SEIZURES AND EPILEPSY


Status Epilepticus

Seizure Disorders in Children

Febrile Seizures

I. Classification

  1. "Idiopathic" epilepsy = no known cause
  2. "Cryptogenic" epilepsy = presumed to be due to an unidentified structural abnormality
  3. "Symptomatic" epilepsy = due to a known structural abnormality

II. Diagnosing the cause of seizures

  1. In a case series of 300 pts (mean age 31y) presenting with first seizure and no known metabolic or neurologic cause for sz, EEG was most likely to show epileptiform discharges if done < 24h after the seizure. Neuroimaging revealed epileptogenic lesions in 13% and tumors in 6%. MRI was more sensitive for tumors than CT (Lancet 352:1007, 1998--JW)
  2. Psychogenic seizures (aka "pseudoseizures", "nonepileptic seizures")
    1. Defined as a behavior disorder that can mimic a seizure but is not associated with epileptic brain activity
    2. Gold standard for diagnosis is video-assisted EEG monitoring that demonstrates absence of epileptiform activity at the time of the seizure-like event
    3. In a study in 35 patients with seizure-like events, features associated with eventual diagnosis of psychogenic seizure (as opposed to authentic seizure) included the following.  Features associated with eventual diagnosis of authentic seizure included abrupt onset, eye opening or widening, and postictal confusion or sleep (Ann. Neurol. 69:997, 2011-JW)
      1. Preserved awareness
      2. Eye flutter or closed eyes
      3. Ability of a bystander to intensify or alleviate the seizure
    4. Serum prolactin is usually elevated 10-20min after a true generalized tonic-clonic or complex partial seizure
    5. Psychogenic seizures may be associated with mood and personality disorders and also with true epilepsy!

III. Treatment of seizures-See also Seizure Disorders in Children

  1. Deciding whether or not to initiate anticonvulsants after a first seizure
    1. In a study of 1,443 pts with initial seizure and no evidence of progressive illness randomized to immediate initiation of anticonvulsant drugs (chosen by their physician) vs. no treatment unless seizures recur, over 5y f/u, 53% of non-treated pts had recurrent seizures (compared with 43% of treated patients), and 41% of non-treated pts were on anticonvulsants (compared with 60% of treated patients) (Lancet 365:2007, 2005--JW)
  2. Choice of anticonvulsant medication
    1. In elderly
      1. In a study in 593 pts (mean age 72y) with newly-diagnosed seizures (mostly from cerebrovascular etiologies) randomized to gabapentin, lamotrigine, or carbamazepine (doses titrated to response & side effects), carbamazepine recipients had higher incidence of discontinuing assigned med due to adverse effects than the other two drugs (64% vs. 44% with lamotrigine and 51% with gabapentin); no sig. diff. in seizure control among the drugs  (Neurology 64:1868, 2005--JW)
  3. Surgery for temporal-lobe epilepsy
    1. In a randomized trial of 80 pts (mean age 35) with refractory temporal-lobe epilepsy randomized to continued medical tx vs. surgery, surgery was ass'd with sig. greater likelihood of being seizure-free and having higher quality-of-life than control group (NEJM 345:311, 2001--JW)
    2. Radiosurgery is also an option in some cases but tends to take longer than invasive surgery for full effectiveness
  4. Predicting response to treatment
    1. Factors ass'd with refractory (not treatable by meds) epilepsy in a 5y study of a cohort of 525 pts 9-93yo (29% idiopathic; 45% cryptogenic, 29% symptomatic); symptomatic or cryptogenic epilepsy ass'd with higher rates of refractoriness (43% and 39%, respectively) than idiopathic (26%); also, h/o > 20 sz in the past ass'd with higher risk of refractoriness (51% vs. 29%)