Infantile spasms

Introduction Infant spasms occur between a few days and 30 months after birth, and are the peak incidence before the age of half. Because the baby is in bed or in bed all day, the young mother has no experience with children, it is easy to be numb, and the episode is mistaken for the child's hunger, wet diapers or head and neck discomfort. The consequences of this disease are bad, with a mortality rate of 13% and more than 90% of intelligence. Symptoms and signs of neurological damage, such as speech disorders, partial blindness, strabismus, paralysis of the limbs, or other types of seizures may be left behind after the sputum has stopped. Therefore, it is very important to recognize the disease and control it in time.

Cause

The cause of infantile spasms

(1) Causes of the disease

Due to the progress of the diagnosis and treatment technology, the cause of the disease has been found to be increasing. The cause of cryptogenic infantile spasm (10% to 15%) is unknown, and there are no other signs of central nervous system dysfunction. Symptomatic infantile spasm (85% to 90%) is characterized by previous signs of brain damage or a clear cause. The most common cause (78%) is cerebral ischemia and hypoxia, brain hypoplasia, intrauterine infection, and brain malformation. And innate metabolic disorders. The most common causes after birth are infection, cerebral hypoxia and head trauma. Some 71 patients with this disease were found to have abnormalities by 73%, including brain atrophy (49%), congenital abnormalities (18%), and hydrocephalus (6%). Brain malformations and calcification have also been reported. More than 20% of patients with tuberous sclerosis develop this disease. In recent years, it has been found that congenital cytomegalovirus infection, Toxoplasma infection, rubella, and herpes simplex can cause this disease. Domestic and ancestors analyzed the cause of 146 cases of this disease, 26% were primary, and the rest were symptomatic, including prenatal factors such as phenylketonuria, head deformity, cerebral palsy, Down syndrome and head deformity. Congenital brain hypoplasia; birth factors include intrauterine and intrapartum asphyxia, birth injury; postnatal factors with infectious diseases combined with encephalopathy, encephalitis, meningitis and brain trauma, vaccination.

(two) pathogenesis

1. Cryptogenic infantile spasm refers to no other cause for finding, and structural or biochemical reasons cannot be found based on current knowledge and technology. With the deepening of understanding and the advancement of diagnostic techniques, more and more cryptogenic infantile spasms will find abnormalities in brain function or anatomy to clarify the cause.

2. Symptomatic infantile spasms are caused by known brain lesions, including organic, structural lesions of the brain, or biochemical metabolic disorders. Can be divided into the following categories:

(1) Brain lesions: brain developmental malformations, such as neural tube development disorders, cerebral neuronal migration disorders, gray matter ectopic, gyrus deformity, hydrocephalus, brain development disorders caused by chromosomal diseases and congenital metabolic diseases, brain Degenerative diseases and demyelinating diseases, such as leukodystrophy, neurocutaneous syndrome, central nervous system infections, such as various encephalitis, meningitis, brain abscess, congenital infection, cerebral cysticercosis and others due to viruses, bacteria, Infections caused by protozoa, parasites and fungi, cerebrovascular diseases such as intracranial hemorrhage, thrombosis, embolism, cerebral vasculitis, arteriovenous malformations, aneurysms, etc., cerebral edema, encephalopathy, increased intracranial pressure, brain trauma, craniocerebral production Injury, brain tumor, hamartoma, etc.

(2) Hypoxic brain damage: diseases that cause hypoxia, such as heart, lung disease, asphyxia, shock, convulsive brain injury, etc.

(3) metabolic disorders: congenital metabolic abnormalities, such as brain lipid deposition, abnormal glucose metabolism, abnormal amino acid metabolism, water and electrolyte disorders, such as hyponatremia, hypernatremia, hypocalcemia, low magnesium Symptoms, vitamin deficiency, such as vitamin B6 dependence, liver and kidney disorders, hypertensive encephalopathy, endocrine dysfunction.

(4) Poisoning: drugs, metals, other chemical substances, such as lead, sputum, isoniazid, convulsions, steroids and other poisoning, drug break syndrome, such as sudden withdrawal of anticonvulsant drugs caused by epilepticus.

an examination

Related inspection

Cerebrospinal fluid cell count cerebrospinal fluid cell count (CST) brain CT examination

The cryptogenic infantile spasm has the following characteristics: 1 normal development before the onset, normal neurological examination and neuroimaging; 2 symmetry convulsions, no other types of episodes; 3 electroencephalogram (EEG) background is typical bilateral Peak rhythm disorder, in a series of episodes of sputum, EEG between each sputum can restore the peak rhythm disorder pattern; 4EEG evidence of infinite anomalies. Symptomatic infantile spasm has mental retardation before onset, and neurological examination and neuroimaging can be found abnormally.

1.EEG characteristics

EEG during infantile spasms is characterized by a peak rhythm disorder. The typical peak rhythm disorder is characterized by a mixed wave pattern of extremely high amplitude slow wave and spike wave in the brain region. The two sides are asymmetric and asynchronous, and the position and amplitude of the spike wave change irregularly or multifocal. There is no fixed relationship between the spike and the slow wave.

Peak rhythm disorders are more pronounced during sleep. Normal sleep waveforms such as top waves, sleep spindles, and K-complex waves often disappear. Studies have shown that the incidence of peak rhythm disorders during waking is 64%, NREM sleep I is 86%, and stage II to IV is 99%. After 1 year of age, the peak rhythm disorder gradually decreases during waking, but still exists during sleep. The peak rhythm disorder during deep sleep gradually shows the characteristics of periodic distribution, and the asymmetry on both sides can be more obvious.

In the onset of infantile spasms, peak rhythm disorders disappear, EEG can be characterized by high amplitude slow wave or spine slow wave burst, and (or) extensive low voltage fast wave. Sometimes it can be displayed as pseudo normalization, which is a low to medium amplitude fast wave or fast and slow mixed wave lasting about 10 seconds, which looks like normal background activity.

2. Other auxiliary inspections

Neuroimaging studies such as CT, MRI, PET, and SPECT can assist in the discovery of structural or functional lesions in the brain. SPECT studies have shown that cerebral blood flow in low perfusion areas is associated with cortical lesions in infantile spasms (often in the occipital region), and high perfusion areas (often in the frontal area) are associated with the persistence of epilepsy, with high perfusion areas similar to the onset of seizures. cut back. MRI can detect abnormal brain structures that are difficult to detect by CT. Ultraviolet examination of the skin can reveal nodular sclerosis of skin pigmentation spots. Various metabolic tests, enzyme assays, and chromosome tests can help find the cause. Intravenous injection of vitamin B6 under EEG monitoring may exclude pyridoxine dependence.

Differential diagnosis

Symptoms of infantile spasms

Increased muscle tone in the extremities: Tillering is both tonic. Increased spasm of the sacral muscles is associated with damage to the cone, and spinal cord reflexes are facilitated. When passively moving a patient's joint, a sense of impedance occurs in the case of increased muscle tone, which is related to the speed of being exercised. When the muscles in the shortened state are quickly drawn, the contraction and the embarrassing state are immediately caused, and when the force is drawn to a certain extent, the resistance suddenly disappears. Increased spastic muscle tension is not related to "sputum", which refers to an involuntary muscle contraction.

Increased tonic muscle tone is seen in some extrapyramidal lesions with special tension changes, which are selective for increased muscle tone. The upper limbs are mainly adductor, flexor and pronator, and the lower extremities are superior to extensor muscle tension. The resistance encountered when passively moving a patient's limb is generally smaller than that of a sputum, but it has nothing to do with the length of the muscle at that time, ie, the contraction morphology. There is no difference between the extensor and the flexor. Regardless of the speed, amplitude, and direction of the action, the same resistance is encountered. This increase in muscle tone is called lead-like tonic, such as alternating loose and tight changes due to tremor, called gear-like rigidity.

Cramps: Cramps are a common name for convulsions and are a manifestation of temporary disturbances in brain function. The movement of human muscles is controlled by the brain. When the brains that manage muscle movement are temporarily over-excited, muscle movements that cannot be controlled can occur, which can be limited to a certain group of muscles or body side, or to the whole body, that is, cramps.

Convulsion: Con Vulsion is a common emergency in children, especially in infants and young children. Cerebral nerve dysfunction caused by a variety of reasons. It is characterized by a sudden systemic or local muscle group with tonicity and clonic convulsions, often accompanied by conscious disturbances. The incidence of convulsions in children is very high. According to statistics, the incidence of convulsions in children under 6 years old is about 10 to 15 times that of adults. About 5 to 6% of children have had one or more convulsions. The reason is: infant cerebral cortex development is not perfect, so the analysis and identification and inhibition function is poor, the nerve myelin sheath is not completely formed, the insulation and protection are poor, after stimulation, the excitatory impulse is easy to generalize, the immune function is low, and the infection is easy. The convulsions, blood-brain barrier function is poor, various toxins easily penetrate into the brain tissue, and some special diseases such as birth injury, brain development defects and congenital metabolic abnormalities are more common, which are caused by high incidence of convulsions in infants and young children. s reason. Frequent seizures or persistent states are life-threatening or can leave serious sequelae in children, affecting children's mental development and health.

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