Epilepsy

What is Epilepsy?

Epilepsy, commonly known as a seizure disorder, is a neurological condition which affects the nervous system. An individual who has two unprovoked seizures in a ten year period is considered to have epilepsy.

A seizure is a caused by a disruption of normal communication between neurons in the brain. This disruption can cause changes in awareness, behavior, and/or abnormal movement.

Epilepsy can be inherited genetically, as well as result from a traumatic brain injury. However, most cases are considered idiopathic and a cause cannot be determined.

Over 2 million people in the United State have epilepsy and 1 in 26 people in the US will develop epilepsy at some point in their lifetime.

One-third of people with epilepsy live with uncontrolled seizures because all available treatments fail.

Physiology of a Seizure

A neuron or nucleus in the brain becomes hyperexcitable (loses inhibition)

Depolarization is sustained

An influx of extracellular Ca2+ signals the opening of voltage-gated Na+ channels

Repetitive action potentials are generated

Action potentials are discharged irregularly and without control

Types of Seizures Common to Epilepsy

Primary generalized seizures

Occur in both sides of the brain

Partial seizures

Occur in one localized portion of the brain

Simple - interruption of one main brain function or motor skill

Complex - able to travel throughout the brain, affecting multiple brain functions

Absence seizures A lapse in the brain - a person may appear

dazed or repeat a movement such as blinking or chewing

Tonic seizures Cause a sudden and dramatic stiffening of the

muscles

Clonic seizures Cause a sudden and dramatic jerking of the

muscles

Tonic Clonic seizures (Grand Mal seizures) Combined symptoms of tonic and clonic

seizures

Long recovery period and can be dangerous if they go on too long due to the stress they inflict on the body

Psychosomatic seizures Seizure-like activity becomes the body's default

reaction to stress

Potential Symptoms of a Seizure

Loss of awareness

Loss of consciousness

Feelings of distraction, confusion or memory lapse

Inability to speak or confused speech

Dilated pupils

Hyperactivity or lack of activity in the eye and eyelids

Increased flexion or relaxation of muscles

Involuntary tremors or automatisms

Convulsions

No two seizures are identical and symptoms can manifest very differently from one person to the next. Some people show almost no symptoms at all while others are completely debilitated with every seizure.

Common Causes of Epilepsy

Genetic inheritance Influencing genes are currently

unknown

Change in brain structure Reason for change often unknown

Autism spectrum A specific connection between

epilepsy and autism is unknown but suspected

Brain infections

Head injuries

Stroke

Brain tumor

In approximately 60% of epilepsy cases, a cause for the development of epilepsy cannot be determined.

Treatments for Epilepsy

Traditional Treatments Anti-epileptic drug therapy

Approximately 26 AEDs used to treat seizures

Diet

Ketogenic diet, medium chain triglyceride diet, modified Atkins diet, low glycemic index diet

Surgery

Removal or disconnection of abnormal area of the brain

Separation of the hemispheres of the brain by cutting of the corpus callosum

Vagus Nerve Stimulation

Electrical stimulation of the brain via the vagus nerve to counteract the effects of overactive nerve tracts

Alternative Treatments Melatonin

Cannabis

Acupuncture

While many treatment options are available, in approximately 30% of epilepsy cases, no known treatments are effective in controlling seizures.

Case StudyMegan is a 26-year-old white female who has been living with epilepsy for the past 11 years. Megan developed post-traumatic epilepsy after a moderate closed head injury in 2003. Over the years, Megan has been put on more than 10 different anti-epileptic medications, none of which relieved her seizures.

In the summer of 2013, Megan changed medications and began a ketogenic diet. Within 6 months, she had stopped having seizures and has now been seizure free for over a year.

Case Study – Cont.

Additional Possible Contributing Factors Polycystic Ovarian Syndrome

It is estimated that 25%-30% of epileptic women have or exhibit symptoms of PCOS

Genetic Tendency

Maternal Great-Aunt and Great-Uncle also have post-traumatic epilepsy

Chiari Malformation

A structural defect in the cerebellum

Part of the cerebellum is located inferior to the foramen magnum

Active Treatments Controlling Seizure Activity Lamictal

Anti-epileptic medication

Ketogenic Diet

The Ketogenic Diet

The diet structure is high fat, adequate protein, and low carbohydrates, which causes metabolic changes similar to starvation.

Levels of plasma ketones, insulin, glucose, glucagon, and free fatty acids change.

Which metabolic change is responsible for seizure control is not yet known although it is likely multifactorial.

In a 2006 analysis of 19 separate studies, it was found that the ketogenic diet was effective in reducing seizures regardless of age or seizure type. After six months, approximately 60% of patients had a greater than

50% reduction in seizures, while 30% had a greater than 90% reduction in seizures.

References

McCormick DA, Contreras D. On the cellular and network bases of epileptic seizures. Annu Rev Physiol 2001; 63:815.

Wilfong MD. Overview of the classification, etiology, and clinical features of pediatric seizures and epilepsy. UpToDate Nov 2014.

Schachter MD. Overview of the management of epilepsy in adults. UpToDate Nov 2014.

Kossoff MD. The ketogenic diet. UpToDateNov 2014.

http://www.epilepsy.com

http://www.ncbi.nlm.nih.gov

http://neuropathology-web.org

http://www.epilepsymatters.com

http://www.epilepsysociety.org.uk