Arnold-Chiari malformation is one of the most common neurological abnormalities in children. It may be associated with a wide range of symptoms. The most skilled doctors in Turkey can diagnose and treat it.
What is Arnold Chiari malformation?
The physician Hans Chiari first described Arnold-Chiari syndrome in 1890. Later, the physician Jules Arnold described it more clearly, and it was called Arnold-Chiari malformation.
The malformation is thought to occur during fetal life due to genetic mutations or the mother’s lack of nutrients during pregnancy.
The syndrome occurs when part of the lower brain (cerebellum) descends towards the vertebral canal through the foramen magnum due to the small bony space at the base of the skull, which causes the cerebellum to be over-pressurized and descend.
This drop prevents the drainage of cerebrospinal fluid, causing hydrocephalus.
Arnold-Chiari malformation patterns
Arnold-Chiari malformation is categorized into four types according to the degree of subsidence, symptoms, and the presence of accompanying neurological abnormalities.
Type I Arnold-Chiari malformation
This type is seen in late childhood (adolescence), where the pressure increases, and the cerebellum descends down through the foramen magnum towards the vertebral canal. This pattern can be caused by acquired pressure-raising causes (such as infections and drugs) and is the mildest and most prognostic form.
Type II Arnold-Chiari malformation
In this pattern, a larger amount of brain tissue descends through the foramen magnum towards the vertebral canal. In younger children, the cerebellum and part of the brain stem descend. This pattern is associated with another neurological spinal deformity: myelomeningocele, or spina bifida.
Type III Arnold-Chiari malformation
This is the most serious type, where the cerebellum and brainstem descend through the large fossa into the spinal column; this type is rare and poorly prognostic and is diagnosed in newborns or during pregnancy using ultrasound.
Type IV Arnold Chiari malformation
This pattern includes an undeveloped or underdeveloped cerebellum. In this pattern, the cerebellum is in its normal position, but parts of it are undeveloped. This type is the rarest of all patterns.
Arnold-Chiari malformation symptoms
The malformation can be asymptomatic, detected by chance and does not require treatment, which is often the case in Chiari malformation type I. It may be associated with many symptoms, especially those related to cerebellar function, we mention some of the symptoms seen in children with Arnold-Chiari malformation:
- Headaches and pain in the neck and base of the head, especially when coughing
- Central equilibrium defects
- numbness and tingling
- Poor motor-muscular coordination
- Loss of sensation in the hands or feet
- Some have visual issues
- Tinnitus
- Vocal cord dysfunction (speech difficulties)
- Difficulty swallowing
Other symptoms associated with cranial nerve function localized to the brainstem can be seen in more severe patterns, such as pattern III, and are considered signs of neurological injury.
Arnold-Chiari malformation diagnosis
The diagnosis of Arnold-Chiari malformation involves using modern imaging techniques, most notably magnetic resonance imaging (MRI) of the head, which is the best method.
3D CT can also be used.
When diagnosing the patient, the need for intervention and the prognosis of the disease can be determined.
How to Treat Arnold-Chiari malformation in Turkey
Treatment aims primarily to relieve symptoms and improve quality of life. The treatment of Arnold-Chiari malformation depends on the severity of the condition and symptoms. If there are no symptoms, treatment is not needed. However, if there are severe symptoms, intervention must be done as soon as possible.
In mild cases of the disease, some symptoms, such as headaches, can be treated with painkillers as a symptomatic treatment only.
The cornerstone of treatment is surgery, which is carried out in advanced centers with the best doctors, and Turkey is one of the best examples of this.
In fact, the main goal of surgery is to relieve pressure and drain the cerebrospinal fluid, and to do this, we use the following well-known technique:
Decompression Surgery
It is the best surgical procedure that depends on removing a small part of the skull base, and this amount may be sufficient to relieve pressure. In some cases, the surgeon resorts to opening the dura and exposing the cerebellar tonsils so that the surgeon reduces the size of the tonsils using electrocautery, which leads to relieving pressure and draining the cerebrospinal fluid.
The decision to open the dura depends on several factors related to the condition, including the patient’s symptoms, age, and the presence or absence of an accompanying disease such as syringomyelia.
The surgeon may use real-time Doppler ultrasonography during the operation to determine whether the dura needs to be opened.
The traditional Arnold-Chiari decompression surgery that includes opening the dura takes about 3 to 4 hours, while the operation without opening the dura takes about two hours.
Surgical techniques to drain cerebrospinal fluid
Endoscopic third ventriculostomy (ETV)
The surgeon inserts a small camera into the brain through a yolk hole in the skull and makes a small hole in one part of the ventricle, which leads to decompression.
Some patients complain of headaches and nausea for several days after the procedure.
Cerebral shunt
A good technique to use in the case of hydrocephalus is hydrocephalus.
As a result of severe fluid accumulation, we place a shunt that withdraws fluid from the brain, and the other end of the catheter is placed in the peritoneal cavity. The shunt may be associated with complications such as infection spreading to the brain or mechanical problems such as shunt blockage or shunt displacement from its place.
Risks of the Arnold-Chiari malformation procedure
In fact, no surgical procedure is completely risk-free. Some of the risks of Arnold-Chiari malformation surgery include the following:
- Heavy bleeding due to an artery injury and the formation of a hematoma
- Leaking cerebrospinal fluid
- sepsis or stroke
- Anesthesia-related disorders
- Cranial nerve injury
- In some cases, there is no improvement in symptoms after surgery
Chiari malformation can be associated with spinal lesions due to the compression of the spinal cord with the cerebellum and the lower part of the brain. If the spinal cord is injured, it can cause permanent injuries such as paralysis that do not regress after decompression surgery, and the doctor resorts to spinal surgery.
Preparation before Arnold-Chiari malformation operation
The doctor should be aware of the medications the patient is taking. NSAIDs and laxatives (aspirin) should be discontinued at least one week before the procedure, and alcohol and smoking should be avoided one week before surgery.
Avoid eating or drinking the night before the procedure to prevent the risk of aspiration and inhalation of food through the gastrointestinal tract that occurs during anesthesia.
Recovering from Arnold-Chiari malformation surgery
The recovery period from surgery varies depending on the patient’s health and ranges from 4 to 6 weeks.
Full recovery from symptoms may take months, and a follow-up brain MRI should be done six months or a year after the operation.
Some patients suffer from a postoperative headache that lasts for several days and can be treated with painkillers. After surgery, the patient is prevented from any activity that increases pressure, such as lifting heavy weights and avoiding bending while lowering the head.
Constipation can be prevented by drinking plenty of water, eating high-fiber foods, avoiding prolonged coughing, and avoiding strenuous activities such as housework.
After surgery, the patient should not drink alcohol because alcohol increases the risk of bleeding, and it is preferable to avoid smoking and driving.
Do not take NSAIDs or laxatives without consulting your doctor.
Arnold-Chiari malformation surgery success rate
In fact, the success rate of decompression surgery in studies is as high as 85%, which means the surgery is fairly safe.
85% to 95% of patients are symptom-free after decompression surgery. The success of the surgery depends on the patient’s health status and whether the surgeon opens the dura or just removes part of the skull base.
Prevalence
The first type of Arnold-Chiari malformation is the most common among the other types.
The incidence is estimated at 1 in 1,000 births. It is often asymptomatic and detected by chance when imaging for other reasons. Females are affected more than males by a simple ratio of 1.3:1.
Type II Arnold-chiari malformation is associated with other neural tube defects and occurs particularly with a pathologic congenital anomaly called myelomeningocele.
Type II Arnold-Chiari malformation is almost always associated with myelomeningocele, a type of spina bifida.
Spina bifida is a serious congenital anomaly that requires urgent intervention after birth.
Arnold-Chiari malformation Type III is the most serious but rare form, while Arnold-Chiari malformation Type IV is the rarest form.
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