Tonsillar Ectopia - Causes, Symptoms, Diagnosis, and Treatment

Introduction:

Tonsillar ectopia or cerebellar tonsils, also known as Chiari malformation type 1, are present just above the brainstem. These are egg-shaped or ovoid structures present at the base of the brain. In some cases, these tonsils protrude via the skull into the upper part of the spinal canal. This condition is known as Chiari malformation, cerebellar tonsils, or tonsillar ectopia. It is mainly a para-axial mesoderm disorder, usually distinguished by posterior fossa hypoplasia and overcrowding of the content.

It is the downward herniation of the cerebellar tonsils via the foramen magnum. The disease is uncommon and mostly present in the asymptomatic general population showing a clear mass effect of descent into the spinal canal. It is approximately 5 mm (millimeter) and presents in 0.5 to 1 % population. The condition is accidentally found in people during an MRI (magnetic resonance imaging) scan or and specific neurological examination. The article discusses the tonsillar ectopia condition and its diagnosis and treatment options.

What Are the Various Other Terms Used for Tonsillar Ectopia?

• Tonsillar herniation.

• Herniated cerebellar tonsils.

• Cerebellar tonsil ectopia.

• Cerebellar tonsils.

What Are the Causes of Tonsillar Ectopia?

The main cause of tonsillar ectopia is increased intracranial hypertension caused by blocking cerebrospinal fluid flow in the foramen magnum. Cerebellar tonsillar ectopia or Chiari malformation (CM) can also cause the symptoms of tonsillar ectopia by affecting the normal cerebrospinal fluid flow due to upper cervical instability and herniated tonsils.

Tonsillar ectopia can occur from birth due to malformation during fetal growth. It is the primary and most common type of Chiari malformation. Also, it can occur in later life due to any infection, traumatic injury, or disease and is often referred to as secondary or acquired Chiari malformation. The acquired type of CM is believed to be caused by hematomas, tumors, and cysts.

Tonsillar ectopia is considered normal if no structural irregularities are present in the brain. Otherwise, it can be life-threatening. However, treatment options are available to treat tonsillar ectopia conditions.

What Are the Symptoms of Tonsillar Ectopia?

The symptoms of tonsillar ectopia include:

• Dizziness.

• Difficulty in walking or body balancing.

• Swallowing difficulties.

• Neck pain.

• Headaches.

• Inability to feel temperature and pain in the upper body.

• Numbness and tingling sensation in the feet and hands.

• Hearing loss.

• Weakness in the upper body.

• Fainting.

• Palpitations.

• Vertigo.

• Syncope or fainting episodes.

• Involuntary eye movements.

• Sleep apnea.

How Is Tonsillar Ectopia Diagnosed?

The doctor diagnoses tonsillar ectopias or cerebral tonsils by reviewing the patient’s medical history and symptoms and performing a neurological examination.

In addition, the doctor advises various diagnostic tests to analyze the condition. These tests include:

• MRIs (Magnetic Resonance Imaging): These tests show cerebrospinal fluid accumulation and loss of neural tissues in a person's spinal cord and brain. The test can also reveal the extension of cerebellar tonsils into the spinal canal.

• X-rays: The test shows various brain and spine irregularities, skull abnormalities, spine motion, and irregular curvature.

• CT (Computed Tomography) Head Scans: These reveal abnormalities in the bone at the base of the skull. In addition, it can also show bone deformities, tumors, brain damage, blood vessel defects, and other condition that may cause cerebellar tonsils.

• Cine MRIs: This type of MRI is used by healthcare providers to diagnose any abnormality or defect in the cerebrospinal fluid (CSF) flow.

How Is Tonsillar Ectopia Treated?

First-line treatment for tonsillar ectopic includes the management of headaches with conservative treatment options, such as

1. Nasal sprays.

2. Nonsteroidal anti-inflammatory drugs.

3. Vagus nerve stimulation.

4. Preventive treatment methods, antidepressants, antiseizure medication, calcium channel blockers, and antipsychotic medication.

The most common surgical procedure treats tonsillar ectopic or primary CM in patients who do not respond well to conservative treatment options.

Surgical procedures include:

1. Posterior Fossa Decompression Surgery -In this procedure, a small piece of posterior skull bone is removed to relieve compression and pressure on the brainstem. The surgical procedure also helps in enlarging the foramen magnum.

2. Cerebellar Tonsillar Reduction - This microsurgical procedure allows the cerebrospinal fluid to move freely by causing the shrinkage of the lower part of the tonsils, which are unimportant for body and brain function.

3. Duraplasty - In this procedure, the outer protective layer of the brain, called the dura, is expanded by cutting and closing it with another soft tissue outside the brain.

4. Laminectomy - In this procedure, the posterior part of various vertebrae is cut to restore the flow of CSF by relieving pressure on the spinal cord.

These surgical procedures are only done to treat the symptoms affecting the motor and sensory and do not help relieve the symptoms of headaches. Therefore, a person may need regular follow-ups to treat these symptoms and other related discomfort or pain.

What Are the Complications Related to Tonsillar Ectopia?

The complication of tonsillar ectopic mainly depends on the severity of herniated tonsils. It may range from mild discomfort to severe pain symptoms that make everyday tasks difficult for a person.

In some cases, people experience frequent headaches and discomfort, affecting their quality of life. Other serious complications caused associated with tonsillar ectopia are related to orthopedic and neurological problems.

These include:

• Sleep apnea or sleep disorders.

• Spinal curvature.

• Syringomyelia, or cyst or hole in the spinal column.

• Hydrocephalus, or excess fluid accumulation in the brain.

Conclusion:

Chiari malformations or tonsillar ectopia can be congenital or acquired conditions that can occur in any person at any age. However, the condition is usually very rare in both children and adults. People mostly experience severe headaches in this condition, which may accompany other orthopedic and neurological symptoms. Tonsillar ectopia or cerebellar tonsil is usually a mild condition or type of Chiari malformation but can also cause serious complications if they progress. Therefore, if a person experiences severe headaches or migraines without any other symptoms, they might not have tonsillar ectopia. However, they should get medical advice in either case to get the proper investigation and diagnosis of the condition.