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How to Identify and Treat Seizures
Seizures account for between 5%–8% of all EMS responses in the United States, and about 71% of those patients end up being transported to EDs. Rapid treatment is essential to the survival of seizure patients, and even when patients don’t succumb to their seizures, time is brain because prolonged seizures are difficult to treat and can cause lasting brain injury.
Seizures were once described as either petit mal or grand mal. The definition has expanded since then. Seizures are an uncontrolled discharge of electrical activity between the neurons. This may present as a variety of temporary abnormalities, including tonic (stiffening of the muscles) and clonic (rhythmic jerking of the arms and legs). Patients may have focal motor seizures that are simple, where they experience limb shaking and do not lose consciousness, or complex, with altered consciousness and limb shaking. Patients may experience other seizure types where the only signs are staring blankly into space or motor automatisms—subtle, semicoordinated, and repetitive motor activities.
Absence seizures are characterized by a brief loss and return of consciousness. They may be as short as 15 seconds and are typically seen as people staring off into space. They can happen several times a day. Simple motor seizures, where the patient does not lose consciousness and may remain conversant, are also difficult to diagnose.
In one study paramedics missed 50% of children with active seizure activity. Identifying these patients is crucial to reducing death and disability.
Identifying Seizures
Patients having seizures exhibit a range of symptoms, from tonic-clonic activity with severe hypoxia to being fully conscious but with lost movement in one part of their body. Emotionally they may be euphoric or sad. Some patients may be incontinent of urine and feces. If they are experiencing a focal motor seizure, they may have full recollection of the event. With a generalized seizure they may have no recollection.
The time-honored definition for status seizure or status epilepticus was seizure activity continuous or repetitive for 30 minutes or more. This was modified to seizure activity for 5 minutes, since there is evidence to suggest that failing to treat seizure activity that continues beyond 5 minutes is harmful. The terminology time is brain refers to the potential for brain injury with prolonged seizures and represents the critical nature of the event that makes early diagnosis and treatment key.
The etiology of epilepsy is just as complex. Some people have congenital seizures or develop seizures because of trauma to the brain. Septic patients will seize. Ischemic stroke patients, who have impaired consciousness, can have a complex clinical picture with nonconvulsive status epilepticus. Febrile seizures are commonly seen in infants with spiking fevers and pregnant patients who have eclampsia.
Nonconvulsive status epilepticus may be mistaken for a stroke/TIA. It is defined as a prolonged seizure that exhibits as altered mental status, as opposed to what we typically associate with seizures: intense generalized tonic-clonic status epilepticus. Up to a quarter of the seizure patients we see have nonconvulsive seizures. These patients generally appear staring off into space, unresponsive, and dazed.
Patients who are in status epilepticus, even patients with nonconvulsive seizure activity, are at increased risk for injury to the brain and even death. Early diagnosis will lead to early treatment. By improving the ability to diagnose seizures early, we can improve outcomes in terms of cognitive disability, overall neurologic function, and in some cases even the development of chronic epilepsy.
Determining who these patients may be difficult in the field. Part of it is based on the patient’s history and subtle clues such as automatisms, bilateral mild eyelid fluttering, and mild myoclonic jerks of the patient’s extremities, for example, but subtle signs can be easy to miss or attribute to something else.
Hospital staff may perform an electroencephalogram (EEG) to aid in the diagnosis. The EEG is a powerful device that captures and records electrical signals generated by the brain. Analyzing these impulses can reveal abnormalities in their patterns. We can see if a patient is having status seizures or determine if a patient has suffered a stroke or traumatic brain injury.
The EEG is not without its hurdles. Until recently they could not be done in the field. On arrival at the hospital, it may take some time to perform one. Not just anyone can perform an EEG; the application of tiny electrodes to the skull takes a skilled technician. Currently EEG recordings rely on the interpretation of neurologists. These aspects create significant diagnostic and ultimately therapeutic delays that can impact patients’ clinical outcomes. As use of EEGs expands, these experts are increasingly limited resources.
Treatment for Status Seizures
Regardless of whether a patient has a history of epilepsy or first-time seizures, treatment focuses on maintaining the airway, oxygenation (>95% SpO2), and ventilation status. Circulation is key as well; if the patient’s blood pressure is low, they may not have adequate cerebral perfusion, and coupled with low oxygenation during status epilepticus, this may accelerate neuronal death. Determining if the patient is hypoglycemic is also important—if they are actively seizing, glucagon may be your only choice of treatment if you cannot gain venous or IO access. If the patient is between seizures, this would be an opportune time to secure IV access—but make sure it is secured. If the patient is actively seizing without IV access, treatment should be IM benzodiazepines to terminate seizure activity. Midazolam is effective in this regard.
For patients who are experiencing more subtle seizures, such as absence seizures or focal motor seizures, determining if they are having status epilepticus may be more difficult.
New Diagnostics
A new device used in hospitals has promise for the prehospital care environment. Roughly the size of a portable radio, the Ceribell is a portable rapid-response EEG device. It has a special headband that facilitates electrode placement, making it easy enough for anyone to apply. It is battery operated and has an algorithm that can read the EEG and alert anyone that someone is having a status seizure, especially if they are having an absence or focal motor seizure. The Ceribell device even has a screen that lets you see the actual EEG in real time.
Alameda County EMS in California, along with the University of California San Francisco, Alameda Health system, Ceribell, and the Alameda Fire Department’s EMS Division, is conducting a study to determine if it is possible to use the Ceribell EEG in the field and capture an EEG of the same quality as the ones obtained in the ED and ICU. The Ceribell device has been able to identify patients who are having seizures in a hospital environment, but its utility in the rough-and-tumble environment of EMS has not been determined yet.
The current study does not affect current clinical care standards—patients will not wait for care just to obtain an EEG. All protocols for patients suffering seizures, altered mental status, or stroke will be followed. During the study the Ceribell device will not be used to make treatment decisions by personnel in the field.
This is a critical first step in determining if the Ceribell can be applied in the field. If it can be utilized, then assessment and treatment protocols can be developed to leverage this diagnostic information.
This will not affect just patients having status seizures. In the future use of the Ceribell may improve determination of patients who have suffered TBI or are having a large vessel occlusion stroke, influencing not only treatment in the field but transport decisions to specialty care centers.
The author thanks Elan L. Guterman, MD, MAS, assistant professor of neurology at UCSF, for editing assistance with this article.
Additional thanks to Mary Mercer, MD, medical director, Alameda Fire; Karl Sporer, MD, medical director, Alameda County EMS; Nikita Joshi, MD, medical director, Alameda Hospital Emergency Department; Courtney Shay, MD, UCSF EMS fellow; the Ceribell team; Capt Dave Buckley, Alameda Fire Department; and Local 689 and the members of the Alameda Fire Department.
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