Symptomatic epilepsies

Symptomatic epilepsies There is an identifiable cause for the seizures, such as trauma or hypoxia. 

Tables 37-3 and 37-4 list the genes responsible for idiopathic and symptomatic epilepsies in humans, respectively. Table 37-5 lists genes identified as causing epilepsy...

The epilepsies are estimated to affect 20-40 million individuals worldwide and are more common in children than in adults. They are classified into two broad groups primary or idiopathic epilepsy is the term applied to those types for which no specific cause can be identified, and secondary or symptomatic epilepsy arises when the symptoms are associated with trauma, neoplasm, infection, cerebrovascular disease or some other physically induced lesion of the brain. Seizures that accompany severe metabolic disturbances are not classified as epilepsy. 

Crosby AH (2004) Infantile-onset symptomatic epilepsy syndrome caused by a homozygous loss-of-function mutation of GM3 synthase. Nat Genet 36 1225-1229... 

Epilepsy is commonly categorised as idiopathic, symptomatic, probable symptomatic (previously known as cryptogenic) and reactive. Idiopathic epilepsies are presumed to have an underlying genetic canse indeed ion channelopathies have been identified in several human idiopathic epilepsy syndromes (Gardiner, 2(X)5). Symptomatic epilepsies, which are thought to account for up to 50% of all epilepsy cases (Delorenzo et al., 2005), arise secondary to an underlying identifiable brain insult or lesion such as stroke, intracranial neoplasia or encephalitis. Probable... 

Observational studies Topiramate has been retrospectively evaluated in 227 patients with symptomatic epilepsy, of whom 12 withdrew because of adverse effects [292 ]. The incidence of adverse effects was 36% and the most common were weight loss, memory impairment, paresthesia, headache, and dizziness, most were mild to moderate in intensity and transient. 

One patient who developed impaired vision while taking topiramate for symptomatic epilepsy had signs of a maculopathy [309" ]. The topiramate was withdrawn, but vision failed to improve significantly over 6 months of follow-up. The authors speculated that topiramate, like vigabatrin, may cause persistent visual impairment through direct retinal toxicity. 

Lu Y, Yu W, Wang X. Efficacy of topira-mate in adult patients with symptomatic epilepsy an open-label, long-term, retrospective observation. CNS Drugs 2009 23 (4) 351-9. 

Epilepsy is a clinical disorder characterized by spontaneous, recurrent seizures arising from excessive electrical activity in certain parts of the brain [51]. Currently available drugs, such as phenytoin, carbamazepine, valproic acid, lamotrigine, and topiramate (for molecular structures see Fig. 6), provide symptomatic seizure suppression in only 60-70% of those receiving treatment [52-54]. These drugs are also associated with unwanted side... 

A complete description of a patient s epilepsy should include the seizure type with the epilepsy or syndrome type (i.e., idiopathic, symptomatic, or cryptogenic). 

The epilepsies constitute a common, serious neurological disorder in humans, affecting approximately 60 million people worldwide. Well in excess of 40 distinct epileptic syndromes have been identified to date. Current treatment is only symptomatic except in uncommon instances when surgical treatment is possible. While available antiseizure medications target ion channels such as the y-amino-butyric acid (GABA)a receptor and voltage activated sodium (Na+) channels, current research seeks to elucidate the cellular and molecular mechanisms by which a normal brain becomes epileptic. Hopefully, this research will lead to the identification of new targets for which small molecules can be identified and used for prevention or cure of epilepsy. 

TABLE 37-4 Symptomatic human epilepsies genes and syndromes ... 

Minagawa K, Sueoka H. [Seizure exacerbation by the use of leuprorelin acetate for treatment of central precocious puberty in a female patient with symptomatic localization-related epilepsy. ]No To Hattatsu 1999 31(5) 466-8. 

---