Seizures: Symptoms and Types

A seizure occurs when there is an abnormal burst of electrical activity in the brain that usually lasts a few seconds to minutes. 

There are millions of nerve cells in the brain (neurons). Nerve cells usually transmit small electrical impulses along the nervous system to all regions of the body. Different sections of the brain control distinct organs and functions of the body. The interaction between neurons in a normal brain is orderly and balanced. However, when numerous neurons misfire at the same time, it can produce abrupt changes in a person's feelings, behaviors, and/or awareness.

Symptoms that occur during a seizure are determined by the location of the unexpected burst of electrical activity, and the strength of these electrical interruptions determines the severity of the disorder.

Seizures are often an indication of a more serious condition and can be caused by the following:

• Mental health issues (caused by bleeding, head injury, or infection)
• Sudden drops in blood sodium levels (usually associated with drinking unusually large amounts of water in a short period of time)
• Fluctuation of blood sugar levels (either too low or too high)
• Brain tumors (relatively rare)
• Stroke
• Pregnancy complications
• Toxin accumulation (kidney failure, liver dysfunction)
• Alcohol or drug use or withdrawal

Seizures with generalized onset do not begin in one section of the brain but are caused by simultaneous abnormal nerve discharge spikes in the cortex. They can be hereditary although they are often due to sleep deprivation or excessive alcohol intake.

Generalized tonic-clonic or grand mal seizures

• The tonic phase of the seizure begins with the person crying out or groaning as if the air is being driven out of the lungs, then stiffens and collapses unconscious on the ground.
• During the clonic phase, the person's limbs begin to twitch. The jerking diminishes and eventually ceases after a few minutes.
• One seizure episode may last 1-3 minutes, after which the person may feel lethargic, disoriented, irritated, and sleepy.
• Emergency medical treatment is required if the tonic-clonic seizure lasts more than 5 minutes.

Absence or petit mal seizures

• These types of seizures are common among children and are characterized by a lack of symptoms and may resemble staring episodes.
• There are two types:
  • Typical absences: These usually last for a few seconds and may go unnoticed because of the short duration. The person becomes blank and unresponsive and appears to be daydreaming. They may stare aimlessly or flicker their eyelids, becoming unaware of their surroundings and what they are doing.
  • Atypical absences: Characteristics of this type of seizure are the same as typical absences, but they begin and end more slowly and continue slightly longer. Some people may fall because symptoms may involve a shift in muscular tone. The limbs become limp or floppy.

Myoclonic

• Myoclonic seizures are characterized by sporadic (isolated) jerky movements, during which the person is aware of what is happening.
• They are brief but can occur in clusters (several occurring at the same time), usually immediately after waking.
• These are classified as generalized seizures because of the possibility of additional seizures (such as tonic-clonic seizures).

Clonic

• Clonic seizures are characterized by a repetitive, rapid stiffening and relaxing of muscles. Restraining the arms or legs will not stop the movements.
• They are uncommon and usually occur in infants.
• Clonic movements are most noticed as part of a tonic-clonic seizure. 
• Like a clonic seizure, jerking movements can persist from a few seconds to a minute. Jerking or clonic movements that occur after muscular stiffness can last seconds to 1-2 minutes.
• They can be difficult to distinguish from a myoclonic seizure, but the jerking is more regular and persistent.

Tonic

• With tonic seizures, the muscle tone of the torso, arms, or legs suddenly gets rigid or tight.
• The person may be alert or have only slightly altered awareness.
• This type of seizure often occurs during sleep and involves all or a part of the brain, affecting both sides of the body.
• They are usually less than 20 seconds long.

Atonic

• With atonic seizures, the muscles get stiff, the person's eyes may droop, and their head may nod or drop forward. The body may go limp.
• This type of seizure may cause a fall if the person was standing during the seizure.
• These convulsions usually last no more than 15 seconds.

Partial or focal seizures occur in a specific area of the brain. These seizures are commonly associated with injury or trauma and are thought to be produced by scar tissue in the brain.

Meningitis, stroke, developmental impairment, and physical brain injury are all potential causes of focal seizures. Symptoms of a focal seizure begin in one section of the brain and can extend to other parts of the brain. Thus, symptoms may occur gradually. They could be preceded by an aura, which some individuals perceive as a foreshadowing of a seizure but is the outcome of minor seizure symptoms.

Generally, as the seizure progresses, the person begins to exhibit additional symptoms, such as:

• Shaking
• Fidgeting
• Muscular rigidity
• Chewing movements
• Disoriented or puzzled

The various types of focal seizures include

Simple partial seizures

• Caused by epileptic activity that is restricted to one area of the brain, generally the cortex or limbic system.
• Consciousness is unaffected; the person can converse, respond to questions, and recall what happened during the seizure.
• Manifest differently in everyone.
• Are divided into subcategories based on the symptoms.

Autonomic seizures or abdominal epilepsy

• Characterized by autonomic symptoms, such as abdominal discomfort or nausea, which may rise into the throat to produce stomach pain, borborygmi (rumbling noises of gas moving in the intestines), belching, farting, and vomiting.
• Pallor, flushing, sweating, hair standing on end (piloerection), pupil dilation, heart rate, and breathing changes, and urination are possible signs.
• Sexual arousal, penile erection, and orgasm may occur in a few people.

Emotional simple partial seizures

• Also called temporal lobe auras or simple partial seizures of temporal lobe origin.
• Frequently manifest as an unusual experience, causing the person to see or hear things that are not present.
• May cause fear, sadness, rage, or joy. 
• May cause the person to experience a terrible odor or flavor, a weird feeling in the stomach, or a choking sensation.

Motor seizures

• Also called Jacksonian motor seizures; the spread is referred to as a Jacksonian march and is unstoppable.
• Convulsive movements could be clonic or jerking.
• Jerking usually starts in one region of the body, such as the face, arm, leg, or trunk, and may progress to other sections.

Sensory seizures

• Also called Jacksonian sensory seizures and are accompanied by a sensory experience.
• The individual may see lights, hear a buzzing sound, or experience tingling or numbness in a specific area of the body.

Complex partial seizure

• When epileptic activity extends to both temporal lobes of the brain, a complex partial seizure follows. A complicated partial seizure frequently follows a simple temporal lobe partial seizure.
• Does not cause convulsions but compromises consciousness.
• Usually starts with a blank or empty stare. After the seizure begins, the person can no longer answer.
• The person may look confused and becomes ignorant of their surroundings.
• May escalate to chewing movements, uncoordinated activities, or meaningless behaviors that look random and awkward. These automatisms may involve activities, such as:
  • Picking at their clothes
  • Attempting to remove their clothes
  • Mindlessly strolling about
  • Picking up objects
  • Murmuring
• The person may not have any recall of the seizure after it has occurred.
• A complex partial seizure often lasts between 2-4 minutes. It may be followed by a prolonged period of perplexity.
• Once a seizure pattern is formed, it is frequently repeated with each successive episode.
• Anticonvulsant medicine is occasionally ineffective.

Partial seizure with a secondary generalization

• Starts as a partial seizure and progresses to a generalized convulsive (grand mal) seizure.
• Most people with partial seizures have simple partial, complicated partial, or secondary generalized seizures.
• Medication can manage seizures in about two-thirds of people with partial epilepsy.
• Frequently treated surgically when medications do not work.