Epilepsy etiology

Both focal and generalized epilepsies are heterogeneous with respect to their etiology and the principles of therapy. 

For nearly 80% of patients with epilepsy, the underlying etiology is unknown.8 The most common recognized causes of epilepsy are head trauma and stroke. Developmental and genetic defects are the cause of about 5% of cases of epilepsy. Central nervous system (CNS) tumors, central nervous system infections, and neurodegen-erative diseases are other common causes. Other important causes of epilepsy are human immunodeficiency virus infection or neuro-cysticercosis infection, primarily occurring in Latin America. 

Classification of epilepsies and epilepsy syndromes is helpful in determining appropriate pharmacotherapy. This classification scheme is based on the type of seizures a patient has and an attempt to identify the etiology of the epilepsy or epilepsy syndrome. 

Idiopathic epilepsies These syndromes are thought to be due to genetic alterations, but the underlying etiology is not identified. Neurologic functions are completely normal apart from the occurrence of seizures. 

GABA) mechanisms, and blockade of glutamatergic mechanisms. Because epilepsy is a disease with multiple etiologies, these combinations of mechanisms explain the clinical efficacy of this drug in this disease [78]. 

Apart from this epileptic seizure classification, an additional classification specifies epileptic syndromes, which refer to a cluster of symptoms frequently occurring together and include seizure type, etiology, age of onset and other factors [2]. The epileptic syndromes have been categorized into partial versus generalized epilepsies. The partial... 

Epilepsy is a chronic brain disease of diverse etiology it is characterized by recurrent paroxysmal episodes of uncontrolled excitation of brain neurons. Involving larger or smaller parts of the brain, the electrical discharge is evident in the electroencephalogram (EEG) as synchronized rhythmic activity and manifests itself in motor, sensory, psychic, and vegetative (visceral) phenomena Because both the affected brain region and the cause of abnormal excitability may differ, epileptic seizures can take many forms. Erom a pharmaco-therapeutic viewpoint, these may be classified as ... 

The mechanism of antiepileptic drags is not sufficiently clear, as the etiology of epilepsy is not yet completely understood. 

Epilepsy affects 0.5% of the world s population and can have a multitude of underlying etiologies, including several mutations in CNS sodium channels. Sodium channel mutations linked to human epileptic syndromes typically shift activation to more hyperpolarized potentials, slow inactivation kinetics, accelerate recovery from inactivation, and/or increase the persistent current [48]. Seemingly paradoxically, some mutations appear to result in non-functional channels [48-50]. 

Interest in the possibility of human Mn deficiency increased in 1979 with the report of Papavasiliou and co-workers (6) that some epileptics were characterized by lower than normal blood concentrations of Mn. Based on the knowledge that Mn deficiency in experimental animals could result in increased susceptibility to electroshock and drug-induced seizures (7), these authors suggested that Mn deficiency could be an etiological factor for epilepsy in some individuals. 

Increased xanthurenic acid excretion after 10 g DL-tryptophan was demonstrated by Lerner et al. (L3) in 3 of 5 patients with rum fits. This metabolic defect was corrected by pyridoxine administration, as observed in a second tryptophan load test. Using the same xanthurenic acid test, significant vitamin Ba deficiency was not observed in patients with alcoholism and associated epilepsy, acute and chronic alcoholism, cirrhosis, acute hallucinosis-tremulousness, acute peripheral neuropathy, Wemicke-Korsakoff syndrome, and nonalcoholic, healthy individuals. It is postulated that pyridoxine deficiency is etiologically related to rum fits (L3). 

Wiegartz P, Seidenberg M, Woodard A, et al. Co-morbid psychiatric disorder in chronic epilepsy recognition and etiology of depression. Neurology... 

---