Tags

Type your tag names separated by a space and hit enter

Seizure Disorder, Focal

Seizure Disorder, Focal is a topic covered in the 5-Minute Clinical Consult.

To view the entire topic, please or purchase a subscription.

Medicine Central™ is a quick-consult mobile and web resource that includes diagnosis, treatment, medications, and follow-up information on over 700 diseases and disorders, providing fast answers—anytime, anywhere. Explore these free sample topics:

Medicine Central

-- The first section of this topic is shown below --

Basics

Description

  • Seizures occur when abnormal synchronous neuronal discharges in the brain cause transient cortical dysfunction.
  • Generalized seizures involve bilateral cerebral cortex from the seizure’s onset.
  • Focal or localization-related seizures have previously been referred to as partial seizures.
  • Focal seizures originate from a discrete focus limited to one hemisphere in the cerebral cortex.
  • Focal seizures are further divided into aware versus unaware and motor versus nonmotor.
  • Presence of impaired awareness is defined as the inability to respond normally to exogenous stimuli due to altered awareness and/or responsiveness:
    • Focal seizures with impairment of awareness (formerly “complex partial seizures”)
    • Focal seizures without impairment of awareness (formerly “simple partial seizures”)

Epidemiology

Prevalence
Focal seizures occur in 20/100,000 persons in the United States.

Etiology and Pathophysiology

  • Focal seizures begin when a localized seizure focus produces an abnormal, synchronized depolarization that spreads to a discrete portion of the surrounding cortex.
  • The area of cortex involved in the seizure determines the symptoms; for example, an epileptogenic focus in motor cortex produces contralateral motor symptoms.
  • In some cases, etiology is related to structural abnormalities that are susceptible to epileptogenesis. Most common etiologies vary by life stage:
    • Early childhood: developmental/congenital malformation, trauma
    • Young adults: developmental, infection, trauma
    • Adults 40 to 60 years of age: cerebrovascular insult, infection, trauma
    • Adults >60 years of age: cerebrovascular insult, trauma, neoplasm
  • A common cause of focal seizure with impaired awareness is mesial temporal sclerosis.

Genetics
Benign rolandic epilepsy, a form of focal seizure disorder, has an autosomal dominant inheritance pattern with penetrance depending on multiple factors.

Risk Factors

  • History of traumatic brain injury (TBI)
  • Children exposed to a thiamine-deficient formula

Commonly Associated Conditions

Epilepsy patients have a higher incidence of depression than the general population.

-- To view the remaining sections of this topic, please or purchase a subscription --

Citation

Stephens, Mark B., et al., editors. "Seizure Disorder, Focal." 5-Minute Clinical Consult, 27th ed., Wolters Kluwer, 2019. Medicine Central, im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688257/1.0/Seizure_Disorder_Focal.
Seizure Disorder, Focal. In: Stephens MB, Golding J, Baldor RA, et al, eds. 5-Minute Clinical Consult. 27th ed. Wolters Kluwer; 2019. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688257/1.0/Seizure_Disorder_Focal. Accessed June 27, 2019.
Seizure Disorder, Focal. (2019). In Stephens, M. B., Golding, J., Baldor, R. A., & Domino, F. J. (Eds.), 5-Minute Clinical Consult. Available from https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688257/1.0/Seizure_Disorder_Focal
Seizure Disorder, Focal [Internet]. In: Stephens MB, Golding J, Baldor RA, Domino FJ, editors. 5-Minute Clinical Consult. Wolters Kluwer; 2019. [cited 2019 June 27]. Available from: https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688257/1.0/Seizure_Disorder_Focal.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC T1 - Seizure Disorder, Focal ID - 1688257 ED - Stephens,Mark B, ED - Golding,Jeremy, ED - Baldor,Robert A, ED - Domino,Frank J, BT - 5-Minute Clinical Consult, Updating UR - https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688257/1.0/Seizure_Disorder_Focal PB - Wolters Kluwer ET - 27 DB - Medicine Central DP - Unbound Medicine ER -