Aikardi syndrome is a rare hereditary disease, which is manifested by the absence of the corpus callosum, epileptic seizures and changes in the fundus. In addition, in patients there is a delay in mental and physical development and a violation of the structure of the facial bones of the skull.
History
In the 60s of the twentieth century, the French neuropathologist Jean Aycardi described a dozen cases of this pathology. There are earlier references to them in the medical literature, but then they were ranked as manifestations of a congenital infection. Seven years after the first publication, the medical community introduced a new nosological unit - Aicardi syndrome.
But the study of the disease continued, the number of symptoms expanded, and even new branches appeared. For example, Aikardi-Gotter syndrome, which manifests itself as encephalopathy with calcification of the basal nuclei and leukodystrophy.
Prevalence
Since its official recognition, Aicardi syndrome has been encountered by neurologists about five hundred times. Most patients lived in Japan and other Asian countries. According to Swiss researchers, the incidence of the disease is 15 cases per hundred thousand children. Unfortunately, statistics most likely give understated figures, since most patients remain unexplored.
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, a defective gene is located on the X chromosome. Three cases were reported when boys with Kleinfelter syndrome had similar symptoms. For male children with the normal XY genotype, this disease is fatal.
All cases of this disease are the result of sporadic mutations. That is, before that, cases of Aicardi syndrome were not established in the proband family. 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 amounts to less than one percent.
If you apply the laws of Mendel, then for 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 currently unknown, research is ongoing.
Pathomorphology
Scientists and doctors are resorting to various methods to establish Aicardi syndrome. A photo of the brain by magnetic resonance imaging is one of the most common, but the whole picture can only be examined by autopsy. During the study of the brain, you can detect multiple abnormalities in the development of the neural tube:
- complete or partial absence of the corpus callosum;
- a change in the position of the cerebral cortex;
- abnormal positions of convolutions;
- cysts with serous contents.
A microscopic examination reveals abnormalities in the cellular structure of the affected areas. Characteristic changes are also present on the fundus, such as thinning of tissues, a decrease in the number of blood vessels and pigment, but at the same time the proliferation of cones and rods.
Clinic
What do children with Aycardi syndrome look like? Symptoms at first are quite nonspecific, because children are born on time, through the natural birth canal and look healthy. Up to three months, newborns develop without clinical manifestations, then epileptic seizures appear. They are presented in the form of retro-pulsive symmetric serial clonic-tonic seizures of limbs. In the vast majority of cases, infantile spasms of the flexor muscles still join this. In rare cases, the onset of the disease occurs in the first month of life. Epileptic seizures do not stop with medication.
In the neurological status of such children, there is a decrease in the size of the skull, a decrease in muscle tone, but at the same time, one-sided inhibition of reflexes or, conversely, paresis and paralysis. In addition, anomalies of skeletal development are noted in half of the patients: agenesis of the vertebrae or absence of ribs. This leads to pronounced scoliotic changes in posture.
Diagnostics
There are currently no reliable tests that can help identify Aicardi syndrome. Genetic diagnosis at the prenatal stage is not possible, since the gene responsible for the development of this disease has not yet been identified.
A neurologist can prescribe studies that will identify specific symptoms. These include:
- inspection;
- ophthalmoscopy;
- electroencephalography;
- Magnetic resonance imaging;
- X-ray of the spine.
This allows you to detect the absence of the corpus callosum and the violation of the symmetry of the cerebral hemispheres, the presence of cysts.