All seizures are caused by abnormal electrical disturbances in the brain. Partial (focal) seizures occur when this electrical activity remains in a limited area of the brain. The seizures may sometimes turn into generalized seizures, which affect the whole brain. This is called secondary generalization.
Partial seizures can be further characterized as:
Simple -- not affecting awareness or memory
Complex -- affecting awareness or memory of events before, during, and immediately after the seizure, and affecting behavior
Patients with focal seizures can have any of the symptoms below, depending on where in the brain the seizure starts.
Patients with simple focal seizures do not lose consciousness and will be aware of and remember the events that occur at the time.
Patients with complex partial seizures will have abnormal consciousness and may or may not remember any or all of the symptoms or events surrounding the seizure.
Foldvary-Schaefer N, Wyllie E. Epilepsy. In: Goetz CG. Textbook of Clinical Neurology. 3rd ed. Philadelphia, PA: Saunders Elsevier; 2007:chap 52.
Krumholz A, Wiebe S, Gronseth G, et al. Practice parameter: evaluating an apparent unprovoked first seizure in adults (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology and the American Epilepsy Society. Neurology. 2007;69:1991-2007.
Tomson T, Hiilesmaa V. Epilepsy in pregnancy. BMJ. 2007;335:769-773.
Review Date:
3/28/2009
Reviewed By:
Reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc., and David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Previously reviewed by Daniel B. Hoch, PhD, MD, Assistant Professor of Neurology, Harvard Medical School, Department of Neurology, Massachusetts General Hospital. (6/19/08)