Dravet syndrome: causes, symptoms and treatment

Within the group of neurological diseases that we know as epilepsy, we find Dravet syndrome, a very severe variant that It occurs in children and involves alterations in the development of cognition, motor skills and socialization, among other aspects.

In this article we will describe what is Dravet syndrome and what are its causes and symptoms most common, as well as the interventions that are commonly applied to treat this type of epilepsy.

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What is Dravet syndrome?

Dravet syndrome, also called myoclonic epilepsy of infancyIt is a severe type of epilepsy beginning in the first year of life. Epileptic seizures are usually triggered by states of fever or by the presence of high temperatures and consist of sudden muscle contractions.

Also, Dravet syndrome It is characterized by its resistance to treatment. and due to its chronic nature. In the long term it usually evolves towards other types of epilepsy and causes alterations in psychomotor development and severe cognitive impairment.

This disorder is named after Charlotte Dravet., the psychiatrist and epileptologist who identified it in 1978. It has a genetic origin and is estimated to affect approximately 1 in 15-40 thousand newborns, which is why Dravet syndrome is considered a rare disease.

• Related article: "Epilepsy: definition, causes, diagnosis and treatment"

Types of epileptic seizures

We call epilepsy a group of neurological diseases whose main characteristic is that they favor the appearance of seizures or epileptic attacks, episodes of excessive brain electrical activity that produce different symptoms.

Epileptic seizures can be very different from each other, depending on the kind of epilepsy that the person suffers. Below we will describe the main types of seizures that can occur in the context of epilepsy.

1. focal seizures

Focal epileptic seizures occur in a limited (or focal) manner in a certain area of ​​the brain. When a crisis of this type occurs, the person maintains consciousness, unlike what is usual in other types. They are often preceded by sensory experiences called an “aura”..

2. tonic-clonic seizures

This type of seizure is generalized, that is, it affects both cerebral hemispheres. They consist of two phases: the tonic, during which the extremities become rigid, and the clonic, which consists of the appearance of spasms on the head, arms and legs.

3. Myoclonic seizures (or myoclonus)

Epileptic seizures that involve sudden muscle contractions, as occurs in Dravet syndrome. Myoclonic seizures are usually generalized (occur throughout the body), although they can also be focal, affecting only a few muscles.

4. Absence crisis

Absence seizures last a few seconds and are more subtle than the rest; sometimes they are only detectable by the movement of an eye or an eyelid. In this type of crisis the person does not usually fall to the ground. Disorientation may occur after the epileptic seizure.

Signs and symptoms

Dravet syndrome usually starts around 6 months of lifeDebuting with febrile seizures, which occur as a consequence of high body temperature and occur almost exclusively in children. Subsequently, the disorder evolves towards other types of seizures, with a predominance of myoclonic ones.

The seizures of childhood myoclonic epilepsy are often longer than normal, and may last more than 5 minutes. In addition to states of fever, other common triggers are intense emotions, changes in body temperature caused by physical exercise or heat and the presence of visual stimuli, such as lights intense.

Children with this disorder often experience symptoms such as ataxia, hyperactivity, impulsivity, insomnia, drowsiness and, in some cases, behavioral and social disturbances similar to those of autism.

Likewise, the appearance of this type of epilepsy usually entails a significant delay in the development of cognitive skills, motor and linguistic. These problems do not diminish as the child grows older, so Dravet syndrome involves severe impairment in multiple areas.

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Causes of this disorder

Between 70 and 90% of cases of Dravet syndrome attributed to mutations in the SCN1A gene, related to the functioning of cellular sodium channels and therefore to the generation and propagation of action potentials. These alterations cause less sodium availability and inhibitory neurons GABAergic are more difficult to activate.

Mutations in this gene do not appear to be hereditary in origin, but rather occur as random mutations. However, between 5 and 25% of cases are associated with a family component; in these cases the symptoms are usually less severe.

The first epileptic seizure of babies with Dravet syndrome is usually associated with the administration of vaccines, which is usually carried out at approximately 6 months of life.

Intervention and treatment

The clinical characteristics and course of Dravet syndrome vary greatly depending on the case, so General intervention protocols have not been established, although there are multiple measures that can be of aid. The main goal of treatment is to reduce the frequency of seizures..

Among the drugs used to treat the epileptic seizures of this disorder we find anticonvulsants such as topiramate, valproic acid and clobazam. Among this group of drugs, sodium channel blockers stand out, including gabapentin, carbamazepine and lamotrigine. Benzodiazepines such as midazolam and diazepam are also administered in cases of prolonged attacks. Of course, the medication is only used under medical supervision.

Also, dietary modification may be effective in reducing the likelihood of epileptic seizures. Specifically ketogenic diet recommended, that is, that the levels of carbohydrates are low and that those of fats and proteins are high. This type of diet can carry risks, so it should not be applied without medical prescription and supervision.

Standard interventions in Dravet syndrome frequently include psychomotor and linguistic rehabilitation, necessary to minimize cognitive impairment and developmental impairments.

The rest of the secondary symptoms of this disease, such as social deficits, sleep disorders or infections, are treated separately through specific interventions.