Kiari's anomaly (Arnold-Kiari's malformation) — a disease at which the structures of a brain located in a back cranial pole are lowered in the kaudalny direction and leave through a big occipital opening. Depending on type Kiari's anomaly can be shown by a headache in a nape, pain in cervical department, dizziness, nistagmy, faints, a dizartriy, cerebellar ataxy, throat paresis, decrease in hearing and ear noise, sight violation, a dysphagy, respiratory , a stridor, disorders of sensitivity, a hypotrophy of muscles and tetraparesis. Kiari's anomaly is diagnosed by carrying out MRT of a brain, cervical and chest departments of a backbone. Kiari's anomaly which is followed by a resistant pain syndrome or neurologic deficiency is subject to surgical treatment (a decompression of a back cranial pole or the shunting operations).
In the field of connection of a skull with a spine column there is a big occipital level at the level of which the trunk of a brain moves in a spinal cord. Above this opening the back cranial pole is localized. In it the bridge, a medulla and a cerebellum is located. Kiari's anomaly is connected with an exit of a part of anatomical structures of a back cranial pole in a gleam of a big occipital opening. At the same time there is a sdavleniye of the structures of an oblong and spinal cord which are in this area, and also the violation of outflow of tserebrospinalny liquid from a brain leading to hydrocephaly. Together with a platibaziya, assimilation of the Atlas, etc. Kiari's anomaly belongs to congenital malformations of kraniovertebralny transition.
Kiari's anomaly occurs according to various data at 3-8 people on 100 thousand of the population. Depending on type Kiari's anomaly can be diagnosed in the first days after the birth of the child or to become an unexpected find at the adult patient. In 80% of cases Kiari's anomaly is combined with a siringomiyeliya.
Causes of anomaly of Kiari
Still Kiari's anomaly remains a disease about which etiology in neurology there is no consensus. A number of authors considers that Kiari's anomaly is connected with the reduced size of a back cranial pole leading to the fact that in process of growth of the structures located in it they begin to leave through an occipital opening. Other researchers assume that Kiari's anomaly develops as a result of the increased sizes of a brain which at the same time as if pushes out contents of a back cranial pole through an occipital opening.
Hydrocephaly at which due to increase in ventricles the total amount of a brain increases can provoke transition of slightly expressed anomaly to the expressed clinical form. As Kiari's anomaly along with a dysplasia of bone structures of kraniovertebralny transition is followed by an underdevelopment of the copular device of this area, any craniocereberal trauma can lead to aggravation of a vklineniye of almonds of a cerebellum in an occipital opening with a demonstration of a clinical picture of a disease.
Classification of anomaly of Kiari
Kiari's anomaly is subdivided into 4 types:
Kiari I's anomaly is characterized by omission of almonds of a cerebellum below a big occipital opening. Usually it is shown at teenagers or at adult age. Often is followed by a gidromiyeliya — a congestion of tserebrospinalny liquid in the central channel of a spinal cord.
Kiari II'S anomaly is shown in the first days after the birth. Except cerebellum almonds at this pathology through a big occipital opening there are also a worm of a cerebellum, a medulla and the IV ventricle. Kiari II'S anomaly of type is much more often combined with a gidromiyeliya, than the first type, and is in most cases connected with the miyelomeningotsel — congenital spinal hernia.
Kiari III'S anomaly differs in the fact that the cerebellum and a medulla which fell through a big occipital opening, settle down in the meningotsel of cervicooccipital area.
Kiari IV'S anomaly consists in a hypoplasia (underdevelopment) of a cerebellum and is not followed by its shift in the kaudalny direction. Some authors refer this anomaly to a syndrome of the Dandy Walker at which the hypoplasia of a cerebellum is combined with existence of congenital cysts of a back cranial pole and hydrocephaly.
Kiari II and Kiari III'S anomaly is often observed in a combination with other displaziya of nervous system: a geterotopiy cerebral cortex, a polimikrogiriya, anomalies of a calloused body, cysts of an opening of Morangdi, an excess of a silviyevy water supply system, a hypoplasia of subcrustal structures, it is mashed also a cerebellum sickle.
Symptoms of anomaly of Kiari
Most often in clinical practice Kiari I's anomaly of type meets. It is shown likvornogipertenzionny, tserebellobulbarny and siringomiyelichesky by syndromes, and also damage of craniocereberal nerves. Usually Kiari I's anomaly demonstrates during puberty or already at adult age.
The headache in a nape and cervical area amplifying during sneezing, cough, a natuzhivaniye or tension of muscles of a neck is characteristic of a likvornogipertenzionny syndrome by which Kiari I's anomaly is followed. The vomiting which is not depending on meal and its character can be observed. At survey of patients with Kiari's anomaly the raised tone of muscles of a neck comes to light. Among cerebellar violations are observed violation of the speech (dizartriya), , a cerebellar ataxy.
Defeat of a trunk of a brain, the kernels of craniocereberal nerves and their backs located in it are shown by decrease in visual acuity, diplopiy, disorder of swallowing, decrease in hearing as cochlear neuritis, system dizziness with illusion of rotation of surrounding objects, ear noise, a syndrome sleepy , the repeating short-term losses of consciousness, an orthostatic collapse. Patients who have Kiari's anomaly, note strengthening of dizziness and ear noise at turns by the head. The turn of the head of such patients can provoke a faint. It can be noted atrophic changes of a half of language and the paresis of a throat which is followed by an osiplost of a voice and difficulty of breath. Tetraparesis with big decrease in muscular force in the top extremities, than in lower is possible.
In cases when Kiari I's anomaly is combined with a siringomiyeliya, the siringomiyelichesky syndrome is observed: violations of sensitivity on the dissociated type, sleeps, muscular hypotrophies, pelvic violations, neyroartropatiya, disappearance of belly reflexes. At the same time some authors point to discrepancy of the size and location of a siringomiyelichesky cyst of prevalence of disorders of sensitivity, degree of expressiveness of paresis and a muscular hypotrophy.
Kiari II and Kiari III'S anomaly have similar clinical manifestations which become noticeable from first minutes of life of the child. Kiari's anomaly of II is followed by noisy breath (a congenital stridor), the periods of short-term respiratory standstill, bilateral neyropatichesky paresis of a throat, violation of swallowing with throwing of liquid food in a nose. At newborns Kiari's anomaly of II is shown also nistagmy, increase in a muscular tone in the top extremities, by the cyanosis of integuments arising during feeding. Motive frustration can be expressed in various degree and progress up to a tetraplegiya. Kiari's anomaly of III has heavier current and often is violation of development of a fruit, not compatible to life.
Diagnostics of anomaly of Kiari
Neurologic survey and the standard list of neurologic inspections (EEG, Ekho-EG, REG) do not give the specific data allowing to establish the diagnosis "Kiari's anomaly". As a rule, they reveal only signs of substantial increase of intra cranial pressure, i.e. hydrocephaly. The X-ray analysis of a skull reveals only bone anomalies by which Kiari's anomaly can be followed. Therefore before introduction diagnosis of this disease presented to neurologic practice of tomographic methods of a research for the neurologist big difficulties. Now doctors have an opportunity to make to such patients the exact diagnosis.
It should be noted that brain MCKT and KT at good visualization of bone structures of kraniovertebralny transition do not allow to judge myagkotkanny formations of a back cranial pole rather precisely. Therefore the only reliable method of diagnostics of anomaly of Kiari is the magnetic and resonant tomography today. Its carrying out demands the patient's obezdvizhennost therefore at small children it is carried out in a condition of medication sleep. Except brain MRT for identification the meningotsela and siringomiyelichesky cysts needs also carrying out MRT of a backbone, especially its cervical and chest departments. At the same time carrying out MRT of researches has to be directed not only to diagnostics of anomaly of Kiari, but also to search of other anomalies of development of nervous system which often are combined with it.
Treatment of anomaly of Kiari
Asymptomatically the proceeding Kiari's anomaly does not need treatment. In cases when Kiari's anomaly is shown only by existence of pains in a neck and occipital area, carry out the conservative therapy including analgetic, anti-inflammatory and miorelaksiruyushchy medicines. If Kiari's anomaly is followed by neurologic violations (paresis, disorders of sensitivity and a muscular tone, violation from craniocereberal nerves and so forth) or the pain syndrome which is not giving in to conservative therapy, then showed its surgical treatment.
Most often in treatment of anomaly of Kiari the kraniovertebralny decompression is applied. Operation includes expansion of an occipital opening due to removal of a part of an occipital bone; elimination of a sdavleniye of a trunk and a spinal cord at the expense of a resection of almonds of a cerebellum and back half of two first cervical vertebras; normalization of circulation of tserebrospinalny liquid by a podshivaniye in a firm brain cover of a patch from artificial materials or an allotransplantat. In certain cases Kiari's anomaly is treated by means of the shunting operations directed to drainage of tserebrospinalny liquid from the expanded central channel of a spinal cord. Tserebrospinalny liquid can be taken away in a chest or abdominal cavity (lyumboperitonealny drainage).
Forecast of anomaly of Kiari
Important predictive value has type to which Kiari's anomaly belongs. In certain cases Kiari I's anomaly can keep an asymptomatic current throughout all life of the patient. Kiari III'S anomaly in most cases leads to a lethal outcome. At emergence of neurologic symptoms of anomaly of Kiari of I, and also at Kiari's anomaly is of the II great importance timely performing surgical treatment as the arisen neurologic deficiency badly is restored even after successfully performed operation. According to various data efficiency of a surgical kraniovertebralny decompression makes 50-85%.