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Source: Rogers SJ, Cavazos JE. Epilepsy. In: DiPiro JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM, eds. Pharmacotherapy: A Pathophysiologic Approach. 8th ed. http://www.accesspharmacy.com/content.aspx?aid=7985219. Accessed July 18, 2012.

  • Seizure disorder

  • Occurrence of at least two unprovoked seizures with or without convulsions separated by at least 24 hours.

  • Genetic predisposition.
  • Seizure onset in elderly may be associated with strokes, neurodegenerative disorders (e.g., Alzheimer's disease), and other conditions.
  • Unprovoked seizures without identifiable cause are called idiopathic or cryptogenic epilepsy.

  • Seizure results from excessive discharge of cortical neurons.
  • Mechanisms contributing to neuronal hyperexcitability may include:
    • Alterations of ion channels in neuronal membranes
    • Biochemical modifications of receptors
    • Modulation of second messaging systems and gene expression
    • Changes in extracellular ion concentrations
    • Alterations in neurotransmitter uptake and metabolism in glial cells
    • Modification in ratio and function of inhibitory circuits
    • Local imbalances between main neurotransmitters (e.g., glutamate, γ-aminobutyric acid [GABA]) and neuromodulators (e.g., acetylcholine, norepinephrine, and serotonin)

  • Incidence: 44 per 100,000 person-years.
  • Approximately 125,000 new epilepsy cases occur in United States each year.
    • Only 30% in people younger than 18 years at time of diagnosis.
    • Bimodal distribution in occurrence of first seizure, with one peak in newborn and young children and second peak in patients older than 65 years.

  • Patients with mental retardation, cerebral palsy, head injury, or strokes at an increased risk for seizures and epilepsy.
  • Seizures can be precipitated by:
    • Hyperventilation
    • Sleep deprivation
    • Sensory stimuli
    • Emotional stress
    • Hormonal changes with menses, puberty, or pregnancy
  • Drugs that may provoke seizures include:
    • Theophylline
    • Alcohol
    • Phenothiazines
    • Antidepressants (especially maprotiline or bupropion)
    • Street drugs
  • Perinatal injuries and small birth weight are risk factors for partial-onset seizures.

  • Obtaining accurate history and description of event (including time course) from third party important because clinician often not in a position to witness seizures.

Signs and Symptoms

  • Symptoms depend on seizure type. Seizures can vary among patients but tend to be fixed within individual.
    • Complex partial seizures may include somatosensory or focal motor features and are associated with altered consciousness.
    • Absence seizures have only very brief (seconds) periods of altered consciousness.
    • Generalized tonic-clonic (GTC) seizures may be preceded by premonitory symptoms (aura).
      • Tonic-clonic seizures begin with short tonic muscle contraction followed by period of rigidity and clonic movements.
      • The patient may lose sphincter control, bite tongue, or become cyanotic.
      • Episode may be followed by unconsciousness, and patient frequently goes into deep sleep.
  • Usually no objective signs of epilepsy between seizure episodes.

Means of Confirmation and Diagnosis

  • Ask patient and family to characterize seizures for:
    • Frequency
    • Duration
    • Precipitating factors
    • Time of occurrence
    • Presence of aura
    • Ictal activity
    • Postictal state
  • Physical exam may help identify underlying causes.

Laboratory Tests

  • Laboratory tests to rule out treatable causes of seizures include:
    • Serum glucose
    • Electrolytes
    • Calcium
    • Magnesium
  • Complete blood count (CBC), serum creatinine, and liver function tests may also be obtained.
  • Serum prolactin level obtained within 10–20 minutes of tonic-clonic seizure may be elevated, which can help differentiate seizure activity from ...

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