West syndrome is a complex of manifestations of a rather severe form of epilepsy that occurs in young children and is a consequence of brain damage. The most striking sign of this pathology is a pronounced lag in mental development. Also, this disease is characterized by a symptomatic complex: involuntary movements in the form of nods and quick tilts of the body, which by their nature represent a repetitive spastic contraction of individual muscle groups or have a generalized character. They appear mainly during falling asleep or upon awakening. Electroencephalography at the same time fixes a clear hypsarrhythmia, which is an abnormally high-amplitude brain activity.
Description of the disease
The disease usually manifests itself in infancy, the majority of manifestations occur before the age of one year.
Diagnostic methods are based on the analysis of clinical symptoms, which are further confirmed by the resultscomputed tomography, magnetic resonance imaging, as well as the results of EEG (electroencephalography). Treatment is carried out with the help of antiepileptic drugs, drugs of the steroid group. Surgical intervention may also be required to remove the area of the brain in which there is a focus of epiactivity.
A bit of history and statistics
For the first time, the West syndrome we are considering was noticed and described by a doctor with the same name in 1841. He observed manifestations in his child and singled them out into a separate symptomatic complex, which was subsequently made into a separate diagnosis. Since this pathology occurs in infancy, the spasmodic and paroxysmal manifestations characteristic of it are called infantile spasms. Initially, this syndrome was not classified as a separate category of diseases, but was considered a variant of the manifestation of a generalized form of epilepsy.
In the middle of the 20th century, based on the data obtained from the study and analysis of EEG data of small patients, the specificity of hypsarrhythmic activity of the brain was identified, characterized by a chaotic alternation of slow-wave periods with high-amplitude spikes. Based on these specific EEG patterns, the disease was identified as a separate diagnostic criterion, specific to young patients.
Separate Syndrome
With the discovery and improvement of neuroimaging diagnostic methods, it became possible to identify foci of cerebralsubstances affected by epiactivity. It is these new approaches and the data obtained on their basis that caused the refusal to consider West syndrome as a generalized form of epilepsy. From that moment on, it began to be classified as epileptic encephalopathy. Thus, this type of epileptic form of encephalopathy was identified as a separate syndrome for childhood. For adult patients, it became known as the Lennox-Gastaut syndrome.
According to statistics, the prevalence of this form of epilepsy (West syndrome) among children with documented brain disorders is about 2%, and among infantile epilepsy, the diagnosis is approximately 25% of all cases. The incidence rate is 2-4 patients per 10,000 newborns. In boys, the disease is found more often than in girls. In 90% of cases, the syndrome manifests itself up to a year, the peak of the disease occurs at the age of 4 to 6 months. By the age of three, spasmodic symptoms either disappear altogether or flow into other forms of epilepsy.
"Child Angels" and West Syndrome
There is a community of parents of special children on the Web. In it you can find information about the syndrome we are describing. Moms share their feedback on the symptoms of the disease in their babies, as well as on treatment methods. The site is called "Children-angels". West syndrome is a pathology that raises many questions among parents of newborns affected by it.
Etiological features
Most cases are symptomatic.
Sorry, does not existaccurate data on the etiology of the disease. The causes may be acute intrauterine infections (cytomegalovirus, herpetic), fetal hypoxic lesions, postnatal encephalitis, premature birth, newborn asphyxia, intracranial birth trauma, postnatal ischemia, etc.
In addition, it is likely that West syndrome in children may be the result of anatomical abnormalities of the brain, such as, for example, agenesis of the corpus callosum, hemimegalencephaly.
Also, infantile spasms can have secondary symptoms, i.e., be a consequence and symptom of other diseases, such as phakomatosis, neurofibromatosis, Down syndrome, some gene mutations. There is also evidence linking infantile spasms with phenylketonuria.
Reasons
In about 10% of cases, the cause of the disease cannot be determined, but there is a genetic predisposition, since a family history reveals the presence of similar epileptic symptoms.
There are also a number of assumptions about the relationship of the occurrence of pathology with vaccination, namely with DPT vaccination. However, the existence of such a relationship is not a proven fact. It is possible that there is a simple coincidence between the calendar time of vaccination and the age at which the primary signs of West syndrome are most characteristic.
The pathogenetic mechanism of infantile spasms in modern medicine has so far only hypothetical justifications. According to one point of view, West syndrome is the result of dysfunctionserotonergic neurons. The origin of this hypothesis is based on the presence of a low content of the hormone serotonin and its metabolites.
The exact causes of West syndrome are not fully understood.
There is also an immunological rationale that argues for a relationship between activated B cells and disease.
Separately, it is worth noting the theory of the dependence of pathology and impaired functioning of the brain and adrenal glands. The basis for this assumption is the positive result of treatment of West syndrome with ACTH.
Some scientists see the cause of the syndrome in the excessive production of excitatory synapses and conductive collaterals, which cause an increased level of excitability of the cerebral cortex, and the lack of myelin, physiological for infancy, causes an asynchronous EEG pattern.
As a child matures and his brain develops, the level of myelin increases, leading to a marked decrease in his excitability. Accordingly, the picture of spasmodic manifestations noticeably fades away: they either disappear or turn into Lennox-Gastaut pathology.
Consider the main symptoms of West syndrome.
Symptomatic picture
As we noted above, the disease usually manifests itself during the first year of life. There are cases of a later primary manifestation of the syndrome, but at a maximum of 4 years.
The main clinical picture is represented by serial muscle spasms and physical and mental lagdevelopment. At the same time, the delay in psychomotor development in most clinical cases has a primary manifestation, and paroxysmal symptoms already appear against its background. However, in 30% of children, a noticeable developmental delay is preceded by the appearance of a paroxysm.
Usually psychomotor retardation manifests itself in the absence or unmotivated extinction or complete disappearance of the grasping reflex. There are also cases of lack of ability to fix the gaze on an object or follow it. These symptoms have a rather unfavorable prognosis for further development.
Muscle spasms
It is serial and symmetrical, the time intervals between them are quite short and usually do not exceed a minute. Spasms are most intense at the beginning of the attack, and at the end they subside. Spasmodic attacks are not predictable, their frequency can vary from one to several dozen per day. Their characteristic feature is a rather tight physiological connection to the time of awakening and the time of falling asleep, when the child is between the stage of sleep and wakefulness. They can be provoked by a loud sound, sudden unexpected movement, and even touching.
Flexion and extension
Depending on which muscle group undergoes involuntary contraction, spasmodic manifestations are classified into flexion and extensor, but most often spasms are mixed. They are followed in frequency by flexion, but extensor are the rarest in frequency of cases. Most often the childspasms of various types are disturbing, while the predominant picture of one of them is observed. It is impossible to predict which spasm will prevail, since it depends on the position of the child's body at the time of the onset of the next spasmodic attack.
Spasms can be localized, which occurs most often, or they can be generalized, which means that all muscle groups are contracting.
Describe the relationship between the contractile activity of different muscle groups and their clinical picture:
- Convulsive flexion of the neck muscles causes head nodding, which is one of the hallmark symptoms of West syndrome.
- Spastic contractions of the muscles of the shoulder girdle appear as a shrug of the shoulders.
- Jackknife paroxysm is the result of involuntary flexion of the abdominal muscles.
- The spasmodic contractions of the muscles of the upper limbs look like a child hugging himself. The combination of this type of spasm with the previous one (“folding knife”) is called the “Salaam attack”. The combined picture of these two types of spasms is reminiscent of the Eastern greeting and "salaam".
- If a child already knows how to walk, then spasms can manifest themselves as follows: the child walks and suddenly falls, but remains conscious.
- Sometimes there are non-convulsive seizures, which manifest as a sudden stop of motor functions.
- Spastic attacks of the respiratory system are manifested by a violation of respiratory activity, which is a particularly dangerous symptom.
- There are otherstypes of seizures, they can have both an independent manifestation and occur in combination with others.
Diagnosis
The diagnosis of West syndrome is based on three factors:
- mental and mental retardation;
- hypsarrhythmic picture of the EEG pattern;
- muscle spasms.
Of great importance is the age at which the disease begins to manifest itself, as well as the relationship of spasms with sleep. In the case when the disease manifests itself at an atypically late age, it may be difficult to diagnose.
If West syndrome is suspected, the child is consulted by a neurologist, with further examination by a geneticist and an epileptologist. It is important to timely differentiate such diseases as benign infantile myoclonus, infantile myoclonic epilepsy, Sandifer's syndrome, in which the tilt of the head is pronounced like torticollis, as well as episodic manifestations of opisthotonus, which resemble spasmodic contractions, but, in fact, they are not.
EEG
EEG (interictal) is done both in sleep and during wakefulness. It shows chaotic, dynamically changing spike-wave activity in both cases. EEG during sleep (polysomnography) captures the absence of this activity during deep sleep. At an early stage of the disease, in about 66% of clinical cases, the EEG shows hypsarrhythmia. At later stages, EEG patterns have a chaotic organization, and at about 2-4 years, the EEG is already represented by complexes alternating sharp and slow waves. The EEG during the period of spasms has a pattern of generalized slow-wave high-amplitude complexes and the subsequent extinction of activity.
If the EEG detects focal changes, it is generally accepted that there is a focal brain lesion or that it has some structural anomalies.
The most accurate method for diagnosing focal brain lesions is MRI.
Treatment
A real breakthrough in the treatment of West's syndrome in children was the use of ACTH (adrenocorticotropic hormones) for the relief of epileptic seizures. The use of ACTH in combination with prednisolone leads to a reduction and even complete disappearance of muscle spasms. In turn, the EEG pattern confirms the absence of hypsarrhythmic characteristics. The only stumbling block in the treatment of West's syndrome is that the selection of doses and the duration of the course of treatment with these drugs is a purely individual factor and is made empirically. In 90% of cases, the use of significant dosages of drugs gives a good effect.
In the early 90s of the 20th century, a positive effect of treatment with vigabatrin was discovered, but the benefit of this drug was proven only for patients with tuberous sclerosis. For the rest of the category of patients, steroid therapy remained in first place. However, the disadvantage of steroid therapy is the worst tolerability of drugs and the tendency of the disease to relapse.
Anticonvulsants
Anticonvulsants are also used for treatment, among which Nitrazepam and valproic acid have the highest clinical efficacy. Some patients achieved positive treatment dynamics during therapy with large doses of vitamin B6.
In case of hardware confirmation of damage to brain foci and the absence of positive dynamics in stopping seizures with medication, neurosurgical intervention can be recommended to remove the lesion, which is a catalyst for epileptic seizures. If such an operation is not possible and if the patient has a tendency to muscle spasm with a complete loss of motor activity (drop attack), a callosotomy may be necessary.
Was there a cure for West's syndrome? We will talk about this later.
Prognostic criteria
In West syndrome in children under one year old, in about half of the cases, infantile spasms regress and completely disappear by the age of three. However, in the remaining 50-60% of cases, an unfavorable continuation of the course of the disease is observed, followed by a transition to other epileptic forms. The transition to the Lennox-Gastaut syndrome is most likely. If infantile spasms occur in the context of Down syndrome, medication is usually ineffective.
However, it is worth remembering that even in the event of the complete disappearance of spasmodic symptoms, the question remains about the psychomotor development of the child, which, as we remember, is an integral factor in West's syndrome. Unfortunately, the forecast of the further coursedisease even in the absence of paroxysmal manifestations is disappointing. This applies to the lag in both mental and physical development, which subsequently manifests itself in the form of cerebral palsy, and in the form of autistic disorders, and in the lag in cognitive-emotional development in general. Approximately 70-80% of children suffer from mental retardation, and half of the patients suffer from physical retardation. And only a small percentage of the lucky ones do not have serious consequences for further development and growth.
If the disease is the result of anatomical structural defects and pathological changes in the brain that are not subject to diagnosis and subsequent surgical correction, the prognosis is even more unfavorable, including probable mortality.
If there is an idiopathic variant of West's syndrome, that is, when the appearance of spasms was not preceded by any symptoms of psychomotor retardation, the prognosis is much more favorable. The percentage of children with no residual psychomotor deficit is much higher and reaches 37-44%.
Reviews about West syndrome
Reviews about this disease are contradictory. The timeliness of diagnosis and treatment of West syndrome is also of great importance. The earlier the disease is detected and therapy begins, the higher the likelihood of the most favorable prognosis for the further mental and physical development of children. Neurologists say that all brain pathologies and delays in psychomotor development are most effectively amenable toadjustment in early infancy. The older the child, the less chance of favorable consequences for his development.
