Approach to epilepsy: Clinical sciences

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Introduction 0:00–0:33

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.

Unstable patient / Convulsive status epilepticus 0:33–2:14

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.

Stable patient / Epilepsy 2:14–3:35

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.

Tonic-clonic seizures 3:35–4:29

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 seizures 4:29–5:34

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.

Atonic seizures 5:34–5:48

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.

Absence seizures 5:48–6:56

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.

Generalized seizures 6:56–7:26

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.
On the flip side, if you notice focal motor movements or the EEG reveals abnormal focal electrical activity of the brain, diagnose focal seizures.

Focal seizures 7:26–9:30

Now, here’s a clinical pearl! In all types of focal seizures, you should obtain brain imaging to assess for possible structural lesions that could cause the seizure.
However, remember that the history and seizure descriptions can also suggest what part of the brain is affected. For example, the seizure characterized by a progressive spread of jerking throughout a limb is known as a Jacksonian march due to epileptic activity spreading through the motor cortex in the frontal lobe.
The sensation of déjà vu, fear or anxiety, an abnormal smell, or automatisms preceding a seizure suggest a temporal lobe seizure.
This kind of seizure might be a result of mesial temporal lobe sclerosis, or simply hippocampal sclerosis, in which there is scarring and neural loss in the hippocampus affecting neuronal circuits.
Finally, visual hallucinations or seeing flashing lights point to an occipital lobe seizure. Sometimes, seizures can be focal in onset and quickly spread and affect the whole brain, causing generalized seizures.
These seizures are called focal to bilateral tonic-clonic seizures. In this case, it’s hard to clinically determine the type, so carefully assess the EEG findings, which will reveal abnormal electrical activity that starts focally then becomes diffuse.
Some examples of focal and generalized seizure syndromes include Dravet and Lennox-Gastaut syndromes. Dravet syndrome presents in early infancy and usually begins as clonic seizures affecting half of the body and progresses to involve other seizure types.
On the flip side, Lennox-Gastaut syndrome usually presents in early childhood and consists of multiple seizure types, particularly tonic seizures.
Both syndromes are medically refractory and associated with intellectual disability. Once you diagnose focal seizures, the next step is to assess for impaired awareness during the seizures.

Focal aware seizures, focal impaired awareness seizures 9:30–11:20

This could range from mild confusion to loss of consciousness. If there is no impaired awareness, diagnose focal aware seizures.
However, if you notice impaired awareness, diagnose focal impaired awareness seizures. Here’s one last high-yield fact to keep in mind!
The management primarily includes anti-seizure medications. First, there’s valproic acid, which is a broad-spectrum medication used to treat both generalized and focal seizures.
However, it can cause pancreatitis and thrombocytopenia. Another important side effect involves neural tube defects, so you should avoid it in biological female individuals of childbearing age.
Levetiracetam is another medication used for both generalized and focal seizures, but it can cause or worsen mood disorders, such as depression, and cause irritability and aggression.
Another option for generalized and focal seizures is Topiramate, which is associated with adverse effects, like birth defects, such as cleft lip or cleft palate; kidney stones; weight loss; and even glaucoma.
Medications more commonly used for focal than generalized seizures include carbamazepine, which can cause hyponatremia and serious skin reactions like Stevens-Johnson Syndrome or toxic epidermal necrolysis; and phenytoin, which can cause hepatotoxicity and osteoporosis.
If seizures are medically refractory, you can consider surgical resection of a structural lesion such as sclerosis; or vagal nerve stimulator placement, which works by sending electrical impulses to the brain via the vagus nerve and altering electrical activity and levels of neurotransmitters in the brain.
Alright, as a quick recap... If your patient presents with a chief concern suggesting epilepsy, first perform the ABCDE assessment to rule out the possibility of convulsive status epilepticus.

Review 11:20–12:09

Next, obtain a focused history and physical exam. If history reveals at least two unprovoked seizures more than 24 hours apart, you can diagnose epilepsy.
However, to call a seizure unprovoked, you need to rule out secondary causes of seizures, such as alcohol withdrawal, hypoglycemia, and sepsis.
Once you diagnose epilepsy, your next step is to determine the type. Some important types include tonic-clonic, myoclonic, atonic, and absence seizures.
Finally, don't forget to assess the onset of seizure activity, which is going to help guide the management.