Seizures
Jill C. Cash and Cheryl A. Glass
Definition
A.In 2013 the International League Against Epilepsy (ILAE) adopted its commissioned task force’s definition of epilepsy to be utilized in clinical diagnosis. The official report of the ILAE was published in 2014 in the journal Epilepsia and is available at www.ilae.org/files/dmfile/Definition2014-RFisher.pdf. Epilepsy is a disease of the brain that is defined by any of the three following conditions:
1.At least two unprovoked (or reflex) seizures occurring more than 24 hours apart.
2.One unprovoked (or reflex) seizure and a probability of further seizures similar to the general recurrence risk (at least 60%) after two unprovoked seizures, occurring over the next 10 years.
3.Diagnosis of epilepsy syndrome.
B.The ILAE’s clinical definitions also state that epilepsy is considered to be resolved for individuals who had an age-dependent epilepsy syndrome but are now past the applicable age or those who have remained seizure-free for the past 10 years, with no seizure medications for the past 5 years.
C.The 2017 ILAE classification of epilepsies now defines three seizure types:
1.Focal onset:
a.Focal awareness seizure (FWS).
b.Focal impaired awareness seizure (FIAS).
c.Focal motor seizure (FMS).
d.Focal nonmotor seizure (FNMS).
e.Focal to bilateral tonic-clonic seizure (FBTCS).
2.Generalized onset:
a.Generalized tonic-clonic seizure (GTCS).
b.Generalized absence seizure (GAS).
c.Generalized motor seizure (GMS).
d.Generalized epileptic spasm (GES).
3.Unknown onset (motor and nonmotor):
a.Unknown onset tonic-clonic seizure (UTCS).
D.Accurate classification of seizures is dependent on observations of witnessed seizures, full medical history including comorbidities, and clinical findings. The new basic classification is based on where the seizure begins in the brain, level of awareness, and other features of seizures:
1.Focal onset seizures—generally only in one area of the brain:
a.Motor symptoms: Jerking (clonic), tense or rigid muscles (tonic), muscular limpness or weak (atonic), brief muscle twitching (myoclonus), or epileptic spams. May also have automatisms or repeated automatic movements such as clapping or rubbing hands, lip smacking or chewing, or running.
b.Nonmotor symptoms: Does not affect movement such as changes in sensation, emotions, cognition change, lack of movement (behavior arrest), or autonomic function changes (gastrointestinal [GI] sensations, waves of heat or cold, goosebumps, racing heart rate).
2.GMS–involves networks on both side of the brain at the onset:
a.Motor seizures—generalized tonic-clonic. Seizure with stiffening and jerking; this loosely corresponds to grand mal.
b.Nonmotor seizures are primarily absence seizures and corresponds to the old term petit mal.
Involves brief changes in awareness, staring, and may have automatic or repeated movements like lip smacking.
3.Unknown onset seizures—may fall into the unknown onset category and later the seizure type becomes clear:
a.Motor seizures are described as tonic-clonic or epileptic spasms
b.Nonmotor seizures include a behavior arrest; the movement stops and the person may stare and not make any other movements.
4.Focal to bilateral seizure—starts on one side or part of the brain and spreads to both sides.
E.Awareness—whether a person is aware during a seizure is one of the main factors affecting a person’s safety. Awareness is used instead of consciousness, because it is simpler to evaluate:
1.Focal aware: The person’s awareness remains intact, even if they are unable to talk or respond during a seizure (previous term simple partial).
2.Focal impaired awareness: Impaired or affected awareness at any time of the seizure, even if a person has a vague idea of what happened (previous term complex partial seizure).
3.Awareness unknown—unable to determine if a person is aware or not, such as an unwitnessed seizure.
4.Generalized seizures—all presumed to affect a person’s awareness or consciousness in some way. There are no special terms to describe awareness in generalized seizures.
F.Lennox–Gastaut syndrome (LGS) is a rare form of epilepsy consisting of multiple seizure types. Types include cognitive impairment and drop seizures. LGS patients may require antiseizure medications, steroids or immune globulin, vagus nerve stimulation, surgical resection, and ketogenic diet.
G.Eclampsia occurs anytime in pregnancy from the second trimester to the puerperium. It is notable for the occurrence of one or more generalized convulsions and/or coma in women with preeclampsia (in the absence of other neurologic conditions):
1.Eclampsia is self-limited, and delivery is the treatment.
2.The tonic-clonic seizure generally lasts 60 to 75 seconds.
3.Fetal bradycardia lasts 3 to 5 minutes but does not necessitate an emergent cesarean section delivery. Compensatory fetal tachycardia and transient fetal heart rate decelerations occur. Delivery should be considered for the lack of improvement in 10 to 15 minutes after maternal/fetal resuscitative interventions.
4.Seizures due to eclampsia generally resolve within a few hours to days postpartum. HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome develops in approximately 10% to 20% of women with preeclamp sia/eclampsia.
Incidence
A.Epilepsy is the fourth most common neurological disease and affects people of all ages.
B.3.4 million Americans are affected by epilepsy. There are 150,000 new cases of epilepsy every year. One in 26 people in the United States will develop epilepsy at some point in their lives.
C.Seniors: Most rapid population with comorbidity of epilepsy:
1.Stroke is the leading cause of new-onset epilepsy in adults after age 65.
D.Eclampsia:
1.Mild preeclampsia 0.5%.
2.Severe preeclampsia from 2% to 3%.
3.48 hours postpartum up to 33%.
E.Photosensitivity seizures are more common in children and adolescents.
Pathogenesis
A.Epilepsy is a functional disorder of the brain when neurons signal abnormally. The exact cause of epilepsy and eclampsia is unknown.
Predisposing Factors
A.Tumors.
B.Alcohol/drugs.
C.Cerebral infarction/stroke.
D.Hypoglycemia.
E.Alzheimer’s disease (AD).
F.Posttrauma (head injury).
G.Surgery.
H.Pregnancy (eclampsia).
I.Febrile illness.
J.Photosensitivity.
K.Risk factors for recurrent seizures:
1.Identifiable brain disease.
2.Mental retardation.
3.Abnormal neurologic examination/EEG.
4.Seizures onset after age 10.
5.Multiple types of seizures
6.Family history/genetics.
7.Poor response to antiepileptic drugs (AEDs)/combination therapy at time of withdrawal.
8.Chronic alcoholism.
L.Eclampsia risk factors:
1.Nulliparous.
2.Pregnancy-induced hypertension (PIH).
3.Teens to lower 20s and again older than 35 years.
4.Other conditions to be ruled out:
a.Stroke.
b.Hypertensive disease.
c.Space-occupying lesion.
d.Metabolic disorders (hypoglycemia, uremia, water intoxication).
e.Meningitis or encephalitis.
f.Drug use (methamphetamine, cocaine).
g.Idiopathic epilepsy.
h.Thrombotic thrombocytopenic purpura (TTP).
Common Complaints
A.Aura: Epigastric discomfort, fear, or unpleasant smells.
B.Automatisms (swallowing, chewing, fumbling, picking clothes, or lip smacking).
C.Stiffening, then jerking of limbs.
D.Staring with/without repetitive motor behaviors.
E.Eclampsia:
1.Headache: Severe or persistent frontal or occipital.
2.Blurred vision.
3.Photophobia.
4.Right upper quadrant pain/epigastric pain.
5.Altered mental status.
6.Nausea and vomiting
7.Hyperreflexia.
Other Signs and Symptoms
A.Lack of memory of seizure.
B.Impaired consciousness.
C.Postictal:
1.Confusion.
2.Amnesia
3.Fatigue.
4.Headaches.
5.Loss of urine or bowel control.
Subjective Data
A.Obtain a history from the patient or a person who witnesses the seizure:
1.Have the witness describe the duration, part of the body affected, and qualities of the seizure.
2.Does the patient have a recollection of the seizure?
3.How long did it take to feel better after the seizure?
B.Evaluate if the patient has ever had seizures, and ask whether this was an isolated event:
1.Were there any warning symptoms prior to the seizure?
2.What kind of warning was noted?
C.Did the patient have a fever or an active/recent infection?
D.Do a thorough review of the patient’s medical history, including head injury, pregnancy, diabetes, and cancer.
E.Ask if there is a family history of seizures.
F.Take a full medication history including over-the-counter (OTC) and herbal products:
1.Is the patient on an AED?
2.Has the patient missed any doses?
3.When was the last blood level checked to evaluate therapeutic dosing?
G.Review alcohol intake. Alcohol interferes with the efficacy of AEDs.
Physical Examination
A.Check blood pressure (BP), pulse, respirations, and temperature (if indicated to rule out infection).
B.Inspect: Level of awareness, orientation, general overall exam for secondary injuries from fall or striking objects.
C.Auscultate lungs for possible aspiration.
D.Palpation (if applicable for any injuries):
1.Elevate neck for nuchal rigidity.
E.Neurologic examination:
1.Central nervous system (CNS) testing:
a.Wrinkle forehead/raise eyebrows.
b.Smile and show teeth.
c.Stick out the tongue/lateral tongue movement.
d.Ocular movements.
e.Visual field.
f.Finger-to-nose test.
2.Motor strength:
a.Shrug shoulders.
b.Test muscle strength: Grasp hands and squeeze.
c.Check reflexes of biceps, triceps, patellar, brachioradial, and Achilles.
3.Sensory testing: Pinprick.
4.Gait and posture.
Diagnostic Tests
A.Diagnosis is confirmed by the patient’s history, witness accounts, neurologic examination, blood work, and clinical testing, such as EEG.
B.EEG is essential in all cases of undiagnosed transient loss of consciousness, especially in the elderly, to rule out cardiac arrhythmias as the sudden loss of consciousness.
C.MRI is the gold standard for neuroimaging. The MRI is more accurate than a CT.
D.Blood glucose.
E.Drug/alcohol screen.
F.Serum level of anticonvulsant.
G.Lumbar puncture (LP) if indicated for signs of infection/meningitis.
Differential Diagnoses
A.Seizures.