Table 83-1. Classification of seizures.

General ized Seizures (always loss of consciousness)

Tonic-clonic seizures (grand mal)

Absence seizures (petit mal)

Myoclonic seizures

Clonic seizures

Atonic seizures

Partial (focal) Seizures

Simple partial (no alteration of consciousness)

Complex partial (impaired consciousness)

CHAPTER 83

Partial seizures (simple or complex) with secondary generalization

Note the onset of symptoms, the presence of a prodrome or

aura, loss of consciousness, diffuse or focal motor activity,

bowel or bladder incontinence, length of the event, and

postictal period. Ask about recent trauma (head injury),

headaches (mass lesions), pregnancy (eclampsia), history of

metabolic abnormalities such as diabetes (hypoglycemia),

drug ingestions (tricyclic-antidepressants, isoniazid), alcohol use (withdrawal seizure), and sleep disturbances. If the

patient has a known seizure disorder, obtain a description of

the patient's typical seizure pattern and medication history.

..... Physical Examination

As with any high-acuity patient, perform a primary s urvey

of the patient, assessing airway, breathing, and circulation

(ABCs), vital signs, bedside glucose level, basic mental status,

and pupillary symmetry and reactivity. In most patients, the

seizure will stop spontaneously within 2 minutes, and the

initial postictal period will result in profound alteration of

mental status. At this time, manage the airway by using jaw

thrust/chin lift, repositioning the patient's head, or inserting

a nasopharyngeal airway. Look for physical examination

signs of toxidromes ( eg, sympathomimetic), trauma (abrasions, contusions, fractures), increased intracranial pressure

(papilledema or Cushing reflex), and any focal neurologic

abnormality that would indicate a secondary cause of seizure. A complete neurologic examination should be performed as soon as possible. Transient focal muscle paralysis

after a seizure is known as Todd paralysis and usually

resolves within 24-48 hours. Up to 25% of patients with a

generalized seizure sustain a tongue laceration, usually of the

lateral tongue. Tongue biting has a 99% specificity and 24%

sensitivity for diagnosis of generalized tonic-clonic seizure.

DIAGNOSTIC STUDIES

..... Laboratory

In addition to an immediate bedside glucose for all seizure

patients, check the sodium level in patients with first-time

seizures. All women of child-bearing age should have a pregnancy test. In patients with significant comorbid illnesses

such as renal failure, broaden laboratory testing to include

renal function tests, complete blood count, alcohol, calcium,

magnesium, and phosphorus levels. To differentiate between

true seizures and pseudoseizures (also known as psycho ­

genic nonepileptic seizures), check prolactin level, lactate,

and electrolytes. Elevated serum prolactin level within 60

minutes of seizure onset can support the diagnosis of seizure. Additionally, an increased lactate level and anion gap

with decreased bicarbonate suggests generalized seizure

activity. This metabolic acidosis should resolve within 1

hour of seizure cessation. Patients with a known seizure

disorder should have antiepileptic medication levels checked.

.... Imaging

Obtain a noncontrast brain computed tomography (CT)

scan in all patients with first-time seizure or those with a

change in their normal seizure pattern. Other indications to

perform CT include patients with a new focal neurologic

deficit, severe headache, persistent altered mental status, fever,

trauma, cancer, anticoagulant use, or history of immunocomprornise (Figure 83-1). Magnetic resonance imaging (MRI) is

more sensitive for mass lesions such as vascular malformations, certain tumors, and strokes, but is not usually necessary

in the ED setting. Patients with a known seizure disorder and

a typical seizure without any new secondary causes identified

do not need any imaging performed in the ED .

.A. Figure 83-1 . Head CT sca n of a patient from Mexico

who presented to the ED with a first-time seizure.

CT scan demonstrated multiple ca lcifications from

neurocysticercosis.

SEIZU RES AND STATUS EPILEPTICUS

Consider lumbar puncture in the setting of seizure if

the patient is febrile, immunocompromised, or at high risk

for subarachnoid hemorrhage despite normal CT findings.

Lumbar puncture is not a routine part of first-time seizure

evaluation. Electroencephalogram (EEG) is indicated in

the ED only when nonconvulsive status epilepticus is

suspected in patients with persistent altered mental status

or in patients who receive paralytics or phenobarbital, both

of which may mask continued seizure activity.

MEDICAL DECISION MAKING

Once normal vital signs, blood glucose, and mental status

have been achieved, a patient's seizure history determines

the management pathway. If the present seizure is typical of

past seizure patterns, antiepileptic drug levels should be

obtained and repleted. If any part of the seizure was atypical

or this was a first-time seizure, the patient should be evaluated for secondary causes. If no secondary cause is identified and the seizure was an isolated event, the remainder of

the evaluation can occur as an outpatient (Figure 83-2).

Discharge for

outpatient fol low-up if

no secondary cause

identifi ed

TREATMENT

Specific management is based on the patient's clinical sce ­

nario.

..... First-Time Seizure, Resolved

Patients with a first-time seizure who have a normal neurologic examination, no medical comorbidities, normal

diagnostic testing including a normal CT brain scan, and

normal electrolytes do not require further treatment in the

ED. Patients with seizures attributed to other causes (secondary seizures) will need specific treatment for the

underlying etiology.

..... Known Seizure Disorder, Resolved

If antiepileptic drug levels are very low, begin repletion in

the ED. Simply resuming home dosing in these cases delays

therapeutic levels for several days. Phenytoin can be loaded

either intravenously (IV) or by mouth (PO) at 18 mg/kg.

IV loading results in therapeutic serum levels within

Atypical

(tra uma, fever,

headache, AMS)

Check

an ticonvulsant

levels

Load subtherapeutic

anticonvulsants;

d ischarg e home with

outpatient fol low-up

• Figure 83-2. Seizures and status epilepticus diag nostic algorithm. AMS, altered mental status; CT,

com puted tomography.

CHAPTER 83

1 hour, and oral loading within 12 hours. In patients with

subtherapeutic levels, the correct amount of phenytoin to

administer is determined by the following formula:

Phenytoin load (mg) = (0.75 L/kg) x (desired level- current level)

x (patient's weight in kg)

An alternative to phenytoin administration is fosphenytoin (20 mg/kg phenytoin equivalents), a prodrug of

phenytoin. Fosphenytoin can be given N or intramuscu ­

larly (IM) and has fewer side effects but is more expensive.

..... Actively Seizing Patient

The mainstays of treatment are to protect the patient

from physical injury; reduce the risk of aspiration; monitor ABCs, vital signs, and bedside glucose; and observe

the seizure for resolution. There isno indication for IV

anticonvulsant medications duringan uncomplicated seizure, as most are self-limited. Benzodiazepines are used

for patients with frequent or continuous seizures to temporarily subdue seizure activity until a permanent solution is determined. Administer lorazepam 2 mg N or IM

(up to a total dose of 0. 1 mg/kg) or diazepam (0.1 mg/kg/

dose) to control seizure activity. Multiple studies have

shown that lorazepam and diazepam are both equally

effective at terminating seizures, although lorazepam

administration decreases the occurrence of repeat seizures when compared to diazepam. If the seizure does not

resolve or the patient does not return to baseline between

events, treat for status epilepticus.

..... Status Epilepticus

Administer medications in stepwise fashion until seizure

activity ceases. Benzodiazepines remain first-line agents

(see preceding doses) with the addition of antiepileptic

drugs as second- and third-line agents. Phenytoin (20-30

mg/kg) or fosphenytoin (20-30 mg/kg phenytoin equivalent [PE] ) should be loaded IV depending on availability

in ED. Fosphenytoin is preferred as it can be loaded faster.

If seizure activity persists, phenobarbital is a third-line

agent and is dosed at 20 mg/kg. Phenobarbital administration will result in profound respiratory depression, so a

definitive airway should be secured at this time. Valproic

acid (20 mg/kg) can be used instead of phenobarbital as a

third-line agent. For refractory status epilepticus, use propofol, midazolam, or ketamine. Emergent EEG monitoring and neurology consultation should be obtained

(Figure 83-3).

..... Special Cases

Seizures In HIV Patient

Seizures are a common manifestation of central nervous system (CNS) disease in an HN-positive patient. HN e ncephalopathy, CNS lymphoma, and many opportunistic infections

can cause seizures. In this population, lumbar puncture

should be performed with standard tests as well as specific

assays for tubercular, viral, and fungal agents.

Neurocysticercosis

Neurocysticercosis is caused by the parasite Taenia solium

and is the most common cause of secondary epilepsy in the

developing world. CT may show 1 - to 2-cm cystic lesions

within the cerebral cortex. Definitive diagnosis depends on

the clinical picture, serologic testing, and imaging.

Noncontrast studies demonstrate calcification of inactive

cysts, which is the most common finding at presentation

(see Figure 83-1). In patients with active disease, contrast

CT demonstrates ring enhancement signifying edema s urrounding the active cysts. Seizures due to neurocysticercosis are usually controlled by antiepileptic monotherapy

until definitive antiparasitic medication and/or surgical

excision is successful.

Pregnancy

Test all female patients of child-bearing age for pregnancy.

Pregnant patients with proteinuria, hypertension, and seizure likely have eclampsia. The treatment is N magnesium

sulfate 4- to 6-g bolus followed by a 2-g hourly infusion.

Eclamptic seizures can occur postpartum and the treatment is the same.

Alcohol Withdrawal

Alcohol withdrawal seizures can occur in those with

chronic alcohol dependence and are most likely to occur

12-36 hours after last alcohol intake. Benzodiazepines

administered on arrival have been shown to prevent

sequential seizures. It is important to remember that alcohol withdrawal seizures are a diagnosis of exclusion, and

other secondary etiologies should be investigated.

Isoniazid

Patients undergoing treatment for tuberculosis are often

taking isoniazid, which can cause seizures resulting from

vitamin B6 deficiency. The typical presentation will be seizures unresponsive to conventional treatment for status

epilepticus. The treatment is N vitamin B 6 (pyridoxine).

Dose-dependent algorithms are available for treatment;

empiric therapy if the dose of isoniazid is unknown is 5 g

of B6 IV, which can be repeated.

DISPOSITION

..... Admission

Patients in status epilepticus should be admitted to an

intensive care unit. Patients with a first-time resolved

seizure with an identified secondary cause should be

admitted to the hospital for further evaluation. Patients

with a known seizure disorder and atypical features should

undergo further work-up and may warrant admission.

SEIZU RES AND STATUS EPILEPTICUS

Status epilepticus Refractory status epi lepticus

L S min. 30 min.

IV Lorazepam 2 milligrams, up to 0.1 milligram/kg

or if Lorazepam is

unavailable,

IV P henytoin

20-30 milligrams/

kg at 50 milligrams/min

IV Phenobarbital

20 milligrams/kg

at so-75 milligrams/min

IV Propofol loading

dose 2-5 milligrams/

kg, then i nfusion of

2-1 0 milligrams/kg/h

IV Ketamine

bolus 1 .5 millig rams/kg, then

0.01-{).05

mi lligram/kg/h or or or

+ or or

IV Diazepam 5-1 0

milligrams, up to 0. 15

milligram/kg

IV Fosphenytoin

20-30 milligrams/

kg/P E at 1 50

milligrams/min

Valproic acid

2o-40 milligrams/

kg at 5 milligrams/

kg/min

IV Midazolam

loading bolus 0.2

milligram/kg, then

infusion of 0.05-2

milligrams/kg/h

and/or

Other drugs

Electroencephalographic monitoring?

Ai rway, blood p ressure, temperature, IV access, electrocardiography, CBC,