Page of

Seizure 

Seizure
Chapter:
Seizure
Source:
Acute Care Casebook
Author(s):

Olga Kovalerchik

DOI:
10.1093/med/9780190865412.003.0026

Setting

Emergency Department

Chief Complaint

Seizure

History

A 23-year-old male is brought in by ambulance after an episode of witnessed seizure-like activity lasting about 7 minutes. A friend provides most of the history due to the patient’s condition.

The patient was celebrating the end of final exams when his friends suddenly noticed “he looked out of it.” He dropped his drink, became unresponsive, and stiffened up all of his extremities. His friends caught him and lowered him down onto his side; he did not sustain any trauma. Within a few seconds, he developed shaking activity of his entire body, and emergency medical services was called. The patient continued shaking until paramedics arrived about 5 minutes later.

The patient was given 10 mg midazolam intramuscularly and intravenous (IV) access was established by the paramedics. The shaking activity stopped, but the patient was sleepy and confused for the remainder of the way to the hospital.

The patient is a graduate student who completed final exams this morning. He “pulled an all-nighter” with his friend last night. The friend thinks the patient takes some medication, but no additional medical, social, or family history are available.

Physical Examination

Vital signs: HR 70, BP 125/85, RR 14, SpO2 98% on room air, temp. 38.0°C.

Examination reveals a well-developed, well-nourished male in no acute distress. He is resting with his eyes closed. He opens his eyes to voice and follows commands. Examination of his head and neck reveals no signs of trauma. Pupils are equal and reactive to light bilaterally. Mouth examination reveals a 7 mm × 3 mm red lesion on the right lateral aspect of the tongue. His lungs are clear bilaterally with good air movement, and his cardiac rate and rhythm are normal; there are no murmurs, rubs, or gallops. His abdomen is soft, nontender, and nondistended. His underwear is soiled with urine. He has normal peripheral pulses bilaterally, and his capillary refill is <2 seconds. His extremities are warm and well perfused. Neurologic examination is limited by his sleepiness. He has grossly normal and equal strength in all extremities and speaks in a few words at a time. He is disoriented to place, time, and situation.

Differential Diagnosis

  1. 1. Postictal confusion

  2. 2. Primary seizure

  3. 3. Secondary seizure due to subtherapeutic antiepileptic drug levels, abnormal glucose level, hypothyroidism, drugs/toxins, infection

  4. 4. Status epilepticus (SE)

  5. 5. Syncope

  6. 6. Complex migraine

  7. 7. Alcohol withdrawal

  8. 8. Psychogenic seizure

Tests

  • Fingerstick glucose: 98 mg/dL (normal 70–100 mg/dL)

  • Complete blood count: white blood cell (WBC) count: 1,7000/µl (normal 3000–12000/µl); normal WBC differential, hemoglobin, hematocrit, and platelet counts

  • Lactic acid, serum: 6.0 mmol/L (normal 0.0–2.0 mmol/L)

  • Chemistry panel: normal sodium, potassium, chloride, bicarbonate, blood urea nitrogen, creatinine, glucose, calcium, magnesium, and phosphorus

  • Liver function tests: normal alanine aminotransferase/aspartate aminotransferase, alkaline phosphate, bilirubin

  • Toxicology screen: blood alcohol concentration 61 mg/dL (0.061%), remainder negative

  • Valproic acid level: pending (normal therapeutic range 50–100 µg/mL total valproic acid)

  • Ammonia level: pending (normal 9.5–49 mcg/dL)

  • Urine drug screen: pending

Clinical Course

After ordering labs, additional chart review shows that the patient has a past medical history of seizure disorder, and he is prescribed valproic acid. Additional labs for valproic acid levels and ammonia are added.

Minutes after evaluation, he became unresponsive and developed generalized tonic-clonic activity. He was placed on oxygen by nasal cannula and continuous telemetry monitoring. The seizure activity lasted about 4 minutes before a total of 2 doses of lorazepam were given to stop the seizure. Due to concern for SE, the airway cart was brought to the bedside as an added precaution.

Approximately 10 minutes later he again developed generalized shaking activity. Valproic acid 40 mg/kg IV was administered and the seizure stopped, but he remained altered.

Neurology was called for immediate consultation. He was admitted to the neurology intensive care unit with the diagnosis of SE. He was placed on continuous electroencephalography (EEG) monitoring, which showed epileptiform disturbances but no new occurrences of seizure activity. After several hours, his repeated bloodwork was within normal limits. His mental status gradually returned to baseline, and he was subsequently transferred to the floor.

Once the patient woke up, more history was available. He was diagnosed with epilepsy after a traumatic brain injury several years ago. Despite being compliant most of the time, he skipped “a few doses” of valproic acid during the past week due to stress. He had never “pulled an all-nighter” until this most recent exam. He drinks alcohol rarely, not more than 3 times a year. He admitted to using cocaine for the first time last night as part of celebrating. He was counseled about the risks of these activities in the setting of his seizure disorder.

His initial blood level for valproic acid was subtherapeutic. There was a discussion about starting an additional antiepileptic drug, but ultimately this was not thought to be necessary. The episode was attributed to poor compliance and risky behaviors. His seizures had been well controlled with the same medication for the past year, and he denied having side effects. The patient promised to take his medication regularly and avoid risky behaviors.

The patient was ultimately discharged with close neurology follow-up.

Key Management Steps

  1. 1. Prioritize the ABCs: airway, breathing, and circulation. During generalized seizure activity, administer supplemental oxygen and prepare suctioning equipment if available.

  2. 2. Perform a careful neurologic exam. This will help determine whether additional testing is needed (e.g., computer tomography [CT] scan for new focal deficit) and/or interventions (e.g., monitoring or additional medications for nonconvulsive seizure activity).

  3. 3. Obtain a fingerstick glucose early in the workup to identify an easily reversible cause of seizure activity.

  4. 4. First-line therapy for seizing patients without IV access is midazolam given intramuscularly. The efficacy is equivalent compared to IV lorazepam and/or diazepam, the two first-line IV therapies of choice for treatment of ongoing seizure (see Table 26.1).

  5. 5. If second-line drug therapy is needed and/or SE is on the differential, prioritize the airway. The patient is likely to require intubation before receiving additional medications.

  6. 6. If the patient is intubated for SE and third-line agents are required, the patient will need emergent continuous EEG monitoring to exclude ongoing seizure activity.

  7. 7. If a patient with known seizure disorder stops seizing after a short period of time, returns to normal mental status, and has a reasonable explanation for the seizure, he or she can be safely discharged to follow-up with outpatient neurology.

Table 26.1 Seizure and Status Epilepticus Management

Timeline

Therapy

Notes

0–1 min

Airway, breathing, circulation

Obtain IV access as quickly as possible

Consider supplemental oxygen

Prepare suctioning if available

Check blood glucose early

1–5 min

First line medications:

  • No IV: Midazolam IM 10mg

  • IV established:

    • - Lorazepam IV, 0.1 mg/kg/dose (max 4 mg/dose)

    • - Diazepam IV, 0.15–0.2 mg/kg/dose (max 10 mg/dose)

    • - Lorazepam and diazepam each may be repeated after a few minutes if not effective right away.

All 3 first-line drugs are considered equally efficacious and are supported by level A evidence

Status epilepticus: if seizure continues after 2 doses of first line medications or >5 min (approx. 5–20 min)

Second-line medications:

  • Fosphenytoin IV, 20 mg PE/kg (max 1500 mg PE), at 100–150 PE/min

  • Phenytoin IV, 20 mg/kg loading dose at maximum rate 50 mg/min.

  • Valproic acid IV, 20–40 mg/kg, at 3–6 mg/kg/min

  • Levetiracetam IV, 60mg/kg as a single dose (max 4500 mg/dose)

  • Phenobarbital IV, 15mg/kg as single dose

Second-line agents are to be given once as a single dose

There is limited evidence for this stage of treatment; no one agent is preferred

Phenytoin administered IV requires careful cardiac monitoring as it has been associated with hypotension and cardiac arrhythmias. It also is associated with more frequent adverse reactions at the infusion site. Thus, fosphenytoin is generally preferred over phenytoin, though both are equally efficacious.

Consider intubation if seizure continues after administration of second line medications

Refractory status epilepticus: ongoing seizure after second line therapy or >30 min

Intubation indicated

Third-line medications:

  • Repeat one dose of the second-line drug

  • Or administer one of the following intravenously:

    • - Midazolam 0.2mg/kg followed by continuous infusion at 0.05–2 mg/kg/hour

    • - Propofol 1–2 mg/kg, start as continuous infusion at 1.2 mg/kg/hour

    • - Pentobarbital 5–15 mg/kg load at <50 mg/min, then 0.5–5 mg/kg/hour

    • - Thiopental 75–250 mg/dose

    • - Phenobarbital 15 mg/kg single dose

Use of third-line therapy warrants emergent EEG monitoring

Note: IM = Intramuscular. IV = intravenously. PE = phenytoin equivalents. Dosages and indications obtained from www.uptodate.com and Glauser T, Shinnar S, Gloss D, et al. Evidence-based guideline: treatment of convulsive status epilepticus in children and adults: report of the Guideline Committee of the American Epilepsy Society. Epilepsy Curr. 2016;16(1):48–61.

Debrief

A seizure is the clinical manifestation of abnormal electrical activity among neurons. Patients may suffer from recurrent seizures, or epilepsy, typically due to an underlying and fixed condition of the brain. Primary seizures are generally attributed to this condition. Secondary seizures are the consequence of some identifiable and/or reversible condition.1

This patient had more than two discrete seizures without complete recovery of consciousness between the episodes, which, by definition, is SE. SE can also be diagnosed when a single seizure lasts more than 5 minutes. Often in SE, after a short period of tonic-clonic activity, seizure activity may be subtle and the diagnosis can sometimes be made only with EEG.2 It is important to diagnose and treat SE; ongoing electrical activity puts the patient at increased risk of long-term neurologic consequences.1,2

Airway, breathing, and circulation take precedence in the management of seizures. Obtaining IV access and providing supplemental oxygen are also critical actions. If available, suctioning should be provided to assist in clearing oral secretions. Nothing should be inserted between the teeth where it might be crushed and lead to additional complications.

There are few universal findings for patients with seizure activity; however, tongue biting, urinary incontinence, and/or a slight increase in blood pressure or body temperature may be commonly detected. Seizure activity may also cause a transient increase in serum glucose, serum lactic acid, and WBC counts without a leftward shift.

Laboratory and imaging studies are individualized to each case. If a patient with well-documented epilepsy presents with a typical seizure episode, a complete workup might consist of finger-stick glucose and serum antiepileptic drug levels. In situations where the history is not clear or in adults with first time seizure activity, more extensive testing is warranted. Generally, this will include glucose, WBC, electrolytes, blood urea nitrogen, creatinine, magnesium, calcium, and a toxicology screen.1 Prolactin levels are often elevated immediately after a seizure and may be helpful in ruling out pseudoseizure if drawn within 20 minutes of seizure activity.3 Certain seizure medications affect the liver so liver function tests may be indicated. Valproic acid has been associated with hyperammonemic encephalopathy, so if a patient is on this medication and remains altered without another obvious source, consider checking an ammonia level. A pregnancy test should be included for women of childbearing age. Lumbar puncture may be indicated to workup encephalitis or meningitis in a febrile patient with persistently altered mental status, especially if the patient is immunocompromised. Transient shifts in cerebrospinal fluid cell counts may occur during a seizure and do not necessarily indicate infection. Any infectious workup is further complicated by the fact that there is often concurrent leukocytosis and a slight increase in body temperature.

In adults, noncontrast CT of the head or magnetic resonance imaging of the brain should be considered if any of the following conditions apply: (i) first-time seizure, especially if over age 40 years or (ii) there is a high suspicion for a structural lesion (new focal neurologic deficit, focal seizure onset, change from baseline seizure pattern, or a predisposing history such as recent head injury, sickle cell disease, coagulopathy, cerebral vascular disease, malignancy, HIV infection, AIDS, or travel to an area endemic for cysticercosis). Noncontrast CT reveals large cerebral lesions, but magnetic resonance imaging provides more detailed information and may be appropriate when suspicion is high for intracranial pathology.4

While it is not feasible or practical for every patient who presents to the emergency department with seizure, EEG is a useful tool in the diagnostic pathway. EEG can confirm a presumed diagnosis and potentially provide prognostic information for the patient, as certain waveforms are associated with recurrent seizure.5 Emergency EEG is indicated in a patient who has a persistently altered mental status not otherwise explained by medications or other findings. It is also indicated to detect nonconvulsive SE after administration of general anesthesia medications and/or paralytics.1

In a patient with ongoing seizure activity, benzodiazepines are the preferred initial drug of choice. Often patients with known seizure disorder will improve with benzodiazepines. However, if the patient is still seizing after first-line therapy has been given, which includes two doses of either lorazepam or diazepam, second-line therapy includes any of the following administered intravenously: fosphenytoin, phenytoin, valproic acid, levetiracetam, or phenobarbital.6 See Table 26.1 for the drug names and doses.

Second-line agents are to be given once as a single dose, and no agent is strongly preferred due to a lack of evidence. Each of these medications will decrease the patient’s mental status and potentially compromise the airway. A patient requiring these medications will require a higher level of care, and if seizure activity continues, the patient will need to be intubated for airway protection.

Third-line agents for treatment of SE include repeat dose of a second-line drug or administration of an anesthetic agent such as midazolam, propofol, pentobarbital, thiopental, or phenobarbital.6 If third-line drug therapy is required, consult neurology immediately to arrange emergent EEG monitoring while the patient is in the intensive care unit.

References

1. Kornegay JG. Seizures. In: Tintinalli JE, Stapczynski J, Ma O, Yealy DM, Meckler GD, Cline DM. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 8th ed. New York, NY: McGraw-Hill; 2016: 1173–1178.Find this resource:

    2. Lowenstein DH, Alldredge BK. Status epilepticus. New Eng J Med. 1998;338(14):970–976.Find this resource:

    3. Chen DK, So YT, Fisher RS. Use of serum prolactin in diagnosing epileptic seizures: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology. 2005;65(5):668–675.Find this resource:

    4. Harden CL, Huff JS, Schwartz TH, et al. Reassessment: neuroimaging in the emergency patient presenting with seizure (an evidence-based review): report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology. 2007;69(18):1772–1780.Find this resource:

    5. Marks WJ Jr, Garcia PA. Management of seizures and epilepsy. Am Fam Physician. 1998;57(7):1589–1600, 1603–1584.Find this resource:

    6. Glauser T, Shinnar S, Gloss D, et al. Evidence-based guideline: treatment of convulsive status epilepticus in children and adults: report of the Guideline Committee of the American Epilepsy Society. Epilepsy Curr. 2016;16(1):48–61.Find this resource:

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