Tonic-clonic seizures are the medical name for what comes to mind when we think of a seizure. Tonic means stiffening, and clonic means jerking and the combination of the two leads to very intense seizure experiences, with loss of consciousness, harsh muscle movements, and sometimes an inability to breathe. Tonic-clonic seizures occur in three phases, first the prodrome, then the seizure itself, and finally the post-ictal phase. During the prodrome, you might develop a headache, see, smell or taste things that are not there, become nauseous, or feel anxious. Those sensations are known as aura, the sensation that tells your body that a seizure is coming. Not everyone with tonic-clonic seizures will experience auras though.
Then, the seizure starts and muscles of the body start forcefully contracting. Your eyes might roll around, you may bite your tongue, your arms and legs may flex and jerk, you may let out a groan, and you may lose control of your bladder and bowels. The seizure usually lasts 1-3 minutes, and you may lose awareness or consciousness during that time.
The final phase is the post-ictal phase, where you’ll likely feel confused and drowsy. You might have muscle aches and headaches during this phase as well.
Tonic-clonic seizures are classified as generalized seizures because they occur due to abnormal electrical activity in both halves (hemispheres) of the brain. Partial seizures are the other category of seizures, occurring due to abnormal electrical activity in a single region of the brain.
The symptoms of tonic-clonic seizures include the following:
Seizures in general are due to abnormally high electrical activity in a part (or all) of the brain. Generalized tonic-clonic seizures may start off as focal electrical activity (in one area) and then spread to the entirety of the brain causing large, violent seizures. Sometimes this increased electrical activity is due to epilepsy, a condition characterized by recurring seizures without a known cause. Otherwise, generalized tonic-clonic seizures can be due to severe head injuries, or brain infections like meningitis. They may also happen after strokes or circumstances that reduce the flow of oxygen to the brain.
Being too low on important substances like glucose (sugar) and sodium can also lead to tonic-clonic seizures if the deficit is severe enough. Conversely, overusing some drugs and alcohol can lead to tonic-clonic seizures as well.
The risk factors of having tonic-clonic seizures include:
Generalized tonic-clonic seizures are diagnosed with a history, a physical exam and often a special neurological exam that tests brain function. Then blood and urine tests may be done to rule out infectious or metabolic causes of seizures. Finally, an EEG and brain scans (CT and MRI) are done to assess brain activity and the way the brain looks.
Anti-epileptics are medicines that are used to treat most types of epilepsy and seizures, including generalized tonic-clonic seizures. They reduce the rate, intensity, and likelihood of seizures. Some of these medicines include lamotrigine, levetiracetam, topiramate, carbamazepine, and more. Many of these medicines lead to side-effects and are contraindicated in pregnant women, so ask your doctor before starting or stopping them.