Aikardi syndrome: description, diagnosis, prevalence.

Aikardi syndrome is a rare hereditary disease, which is manifested by the absence of a corpus callosum, epileptic seizures and changes in the fundus. In addition, patients experience a delay in mental and physical development and a disruption in the structure of the facial bones of the skull.

History

In the 60 years of the twentieth century, the French neuropathologist Jean Aikardi described a dozen cases of this pathology. There are also earlier references to them in the medical literature, but then they were ranked as manifestations of congenital infection. Seven years after the first publication, the medical community introduced a new nosological unit - the Aikardi syndrome.

But the investigation of the disease continued, the number of symptoms expanded and even new branches appeared. For example, Aikardi-Goter syndrome, which is manifested by encephalopathy with calcification of the basal nuclei and leukodystrophy.

Prevalence

Since its official recognition of Aikardi, the syndrome has met neurologists about half a thousand times. Most of the patients lived in Japan and other countries in Asia. According to Swiss researchers, the incidence of the disease is 15 cases per hundred thousand children. Unfortunately, statistics are likely to yield underreported figures, as most patients remain unopened.

The disease develops in girls. And doctors suggest that it is the cause of most cases of delayed psychophysiological development and infantile spasms.

Genetics

Aikardi syndrome is a sex-linked disease, the defective gene is located on the X chromosome. Three cases were reported when boys with Klinefelter syndrome had similar symptoms. For male children with a normal XY genotype, this disease is lethal.

All cases of the appearance of this disease are the result of sporadic mutations. That is, before that in the family of the proband there were no cases of Aikardi syndrome. Transmission of a defective gene from mother to daughter is unlikely. The risk that a second child will be born with this pathology is very small and is less than one percent.

If you apply the laws of Mendel, then the spouses who already have one offspring with this disease, the following options are possible:

• Stillborn boy;
• Healthy girl (33%);
• Healthy boy (33%);
• Sick girl (33%).

The causes of the disease are unknown at the moment, the research continues.

Pathomorphology

Scientists and doctors resort to different methods to establish Aikardi syndrome. Photo of the brain by magnetic resonance imaging is one of the most common, but the whole picture can be viewed only on autopsy. During the study of the brain, multiple anomalies in the development of the neural tube can be detected:

• Complete or partial absence of corpus callosum;
• Change in the position of the cerebral cortex;
• Abnormal convolutions;
• Cysts with serous contents.

The study under the microscope reveals violations in the cellular structure of the affected areas. On the fundus there are also characteristic changes, such as thinning of tissues, a decrease in the number of vessels and pigment, but the proliferation of cones and rods.

Clinic

How do children with Aikardi syndrome look? Symptoms at first are quite nonspecific, because children are born on time, through natural birthmarks and look healthy. Up to three months newborns develop without clinical manifestations, then there are epileptic seizures. They are presented in the form of retropulsive symmetrical serial clonic-tonic convulsions of extremities. In the overwhelming majority of cases, infantile spasms of flexor muscles still join this. In rare cases, the debut of the disease occurs in the first month of life. Epileptic seizures do not stop drug.

In neurological status in such children, there is a decrease in the size of the skull, a decrease in muscle tone, but one-sided dissociation of reflexes or, conversely, paresis and paralysis. In addition, half of patients have abnormalities of the development of the skeleton: agenesis of the vertebrae or the absence of ribs. This leads to marked scoliotic changes in posture.

Diagnostics

At present, there are no reliable tests to help identify the Aicardi syndrome. Genetic diagnostics in the prenatal stage is impossible, since the gene responsible for the development of this disease has not yet been identified.

A neurologist can prescribe a study that will identify specific symptoms. These include:

• inspection;
• Ophthalmoscopy;
• electroencephalography;
• Magnetic resonance imaging;
• A roentgen of a backbone.

This makes it possible to detect the absence of a corpus callosum and the symmetry of the cerebral hemispheres, the presence of cysts.