Definition of convulsion
Often unpredictable, the convulsions consist in a series of involuntary, abrupt and uncontrolled movements, of the voluntary musculature, responsible for agitation and spasms of the body. During a seizure, the victim's muscles contract and relax repeatedly, for a variable amount of time depending on the severity of the condition.
More than a disease, convulsions are a fairly frequent symptom in the newborn and the child, where they often manifest themselves in conjunction with fever and viral diseases. Seizures can also be induced by transient or permanent metabolic conditions - such as hypoglycemia, hypocalcemia (total serum calcium <9ml / dL), hyponatremia (sodemia <135mmol / L) and pyridoxine-dependence * - or by more or less serious pathologies. In conditions of severity, seizures are an expression of ongoing cerebral suffering.
* pyridoxine-dependent seizures: an autosomal dominant genetically transmitted disease. The onset often coincides with the neonatal age: the child manifests multifocal clonic crises, while developing a certain resistance to anti-epileptic or anticonvulsant drugs. The disease can degenerate to induce epileptic encephalopathy associated with impaired mental and motor development.
Let us not forget that the most immediate side effect of some drugs (eg neuroleptics) can also cause serious seizures.
Clinically, a convulsion can become manifest in a variety of ways; however, in the vast majority of cases, seizures arise in the generalized form.
Convulsions are typical but not exclusive to epilepsy: this means that epileptic seizures are always associated with convulsions, but the latter may be secondary symptoms of other primary pathologies.
Causes
What is certain and undisputed is that convulsions are triggered by a sudden disorganization of the electrical activity of the brain. In particular, the seizure is an expression of an abnormal and rapid hypersynchronous * depolarization of a group of neurons.
Hypersynchronous activity *: a group of neurons favors simultaneous electrical discharges which, read at the encephalogram, form slow and high waves
Going back to the cause that has disrupted brain electrical activity, triggering the seizure, is instead more difficult. In fact, as mentioned, the convulsions are a "simple" symptom of numerous pathologies; this makes it difficult to immediately recognize the etiological factor that arose in the origins.
Below is a list of the possible causes of seizures: as is possible to observe, the predisposing pathologies are very numerous.
- Alcoholism
- Taking drugs (drug addiction) and some drugs (neuroleptics)
- Alcohol withdrawal (in an alcoholic)
- Poisoning
- Extreme race
- Brain damage that appears in the child during labor or delivery
- Congenital cerebral defects
- Epilepsy
- Eclampsia
- High fever (a predisposing factor typical of young children) → febrile convulsions
- Phenylketonuria (can induce seizures in the child)
- Viral infections
- Hepatic failure
- Kidney failure
- Malignant hypertension (extremely high blood pressure)
- Hypoglycemia and other metabolic disorders
- Head injury
- Heart disease
- Meningitis
- Snake bites and stings
- Electric shock
- Bechet syndrome
- Pregnancy toxemia (presence in the blood of substances in concentrations toxic to the body)
- Brain trauma
- Brain tumor (rare)
- Uremia (from kidney failure)
Genetic predisposition also plays an important role in the pathogenesis of seizures. Although there is no certainty about the mode of genetic transmission, an autosomal dominant, autosomal recessive or multifactorial mechanism is assumed.
Convulsions that occur during the neonatal age may be epileptic or non-epileptic: in such circumstances, differential diagnosis is essential.
Symptoms
The specific symptoms of convulsions are heavily conditioned by the underlying cause. Furthermore, the severity and intensity of the prodromes depend on the brain site involved.
The characteristic symptoms of seizures appear suddenly, often without warning:
- unintentional body shaking
- mood alteration (irritability, fear, anxiety, joy) → generally before the seizure
- burrs / foam at the mouth
- bruxism (therefore stiffening of the mandibular muscles)
- cyanosis
- contractions and joint spasms
- breathing difficulties
- ear pain
- uncontrolled eye movements
- eyes wide open
- gastrointestinal symptoms (vomiting and diarrhea)
- swoon
- temporary suspension of respiratory capacity
In high convulsions, the patient loses consciousness, falls to the ground, often losing control of the anal and bladder sphincters.
Warning signs
It is not rare that, before the convulsive crisis, some so-called "warning signs" are perceived: the organism sends general symptoms to alert the patient of the impending convulsion. Anxiety, associated with nausea, dizziness and visual symptoms (flashing lights and spots in front of the eyes) are very recurrent signs in patients suffering from frequent seizures.
Symptoms can last for a few seconds or continue for 15 or 30 minutes: when the duration of the convulsions is considerable, it is likely that the patient is suffering from epilepsy. Convulsions that last more than 5-10 minutes tend to last for a long time: clearly, the longer the crisis, the greater the chance of complications.
Seizures can occur within a well-defined clinical context of encephalopathy (eg hyperexcitability, hypotonia, coma, abnormalities of neurological examination in general) or can be isolated convulsive episodes.
