What is the difference between clonic seizures and other types of muscle spasms?


The difference lies in the duration of the contraction: with tonic muscle spasm remains in this state for some time, and the clonic muscles look like a twitching of a single muscle, limb, or convulsions of the whole body. In the second type of seizures, movements are the result of alternate and contraction of muscle fibers. The combined clonic-tonic variant is often observed during epileptic seizures, when different types of spasms are combined or successively alternate.

general characteristics

Clonic or tonic convulsions are the result of involuntary pathological contractions of muscle fibers. The reasons may be different, in most cases we are talking about neurological diseases. Regardless of the etiology, an attack always develops according to the same scheme:

  • Due to impaired neurohumoral regulation or other causes, excitation processes in the CNS activity begin to prevail over inhibition.
  • In a certain area of ​​the brain, a focus is formed that captures a group of neurons, and brings them into a state of so-called epileptic readiness.
  • Any factor (brain injury, illness, hyperthermia) works like a “trigger”, there are convulsions.

Disruption of skeletal muscle tonic spasm is accompanied by their rigidity, restriction or complete inability to move. For example, muscle spasm of the trunk and neck at epipripsis leads to arching of the body. Clonic abbreviations, depending on the location, look like trembling (eyelids, chewing muscles), chaotic movements of the limbs, convulsions. The spasm of speech muscles is expressed in stuttering. If smooth muscles are affected, dysfunction of the internal organs is observed.

Regardless of the type of spasm, it is accompanied by painful sensations of varying intensity. The pain in this case is a consequence of the infringement of the nerve fibers by the muscle. Blood supply is also impaired in the affected area, so after a seizure paresthesias may occur for a while – numbness or tingling. Painful sensations too remain.

The reasons

Clonic and tonic convulsions, as well as their combined variant, most often occur with neurological disorders. Up to 80% of diseases of the are accompanied by spasms of muscles, the share of somatic, infectious, endocrine accounts for no more than 20%. Main reasons:

  • organic brain damage, tumors, epilepsy;
  • the disturbance of calcium metabolism associated with dysfunction of the kidneys, thyroid gland or insufficient absorption of the microelement;
  • intoxication with poisoning, late gestosis (eclampsia);
  • arterial hypertension with convulsive type crises or renal pathologies;
  • some somatic diseases – heart or liver failure, blood diseases, uremia and others;
  • infections (tetanus, cholera);
  • hysteria;
  • magnesium deficiency, violation of and electrolyte balance;
  • increased exercise.

Modern methods of diagnosis, including instrumental and laboratory, allow us to accurately determine the cause of convulsive syndrome in order to prescribe the appropriate treatment.


Tonic and clonic convulsions may cover one or more muscle groups. Localized muscle spasm always has its own name: Trismus – a pathological contraction of the chewing muscles, blepharospasm – circular muscles of the eye. Similarly, changes in the tone of smooth muscle fibers responsible for the functioning of internal organs are called: cardiospasm, pilorospasm and others.

If convulsions cover the trunk with the limbs, it is a generalized fit. Spasms can be either of the same type or combined, tonic-clonic. The latter type is characteristic of an epileptic seizure that occurs simultaneously with limb convulsions and tonic tension of the trunk muscles. Convulsive syndrome of this type is observed not only in epilepsy: febrile seizures in young have the same symptoms.


A spasm of this type occurs suddenly, gradually increasing, then he passes within a few minutes. Tense muscle has a characteristic convex appearance, hard to the touch. Tonic convulsions are always accompanied by intense pain, as during this time nerve fibers are infringed. Any group of muscles or some of them separately can be affected. The most common causes are gastrocnemius and musculature of the hands, and the main causes are micronutrient deficiencies, hypothermia, and excessive exercise. Such localized seizures usually occur at night.

Pathological prolonged contractions of individual muscles can also be observed in the area of ​​the body and head. If several groups are covered, this is a generalized convulsion. For example, during epileptic seizures, the back is simultaneously arched, the hands are tense, and the jaws are compressed. Spasms of smooth muscle fibers of a tonic nature are of great danger: attacks of bronchial asthma or angina pectoris can lead to respiratory arrest, heart attack.

First aid for localized contraction is self-massage, taking a relaxing position. For example, the calf muscle spasm is relieved if you pull your toes towards yourself, and the spasm of the hands is relieved by clenching the fist by shaking. You can simply hit or prick a spastic muscle with a needle. A generalized seizure requires the patient to be fixed in a side position until the symptoms disappear. Frequent seizures require consultation with a neurologist and other specialized specialists, as they may indicate serious illnesses.


The main difference between this type of muscle spasm is the rapid alternation of periods of contraction with relaxation. Clonic convulsions occur for two main reasons: direct damage to the motor neurons of the brain or a disorder in the transmission of nerve impulses to muscle fibers. As in the case of tonic contractions, during an attack one or several muscles can be involved. Externally, the pathology is manifested by trembling, chaotic movements or intense tremors of the whole body (convulsions). The severity depends on the size of the muscle and the area of ​​the lesion.

What is the difference between clonic seizures and other types of muscle spasms?

When a small muscle spasm occurs, so-called tics arise – winking, head bending, hand tremor. Often a nervous tic has a psychogenic origin. Stuttering is another classic example of clonic contractions of the musculature. Unlike tonic and tonic-clonic seizures, this type of pain is not accompanied by pain. But in time the attack is usually longer, can be repeated several times in a row, in series.

A variety of clonic myospasms – the so-called hyperkinesis. Hyperkinesia can be expressed in small twitches of individual muscle groups, which is observed with the defeat of motor neurons of the brain. Such symptoms in the form of tremor of the head or limbs are characteristic of parkinsonism, neurosis, and hysteria. More pronounced movement disorders in the form of intense movements are another type of hyperkinesis.

What is the difference between clonic seizures and other types of muscle spasms?


Combined spasms in neurology are considered the most severe. Attacks of tonic-clonic seizures are characteristic of epilepsy, which can last for several minutes. The classic picture of a generalized epileptic seizure consists of several stages. Initially, a tonic spasm is observed, often against the background of loss of consciousness. At the same time, the body of the patient is arched due to the stiffness of the muscles of the neck and the contraction of the muscles of the back. Jaws are usually tightly compressed, eyes roll.

What is the difference between clonic seizures and other types of muscle spasms?

At the next stage, there are clonic tremors of the upper and lower extremities, the muscles of the face may be involved in the process. Gradually convulsive convulsive seizure covers the whole body, the skin becomes pale. When spasm of the respiratory muscles is observed cyanosis, foam can appear from the mouth.

At the next stage, the seizure gradually stops. The intensity of movements decreases, giving way to small trembling, slows down the rhythm of clonic contractions. Quite quickly comes complete muscle relaxation, which may be accompanied by involuntary emptying of the bladder. The person regains consciousness, but usually remains disoriented, lethargic, or just falls asleep. First aid is similar to that for tonic spasms: keep the patient on his side or turn his head to prevent aspiration of vomit, placing an object between the teeth.


Episodic tonic convulsions do not pose a particular health hazard. Rare spasms of the arms or legs are most often caused by active muscular work, static or monotonous loads. Another common cause is a lack of calcium, magnesium and iron on the background of an unbalanced or pregnancy. In this case, to get rid of painful attacks will help establish a regime of work and rest, reviewing the diet and taking multivitamin complexes. However, frequent spasms that cannot be corrected by diet and physical exercise restriction are a reason for going to a doctor.

Clonic and tonic-clonic seizures usually indicate neurological disorders of varying severity. Therefore, in this case, a full examination and treatment are required.

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