Seizure Disorder, Focal
- Seizures occur when abnormal synchronous neuronal discharges in the brain cause transient cortical dysfunction.
- Focal or localization-related seizures have previously been referred to as partial seizures and originate from a discrete focus limited to one cerebral hemisphere.
- 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”)
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 within a neuronal network limited to one cerebral hemisphere; it may stay discretely localized or be widely distributed throughout that hemisphere.
- The area of cortex involved in the seizure determines the symptoms; for example, an epileptogenic focus in motor cortex produces contralateral motor symptoms.
- 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
Benign rolandic epilepsy; has an autosomal dominant inheritance pattern
- History of traumatic brain injury (TBI)
- Thiamine-deficient formula
Commonly Associated Conditions
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Domino, Frank J., et al., editors. "Seizure Disorder, Focal." 5-Minute Clinical Consult, 27th ed., Wolters Kluwer, 2020. Medicine Central, im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688257/all/Seizure_Disorder__Focal.
Seizure Disorder, Focal. In: Domino FJF, Baldor RAR, Golding JJ, et al, eds. 5-Minute Clinical Consult. Wolters Kluwer; 2020. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688257/all/Seizure_Disorder__Focal. Accessed June 10, 2023.
Seizure Disorder, Focal. (2020). In Domino, F. J., Baldor, R. A., Golding, J., & Stephens, M. B. (Eds.), 5-Minute Clinical Consult (27th ed.). Wolters Kluwer. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688257/all/Seizure_Disorder__Focal
Seizure Disorder, Focal [Internet]. In: Domino FJF, Baldor RAR, Golding JJ, Stephens MBM, editors. 5-Minute Clinical Consult. Wolters Kluwer; 2020. [cited 2023 June 10]. Available from: https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688257/all/Seizure_Disorder__Focal.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC T1 - Seizure Disorder, Focal ID - 1688257 ED - Domino,Frank J, ED - Baldor,Robert A, ED - Golding,Jeremy, ED - Stephens,Mark B, BT - 5-Minute Clinical Consult, Updating UR - https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/1688257/all/Seizure_Disorder__Focal PB - Wolters Kluwer ET - 27 DB - Medicine Central DP - Unbound Medicine ER -