Arnold-Chiari syndrome is a severe congenital malformation of the human brain. Its essence lies in the discrepancy between the sizes of the posterior fossa of the skull and other brain structures located in this area. This leads to omission, followed by infringement of the tonsils of the cerebellum and brain stem. The frequency of this anomaly is 4-8 cases for every 95-100 thousand people.
Currently, the pathogenesis of this disease is not precisely established. Presumably, there are three pathogenetic factors contributing to the occurrence of this disorder:
- congenital, hereditarily caused neuropathies;
- traumatic injuries of the sphenoid-occipital and sphenoid-ethmoid parts of the slope as a result of birth injury;
- hydrodynamic stroke of the cerebrospinal fluid against the wall of the canal of the spinal cord located in the center.
In 1891, four types of anomalies were identified by Arnold Chiari, and this classification is still used today.
Arnold-Chiari syndrome of the first type consists in lowering the posterior fossa of the skull and nearby structures into the spinal canal much lower than the level of the large occipital foramen. In the second type of anomaly, caudal dislocation of the medulla oblongata, lower parts of the worm and IV ventricle is present, and hydrocephalus often develops. Arnold-Chiari syndrome of the third type is very rare, it is characterized by a gross displacement of all the brain structures of the posterior cranial fossa. The fourth type is represented by cerebellar hypoplasia. The fourth and third types of anomalies are in most cases incompatible with life.
In 80% of cases, Arnold-Chiari syndrome is diagnosed together with syringomyelia - a pathology of the development of the spinal cord, characterized by the development of cysts of the spinal cord, which are formed when the posterior fossa of the skull is lowered and compression in the cervical spinal cord. The presence of these cysts leads to the development of progressive myelopathy.
Arnold-Chiari syndrome: symptoms
The clinical picture of this disease is characterized by the presence of the following symptoms:
- pain in the cervical and occipital regions, which intensifies with sneezing and coughing;
- decrease in temperature and pain sensitivity, as well as muscle strength of the upper limbs;
- spasticity of limbs;
- dizziness, fainting, shakiness, aggravated by turning the head, decreased visual acuity and quality.
In very advanced cases, short-term respiratory arrest (apnea), a weakening of the pharyngeal reflex, and quick, involuntary eye movements join these symptoms.
In some cases, the Arnold-Chiari anomaly may not have any manifestations and is detected completely by accident during diagnostic procedures. Diagnosis of this disease is carried out using MRI tomography and computed tomography with three-dimensional reconstruction of all cervical vertebrae, as well as the occipital bone.
Arnold-Chiari syndrome: treatment
The prescribed treatment depends on the condition of the patient and the severity of the disease. For primary symptoms such as headaches and other types of pain, your doctor may recommend pain medications and regular check-ups. Some patients have noted relief in taking anti-inflammatory drugs that can prevent and even delay surgery.
Most often, doctors prefer to carry out the treatment of anomalies with the surgical method. The purpose of the operation is to stop the progression of changes in the structure of the spine and brain and to stabilize the symptoms. With successful surgical interventions, pressure on the spinal cord and cerebellum is significantly reduced, and the outflow of cerebrospinal fluid is restored. There are various techniques for the operation, which depend on the presence of hydrocephalus. On average, the duration of surgery is one and a half to two hours, the recovery period takes five to seven days.