The International League Against Epilepsy (ILAE) in 2011 recommended abandoning these terms for reasons of clarity and instead trying to place individual cases into one of the following three groups: genetic, structural/metabolic, and unknown. The new terms are more immediately clear in their meaning, except that the structural and metabolic group includes cases that have a genetic component that does not always directly lead to the condition. Only the genetic grouping has a known direct genetic cause. "Unknown" cases may be of unknown genetic, structural, metabolic, or other unknown cause.The old terminology was defined by the ILAE as follows:
symptomatic:  the epilepsy is the consequence of a known or suspected disorder of the central nervous system. cryptogenic: this refers to a disorder whose cause is hidden or occult. Cryptogenic epilepsies are presumed to be symptomatic. idiopathic:  there is no underlying cause other than a possible hereditary predisposition.The remainder of this section will refer to the older terminology. Symptomatic
If a cause presents itself, the syndrome is referred to as symptomatic West syndrome, as the attacks manifest as a symptom of another problem. Almost any cause of brain damage could be associated, and these are divided into prenatal, perinatal, and post-natal. The following is a partial list:
In around one third of the children, there is evidence of a profound organic disorder of the brain. This includes:microcephaly
cortical dysplasia
cerebral atrophy
lissencephaly
bacterial meningitis
phakomatoses (e.g. tuberous sclerosis)
Aicardi syndrome
cephalhematoma and
vascular malformation. Furthermore, other causes increasingly being named in the literature are:
Incontinentia pigmenti
Foix–Chavany–Marie syndrome
Patau syndrome (trisomy 13)
Sturge–Weber syndrome
neurometabolic diseases
congential infections (e.g.
Rarely, bites may cause widespread symptoms, with occasional fatalities.There are a few spiders that can bite human skin and cause a skin reaction, but spiders are blamed for many more reactions. In particular the misdiagnosis of infections and other skin ailments are commonly attributed to brown recluses. Cause
Spiders do not feed on humans and typically bites occur as a defense mechanism. This can occur from unintentional contact or trapping of the spider. Most spiders have fangs too small to penetrate human skin. Most bites by species large enough for their bites to be noticeable will have no serious medical consequences.Medically significant spider venoms include various combinations and concentrations of necrotic agents, neurotoxins, and pharmacologically active compounds such as serotonin. Worldwide only two spider venoms have impact on humans—those of the widow and recluse spiders. Unlike snake and scorpion envenomation, widow and recluse species bites rarely have fatal consequences. In addition to the widespread widow and recluse spiders, some spider families found exclusively in remote tropical regions have a lethal neurotoxic venom: the wandering spider in Brazil and the funnel web in Australia. However, due to limited contact between these spiders and humans, deaths have always been rare, and since the introduction of anti-venom in Australia, there have been no funnel web related deaths. Pathophysiology
A primary concern of the bite of a spider is the effect of its venom. A spider envenomation occurs whenever a spider injects venom into the skin.