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epileptic_seizure

Epileptic seizure

Epileptic seizures (colloquially a fit) are brief episodes of “abnormal excessive or synchronous neuronal activity in the brain”.

The outward effect can vary from wild thrashing movement (tonic-clonic seizure) to as mild as a brief loss of awareness (absence seizure). The syndrome of recurrent, unprovoked seizures is termed epilepsy, but seizures can occur in people who do not have epilepsy. Additionally there are a number of conditions that look like seizures but are not.

After a first seizure, treatment is generally not needed unless specific problems are found on either electroencephalogram or imaging of the brain.

About 5–10% of all people will have an unprovoked seizure by the age of 80 and the chance of experiencing a second seizure is between 40% and 50%.

Epilepsy affects about 1% of the population currently and affects about 4% of the population at some point in time.

Most of affected, nearly 80%, live in developing countries.

Types

Etiology

Seizures may be manifestation of intracranial tumor (IT) and demand thorough neurological evaluation. Tumor histology does not seem to affect seizure predisposition. Most seizures associated with IT occur in fifth and sixth decades of life and affect frontal lobe most often 1).

Thery are a common symptom in patients with low grade glioma (LGG), negatively influencing quality of life, if uncontrolled.

Seizures are the most frequent and often the only manifestation in patients with brain tumors of glial origin, and medical treatment appears to be less effective for seizure control because of incomplete understanding of underlying pathophysiological mechanisms. Particularly, patients with slow-growing low-grade tumors (low-grade gliomas (LGGs) and glioneuronal tumors) in cortical areas of the temporal lobe are more frequently associated with seizures than high-grade tumors 2) 3) 4).

Clinically, tumor-related seizures manifest as simple or complex partial seizures with or without secondary generalization and, in more than 50% of cases, are pharmacoresistant. When uncontrolled, tumor-related epilepsy affects patients' quality of life, causes cognitive deterioration, and may result in significant morbidity 5) 6).

Seizures during status epilepticus (SE) cause neuronal death and induce cyclooxygenase-2 (COX-2).

Traumatic brain injury (TBI)

Seizures may cause diagnostic confusion and be a source of metabolic stress after Pediatric traumatic brain injury. The incidence of electroencephalography (EEG)-confirmed seizures and of subclinical seizures in the pediatric population with TBI is not well known.

Seizure after aneurysmal subarachnoid hemorrhage

Treatment

Besides antiepileptic drugs, antitumour treatment might contribute to a reduction in seizure frequency. Temozolomide may contribute to an important reduction in seizure frequency in patients with LGG. Seizure reduction following TMZ treatment has prognostic significance and may serve as an important clinical outcome measure in patients with LGG 7).

A high-fat, low-carbohydrate diet, often referred to as a ketogenic diet (KD), has been suggested to reduce frequency and severity of chronic pediatric and adult seizures.

1)
Mezue WC, Ndubuisi CA, Chikani MC, Onyia E, Iroegbu L, Ohaegbulam SC. Epilepsy in primary intracranial tumors in a neurosurgical hospital in Enugu, South-East Nigeria. Niger J Clin Pract. 2015 Sep-Oct;18(5):681-6. doi: 10.4103/1119-3077.158980. PubMed PMID: 26096250.
2)
van Breemen MS, Wilms EB, Vecht CJ. Epilepsy in patients with brain tumours: epidemiology, mechanisms, and management. Lancet Neurol. 2007;6:421–430. doi: 10.1016/S1474-4422(07)70103-5.
3)
Chang EF, Potts MB, Keles GE, Lamborn KR, Chang SM, Barbaro NM, et al. Seizure characteristics and control following resection in 332 patients with low-grade gliomas. J Neurosurg. 2008;108:227–235. doi: 10.3171/JNS/2008/108/2/0227.
4)
Lee JW, Wen PY, Hurwitz S, Black P, Kesari S, Drappatz J, et al. Morphological characteristics of brain tumors causing seizures. Arch Neurol. 2010;67:336–342.
5)
Klein M, Engelberts NH, van der Ploeg HM, et al. Epilepsy in low-grade gliomas: the impact on cognitive function and quality of life. Ann Neurol. 2003;54:514–520.
6)
Taphoorn MJ, Klein M. Cognitive deficits in adult patients with brain tumours. Lancet Neurol. 2004;3:159–168.
7)
Koekkoek JA, Dirven L, Heimans JJ, Postma TJ, Vos MJ, Reijneveld JC, Taphoorn MJ. Seizure reduction in a low-grade glioma: more than a beneficial side effect of temozolomide. J Neurol Neurosurg Psychiatry. 2014 Jul 23. pii: jnnp-2014-308136. doi: 10.1136/jnnp-2014-308136. [Epub ahead of print] PubMed PMID: 25055819.
epileptic_seizure.txt · Last modified: 2017/09/07 15:41 by administrador