Epilepsy Seizures Causes

Epilepsy Seizures

Epilepsy represents a particular disease due to its special impact upon social perception in the community. It is a disease with potential complex consequences (economic, social, psychological) that affect both the patient and its family, and although the patients bear no more the stigma of being “devil possessed” they are not exempted from the burden of prejudices of all sorts.

Epilepsy is a chronic cerebral disorder manifested by recurrent, spontaneous epileptic seizures. An epileptic attack or a seizure is an acute, stereotype dysfunctional motor, sensory, sensorial, behavioral and/or consciousness alteration episode. It is caused by a sudden paroxysmal uncontrolled brain activation of a neuronal population followed by the abnormal function. This epileptic attack represents a symptom, not a disease.

Epilepsy

Repeated epileptic seizures represent seizures that repeat at short time intervals (minutes, hours) separated by a clinically normal state in between (called free interval)
Status epilepticus represents the circumstance in which there are repeated epileptic seizures that occur in close succession without regaining the consciousness (no free interval).
Morpheic epileptic seizures (hypnic seizures) are seizures occurring during sleep.
The epileptic syndrome represents an epileptic condition defined by clinical aspects (the semiological seizure type), electroencephalographical data, neurological status, etiology, prognosis and sometimes therapeutic response.

Prevalence

Epilepsy is a disease with a prevalence of 1% out of the general population meaning that an estimated 50 million of persons worldwide have the disease. Lifetime prevalence accounts for 2-5% (estimated as a percentage of the odds of an individual to experience a non-febrile seizure sometime during lifetime) as anyone with the right provoking circumstances (e.g electroconvulsive therapy) may have a seizure. There are two onset peaks one in the first decade of life and another one after 65-75 years.
Causes

There are many causes that can induce epileptic seizures. It is now of classical reference, the statistical data found in a survey in Minnesota, Rochester during 1935-1984 regarding the cause percentage in 100 new diagnosed epilepsy patients

• 65,5% idiopathic or cryptogenetic;
• 10,9% vascular cause;
• 8,0% congenital cause
• 5,5% post traumatic;
• 4,1% neoplastic (cancer)
• 3,5% degenerative;
• 2,5% infectious causes;

Epilepsy Causes can be classified as follows

Hereditary

• Chromosomial disorders (ex trisomy, chromosomial partial deletions)
• Mithocondrial DNA abnormalities (MELAS);
• Metabolic abnormalities (leucodistrophyi, mucopolyzaharidoses, galacto-zemia, pyridoxine deficit, etc.);
• Neurocutaneous diseases (tuberous sclerosis, neurofibromatosis Sturge-Weber syndrome);

Inherited

• Cortical dysplasia or neural migration disorders (schizencephalia, lisencephalia, neuronal heterotopias, complex cerebral malformations)
• Intrauterine central nervous system infections (rubella,toxoplasmosis, cytomegalovirus infections); – materno-fetal medication induced intoxication)
• Hypoxia or ischemic encephalophies as a consequence of dystocic births (pelvic dystocia, ombilical cord abnormalities, forceps aided births, pelvine presentations, prolonged births);
• Spontaneous cerebral hemorrhages (prematurity) or as a consequence of concussions (obstetrical trauma)
• Bacterial meningo-encephalitic infection (hemophilus lissteria ) or viral (herpetic);
• metabolic abnormalities (hypoglicemia, hypocalcemia etc.)
• Toxic encephalopathy due to drug intake by the mother –

Postnatal  (after birth)

• Viral encephalitis;
• Cerebral abscesses (bacterial, tuberculous)- 70% risk
• Parasitic (cysticercosis)
• Prion diseases (Jakob-Kreutzfeld)
• AIDS  associated with: opportunistic infections, cerebral lymphoma, cerebral infarction, encephalopathy, alcoholic withdrawal, electrolytic disturbances.-
• Cerebral trauma – late onset post traumatic seizures occurring after 1 week up to 5 years from the cerebral trauma with an estimated risk of 9-40%. It is more frequently the consequence of severe trauma such as cerebral concussion, to a lesser extent due to loss of consciousness, amnesia after 24 hours, age above 65 years, early onset seizures ;
• Cerebral tumors (accountable for 40% of focal late onset seizures), more frequently associated with slow evolution tumors such as disembrioplasic, meningiomas.
• Alcohol induced seizures occurs in 5-15 % of the alcoholics, it occurs either in acute intoxication or in the withdrawal period in(generally 48 hours after intake cessation) or as recurrent seizures due to chronic alcoholic intoxication;
• Medication related (neuroleptics, antidepressive, fenothyazine, phyline, oral antidiabetic or insulin, penicillin, antihystaminics and occasionally cyclosporin,  anaesthetics, radiological contrast substances, anticonvulsivant medication withdrawal – benzodiazepine, barbiturates) amphetamins, opioids, baclofen, can induce epileptic seizures
• Drugs related (cocaine, amphetamines, canabis, LSD)-
• Toxic substances related insecticides (organo-phospforic or chlorinated carbone monoxyde, organic solvants, antigel, insect poison)
• After cerebral infarcts (5-10%) mainly in the middle-cerebral artery territory;
• After cerebral hemorrages (2-25%) – the main cause of symptomatic epilepsy in elderly and generally occurs in the first 2 years after stroke as partial seizures with possible generalisation;
• Immune system diseases (disseminated lupus erythematous, myasthenia gravis,: primary IgA deficit, multiple sclerosis, other cerebral vasculitis
• Degenerative diseases (Alzheimer disease)