Approach to epilepsy: Clinical sciences

Epilepsy is a neurological condition characterized by recurrent, unprovoked seizures, which refer to sudden changes in the brain's electrical activity that can result in various clinical manifestations, including convulsions and loss of consciousness. Now, there are several different types of seizures, including tonic-clonic, myoclonic, atonic, and absence seizures. All seizures can be classified as focal or generalized based on the affected brain area.

Alright, if a patient presents with a chief concern suggestive of epilepsy, first perform an ABCDE assessment. If the patient is unstable, stabilize their airway, breathing, and circulation. You might need to intubate your patient and start mechanical ventilation. Next, obtain IV access and put your patient on continuous vital signs monitoring, including heart rate, blood pressure, and pulse oximetry, as well as cardiac telemetry.

Most commonly, unstable individuals are presenting with convulsive status epilepticus. So, once you stabilize the patient, your next step is to obtain a focused history and physical examination. History will reveal a tonic-clonic seizure that started 5 or more minutes ago, OR multiple seizures without recovery to baseline mental status between attacks.

On the physical exam, you will notice an altered mental status and alternating body stiffening and jerking movements. With these findings, diagnose convulsive status epilepticus.

Here’s a clinical pearl to keep in mind! Immediate treatment for convulsive status epilepticus includes benzodiazepines, such as lorazepam, midazolam, or diazepam, followed by anti-seizure medications, like fosphenytoin, phenobarbital, valproic acid, or levetiracetam. Once you initiate the treatment, you can use EEG to monitor clinical response. Also, you can use EEG to assess for non-convulsive status epilepticus, which is a condition associated with abnormal brain activity with no or just a few physical manifestations.

Now, let’s go back to the ABCDE assessment and focus on stable individuals. In this case, obtain a focused history and physical exam. History usually reveals at least 2 unprovoked seizures more than 24 hours apart, which is enough to confirm the diagnosis of epilepsy. However, to call a seizure unprovoked, you need to rule out secondary causes of seizures, such as alcohol withdrawal, hypoglycemia, or sepsis.

Some individuals with epilepsy might report a remote history of head trauma, CNS infection, and stroke, as well as degenerative or congenital CNS conditions, like prion disease or tuberous sclerosis.

Lastly, there might be a family history of epilepsy. Depending on the underlying cause, the physical exam between seizures may or may not be normal. At this point, you can diagnose epilepsy.

Now, here's a clinical pearl! In addition to focused history and physical examination, the workup for epilepsy also includes EEG and brain imaging, like CT or MRI. This is because one unprovoked seizure in combination with risk factors, such as an abnormal EEG finding that fits a known epilepsy syndrome, or cortical dysplasia on brain imaging, is enough to confirm the diagnosis of epilepsy.

Alright, once you diagnose epilepsy, your next step is to assess the type of seizure. First, let’s focus on tonic-clonic seizures, which start with the tonic phase characterized by muscle stiffness and extension of the limbs. During this phase, the patient might become cyanotic because they’re not breathing, and they could also bite their tongue. Additionally, the contraction of abdominal muscles and diaphragm can force air through closed vocal cords and cause a specific crying sound called ictal cry.

The tonic phase is followed by the clonic phase, which is characterized by a period of jerking movements throughout the body. During this phase, the patient might experience urinary or stool incontinence.

Once the seizure resolves, there is a period of confusion, also known as postictal confusion. With these findings, you can diagnose tonic-clonic seizures.

On the flip side, myoclonic seizures are characterized by irregular, brief, fast muscle or limb jerking movements. Myoclonic movements can sometimes be difficult to differentiate from clonic movements, but myoclonic jerks are more irregular and faster, sometimes described as lightning-fast movements. Additionally, this type of seizure can occur as a result of hypoxic brain injury after cardiac arrest or anoxic brain injury. With these findings, diagnose myoclonic seizures.

Time for a high-yield fact! Juvenile myoclonic epilepsy is one of the most common types of epilepsy in adolescents. Individuals typically have normal development, and their seizures tend to occur in the morning or when they are not getting enough sleep. For example, when studying for final exams. This type of seizure is photosensitive, meaning your patient might experience attacks when looking at flashing or flickering lights. Finally, the EEG will show 3 to 5.5 Hertz generalized polyspike and wave discharges.

Next up are atonic seizures, which are associated with very brief episodes of loss of consciousness. The patient will suddenly collapse to the ground, or the head will droop. With this presentation, diagnose atonic seizures.

Finally, let’s look at absence seizures, which are nonmotor seizures. In this case, history will reveal that the patient has brief episodes of unresponsiveness, characterized by staring off into space or having a blank expression. During the episode, the patient might present with repetitive small, localized movements such as eye-blinking or head nodding. Remember, these individuals will have no period of confusion afterward, meaning they will immediately go back to what they were doing before the seizure. One important thing to keep in mind is that in most patients, you can provoke this type of seizure with hyperventilation. These findings are highly suggestive of typical absence seizures.

Here's another clinical pearl! Childhood absence epilepsy occurs in children with normal development and has a high rate of remission by adolescence. These seizures are often mistaken for behavioral and attention issues, so you can obtain an EEG, which reveals 3 Hertz generalized spike and wave complexes. The first-line treatment for childhood absence seizures is ethosuximide.

Once you determine the specific type of seizure, the next step is to assess the onset of seizure activity. You can do this by clinically witnessing a seizure or by ordering EEG. Clinically, you might see generalized body jerking movements or an absence seizure without any focal movements beforehand. Similarly, if the EEG reveals abnormal bilateral and simultaneous electrical activity, diagnose generalized seizures. All patients with generalized seizures will have a loss of consciousness.