Seizures is one of the most crucial topics which you must study in-depth during your Emergency Medicine preparation. Questions from this topic are commonly asked in the exam.
This article will help you understand every aspect of the seizures including types, etiology and causes. And best of all, it will help you get an edge in your NEET PG exam preparation.
So, let’s get started!
What are Seizures?
- Seizures result from abnormal, excessive activity of the CNS
- Generalized seizure involves both hemispheres of the brain with loss of consciousness, or focal (partial), in which only one hemisphere is involved.
- Focal seizures are referred to as simple partial seizures when cognition is not impaired and as complex partial seizures when cognition is impaired. Focal seizures may generalize to involve both cerebral hemispheres, referred to as partial seizure with secondary generalization.
Presentation to Emergency Department
- Classically, patients are brought to the ED after a witnessed seizure. Most seizures last 1-2 minutes, but duration can be highly variable.
- When the patient awakens, witnesses or EMS will report that they were confused for several minutes before they returned back to baseline (postictal state). Seizures may also be unwitnessed and a patient may present to the ED stating that they have been waking up confused or on the floor. Rarely, patients who have had seizures will present to the ED having been "found down" without a clear cause of their loss of consciousness
- Common findings include postictal confusion that resolves while in the emergency department. Evidence of tongue trauma from biting, and urinary or bowel incontinence.
- Minor head trauma may be present but does not help to distinguish between seizures and other etiologies. A focal neurologic deficit mimicking a stroke, referred to as Todd's paralysis, may also present.
- Patients may also have tachycardia, diaphoresis, tremulousness, and/or anxiety. These findings may suggest alcohol withdrawal, drug use, or hypoglycemia as possible causes of seizure.
- Medical noncompliance (most common cause of recurrent seizure)
- Sleep deprivation
- Emotional or physical stress
Etiologies of secondary, or reactive, seizures include
- Hypoglycemia (most common cause of reactive seizure)
- Alcohol withdrawal
- Infection (e.g., meningitis. encephalitis, CNS abscess)
- Diagnoses that mimic seizure
- For new-onset, first-time seizure, the only lab values routinely recommended are a chemistry panel (for sodium and glucose) and a pregnancy test.
- Medications have levels that can be checked rapidly in the ED (phenytoin, carbamazepine, phenobarbital etc). Further testing should be guided by the history and physical exam, but can include urine analysis and pregnancy test. Patients in status epilepticus should receive a more complete laboratory profile including LP to identify possible underlying causes
Need CT scan on which patients?
- Every patient with a new-onset seizure should undergo head CT to rule-out intracranial lesions. Although the timing of the CT scan is debated, it can be very quickly and easily done in almost every emergency department in the country. Patients with recurrent seizures should undergo head CT scan if they have a change in their seizure pattern (i.e. new type of seizure, increased frequency of seizures), significant trauma, fever, prolonged postictal time, new neurological deficit, or other concerning symptoms. All patients in status epilepticus should undergo head CT once stabilized
Lumbar puncture considered on which patients?
- LP should be considered for any patient with status epilepticus, severe headache, fever, persistent altered mental status, or immunocompromised state (especially HIV). Head CT scan should be performed prior to LP to rule out an intracranial lesion that may cause herniation during LP.
Causes of Seizures
- Patients that present with seizures from alcohol withdrawal (delirium tremens) may present with anxiety, tremulousness, and altered mental status. Patients in alcohol will have abnormal vital signs including tachycardia, hypertension, hyperthermia and tachypnea. This is predominantly a clinical diagnosis.
- Life threatening disorder that must be treated immediately. All female patients presenting with seizure or possible seizure must be assessed for pregnancy. Pregnant women with an underlying seizure disorder may experience increased seizure frequency during pregnancy, however any pregnant patient with seizure must be suspected of having eclampsia. Clues to the diagnosis include vision complaints, edema of the face, hands, and feet, proteinuria on urine analysis, and hypertension.
Drug history is important!
- Many drugs have the potential to lower the seizure threshold, but several drugs cause seizures more commonly. In any patient being treated for tuberculosis, suspect isoniazid-induced seizures. Patients with a history of depression may have overdosed on trycyclic antidepressants (look for a widened QRS and prominent terminal R wave in aVR on EKG
- Intracranial hemorrhage or brain injury may be the cause of a patient’s seizure and should be suspected in patients with any signs or symptoms of head injury.
- Pseudoseizure is a difficult diagnosis to make since as many as 25% of patients initially thought to have pseudoseizure are eventually diagnosed with a true seizure disorder. Nevertheless, clues to this diagnosis include a rhythmic, controlled shaking activity, ability to talk or follow commands during the seizure, recall of a seizure that involves both sides of the body, or lack of a postictal period.
- EEG monitoring is helpful in assessing for pseudoseizure, but is frequently not available in the ED setting.
- Status epilepticus is present in any patient in whom there is no return to baseline between seizures. In patients with non-convulsive seizures, this can be a difficult diagnosis to make without immediate EEG monitoring. Physicians must have a low threshold to treat patients aggressively even if they Cannot confirm the diagnosis immediately
Treatment of status epilepticus
- General treatment principles that apply to all seizure patients include management of the ABC's and supplemental oxygen.
- Keep the patient safe falling or other injuries and remove restrictive clothing. Do not place anything in the patient's mouth except possibly a bite block or oropharyngeal airway to protect the tongue. First line: Benzodiazepines (usually lorazepam)
- Second line: Fosphenytoin/phenobarbital/valproic acid
- Third line: Versed/pentobarbital/propofol infusions
- The preferred route of seizure medications is intravenous administration.
- However, if it is difficult to obtain an IV, then lorazepam, midazolam, and diazepam can all be given intramuscularly. A common dose of benzodiazepines is 2 mg of lorazepam or midazolam (5 mg of diazepam) every 2-5 min until seizures are controlled. Many emergency departments also have rectal diazepam available. Oral administration of medications should not be used in patients without a normal mental status.
Common Medication Dosing
- Lorazepam/midazolam: 2 mg PO/IM/IV q 2-5 min as needed
- Diazepam: 5 mg PO/IM/IV q 2-5 min as needed (also available PR)
- Phenytoin: 15-20 mg/kg PO/ IV
- Fosphenytoin: 15 – 20 phenytoin equivalents/ kg IV
- Phenobarbital: 20 mg/kg IV (use single dose of 60-120 mg PO for oral load)
- Valproic acid: 15-45 mg/kg IV
- Patients in status epilepticus will usually need to be intubated to control the airway.
- Some etiologies of seizure have specific treatment:
- Eclampsia: Magnesium sulfate
- Hyponatremia: Hypertonic saline
- Isoniazid: Pyroxidine
- Hypoglycemia: Dextrose
- All patients presenting to the ED with seizure must have appropriate outpatient follow-up, usually with a neurologist. First-time seizure patients will usually require further work-up for seizure, typically with MRI and EEG. Patients should be warned to avoid engaging in activities where they or other would be at risk if they had another seizure (e.g. swimming or bathing alone, cooking with open fire, driving etc) until they have been cleared to return to the activities. Additionally, many states required physicians to report any patient with a diagnosis of seizure and have restriction on driving privilege.
We hope this article has helped you understand seizures (status epilepticus) in detail for Emergency Medicine preparation. For more such information, download the PrepLadder app and study with the Dream Team Next Edition (India’s top Medical faculty).