What Do You Mean by Tonic - Clonic Seizures?

Tonic-Clonic (Grand Mal) Seizures: Full Guide & Risk Factors

Tonic‑clonic seizures, previously referred to as "grand mal" seizures, are a severe generalised epilepsy characterised by loss of consciousness and severe muscle contractions. They usually start with a sensation before a migraine, including sensory disturbances, a change of mood, or emotional disturbance, as a warning sign of an impending seizure.

In India, GTCS (generalised tonic-clonic seizure) is the most common type of seizure, developing in about 6.5 per 1,000 people with epilepsy and appearing in 4.1 per 1,000 individuals without epilepsy. Therefore, it is crucial to understand this condition for early diagnosis and timely treatment.

Keep reading for a detailed insight.

What are tonic-clonic seizures?

Tonic-clonic seizures can be generalized onset (starting in both sides of the brain) or focal to bilateral tonic-clonic (starting in one area and spreading). They are classified into 2 phases: the tonic phase, in which muscles become rigid, and the clonic phase, which is rhythmic jerking or convulsions.

Tonic-clonic seizures result from abnormal electrical activity in the brain and could start as focal seizures before generalising. Generally associated with epilepsy, they could also be the result of high temperature or brain damage.

What are the symptoms of tonic-clonic seizures?

Tonic-clonic seizures usually come in stages, with each stage having different symptoms that involve both the body and consciousness. These are the typical symptoms of the condition:

• Aura (Prodrome):Prior to the onset of the seizure, people experience warning signals such as unusual odours, visual changes, nausea, and fear.
• Tonic Phase: The individual suddenly becomes unconscious, and their muscles stiffen, usually resulting in them falling and potentially making a guttural sound or moan as air is forcibly expelled from the lungs.
• Difficulty in Breathing: In the tonic phase, stiffness of the chest muscles can limit breathing, and the individual's face can become bluish or grey with attendant gurgling and gasping sounds.
• Clonic Phase: The body enters rhythmic jerking, particularly of the face, arms, and legs, which can last one to three minutes and slow down gradually.
• Frothing and Bleeding: Saliva or foam can appear in the mouth, and tongue or cheek biting can cause blood to mix with the saliva.
• Loss of Bladder or Bowel Control: Involuntary urination or defecation can be experienced during or following the seizure.
• Postictal Confusion: The individual may be unconscious for a short while after the seizure, and upon regaining consciousness, he or she will feel disoriented, confused, or unaware of the seizure.
• Fatigue and Headache: Following a seizure, people may feel exhausted, weak, or have a bad headache.
• Memory Loss and Behaviour Changes: Short-term memory loss, sadness, embarrassment, or even aggressive behaviour may happen because the brain is recovering.

Why Do Tonic-Clonic Seizures Occur?

Conditions and situations that may result in tonic-clonic seizures include:

• Aneurysms
• Irregular heart rhythms (arrhythmias), particularly when they interfere with blood flow to the brain
• Brain tumours (including cancer)
• Degenerative brain diseases like Alzheimer’s disease or frontotemporal dementia
• Cerebral hypoxia (lack of oxygen)
• Concussion and traumatic brain injury
• Eclampsia (a condition where high blood pressure can trigger seizures in pregnant women)
• Drugs and alcohol (this encompasses prescription medications, recreational drugs, and even caffeine)
• Withdrawal from drugs or alcohol
• Genetic disorders (conditions present at birth, inherited from one or both parents).
• Electrolyte imbalances, particularly low sodium (hyponatraemia), calcium, or magnesium
• Fever, especially high fever (refer to our article on febrile seizures, including how to assist a loved one or child experiencing one), in children
• Flashing or flickering lights, particularly in TV shows, movies, video games, and more
• Hormonal changes leading to more frequent seizures at certain times
• Infections (especially encephalitis or meningitis; viruses, bacteria, parasites, or fungi can cause these)
• Structural brain problems (especially those arising from developmental issues in the uterus)
• Inflammation due to autoimmune conditions (where the immune system attacks the brain)
• Mental health issues (known as psychogenic seizures), such as conversion disorder
• Insomnia and other issues that prevent adequate sleep
• Strokes or transient ischaemic attacks (TIAs)
• Sepsis (a severe immune system reaction due to an infection spreading throughout the body)
• Metabolic issues, particularly high blood sugar (hyperglycemia) or low blood sugar (hypoglycemia)
• Toxins and poisons (like carbon monoxide poisoning or heavy metal poisoning)

How to Prevent Tonic-Clonic Seizures?

Although it is impossible to completely avoid all tonic-clonic seizures, proper adherence to medical recommendations and safe habits can decrease the risk and incidence:

• Adhere to prescribed medications and never skip a dose without a doctor's approval.
• Avoid known triggering factors, such as stress, sleep deprivation, flickering lights, or alcohol, as directed by your physician.
• Identify auras or warning signals—like strange feelings, changes in vision, or unusual tastes—and relocate to a safe area if possible.
• Consider routine medical exams and work closely with your neurologist to modify treatment, if necessary.
• Utilise protective equipment such as helmets and seatbelts to minimise the possibility of traumatic brain injury, a proven seizure trigger.
• Practise good hygiene and food preparation habits to avoid infection and parasitic diseases that can infect the brain.
• Control stroke risk factors by maintaining healthy blood pressure (120/80), quitting smoking, eating healthy, and exercising regularly.
• During pregnancy, receive proper prenatal care to avoid conditions that may result in seizure disorders in the child.
• Educate other individuals on identifying early seizure warning signs so they can assist you in a safe location if necessary.

Tonic-clonic seizures are prevalent and severe seizures characterised by abrupt loss of consciousness and forceful muscle contractions. With appropriate diagnosis and treatment, most people are able to control their condition quite well. Besides, raising awareness and support can significantly enhance the safety and quality of life of those affected.

It is also advised to have health insurance to protect your health and finances during medical emergencies.