Infantile spasms. Main epileptic syndromes in children: neonatal seizures, infantile spasms, febrile seizures, Lennox-Gastaut syndrome
Clinical and electroencephalographic characteristics of epileptic seizures in children vary depending on age. A clear example of such age-dependent phenomena is infantile spasms, a unique type of seizure associated with early childhood. Infantile spasms are a specific age-related phenomenon that occurs in children only in the first two years of life, most often between 4 and 6 months, and in approximately 90% of patients before 12 months. The incidence of West syndrome is estimated to be 0.4 per 1000 live births.
Definition
Characteristic features of this syndrome include myoclonic seizures, hypsarrhythmia on the EEG, and psychomotor retardation. This triad is sometimes called West syndrome. However, infantile spasms do not clearly fit this definition in all cases. There are other names for the disease in the literature: massive spasms, Salaam spasms, flexor spasms, jackknife attacks, massive myoclonic seizures, infantile myoclonic spasms.
Typically, infantile spasms are stereotypical in one child. In addition, the occurrence of infantile spasms in the form of series is characteristic.
Although these seizures resemble myoclonic or tonic seizures, infantile spasms are a separate type of seizure. Myoclonic jerks are rapid, lightning-fast contractions of limited duration, while tonic spasms are prolonged muscle contractions of increasing intensity. A true spasm involves a characteristic muscle contraction that lasts 1-2 seconds and reaches a maximum (peak) slower than myoclonus, but faster than tonic spasms.
Infantile spasms are divided into three types: flexor, extensor and mixed flexor-extensor. Flexor spasms are short-term contractions of the flexor muscles of the trunk, neck, upper and lower extremities. Spasms in the muscles of the upper extremities cause the abduction of the arms, “as if a child were hugging himself with his arms,” or, on the contrary, the spreading of the arms, bent at the elbow joints, in different directions. Extensor spasms involve predominantly extensor muscle contraction, causing rapid, sharp extension of the neck and torso in combination with extension and abduction or adduction of the arms, legs, or upper and lower extremities simultaneously. Mixed flexor-extensor spasms include flexion of the neck, trunk, and upper extremities and extension of the lower extremities, or flexion of the lower extremities and extension of the arms in combination with varying degrees of flexion of the neck and trunk. Sometimes asymmetric spasms develop, reminiscent of the “fencing position.” Infantile spasms are often combined with eye deviation or the appearance of nystagmus.
Asymmetrical spasms can occur when simultaneous bilateral contraction of the limb muscles is not observed. This type of spasm usually occurs in symptomatic infantile spasms in infants with severe brain damage, agenesis of the corpus callosum, or a combination of these disorders. Local neurological symptoms such as eye deviation or head rotation can be combined with both symmetrical and asymmetrical spasms. Asymmetrical spasms usually occur in isolation, but they may also occur after or precede a focal seizure; In some cases, infantile spasms may occur simultaneously with a generalized or focal seizure.
Infantile spasms often occur in series (“cluster spasms”). The intensity and frequency of spasms in each series can increase, reaching a peak, and then progressively decrease. The number of attacks in a series varies significantly, and can exceed 30 spasms. The number of episodes per day also varies; some patients have up to 20 per day. A series of infantile spasms may occur at night, although they are rarely observed during sleep. During or after a series of infantile spasms, the child usually cries or becomes irritable.
Hypsarrhythmia in a child with infantile spasms. Noteworthy is the high-amplitude disorganized activity in the background recording, alternating with multifocal spikes and sharp waves
The chaotic nature of the EEG creates the impression of complete disorganization of the cortical rhythm. During sleep, discharges of polyspikes and slow waves occur. It is surprising that sleep spindles persist in some patients in combination with significant abnormalities in background EEG recordings. During the REM sleep phase, the severity of hypsarrhythmia may decrease or completely disappear. Infantile spasms are associated with a decrease in total sleep duration and REM sleep duration. Various types of hypsarrhythmia have been described, including patterns with interhemispheric synchronization, persistent focus of abnormal discharges, episodes of decreased amplitude, and high-amplitude slow-wave activity in combination with isolated sharp waves and spikes. Various patterns of hypsarrhythmia are common and do not correlate with disease prognosis.
Although hypsarrhythmia or a modified hypsarrhythmic pattern are the most common types of interictal abnormal EEG activity, some patients with infantile spasms may not have these EEG patterns. In some cases, there may be no hypsarrhythmia at the onset of the disease and the appearance of this pattern later, during the development of the disease. Although hypsarrhythmia is associated primarily with infantile spasms, this pattern occurs in other diseases.
Like the interictal pattern, ictal EEG changes during infantile spasms are also variable. The most characteristic EEG pattern during an attack consists of positive waves in the vertex-central region; Low-amplitude fast (14-16 Hz) activity or diffuse flattening of the curve, called an “electro-decremental event,” may also be observed.
The presence of focal abnormalities is one variant of the underlying hypsarrhythmia pattern that may be associated with focal seizures; focal seizures may precede, accompany, or develop in conjunction with a series of infantile spasms. This observation suggests that cortical pacemakers may play an important role in the development of infantile spasms.
The electroencephalographic picture in this disease is not constant and may evolve over time. In some patients with infantile spasms, hypsarrhythmia may be absent at the onset of the disease. In other patients, there may be a slowdown in bioelectrical activity in combination with rare epileptiform activity, which subsequently transforms into a hypsarrhythmia pattern. Repeated electroencephalographic studies during follow-up may be necessary to demonstrate the pattern of hypsarrhythmia (in those children in whom hypsarrhythmia was not detected at the onset of the disease).
The American Academy of Pediatrics has declared December 1 to 7 as Parent Awareness Week.Watching the baby's every move usually brings a lot of joy to parents. But when a child develops symptoms of a serious neurological condition, such as infantile spasms, that joy can quickly turn to anxiety.
Infantile spasms are small seizures with big consequences. Early recognition of this disease leads to better treatment results; and vice versa - late diagnosis and delay in starting therapy increases the risk of developing permanent brain damage.
What are infantile spasms?
Infantile spasms (also known as West syndrome) are a form of epilepsy and occur in 1 in 2,000 children. They usually begin between 2 and 12 months, most often between the 4th and 8th months of life.
Although the "spasm" itself lasts only 1-2 seconds, they usually occur in a series of "attack-break-attack", and the breaks are usually 5-10 seconds. During a spasm, the child's entire body suddenly tenses, the arms describe an arc, the legs and head may bend forward. Despite this, infantile spasms can sometimes be very difficult to notice because they can be manifested by just an upward rolling of the eyes and a slight contraction of the abdominal muscles. Most often, infantile spasms appear immediately after the baby wakes up; most rarely they occur during sleep.
Soon after seizures begin (in the coming weeks), parents may notice a number of changes in their child:
- - Loss of previously learned skills (for example, the child stops rolling over, sitting, crawling, babbling - although he has already mastered these stages of development well)
- - Loss of social interaction skills and smiling
- - Increased tearfulness, or vice versa, silence that is unusual for a child.
What exactly do infantile spasms look like?
Parents and all other people caring for the baby are recommended to watch video No. 1 of the videos attached to the post. Here we see a series of typical infantile spasms in a baby. Each spasm lasts less than 1 second; during each spasm, surprise is visible on the child’s face, his gaze freezes, his arms rise and spread slightly to the sides. Between each spasm the baby appears fine - this is very typical of infantile spasms.
Early diagnosis is extremely important!
It is very important to diagnose infantile spasms as early as possible. If you suspect your child has infantile spasms, contact your pediatrician immediately. It will be very good if you can videotape your child’s “attack” so that the doctor can see it with his own eyes. Many conditions, conscious or unconscious movements, can be mistakenly regarded by parents as infantile spasms: infant masturbation, the child “jerking” after urination, chills during fever, conscious movements for play, etc. - in this case, the pediatrician will simply reassure you. If the pediatrician finds your description or your video really similar to infantile spasms, he will refer the child for a consultation with a pediatric neurologist.
To help the neurologist better understand the characteristics of your child's illness, he may order a test called Electroencephalogram video monitoring (Video-EEG monitoring). This research method allows you to record specific brain electrical impulses characteristic of infantile spasms. When transcribing the recordings obtained during the study, the neurologist will look for a special type of EEG pattern called hypsarrhythmia. It is usually easy for a neurologist to confirm the diagnosis of infantile spasms, but identifying the causes of these seizures can be a very difficult task for the doctor.
Causes of infantile spasms:
There are many causes of infantile spasms; Almost any brain abnormality or traumatic brain injury can lead to them. More than 50 genetic/metabolic diseases are associated with infantile spasms, which means that many patients have other developmental delay disorders (eg, cerebral palsy, Down syndrome, tuberous sclerosis, etc.) before the onset of seizures.
Determining the cause of infantile spasms is very important as it affects treatment and prognosis.
Treatment options:
The American Academy of Neurology and the Children's Neurological Society recommend http://www.neurology.org/content/62/10/1668.long adrenocorticotropic hormone (ACTH) as first-line treatment for infantile spasms. This medicine is given as an injection. The child will be given the first doses in the hospital and will be kept there to be monitored for side effects to the drug. Then, if everything is fine, you will be discharged home with instructions on how to give your child injections. Because your baby must receive the medicine for 6 weeks, you will administer it at home yourself. The purpose of this therapy is to:
- - Complete cessation of infantile spasms.
- - Reducing abnormal changes in the electroencephalogram.
What is the prognosis for children with infantile spasms?
Even if infantile spasms are completely eliminated with treatment, many such children develop other types of epilepsy, as well as intellectual or other developmental disabilities, later in life.
The sooner treatment is started, the better the prognosis. In children who had normal development before the onset of infantile spasms, if therapy was started in a timely manner, even a complete recovery is possible without any consequences in the future.
P.P.S. You can read more detailed and scientific information about West syndrome here.
Infantile spasms are convulsions characterized by sudden flexion of the torso, bending or straightening of the arms, or stretching or bending of the legs.
This type of attack is usually combined with hypsarrhythmia on the EEG.
Seizures may go away on their own around age 5, but can develop into other types of seizures.
The pathophysiology of infantile spasms is not completely known, but these seizures may reflect disruption of the interaction between the cortex and the brainstem. The cause of infantile spasms may be immaturity of the central nervous system, malformations of the brain, and brain damage in the first months of life. A common cause of infantile spasms is tuberous sclerosis. The nature of the attacks can also be idiopathic.
Symptoms and signs of infantile spasms in children
Infantile spasms begin with sudden, rapid tonic contractions of the trunk and limbs, sometimes within a few seconds. Spasms range from slight head nodding to whole body shaking. They are accompanied by flexion (flexion), extension (extension) or, most often, both flexion and extension in the muscles of the limbs (mixed spasms). The spasms usually recur throughout the day in clusters, often of several dozen, mostly shortly after waking up, and sometimes during sleep.
As a rule, infantile spasms are accompanied by impaired motor and mental development. In the initial stages of the disease, developmental regression is possible (for example, children may lose the ability to sit or roll over).
The premature mortality rate for infantile spasms ranges from 5 to 31%, death occurs before the age of 10 years and depends on the etiology of the latter.
Diagnosis of infantile spasms in children
- Neuroimaging.
- Video-ZEGs of sleep and wakefulness.
- Laboratory tests for clinical indications.
The diagnosis is established on the basis of clinical symptoms and characteristic EEG patterns. Physical and neurological examinations are carried out, but often pathognomonic symptoms are not detected, with the exception of tuberous sclerosis.
In the EEG, during the interictal period, as a rule, a picture of hypsarrhythmia is revealed (chaotic, high-voltage polymorphic delta and theta waves with superimposed multifocal peak discharges). Several options are possible (for example, modified - focal or asymmetric hypsarrhythmia). The ictal background EEG changes, interictal epileptiform activity is noticeably weakened.
Tests to determine the cause of infantile spasms may include:
- laboratory tests (for example, complete blood count, determination of serum glucose, electrolytes, urea, creatinine, Na, Ca, Mg, P, liver tests) if a metabolic disorder is suspected;
- CSF analysis;
- brain scan (MRI and CT).
Treatment of infantile spasms in children
Infantile spasms are difficult to treat, and the optimal treatment regimen is controversial. ACTH is used 20-60 units intramuscularly once a day. Many anticonvulsants are ineffective; valproate is preferable; clonazepam is the second-line drug of choice. An effect was also noted from the use of nitrazepam, topiramate, zonisamide or vigabatrin.
The ketogenic diet may also be effective, but it is difficult to maintain.
In some cases, surgical treatment may be successful.
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Convulsions due to hypoxia and intracranial birth injury. They are most common in newborns. Hypoxia, which is usually accompanied by disturbances in cerebral hemo- and cerebrospinal fluid dynamics, leads to general or local cerebral edema, acidosis, and diapedetic hemorrhages.
Seizures in such children appear immediately after birth or on the 2-3rd day; with subarachnoid hemorrhage, they most often occur after breastfeeding. Convulsions develop against the background of neurological disorders: anxiety, sleep disorders, increased muscle tone and tendon reflexes, inhibition of unconditioned reflexes, difficulty sucking and swallowing, paresis of cranial nerves. They are most often clonic in nature, starting in the facial muscles and then spreading to the limbs. The course of seizures varies. They can stop completely in the maternity hospital or reappear after a few months. Sometimes, starting in the maternity hospital, they recur periodically.
Seizures due to abnormal development of the nervous system. Microcephaly, hydrocephalus, porencephaly, atrophy of the cerebral cortex, cerebellar hypoplasia may be accompanied by seizures during the newborn period. Developmental defects are often combined with intrauterine hypoxia, birth asphyxia and intracranial birth trauma. Convulsions are tonic-clonic in nature and occur against the background of pronounced focal changes in the nervous system (paresis, paralysis, sharp inhibition of unconditioned reflexes, malnutrition). Neuroradiological studies confirm the diagnosis.
Convulsions in infectious diseases. During the neonatal period, seizures are most often observed with sepsis. They also occur in 30-50% of newborns with meningitis and usually occur when there are significant changes in the cerebrospinal fluid. Convulsions begin with twitching of the eyes and facial muscles, and then, as the severity of the condition increases, they become generalized. Convulsive attacks during meningitis are accompanied by fever, inflammatory changes in the blood and cerebrospinal fluid.
Seizures in young children
After the period newborns the motor component of the seizure becomes more pronounced. However, in infants, the classic sequence of seizures, as well as in newborns, is rarely observed. Psychomotor automatisms are observed less frequently than other forms of seizures and are difficult to diagnose at an early age.
Myoclonic type of seizures(minor propulsive seizures or infantile spasms) are observed mainly in infants. The frequency of propulsive seizures is 1:4000-6000 newborns; among children of the 1st year of life with convulsive syndrome they are 30.8%. This type of seizures is characterized by: lightning-fast convulsive paroxysms; impaired mental function; specific changes on the EEG. The classic picture of infantile spasms is characterized by bilateral symmetrical muscle contraction. Spasms can be of flexor, extensor or mixed type.
With flexor spasm there is a sudden flexion of the neck, torso and limbs with simultaneous abduction or adduction of the latter. The mixed type is characterized by flexion or extension of the torso, arms and legs extend. Flexor spasm is the most common; mixed spasm is more rare, and extensor spasm is even less common. The same child can have different forms of spasms at the same time. Infantile spasms also include partial fragmentary forms - nodding, shuddering, flexion and extension of arms and legs, turning the head. In this case, lateralization is possible - preferential contraction of the muscles of one side of the body. Nodding looks like a quick tilt of the head forward. They are often combined with shudders and precede or replace flexor or extensor spasms. The most characteristic feature of infantile spasms is their tendency to be serial. Isolated spasms are observed less frequently. The duration of the spasms is from a fraction of a second to several seconds. The duration of a series of attacks can be from a few seconds to 20 minutes or more. During the day, the number of paroxysms ranges from a few to several hundred and even thousands. The loss of consciousness during this form of convulsions is short-term.
Infantile spasms sometimes accompanied by a scream, a grimace of a smile, a frightened facial expression, rolling of the eyes, nystagmus, dilated pupils, trembling of the eyelids, limbs, pallor or redness of the face, and respiratory arrest. After convulsions, drowsiness is observed, especially if the series of attacks was prolonged. During the interictal period, children are irritable, whiny, and sleep is disturbed. Cramps most often occur before falling asleep or after waking up. Factors that provoke paroxysms include fear, various manipulations, and feeding.
Infantile spasms begin in infancy and disappear in early childhood. At the age of up to 6 months, they account for 67% of the total number of paroxysmal episodes; from 6 months to 1 year - 86%; after 2 years - 6%.
Infantile spasms may be the first manifestation of convulsive syndrome in a child. The first attacks are abortive in nature and can be mistaken by parents for a fear reaction, a manifestation of abdominal pain, etc. At first they are isolated, then their frequency increases. At this stage there may be remissions and exacerbations that are difficult to predict. As the child grows and develops, the frequency of seizures decreases. The average duration of infantile spasms is from 4 to 30-35 months. After 3 years they are rare. According to P. Jeavons et al. (1973), in 25% of children, infantile spasms stop before the age of 1 year, in 50% - before 2 years, in the rest - up to 3-4, sometimes 5 years.
Changes to EEG(hypsarrhythmia) do not always correlate with the onset of seizures; sometimes they appear a little later. Hypsarrhythmia is characteristic of the developing brain and is observed only with infantile spasms in young children.
Universal accompanying a sign of infantile spasms is a delay in mental development, which is observed in 75-93% of patients, the formation of motor skills is also impaired. Therefore, in young children it is more correct to talk about delayed psychomotor development, which is noted already in the initial stage of the disease. It becomes more pronounced when a series of seizures appear. The degree of delay depends both on the time of onset of seizures and on the premorbid characteristics of the child. Normal psychomotor development before the onset of seizures is observed in 10-16% of children.
Focal neurological disorders(paresis, paralysis, strabismus, nystagmus) occur in 34-70% of cases. As a rule, they are observed in children with cerebral palsy, microcephaly, and developmental abnormalities of the central nervous system.
Prognosis for infantile spasms favorable in children with normal psychomotor development, with short-term seizures uncomplicated by other forms of seizures. With early onset, seriality and duration, combination with other types of seizures, the presence of neurological and mental disorders, a profound delay in psychomotor development is observed.
Absence seizures- a form of small seizures, which are also observed in young children and are characterized by a short-term stop of gaze. Sometimes at this time the child makes sucking, chewing movements, smacking, and licking with his tongue. The attack may be accompanied by redness or paleness of the face, and slight withdrawal of the eyeballs. They are observed less frequently than propulsive seizures.
Grand mal seizures in children early ages are more often abortive in nature. The tonic component predominates in the structure of the seizure. When turning their heads to the side, infants often become fixed in an asymmetrical position. Attacks may be accompanied by fever, vomiting, abdominal pain and other vegetative symptoms. Involuntary urination occurs less frequently than in older children. After a seizure, the child is lethargic, stunned, falls asleep or, on the contrary, is excited, and muscle hypotension is pronounced.
Partial seizures in children early ages are manifested by clonic twitching of the facial muscles, muscles of the tongue, and distal parts of the limbs. A seizure, starting locally, can become generalized. Often at this age, adverse convulsive seizures are observed, accompanied by turning the head and eyes, and sometimes the body, to the side. The seizure is often accompanied by tonic tension of the arm and leg on the side where the head is turned.
