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Seizures and Epilepsy

Understanding the Brain:The Neurobiology of Everyday Life

Final PresentationJuly 2014

Seizures and Epilepsy: A Primer

Seizures are caused by an excess of neuronal activity in the brain, and can occur anywhere in the brain

Epilepsy is a disorder of the brain characterized by recurrent and spontaneous seizures

Epilepsy encompasses the neurological, cognitive, psychological, and socio-emotional changes that result from seizures

Seizures are often thought of as an event, while epilepsy is the disorder

Seizures and Epilepsy: A Primer

Seizures occur when the balance between neuronal excitation and inhibition in the brain shifts towards excitation

Seizure types are primarily dependent upon the location of the seizure and associated behaviors E.g., seizures that occur in the motor cortex affect motor

movement and control and are broadly referred to as “motor seizures”

Some areas of the brain are more prone to seizure activity than others (e.g., temporal lobe)

Seizures and Epilepsy: A Primer

Seizures and Epilepsy: A Primer

Seizure Classification

Seizures are first divided into 2 categories: Partial seizures Generalized seizures

Partial seizures are found on one side of the brain, thus they are focal

Generalized seizures occur bilaterally, or on both sides of the brain

Seizure Classification

Partial seizures are then divided into 2 categories: Simple partial seizures have no loss of consciousness or

memory Complex partial seizures result in a loss of consciousness

or memory, and may include an aura (which is a “warning” before a seizure)

Although rare, some experience secondarily generalized seizures These are seizures that are focal, but then spread to both

sides of the brain

Seizure Classification

Seizure Classification

Seizure Classification

Generalized seizures are divided into several categories: Absence (formerly called petit mal): characterized by

staring spells; may include eyelid fluttering Tonic-clonic: characterized by a loss of consciousness

followed by stiffening and rhythmic limb jerking Myoclonic: characterized by jerks or series of jerks that are

not rhythmic Atonic: characterized by drop attacks, where the person

may feel weak and fall to the ground Tonic: characterized by muscle stiffening

Seizure Classification

Complex partial seizures are the most common in adults (estimates point to 40%)

Simple partial seizures account for 20% of episodes in adults

Tonic-clonic seizures (which are generalized) account for 20%

Absence seizures account for 20% of seizure episodes

Controlling Seizures

There is no single method or intervention that will uniformly control seizures, although medicine is often used

Seizures that are not controlled are controlled intractable (or refractory) seizures

The amygdala and hippocampus are often targets for retraction (or removal), although their relationship to seizures is not well understood

Increasing somatostatin (a hormone responsible for regulating the endocrine system) has also been used to reduce episodes

Seizures and this course…

My interest in seizures stemmed from work I completed at two children’s hospitals

This course broadened my understanding of neurology, disorders that affect the nervous system, basic neuroanatomy, and the brain-behavior relationship

Dr. Mason’s practical application of dense material made it easier for me to understand how epilepsy mainfests

Seizures and this course…

Lectures on neurocommunication helped me understand how electrical information travels through nerves, and how neural dysfunction impedes this process

Lectures on neural tube formation peaked my interest in the relationship between women with epilpesy bearing children who have neural tube defects

Lectures on motor control helped me understand how seizures present in children and adults