Seizures in epilepsy: what you need to know
- What is epilepsy seizure?
- What is the difference between a seizure and epilepsy? And what causes seizures in epilepsy?
- What is the general pathophysiology of epilepsy?
- Upregulation of excitatory neurons
- Downregulation of inhibitory neurons
- What are the clinical manifestations of epilepsy?
- Simple Partial Seizure
- Complex partial seizure (CPS)
- Secondary generalized seizure
- Generalized motor seizure
- Generalized non-motor seizure
If someone gets seizures in epilepsy. You must have seen a sudden violent attack like vigorously shaking the hand, up-rolling eyes, staring, loss of consciousness, jerking of arms and legs, etc.
If you or your relatives are having this neurological problem. Keep reading this post. Because here I am going to explain the epilepsy disease in detail.
According to WHO, more than 50 million people are already suffering from epilepsy worldwide. You may find around 4 to 10 epileptic people easily in a population of 1000 people.
In some countries, there are some misconceptions and myths about epilepsy. Most of the people think –
- Fits occurring due to evil possession or supernatural cause
- Contagious disease
- Spiritual disease
- Psycho illness
Due to poor medical knowledge, many epileptic people suffer from problems like stigma and social discrimination.
So, it is important for all of us to know about this disease. And we need to create epilepsy awareness everywhere.
In this post, I am going to clear all your doubts regarding seizures in epilepsy.
Here, I will cover some major points –
- causes of epilepsy seizures
- types of seizures in epilepsy
- pathophysiology for epilepsy
- clinical manifestation of seizures
Let’s begin this topic.
What is epilepsy seizure?
Epilepsy is a chronic neurological medical condition. Seizure is the main clinical sign of epilepsy.
Typically, the neuron firing rate is around 80 times a second. During a seizure, it increases and starts to fire at the rate of 500 times a second.
Due to this excessive electrical activity, you may have involuntary movements, sensations, emotions, and behavior disturbances.
If you got a single seizure, it does not mean you have epilepsy. But when you get repeated unprovoked seizures (unknown cause) that indicate epilepsy.
Epilepsy is sometimes called “Seizure disorder.“
What is the difference between a seizure and epilepsy? And what causes seizures in epilepsy?
If you get a sudden uncontrolled electrical impulse in your brain, that represents a seizure. It is being fired from the neurons at a rate of 500 times a second.
Seizures may be provoked or unprovoked.
Unprovoked seizures are those that have no exact cause; it is also called idiopathic seizures. In most cases, epilepsy has no identifiable reason.
If you have had two unprovoked repeated seizures that represent idiopathic epilepsy. Most cases of epilepsy are idiopathic.
In contrast to provoked seizures, the cause of seizures is well known. Provoked seizures are a single occurrence.
If you get repeated (two or more seizures) provoked seizure in your life is called symptomatic epilepsy. It may be due to certain medical conditions (like brain injury, electrolyte disturbances, etc.) or drugs.
Reason for provoked seizures
1. Cerebrovascular diseases
You may have a seizure if you are suffering from –
- Acute Ischemic Stroke (clot formation in brain artery)
- Intracerebral hemorrhage (bleeding within the brain tissue)
- Subarachnoid hemorrhage (bleeding into the subarachnoid space)
- Anoxic brain injury (severe hypoxia or lack of oxygen in your brain)
- Posterior reversible encephalopathy syndrome (PRES) – In severe high blood pressure in the brain.
2. Infectious diseases
Many bacterial or viral infection in your brain that may be a reason for the seizure. For example –
- Meningitis (inflammation of meninges membrane)
- Encephalitis (inflammation of the brain due to herpes simplex virus)
- Brain abscess (pus formation in brain tissue)
3. Traumatic brain injury
Generally, your skull adheres with meninges. Meninges membrane is made up of three layers dura mater (outer), arachnoid mater (middle), and pia mater (inner).
If any injury occurs in the meninges membrane may cause a seizure. It is mainly happened in –
- Epidural hematoma (bleeding in between skull and dura mater)
- Subdural hematoma (bleeding in between dura mater and arachnoid mater)
4. Autoimmune disease
Systemic lupus erythematosus (SLE) also contributes to the development of seizures.
5. Metabolic disorders
Metabolic disturbances also play a significant role in seizures. You may have episodes if you are suffering from –
- Hypoglycemia conditions (low blood glucose level)
- Thiamine deficiency (low level of vitamin B1)
- Hyponatremia (low sodium level)
- Hypocalcemia (low calcium level)
- Hypomagnesemia (low level of serum magnesium)
- Hypophosphatemia (low level of phosphorus)
- Hepatic encephalopathy (increased ammonia level in your brain)
- Hyperthyroidism (increased level of T3/T4)
- Uremic encephalopathy – High BUN (Blood Urea Nitrogen)
6. Brain tumor
Glioblastoma multiforme (GBM) may rapidly spread in any lobes of the brain. It may also be a cause of the seizure.
7. Drug-induced seizures
Seizures may also induce by various drugs like –
- TCA (Tricyclic antidepressants)
- Alcohol withdrawal
- Excess consumption of caffeine
- Benzodiazepine withdrawal
8. Other causes
You may also have seizures due to –
- Viral fever or febrile fever
- Degenerative diseases like Alzheimer’s, Parkinson’s, etc.
- Demyelinating diseases like Multiple sclerosis
- Genetic predisposition
What is the general pathophysiology of epilepsy?
Suppose you are driving a car and you found brake fail.
What will happen?
There is a maximum chance you will get an accident. So, there is a need for a balance of your accelerator and brake for proper driving.
Similarly, there are two important neurotransmitters, i.e., glutamate and GABA (gamma-aminobutyric acid). They play a significant role in the action potential (or electrical activity) of your neuron.
Here, Glutamate act as an accelerator, whereas GABA act as a brake of your car.
Glutamate is known as an excitatory neurotransmitter. It is a non-essential amino acid.
It is generally stored in the vesicles of the synaptic node. When your glutamate is released from the nerve ending, it binds to the NMDA receptor.
As soon as glutamate binds on NMDA, electrolytes (Na+ and Ca+2) stimulates the voltage-gated channel.
Due to this stimulation, sodium (Na+) and calcium (Ca+2) ions enter the nerve cell. It starts to make nerve cells more electropositive (or less electronegative). As a result, depolarisation occurred, and an actional potential started to conduct.
To control the excess activity of glutamate, GABA plays an important role.
GABA normally inhibits your brain activity and puts you in relax mode. It is your primary inhibitory neurotransmitter.
When GABA binds to the GABA-A receptor, chloride ions (Cl–) move into the nerve cell. As a result, your nerves cells become electronegative and decrease the action potential by hyperpolarisation.
In epilepsy, if you receive too much stimulation in the glutamate pathway and too little inhibition in the GABA pathway, that may lead to a seizure.
The imbalances of these neurotransmitters are the main cause of epilepsy.
Upregulation of excitatory neurons
More stimulation of excitatory neurons
Excess production of glutamate
Increase sensitivity of NMDA receptor
An excess influx of sodium and calcium ions
Abnormal increase depolarisation
Abnormal increase action potential and nerve firing start.
Downregulation of inhibitory neurons
Dysfunction of GABA-A receptor
GABA unable to bind on GABA-A receptor
Decrease influx of chloride ions
Abnormal increase action potential
What are the clinical manifestations of epilepsy?
The symptoms of epilepsy are depended on the site of origin of the seizure. The abnormal impulse may trigger anywhere in your brain lobe.
The origin of seizures has classified the types of seizures in epilepsy. So, the seizures are generally divided into two major groups – partial seizure and generalized seizure.
Partial seizure or focal seizure (part of the brain involved)
Simple Partial Seizure
Suppose the abnormal electrical activity hits in a small area of your brain (or single lobe). In that case, it is called a simple partial seizure (SPS). It does not spread in other lobes.
This type of seizure does not affect your consciousness. You may remain aware and awake throughout the attack, and sometimes you can even talk during the episode of a simple partial seizure.
It usually occurs up to 30 sec. to 1 min. Simple partial seizure is also known as “focal onset aware seizure.”
The symptoms of SPS depending upon the part of the brain affected. You may have different types of simple partial seizure –
1. Focal motor seizures
If the seizure hits on motor areas, especially the contralateral frontal lobe. It may cause abnormal movements. It mainly affects your face, hands, and toes.
During this seizure, you may have unilateral shaking of the hand. Moreover, eyes and head deviate to one side (contralateral side).
Your muscles may move like this –
- Atonic (relaxing of muscle)
- Tonic (stiffening of muscle)
- Clonic (quick jerking muscle)
- Myoclonic (very rapid jerking of muscle)
- Jacksonian march
In Jacksonian March, seizure starts with tonic contractions on one side and spreads (march) to the other side. It typically happens for a short time (20 to 30 seconds).
For example, if you got a seizure in your finger and it spreads throughout your hand, that represents Jacksonian March.
It can also associate symptoms like automatism (lip-smacking, rapid eye blinking, chewing, or tapping movements)
2. Focal somatosensory seizures
During this seizure, you may feel like-“pins and needles.”
The seizure mainly hits the parietal lobe of your brain. Due to this, you may feel numbness, tingling, crawling sensation, pain, or thermal sensations.
It may affect your aura (disturb perceptually) too, like –
- Visual hallucination
- Hear the abnormal sound
- Abnormal smell
- Abnormal taste
3. Focal autonomic seizures
If the seizure altered your autonomic function. Then you have symptoms like
- Most commonly epigastric rising sensation – nausea, indigestion, stomach pain, etc.
- Changes in blood pressure and heart rate (commonly tachycardia)
This seizure is primarily affecting your mesial temporal lobe.
4. Focal psychological seizures
In this type of seizure, you may have experienced –
- Memory flashbacks
- Dream-like events
- Deja Vu feeling (feel like already seen)
- Depersonalization (dissociation from oneself)
- Derealization (detached from your surroundings)
- Sudden emotional disturbance – anxiety, agitation, fear, and uncontrolled laughter or crying.
Complex partial seizure (CPS)
Sometimes, abnormal electrical activity spreads from one lobe to another lobe into a hemisphere. Due to this, it impairs your consciousness that represents a complex partial seizure.
It is also known as “focal impaired awareness seizures.”
A complex partial seizure can present with or without an aura. It generally arises from the temporal lobe of your brain.
The duration of auras can last from a few seconds to few minutes before the consciousness is impaired.
Hallucination and mental distortion are more common in complex partial seizures.
- If seizure spreads in your frontal lobe, then it may cause 40% to 80% automatism like running, walking, bicycling movements, lip-smacking, rapid blinking, chewing, or tapping movements.
- Suppose seizure originates from the mesial temporal lobe. In that case, you may have auras such as epigastric sensations like vomiting, deja vu, fear, and unpleasant smells.
- If the seizure occurs in the lateral temporal lobe, you may have vertigo, auditory (buzzing, ringing), or visual symptoms.
- Suppose the seizure hit on the parietal lobe and occipital lobe In that case, you may have a feeling of numbness like-“pins and needles.” It may also cause visual hallucinations like pictures of people, animals, flashing lights, etc.
Secondary generalized seizure
If a seizure starts in one area of the brain, then spreads to both sides of the brain is called a secondary generalized seizure. It is also called a focal to a bilateral tonic-clonic seizure.
In other words, when focal seizure (or partial seizure) becomes generalized, that seizure represents secondary generalized seizure.
Generalized seizure (entire brain involved)
If the abnormal electrical impulse hits the entire area of your brain (affects both hemispheres), then it is called Generalised Seizure.
This type of seizure completely affects your consciousness. You may feel unaware or unconscious during the attack. Most generalized seizures typically last up to 5 mins.
A generalized seizure is divided into two types – Generalised motor seizure and Generalised non-motor seizure.
Generalized motor seizure
This seizure changes your muscle activity. Due to this, you may have –
- Atonic (relaxing of muscle)
- Tonic (stiffening of muscle)
- Clonic (quick jerking muscle)
- Myoclonic (very rapid jerking of muscle)
Generalized tonic clinic seizure (GTCS) mostly happens in generalized motor seizures. It is also called “Major epilepsy” or “Grand mal epilepsy.”
In GTCS, seizure hits rapidly in bilateral cortical, subcortical, and brainstem networks of your brain.
During GTCS, if you are standing, then you will fall backward. Meanwhile, your limbs (hands and legs) may start jerking and shaking vigorously.
Moreover, you may also have experienced like –
- Produce excess saliva from the mouth
- Involuntary screaming or cry
- Up-rolling of eyes (your eyes can roll back towards your head)
- Tongue biting due to intense crunch of mastication muscles
- Loss of bladder control due to urinary incontinence
- Stool leaks out from rectum due to fecal incontinence
- Increase heart rate and blood pressure
If the seizure occurs more than 5 minutes or two episodes within 5 minutes, this medical emergency is called status epilepticus.
The postictal (after seizure) event is mostly seen in almost all types of seizures except absence seizures.
You may have developed the following symptoms after seizure for a brief period –
- Memory loss (blacked out)
- Todd’s paralysis – a short period of temporary paralysis
Generalized non-motor seizure
If there is no abnormal muscle movement involve during a seizure, that is called an absence seizure. It is also known as “Petit Mal epilepsy” or “Minor epilepsy.”
This type of seizure is most prevalent in children. It usually occurs up to 30 sec.
During this absence seizure, you may stare in one direction for a few seconds. It’s just like you freeze for some time.
The postictal state is not seen in absence seizure.
We have seen that epilepsy is a disorder of neurochemicals. Epilepsy can develop in any person at any age.
In general, 1 in 10 people worldwide has a first seizure in their lifetime.
The seizures in epilepsy can affect many parts of your life, like driving, handling dangerous machines, crossing the busy road, etc. Because you never know when a seizure will arise.
Epilepsy can’t be cured completely, but seizures can be controlled with the help of antiepileptic or anticonvulsant drugs.
In my next post, I will explain a list of drugs used in epilepsy disorder.
If you found this post (seizures in epilepsy) informative, please share it on social media.
1. K.D. Tripathi. Essentials of medical pharmacology. 7th edition. Jaypee brothers medical publishers 2013. Chapter -30, antiepileptic drugs, Page- 411.
2. Lippincott Wiliams and Wilkins. Lippincott’s Illustrated Reviews: Pharmacology 5th edition. Wolters Kluwer Health, 2012. Chapter-15, Epilepsy, Page-181 to 183.
3. Simple partial seizure. NCBI
4. Complex partial seizure. NCBI
5. Generalized tonic-clonic seizure. NCBI