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<< Seizures and Status Epilepticus: Diagnosis and Management in the Emergency Department
Management
First Time Seizures With Spontaneous Resolution
The need for hospital admission is obvious in those patients who are clinically ill. The dilemma arises when determining disposition for the patient who returns to a normal baseline after a first-time seizure.
A rational decision regarding whether a patient needs to receive antiepileptic drug (AED) therapy or admission is problematic. The recurrence risk of unprovoked (i.e., epileptic) seizures has been studied rigorously but is, unfortunately, reported in one and five year recurrence rates.15, 72, 73, 74 Moreover, these studies also exclude patients who had an identifiable cause of their seizure. It is also not clear that AED treatment will lower the risk of recurrence in all subsetsof patients who have had a seizure. While an uncontrolled study with a high rate of noncompliance demonstrated a benefit of early initiation of AED treatment,78 patients with a history of traumatic brain injury have no decrease in seizure recurrence on phenytoin.75 An extended follow-up study of seizure recurrence found that AED treatment was actually associated with an increased recurrence risk.15
The best predictor of seizure recurrence is the causative etiology combined with EEG neuroimaging findings.78 This information often requires modalities that are not routinely available in the ED. Recurrence rates are lowest (approximately 24% in two years)when no etiology is identified and the EEG is normal. Patients who have structural lesions on CT or patients with focal seizures that generalize secondarily have a risk of recurrence within one year of up to 65%, and are the group of patients that probably benefit from initiating AED therapy.15, 78 ED-based studies have reported rates of hospital admission, but the decision to admit was not standardized, and the ability of admission to improve outcomes was not studied. 6 50
Only one study investigated the incidence of seizure recurrence within 24 hours of ED presentation.50 This was a retrospective review of all adult patients admitted to the hospital with a first time seizure during a two-year period. The authors reported a 19% seizure recurrence rate within 24 hours of presentation, decreasing to 9% if those patients with alcohol related events or focal lesions on CT were excluded.
However, the applicability of these results is limited because those patients with recurrent seizures were not described well, making it impossible to assess whether recurrence could have been predicted based on physical findings or co-morbid factors. Other than patients who obviously require admission for treatment of a defined illness, there is insufficient evidence to support a recommendation to admit or discharge the patient with no co-morbidities who returns to a normal baseline after a first seizure. The decision must be tailored to the patient, taking into consideration the patient’s access to follow-up care. On the other hand, patients with co-morbidities, including age over 60 years, known cardiovascular disease, history of cancer, or history of immunocompromise, should be considered for admission to the hospital.
There is no set standard for whether a patient should be started on an antiepileptic drug after a first time seizure in the ED. The decision to initiate an AED in the ED for a first-time seizure varies depending upon the patient, physician, and local practices. This decision is best made in conjunction with the patient’s primary care provider or neurologist and should include the estimated risk for seizure
recurrence.
Patients With A Known History Of Seizure Disorder
Patients with a known seizure disorder, who have a “typical” event while on medications and who return to baseline mental status need only a serum anticonvulsant level (if appropriate). Exceptions to this include those with underlying disease, such as diabetes, that could result in a metabolic derangement. In such patients, it is important to investigate for precipitants, such as infections or new medications. If the seizure represented a change in the patients stable seizure pattern (more frequent or recurrent), the physician needs to look for a reason, e.g., an underlying infection. Any consideration to changing AED regimens should only be made in conjunction with the patient’s primary care provider or neurologist.
Noncompliance and low AED levels in the ED are frequently encountered problems and the emergency physician must decide how to best increase serum levels to the therapeutic range. Current recommendations for the management of epilepsy emphasize monotherapy, see Table 4. This often means increasing a single drug to the point of seizure control or clinical toxicity.76 Serum drug levels are used only to guide therapy and must be interpreted in the context of the patient’s clinical status.
In addition, drug levels may vary depending on the patient’s dosing schedule. For example, single dosing of phenytoin may result in a peak serum level that is two to three times that of the trough.77 For a patient who has a seizure due to a low serum concentration of phenytoin, oral administration of phenytoin is an appealing option given the problems associated with parenteral administration. There has been hesitation to use this strategy due to a study in 1987 that demonstrated that only 60% of patients loaded with 18 mg/kg were therapeutic after 6 to10 hours.78 Since then, two well designed studies have demonstrated that oral loading (19 mg/kg in men and 23 mg/kg in women) is both safe (patients should be watched for ataxia and dizziness) and provides therapeutic serum levels by four hours in almost all patients. 79, 80 Some EPs still prefer parenteral loading of phenytoin or fosphenytoin to ensure an adequate serum level on discharge.
The need for hospital admission is obvious in those patients who are clinically ill. The dilemma arises when determining disposition for the patient who returns to a normal baseline after a first-time seizure.
A rational decision regarding whether a patient needs to receive antiepileptic drug (AED) therapy or admission is problematic. The recurrence risk of unprovoked (i.e., epileptic) seizures has been studied rigorously but is, unfortunately, reported in one and five year recurrence rates.15, 72, 73, 74 Moreover, these studies also exclude patients who had an identifiable cause of their seizure. It is also not clear that AED treatment will lower the risk of recurrence in all subsetsof patients who have had a seizure. While an uncontrolled study with a high rate of noncompliance demonstrated a benefit of early initiation of AED treatment,78 patients with a history of traumatic brain injury have no decrease in seizure recurrence on phenytoin.75 An extended follow-up study of seizure recurrence found that AED treatment was actually associated with an increased recurrence risk.15
The best predictor of seizure recurrence is the causative etiology combined with EEG neuroimaging findings.78 This information often requires modalities that are not routinely available in the ED. Recurrence rates are lowest (approximately 24% in two years)when no etiology is identified and the EEG is normal. Patients who have structural lesions on CT or patients with focal seizures that generalize secondarily have a risk of recurrence within one year of up to 65%, and are the group of patients that probably benefit from initiating AED therapy.15, 78 ED-based studies have reported rates of hospital admission, but the decision to admit was not standardized, and the ability of admission to improve outcomes was not studied. 6 50
Only one study investigated the incidence of seizure recurrence within 24 hours of ED presentation.50 This was a retrospective review of all adult patients admitted to the hospital with a first time seizure during a two-year period. The authors reported a 19% seizure recurrence rate within 24 hours of presentation, decreasing to 9% if those patients with alcohol related events or focal lesions on CT were excluded.
However, the applicability of these results is limited because those patients with recurrent seizures were not described well, making it impossible to assess whether recurrence could have been predicted based on physical findings or co-morbid factors. Other than patients who obviously require admission for treatment of a defined illness, there is insufficient evidence to support a recommendation to admit or discharge the patient with no co-morbidities who returns to a normal baseline after a first seizure. The decision must be tailored to the patient, taking into consideration the patient’s access to follow-up care. On the other hand, patients with co-morbidities, including age over 60 years, known cardiovascular disease, history of cancer, or history of immunocompromise, should be considered for admission to the hospital.
There is no set standard for whether a patient should be started on an antiepileptic drug after a first time seizure in the ED. The decision to initiate an AED in the ED for a first-time seizure varies depending upon the patient, physician, and local practices. This decision is best made in conjunction with the patient’s primary care provider or neurologist and should include the estimated risk for seizure
recurrence.
Patients With A Known History Of Seizure Disorder
Patients with a known seizure disorder, who have a “typical” event while on medications and who return to baseline mental status need only a serum anticonvulsant level (if appropriate). Exceptions to this include those with underlying disease, such as diabetes, that could result in a metabolic derangement. In such patients, it is important to investigate for precipitants, such as infections or new medications. If the seizure represented a change in the patients stable seizure pattern (more frequent or recurrent), the physician needs to look for a reason, e.g., an underlying infection. Any consideration to changing AED regimens should only be made in conjunction with the patient’s primary care provider or neurologist.
Noncompliance and low AED levels in the ED are frequently encountered problems and the emergency physician must decide how to best increase serum levels to the therapeutic range. Current recommendations for the management of epilepsy emphasize monotherapy, see Table 4. This often means increasing a single drug to the point of seizure control or clinical toxicity.76 Serum drug levels are used only to guide therapy and must be interpreted in the context of the patient’s clinical status.
In addition, drug levels may vary depending on the patient’s dosing schedule. For example, single dosing of phenytoin may result in a peak serum level that is two to three times that of the trough.77 For a patient who has a seizure due to a low serum concentration of phenytoin, oral administration of phenytoin is an appealing option given the problems associated with parenteral administration. There has been hesitation to use this strategy due to a study in 1987 that demonstrated that only 60% of patients loaded with 18 mg/kg were therapeutic after 6 to10 hours.78 Since then, two well designed studies have demonstrated that oral loading (19 mg/kg in men and 23 mg/kg in women) is both safe (patients should be watched for ataxia and dizziness) and provides therapeutic serum levels by four hours in almost all patients. 79, 80 Some EPs still prefer parenteral loading of phenytoin or fosphenytoin to ensure an adequate serum level on discharge.
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