DESCRIPTION

• 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:
  • Focal seizures with impairment of awareness (formerly “complex partial seizures”)
  • Focal seizures without impairment of awareness (formerly “simple partial seizures”)

EPIDEMIOLOGY

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

RISK FACTORS

• History of traumatic brain injury (TBI)
• Thiamine-deficient formula

COMMONLY ASSOCIATED CONDITIONS

Depression