Joseph I. Sirven, MD Mayo Clinic College of Medicine Phoenix, AZ

Distinguishing Types of Seizures

Accurately identify and document the seizure type or syndrome and seizure frequency from the patient history before initiating a treatment plan

Learning Objective

Points to Consider When Evaluating Spells

● Precipitating or ameliorating factors ● Description of behavior during event ● Is it stereotyped? ● Duration ● Aura or Prodrome ● When do they occur? ● Nature of recovery

Definitions

● Seizure: the clinical manifestation of an abnormal, excessive excitation and synchronization of a population of cortical neurons ● Epilepsy: recurrent seizures (two or more)

which are not provoked by systemic or acute neurologic insults

Fisher RS, et al. Epilepsia. 2014;55(4):475-482.

Practical Definitions

● Seizure – disturbances in the electrical activity of the brain ● Epilepsy – two or more unprovoked

seizures separated by at least 24 hours ● Epilepsy is a spectrum of disorders: – Many different types of seizures – Many causes – Many syndromes and types of epilepsy

Sirven JI. Semin Neuro. 2002;22(3):237-246. PMID: 12528049.

ILAE Classification of Seizures

Seizures

Generalized Absence

Myoclonic

Atonic

Tonic

Tonic-Clonic

Focal

Simple Partial

Complex Partial

Secondary Generalized

ILAE – International League Against Epilepsy Sirven JI. Semin Neuro. 2002;22(3):237-246. PMID: 12528049.

ILAE Classification of Seizures

Seizures

Generalized Focal

Simple Partial

Complex Partial

Secondary Generalized

Sirven JI. Semin Neuro. 2002;22(3):237-246. PMID: 12528049.

Seizure Differential Diagnosis

Rowan AJ, et al. Neurology. 2005;64(11):1868-1873. PMID: 15955935.

Non-epileptic Epilepsy

Primary Secondary Syncope Cardiovascular Migraine Cerebrovascular Metabolic Psychogenic

Age dependent Genetic Family History Neurochemical imbalance

Non-lesional Epilepsy Syndromes

Symptomatic Structural Lesions Progressive

Focal & Generalized

Focal & Generalized

Seizure vs. Non Epilepsy Seizures (NES)

Hoerth MT, et al. Neurologist. 2008;14(4):266-270. PMID: 18617856. Brown RJ, et al. Epilepsy Behav. 2011 Sep;22(1):85-93. PMID: 21450534.

Clues Favoring Epilepsy ●  Autonomic changes –  Pupil dilation –  Incontinence –  Corneal reflex

suppression ●  Post-ictal Babinski sign ●  Self injury ●  Not responsive during event ●  Amnesia for the event ●  Duration less than 2 minutes

Clues Favoring NES ●  Never witnessed or vice versa ●  Provoked by emotional stress ●  Variable form one event to

another ●  Screaming or vocalizing

throughout the entire event ●  Prolonged, greater than a

couple of minutes ●  Sudden termination of event ●  No post-ictal confusion ●  Induced by suggestion ●  Responsive during event ●  Usually NO injury ●  Usually NO incontinence

Routine EEG and Role in Diagnosing Seizures

● Often over-interpreted ● 2% adults and 3% pediatrics without spike

wave but no seizure ● Persons with epilepsy (PWE): 50% normal

with one EEG; if 4 normal EEGs not likely to see abnormality ● 10-20% PWE have normal EEG

AAN Recommendations for First Seizure

● Adults presenting with an unprovoked first seizure should be informed that the chance for a recurrent seizure is greatest within the first 2 years after a first seizure (21%-45%) (Level A).

● Clinicians should also advise such patients that clinical factors associated with an increased risk for seizure recurrence include a prior brain insult such as a stroke or trauma (Level A), an EEG with epileptiform abnormalities (Level A), a significant brain-imaging abnormality (Level B), or a nocturnal seizure (Level B).

Krumholz A, et al. Neurology. 2015; 84(16 ):1705-1713. PMID: 25901057.

AAN Recommendations for First Seizure ●  Clinicians should advise patients that, although

immediate anti-epileptic drug therapy (AED), as compared with delay of treatment pending a second seizure, is likely to reduce the risk for a seizure recurrence in the two years subsequent to a first seizure (Level B); it may not improve QOL (Level C).

●  Clinicians should advise patients that over the longer term (> 3 years) immediate AED treatment is unlikely to improve the prognosis for sustained seizure remission (Level B).

●  Patients should be advised that their risk for AED adverse effects ranges from 7% to 31% (Level B) and that these adverse effects are predominantly mild and reversible.

Krumholz A, et al. Neurology. 2015;84(16 ):1705-1713. PMID: 25901057.

Questions & Answers