Dravet syndrome is recognized as a serious kind of epilepsy which gets characterized by prolonged and frequent seizures that are habitually triggered by developmental delay, high body temperature, ataxia, speech impairment, sleep disturbances, hypotonia, and various other health problems. It is important to know the symptoms, causes, diagnosis and treatment of Dravet syndrome.
Dravet syndrome is considered to be the serious end of a range of disorders that are connected with alterations in genes that are needed for sodium ion channel, which is a gated pore-like structure present in the cell membrane. This structure normalizes the sodium ions movement in and out of the cell, thus, aiding in spreading electrical signals along neurons. The sodium ion channel is viewed as a critical component of a tissue that Dravet syndrome electrical signals and it includes the heart and brain. Above 80% of patients suffering from Dravet syndrome possess a transformation in the SCN1A gene; however, not all the SCN1A transformations result in Dravet syndrome.
Dravet syndrome is an epileptic encephalopathy or a disorder of the brain because of the seizures. Additionally, it is recognized as a ‘channelopathy’ as the impacts of the transformation on the sodium channel seems to make a contribution to the disorder on the seizures.
Symptoms of Dravet Syndrome
Seizures are considered to be one of the main symptoms of Dravet syndrome. As a child gets older, seizures and developmental problems become apparent.
The noteworthy symptoms of Dravet syndrome are:
- Seizures. Seizures are habitually linked with fevers, though they can happen without fevers. In fact, there are many types of seizures which commonly happen in this disorder that includes tonic-clonic seizures, myoclonic seizures, as well as non-convulsive seizures. Status epilepticus and prolonged seizures too are characteristic of this disorder.
- Seizure Triggers. People suffering from Dravet syndrome may present symptoms like seizure photosensitivity, i.e., a tendency to have seizures with an exposure to flashing or bright lights. Additionally, the patient is more prone to seizures.
- Ataxia. Issues with walking or coordination, recognized as ataxia, start in childhood and continue in adolescence as well as adulthood, a common symptom of Dravet syndrome.
- Motor Impairment in Dravet Syndrome. People suffering from Dravet syndrome are recognized as having a bent position at the time of walking. At times, low muscle tone too remains present which gets manifested as muscle weakness. These are some of the noticeable symptoms of Dravet syndrome.
- Behavioral Problems in People with Dravet Syndrome. Children as well as adults suffering from Dravet syndrome might exhibit aggression, irritability, or a behavior which resembles autism.
- Cognitive Impairment in Dravet Syndrome. Children living with Dravet syndrome may develop cognitive and speech problems which last all through their life. There can be a huge range of cognitive capabilities present in children with Dravet syndrome and some other children with this condition possess a higher capability for learning compared to others.
- Temperature and Sweating Regulation Irregularities. People suffering from Dravet syndrome may experience changes in the autonomic nervous system, especially causing excessively low or high body temperatures and lowered sweating.
- Infections. People with this disorder are prone to infections. Repeated infections is one of the important symptoms of Dravet syndrome.
- Heart Rhythm Irregularities. Nearly 1/3 of people living with this disorder possess an irregular heartbeat, like a slow heart rate, a rapid heart rate, or other irregularities, like an extended QT interval.
- Bone Problems. Dravet syndrome is commonly linked with a predisposition to bone fractures and frail bones.
Causes of Dravet Syndrome
The main cause of Dravet syndrome is identified as defective functioning of sodium channels and it is described as a type of channelopathy. Sodium channels do regular nerve and brain function. An irregularity in the functioning of the sodium channels can give rise to various problems that include seizures, erratic brain activity, along with defective communication between the brain cells, thus, demonstrating developmental impairment.
Diagnosis of Dravet Syndrome
The diagnosis of Dravet syndrome is based on a doctor’s clinical evaluation. A diagnostic study can support the diagnosis, but it doesn’t exclude or confirm it. Based on the Dravet Syndrome Foundation, a person having Dravet syndrome must have four to five characteristics from the various clinical characteristics of this disorder that are mentioned below:
- Normal motor and cognitive development prior to the first seizure.
- A couple of or more than two seizures prior to a patient attaining the age of one year.
- A combination of hemiclonic, myoclonic, or generalized tonic-clonic seizures.
- A shortage of improvement with continued seizures and standard anticonvulsant treatment after the age of two years.
- A couple of or more than two seizures that last longer than ten minutes.
Some of the tests that help to confirm the diagnosis of Dravet Syndrome include the following:
- Brain MRI to Diagnose Dravet Syndrome. Commonly, the MRI of a person’s brain suffering from Dravet syndrome is assumed to be normal. This can exhibit atrophy of the hippocampus or the entire brain at the time of childhood.
- Electroencephalogram or EEG. EEG remains commonly normal at a time when a person suffering from Dravet Syndrome isn’t having a seizure, particularly in a very young child. EEG will display abnormalities that are consistent with the activities of seizure. However, in later childhood and all through adolescence as well as adulthood, the EEG might reflect some patterns of slowing in-between seizures.
- Genetic Testing for Dravet Syndrome. This testing is capable of identifying the SCN1A mutation which is habitually present among people having DRAVET SYNDROME. It has been observed in a mosaic pattern, by which it is meant that an individual can have some cells having the mutation and some without it.
Treatment of Dravet Syndrome
There are various problems that an individual with Dravet syndrome can experience and all of them are pretty tough to treat. However, treatment of Dravet syndrome aims at addressing the cognitive, behavioral and physical problems. It is an individualized approach and might comprise speech therapy, behavioral therapy, and physical therapy.
The seizures aren’t easily controlled, and commonly, anticonvulsants that are used in treatment of Dravet syndrome consist of a combination of clobazam, valproate, topiramate, stiripentol, bromides, and levetiracetam. A vagus nerve stimulation and ketogenic diet are regarded as the treatment of seizures.
In the year 2018, the FDA (United States Food and Drug Administration) of the US did sanction Epidiolex for treating Dravet syndrome and another epilepsy syndrome, named Lennox Gastaut Syndrome. Previous studies proved that children having Dravet Syndrome experience a lessened seizure frequency with Epidiolex and could tolerate this medication.
If unfortunately, your child has been identified with Dravet syndrome, then it certainly turns into a challenging situation. Here, in this condition, your child will require close care and management throughout the life. Numerous symptoms of Dravet syndrome can be managed with ideal treatment. However, treatment strategies might change as your child grows depending on the condition, as things can improve or worsen with age. A feeling of isolation and not being aware of what is going to happen next can be frustrating. Hence, emotional support for the child and the family can help a great deal.