Seizure

This is a very large topic and an important one! I am currently on the stroke service right now but will be starting the general neurology service in one week so I wanted to attempt to get a solid foundation of seizures before jumping in.

Definition - A seizure is a sudden change in behavior that is the consequence of brain dysfunction. Seizures can be divided into different categories…

-Epileptic Seizures - result from electrical hyper synchronization of neurons in the cerebral cortex. There are different classes of epileptic seizures and are named according to how they present such as simple partial (consciousness not impaired), complex partial (consciousness impaired) and generalized (involving the entire cortex). Epilepsy the disease is characterized by recurrent epileptic seizures due to a genetically determined or acquired brain disorder. Approximately 0.5 to 1 percent of the population has epilepsy.

-Provoked seizures - some seizures are provoked and occur secondary to alcohol or drug withdrawl, metabolic derangements, strokes or encephalitis. These patients are not considered to have epilepsy because the seizure would not occur in the absence of any of the above situations.

-Nonepileptic seizures - sudden changes in behavior that appear to be epileptic in nature (epileptic imitators) but are not associated with the same neurophysiologic changes seen in epilepsy

After looking at the groupings of seizures, one can see that a primary goal when assessing the cause of the patient’s seizure, is to understand whether it occurred secondary to a treatable systemic process (provoked) or if this is secondary to a true dysfunction of the neuronal network (epilepsy). If it is due to a dysfunction of the CNS, the nest step would be to figure out the underlying brain pathology. These are all important steps when decided the treatment plan.

Etiologies

Epilepsy

-Head trauma

-Brain tumors

-intracranial infection

-cerebral degeneration

-stroke

-congenital malformation

-inborn errors of metabolism

Nonepileptic seizures (imitators or epileptic seizures) – etiologies divided into age groups

Neonates – apnea, jitterinus, hyperplexia and benign neonatal sleep myoclonus

Infants – breath holding spells, benign myoclonus of infancy, shuddering attacks, torticollis and rhythmic movement disorder.

Children - Breath-holding spells, Vasovagal syncope, Migraine, Benign paroxysmal vertigo, Staring spells, Tic disorders and stereotypies, Rhythmic movement disorder, Parasomnias

Adolesence - Vasovagal syncope, Narcolepsy, Periodic limb movements of sleep, Sleep starts, Paroxysmal dyskinesia, Tic disorders, Hemifacial spasm, Stiff person syndrome, Migraine, Psychogenic nonepileptic pseudoseizures, Hallucinations

Adults - Cardiogenic syncope, Transient ischemic attack, Drop attacks, Transient global amnesia, Delirium or toxic-metabolic encephalopathy, Rapid eye movement sleep disorder

Clinical Features

As always, a good history and physical is important to formulate a diagnosis. Questions to ask…

Triggers?  Strong emotions, intense exercise, loud music or flashing lights? Interestingly, in 1997 the cartoon Pokemon caused in Japan 685 children out of 7 million viewers to seek medical attention for neurological symptoms and about 80% of the cases were diagnosed as seizures. Three fourths of the cases included first time seizure activity. The stimuli that caused these photic-induced seizures appear to be identifiable because the British and Japanese government have guidelines restricting the use of certain signals on television.

Auras? An aura (sound, light, smell and sensation distortion) is something that occurs when enough of the brain has been affected to cause it but not affected enough to cause loss of consioucness. Auras fall under the category of simple-partial seizures.

Loss of Consciousness? Loss of consciousness occurs in complex partial seizures and generalized seizures. Complex partial seizures are the most common type of seizure in epileptic adults. Patients often appear to be awake but are not consciousness. They often seem to stare into space and either remain motionless or engage in repetitive behaviors, called automatisms, such as facial grimacing, gesturing, chewing, lip smacking, snapping fingers, repeating words or phrases, walking, running, or undressing. Patients may become hostile or aggressive if physically restrained during complex partial seizures. Generalized seizures involve more than one portion of the brain rather than a focal portion and include absence seizures and generalized tonic-clonic seizures. Absence seizures can cause impaired consicouness along with staring spells. They occur in clusters, are short in duration (usually less than 10 seconds) and can happen multiple times a day. Tonic clonic siezures are the most dramatic type of seizure. They being with an abrupt loss of consciousness often in conjunction with a scream or a shriek. All of the muscles of the arms and legs as well as the chest and back then become stiff which is considered to be the tonic phase. After approximately one minute, the muscles begin to jerk and twitch for an additional one to two minutes. During this clonic phase the tongue can be bitten, and frothy and bloody sputum may be seen coming out of the mouth. The postictal phase begins once the twitching movements end. In the post-ictal state, the patient returns to consciousness and is groggy, confused and may have some residual aphasia or sensory loss.

Other questions to ask…

Medication history?

Family history of neurologic disease?

Drug or alcohol use?

History of head trauma?

History of intracranial infection?

Acute management of seizure

Most seizures do not need medical intervention and remit on their own. If the seizures are lasting 5-10 minutes or are occurring in close enough proximity and prevent the patient from returning to interictal baseline, then benzos or anti-epileptic drug (AED) is warranted. The first episode of a seizure, especially if it was provoked, is not enough to consider starting an AED. After the second seizure, AED is usually started. 

All of this research came from UptoDate