/2012; 7(8):e42920. DOI:10.1371/journal.pone.0042920 · 3.23 Impact Factor
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ABSTRACT: The blood-brain barrier (BBB) is located within a unique anatomic interface and has functional ramifications to most of the brain and blood cells. In the past, the BBB was considered a pharmacokinetic impediment to antiepileptic drug penetration into the brain; nowadays it is becoming increasingly evident that targeting of the damaged or dysfunctional BBB may represent a therapeutic approach to reduce seizure burden. Several studies have investigated the mechanisms linking the onset and sustainment of seizures to BBB dysfunction. These studies have shown that the BBB is at the crossroad of a multifactorial pathophysiologic process that involves changes in brain milieu, altered neuroglial physiology, development of brain inflammation, leukocyte-endothelial interactions, faulty angiogenesis, and hemodynamic changes leading to energy mismatch. A number of knowledge gaps, conflicting points of view, and discordance between clinical and experimental data currently characterize this field of neuroscience. As more pieces are added to this puzzle, it is apparent that each mechanism needs to be validated in an appropriate clinical context. We now offer a BBB-centric view of seizure disorders, linking several aspects of seizures and epilepsy physiopathology to BBB dysfunction. We have reviewed the therapeutic, antiseizure effect of drugs that promote BBB repair. We also present BBB neuroimaging as a tool to correlate BBB restoration to seizure mitigation. Add-on cerebrovascular drug could be of efficacy in reducing seizure burden when used in association with neuronal antiepileptic drugs.Epilepsia 08/2012; 53(11). DOI:10.1111/j.1528-1167.2012.03637.x · 4.57 Impact Factor
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ABSTRACT: Children with a history of a prolonged febrile seizure show signs of acute hippocampal injury on magnetic resonance imaging. In addition, animal studies have shown that adult rats who suffered febrile seizures during development reveal memory impairments. Together, these lines of evidence suggest that memory impairments related to hippocampal injury may be evident in human children after prolonged febrile seizures. The current study addressed this question by investigating memory abilities in 26 children soon after a prolonged febrile seizure (median: 37.5 days) and compared their results to those of 37 normally developing children. Fifteen patients were reassessed at a mean of 12.5 months after their first assessment to determine the transiency of any observed effects. We used the visual paired comparison task to test memory abilities in our group, as this task does not depend on verbal abilities and also because successful performance on the task has been proven to depend on the presence of functional hippocampi. Our findings show that patients perform as well as controls in the absence of a delay between the learning phase and the memory test, suggesting that both groups are able to form representations of the presented stimulus. However, after a 5-min delay, patients' recognition memory is not different from chance, and comparison of patients and controls points to an accelerated forgetting rate in the prolonged febrile seizure group. The patients' performance was not related to the time elapsed from the acute event or the duration of the prolonged febrile seizure, suggesting that the observed effect is not a by-product of the seizure itself or a delayed effect of medication administered to terminate the seizure. By contrast, performance was related to hippocampal size; participants with the smallest mean hippocampal volumes revealed the biggest drop in performance from the immediate to the delayed paradigm. At follow-up, children were still showing deficiencies in recognizing a face after a 5-min delay. Similarly, this suggests that the observed memory impairments are not a transient effect of the prolonged febrile seizures. This is the first report of such impairments in humans, and it is clinically significant given the links between mesial temporal sclerosis and prolonged febrile seizures. The persistence of these impairments a year onwards signals the potential benefits of intervention in these children who run the risk of developing episodic memory deficits in later childhood.Brain 09/2012; 135(Pt 10):3153-64. DOI:10.1093/brain/aws213 · 9.20 Impact Factor