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Chiari Malformation

Causes, Symptoms, Treatment, & Other Resources

The headaches and neck pain got worse over time.  The dizziness made simple tasks challenging.  Medications and physical therapy did not help.  Your doctor is concerned and thinks you may have a Chiari Malformation.  What is a Chiari Malformation (CM)? What are the different types of Chiari Malformations? What are the symptoms of a Chiari Malformation? What are the causes of a Chiari Malformation? What are the common treatments for Chiari Malformations? How is it diagnosed? What other conditions are associated with Chiari Malformations?  Let’s dig in.


Chiari Malformation is a medical condition where a part of the brain bulges through a normal opening at the base of the skull.  Under normal circumstances, the brain is not intended to descend or bulge through this opening.  This creates additional pressure on the delicate brain tissue which can cause multiple symptoms.

What Is a Chiari Malformation (CM)? chiari malformation

Chiari Malformation Is a medical condition where a part of the brain at the back of the skull abnormally descends through an opening in the skull.  It is named after Dr. Hans Chiari who was an Austrian pathologist who in the late 1880’s studied deformities of the brain.

The brain is a large structure divided into different parts that reside within the skull.  Important parts of the brain called the Cerebellum and Brainstem sit at the base of the skull.  The Foramen Magnum is a large hole at the base of the skull that allows the brain to join the spinal canal.  The Cerebellum and Brainstem under normal conditions sit above the boney opening at the base of the brain (Foramen Magnum).

In Chiari Malformations the Cerebellum and Brainstem move below the level of Foreman Magnum putting pressure on the lower parts of the brain (1).  It can also affect the flow of spinal fluid around the brain and spinal cord.

Chiari Malformation can occur when the opening at the base of the skull is not large enough or when there is abnormal pressure in the brain pushing it downward.

Chiari Malformations are categorized into 4 major types based upon anatomical abnormality and whether congential defects are present (2).

Chiari Type 1 Malformation

This malformation occurs during fetal development and is characterized by downward movement of the Cerebellum beneath the boney opening at the base of the skull (Foramen Magnum).  It is typically 4 mm.  Why is this important?

It can block the flow of spinal fluid between the spinal canal and brain leading to an increase in pressure.  It can also put pressure on the lower portion of the brain with varying symptoms.  Chiari Type 1 Malformation is typically associated hydrosyringomyelia which is a fluid-filled cyst within the spinal cord.

Chiari Type II Malformation

In Chiari Type II Malformation a greater amount of tissue extends down into the spinal canal compared to Chiari Type 1.  It is usually associated with a myelomeningocele which is a form of Spina Bifida.  This is a condition where the spinal canal and the backbone do not close before birth.

Chiari Type III Malformation

This is the most severe form of Chiari Malformation.  A significant amount of the brain is pushed through the opening at the base of the skull. This form of CM is diagnosed at birth or with ultrasound during pregnancy.

Chiari Type IV Malformation

Type IV is rare and involves an incomplete or underdeveloped Cerebellum.  This is also referred to as Cerebellar Hypoplasia.  In this type of CM the cerebellum is in its normal position in relation to the Foramen Magnum but parts of it are missing.

Symptoms of Chiari Malformation

Many people with Chiari Malformation have no signs or symptoms (3).  Symptoms can change depending upon the amount of brain and nerve compression and increase in cerebral spinal fluid pressure.  The downward displaced Cerebellum and Brainstem restrict the flow of cerebral spinal fluid from the brain into the spinal cord.  Accordingly, it backs up with increased pressure within the skull.  Abnormal pressure is also applied to the Cerebellum and Brainstem.  The Cerebellum controls the coordination of movement.  You know the wonderful coordination that is involved with walking, talking, dancing, and running. The Brainstem on the other hand controls many basic life functions such as heart rate, blood pressure, breathing, and level of consciousness.

Symptoms may include:

  • Headache
  • Neck Pain
  • Dizziness
  • Ringing in the ears (tinnitus)
  • Arm and Leg weakness and numbness
  • Difficulty with swallowing
  • Breathing problems
  • Problems with hand coordination
  • Nausea and Vomiting
  • Balance problems

A deeper dive into each of the symptoms:

Brain Fog

Brain fog is one of the hallmark symptoms of Craniocervical instability. It is characterized by slow thinking, difficulty focusing, confusion, lack of concentration, forgetfulness, or haziness in thought. The severity of symptoms varies from patient to patient. Ever had a bad hangover or high fever and had trouble concentrating or completing simple tasks? This brain fog. Some patients describe it as a generalized haziness in thought as if cotton were stuck in the head. In addition to cognitive impairments, many patients also report generalized mental fatigue making complex tasks almost impossible. The exact cause of brain fog is unknown. Possible explanations include…

Read More About Brain Fog

Cervicalgia / Neck Pain

Cervicalgia is also known as neck pain, which is an all-too-common, unpleasant pain. Read here to learn the symptoms, diagnosis, and treatment options. We will discuss other causes for cervicalgia. What symptoms are associated with cervicalgia? How is cervicalgia diagnosed? What are the treatment options for cervicalgia? Cervicalgia is a medical term used to describe neck pain. It is very common and affects approximately 2/3 of the population at some point in their life. Cervicalgia is the 4th major cause of disability. Risk factors include injury, prior history of neck and musculoskeletal pain, jobs that require a lot of desk work, low social support, job insecurity, physical weakness, and poor computer station setup.

Read More About Cervicalgia / Neck Pain

Chronic Fatigue

Have you ever had a challenging all-day hike, athletic endeavor, or worked a double shift and felt exhausted the next day? Later that day or the next morning, moving across the room may have seemed almost impossible and took herculean power. Now image this occurs on a daily basis without any provocation. 24/7 simple tasks are nearly impossible due to a lack of strength and energy. This is chronic fatigue, and it is one of the common symptoms associated with craniocervical instability. Severity can vary and in severe cases, patients are confined to their beds. Aggravating and alleviating factors often times can not be identified.

Read More About Chronic Fatigue

Chronic Headaches

Do you suffer from chronic headaches? Maybe it’s a daily issue, maybe once a week, maybe even less often, but one thing’s for sure—when a chronic headache kicks in, it can be a real pain in the neck, literally. In order to effectively address chronic headaches, you have to first determine if the pain is caused by a problem in your neck. Let’s take a look at a few neck issues that can cause headaches: Weak neck muscles – The head, on average, weighs about ten pounds, so when the neck muscles are weak, it can make your head feel a bit like a bowling ball that your neck can’t quite balance. There are many muscles that, along with the cervical spine, work together to help support the neck and aid movement…

Read More About Chronic Headaches

Muscle Pain After Cervical Fusion Surgery

Cervical Fusion is a major surgery that involves joining one or more of the spinal bones together using screws, bolts, and plates (1). The hardware may be placed in the front (anterior) or the back( posterior) of the cervical spine. The disc between the spinal bones is often times removed and replaced with a bone graft or a spacer. The neck of composed of 7 boney building blocks that are numbered from 1-7. The letter C is associated with the numbers to designate the cervical spine. Hence the bones in the neck are C1 through C7. Sandwiched between neck bones are important shock absorbers called discs. A cervical fusion surgery removes…

Read More About Muscle Pain After Cervical Fusion Surgery

Neck Pain And Dizziness

Our body’s balancing system is compromised of three separate systems that work closely together to keep the body in balance: the eyes, inner ear, and upper cervical spine. The upper cervical spine contains and processes information about your position in space and communicates this information to your eyes and inner ears via nerves. There is a constant highway of electrical signals between the cervical spine, inner ear, and eyes that keep us upright, make us aware of our position and enable us to walk, move and run. This balancing system requires the inner ear, eyes and cervical spine to be operational…

Read More About Neck Pain And Dizziness

Pain At The Base Of The Neck And Skull

The base of the skull is a complex area.  It involves the upper cervical spine, facet joints, muscles, tendons, ligaments, and nerves.  Irritation or injury to any one of these structures can result in pain at the base of the skull.  Unfortunately, this area is not understood by many providers.  This can lead to a delay in treatment and unnecessary pain and suffering.Treatment options depend upon the underlying cause of the pain.  Conservative therapy in the form of physical therapy when appropriate is the best first-line treatment.  Steroids are often recommended but should be avoided as they are toxic to orthopedic tissue and have significant side effects…

Read More About Pain At The Base Of The Neck And Skull
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Symptoms of Chiari Malformation Type I

In Chiari Malformation Type 1 symptoms typically occur in late childhood or early adulthood. Headaches are the classic symptom for Chiari Malformation.  They are typically in the back of the head and brought on by coughing or sneezing.  A patient may also experience any of the symptoms listed above including headache and balance problems.

Symptoms of Chiari Malformation Type II

In CM Type II a larger amount of the brain extends through the Foramen Magnum into the spinal canal. Increased pressure is applied to the brain resulting in varying symptoms.
What is unique about CM Type II is its association with a form of spina bifida.  Spinal Bifida is a birth defect in which the spinal column does not form properly.  It has many different forms and presentations. Symptoms of CM Type II typically appear during childhood and typically are caused by problems associated with Spina Bifida.  These include:

Involuntary rapid eye movements

Irregular breathing

Loss of arm and leg strength.

Symptoms of Chiari Malformation Type III

Symptoms of this severe and rare condition appear at birth or in infancy. They can cause life-threatening complications.  They can also be associated with severe neurologic conditions such as seizures and delayed growth.

Causes of Chiari Malformation

Chiari Malformations are complex with different types with varying symptoms depending upon the severity of the injury.  In general, there are two principal causes of Chiari Malformations:


Otherwise known as a birth defect, these involve structural defects in the brain and spinal cord during pregnancy.


Unlike congenital causes of Chiari Malformation, these typically occur later in life.  They may be due to traumatic injury, disease, or infection.   Illness or trauma may cause an increase in the pressure within the skull.  The skull is a boney structure that is not pliable or expandable.  The opening at the base is the only outlet.  Increased pressure within the brain therefore can put downward pressure on the brain.

Common Treatments for Chiari Malformation

Chiari Malformations are classified into four major groups based upon type and severity of tissue injury.  Type 1 and 2 Chiari Malformations are the most common.  Treatment is dependent upon the type of the malformation, its severity, the amount of tissue involvement, and symptoms.


Most patients with Chiari 1 Malformation do not have symptoms or functional limitations and therefore only require regular follow-up with their providers.  Period imaging may be required along with medications to address pain and headache.


There are several surgical options depending upon the type of CM, its severity, and associated problems.  The most common surgery is called posterior fossa decompression.  It involves removing a portion of the bone at the base of the skull.   The surgery creates more space for the brain.  It doing so reduces the amount of pressure on the brain and can improve spinal fluid flow. The intended goal is to improve symptoms and function.

Cervical Fusion

Cervical Fusion is often recommended when chronic neck pain problems worsen over time. What exactly is it? Cervical Fusion is a major surgery that involves joining one or more of the spinal bones together using screws, bolts, and plates (1). The hardware may be placed in the front (anterior) or the back( posterior) of the Cervical spine. The disc between the spinal bones is often times removed and replaced with a bone graft or a spacer. The neck of composed of 7 boney building blocks that are numbered from 1-7. The letter C is associated with the numbers to designate the Cervical Spine.

Read More About Cervical Fusion

Chiari Decompression Surgery

Chiari Decompression surgery can also called a Posterior Fossa Decompression or Craniectomy.  The Cranium is that part of ther skull that contains the brain.  Chiari Decompression surgery involves removing a bone at the base of the skull so as to widen the boney opening at the base of the skull.  This opening is called the Foramen Magnum. The decompression surgery has four principal goals: create more space for the brain, slow or stop the progression of symptoms, relieve compression of the cerebellum and brainstem, restore normal cerebral spinal fluid flow. The Dura is one of three layers of connective tissue that…

Read More About Chiari Decompression Surgery


The other day I was evaluating a patient and reviewing the treatment options for their spine condition.  After discussing prior treatments, we got to the topic of medications taken for pain relief. She explained that she mainly utilized anti-inflammatory (NSAID) medications and then she told me to hold much she takes and has been for many years…..she takes close to 2 grams (2000 milligrams) on a daily basis which equated to about 9-10 capsules of medication per day.  I was shocked, considering she was pre-diabetic and with high blood pressure plus the kicker of it is that her PCP (primary care physician) is ok with this…

Read More About NSAIDs

Occipital Cervical Fusion

An Occipital Cervical Fusion also known as Occipitocervical Susion is a Major Surgery. It is not a routine operation and is a challenging procedure due to complex anatomy of the upper neck. The procedure involves rods, plates and screws that are placed into the Cervical Spine and Occiput. A plate secured by screws are placed at the base of the Occiput. Screws are also placed into one or more Cervical bones. Rods then connect the Occipital plate to the Cervical screws as shown below. The goal of Occipital Cervical Surgery is a boney fusion between the skull and neck and to relieve…

Read More About Occipital Cervical Fusion

PICL Procedure

CCI stands for cranial cervical instability which means that the ligaments that hold the head on are too loose. To help that problem, we developed a new procedure called PICL which stands for Percutaneous Implantation of the CCJ Ligaments. This is still an investigational procedure that has already changed many lives and helped patients avoid a complication-laden upper cervical fusion. Given the interest in the PICL procedure from patients who have CCI, there are lots of questions. Since the procedure isn’t yet covered by insurance, a few have asked why it costs more than their co-pay and deductible if they decide to have a more invasive cervical fusion.

Read More About PICL Procedure

Diagnosis and Examination

Many patients with Chiari malformation have NO symptoms and their malformation is only discovered during the evaluation and treatment of another disorder.

There are a number of tests that can help diagnose and determine the severity of the malformation. The most common includes:

Magnetic Resonance Imaging (MRI)

A powerful imaging tool that uses a strong magnetic field, magnetic field gradient, and radio waves to create 3-D images of the body. The brain, Cerebellum, Brainstem, and spinal fluid are easily visualized and evaluated.

Computed Tomography Scan (CT)

Another powerful imaging tool that uses x-ray.  Multiple x-rays are taken at different angles to provide detailed imaging.

Sleep Study

A dedicated study where your breathing, snoring, level of oxygenation, and seizure activity is closely monitored and recorded.  Lack of breathing called apnea is also evaluated.

Swallowing Study

A specialized x-ray procedure that watches the swallowing process to determine if any lower brain dysfunction is present.


Other Conditions Associated with Chiari Malformations

Chiari Malformation is a collection of conditions characterized by abnormal bulging or descent of the cerebellum and or brain stem through a boney opening at the base of the skull called the foramen magnum.  There are other conditions associated with Chiari malformations which include:

Tethered Cord Syndrome

A tethered cord syndrome is a group of neurologic disorders that occur as a result of chronic traction on the spinal cord due to it’s being “tethered” or held by various structures.

Spinal Curve

Spinal curvature is common and may involve curving of the spine to the right or left which is called Scoliosis.  Another form is where one is abnormally bent forward which is called Kyphosis.  There may also be rotational curving of the spine which is called Rotatory Scoliosis.


Hyrdocephalus is a medical condition characterized by an excessive buildup of cerebral spinal fluid in the brain. If left untreated the condition can become life threatening.  This can occur with CM as it blocks the flow of cerebral spinal fluid which then backs up into the brain.


This is a medical condition characterized by a fluid-filled cyst within the spinal cord.  It is oftentimes called a Syrinx.  If expanding, the Syrinx can damage the spinal cord and compromise the nerves, and transmitted information from the brain to the rest of the body.

Treating Chiari Malformations and Associated Symptoms

Many patients with Chiari Malformations have no signs or symptoms. The list of symptoms associated with Chiari Malformation is extensive.   Oftentimes the symptoms are not unique to Chiari Malformations.  For example, neck pain is a common complaint but can arise from a number of different clinical conditions other than CM.  So too with headaches.  It is critical that a thorough and extensive evaluation be completed.  Evaluation of all possible sources of a given complaint must be examined.

Many of these symptoms associated with Chiari Malformations and how they are interrelated is poorly understood by many medical providers.  What is worse is many are simply not interested nor have sufficient time to put together all the pieces. All too often patients with headache, neck pain and other mild neurologic symptoms are dismissed as drug seekers or as having emotional and psychological issues.

At the Centeno-Schultz Clinic, we are experts in the evaluation and treatment of neck and head pain.  At a new patient, evaluation time is dedicated to reviewing past medical history, current symptoms, alleviating and aggravating factors, current radiographic imaging in addition to performing a thorough evaluation.  Rather than treat symptoms, we focus on establishing an accurate diagnosis so that a successful treatment plan can be developed.  Patients with Chiari type 1 Malformations for example may have neck pain for reasons other than the CM.  Neck pain can arise from many different sources including:

  • Tight or dysfunction muscles
  • Ligament instability
  • Facet injuries
  • Disc injuries
  • Compressed nerves
  • Craniocervical Instability (CCI)

To learn more about the Craniocervical instability please click on the link below

In Conclusion

Under normal circumstances, the Cerebellum and Brainstem reside at the base of the skull.

Chiari Malformation is a medical condition where a part of the brain bulges through a normal opening at the base of the skull.  This boney opening is called the Foramen Magnum.

This creates abnormal pressure on the lower brain, restricts spinal fluid flow, and causes a variety of symptoms.

Chiari Malformations are categorized into four major types based upon the anatomical abnormality and whether birth defects are present.

Many patients with Chiari Malformations have NO signs or symptoms.

Symptoms of Chiari Malformations include:

  • Headaches
  • Neck Pain
  • Dizziness
  • Ringing in the ears
  • Arm and leg weakness

Chiari Malformations can be due to birth defects or secondary causes such as trauma, disease, or infection.

Treatment of Chiari Malformations depends upon the type of malformation, the severity of tissue injury, and symptoms. Most patients with Chiari Type 1 Malformation do not have symptoms or limitations.

Other conditions associated with Chiari Malformations include Tethered Cord, Spinal Curve, Hydrocephalus, and Syrinx.

There are many causes of neck and headache other CM.  Not all headaches and neck pain in patients with CM type 1 are due to malformation.  The upper cervical spine is complex and requires a dedicated and compassionate team of experts to clearly establish an accurate diagnosis.

If you or a loved one have ongoing neck, headache, and dizziness that has not responded to conservative treatment, please schedule a telephone candidacy discussion with a board-certified, fellowship-trained physician. At the Centeno-Schultz Clinic, we are experts in the evaluation and treatment of upper neck injuries.  From the comfort of your home or office learn what treatment options are available for you.

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Our Doctors Who Treat Chiari Malformations

Christopher J. Centeno, MD

Christopher J. Centeno, M.D. is an international expert and specialist in Interventional Orthopedics and the clinical use of bone marrow concentrate in orthopedics. He is board-certified in physical medicine and rehabilitation with a subspecialty of pain medicine through The American Board of Physical Medicine and Rehabilitation. Dr. Centeno is one of the few physicians in the world with extensive experience in the culture expansion of and clinical use of adult bone marrow concentrate to treat orthopedic injuries. His clinic incorporates a variety of revolutionary pain management techniques to bring its broad patient base relief and results. Dr. Centeno treats patients from all over the US who…

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John Schultz, MD

John R. Schultz M.D. is a national expert and specialist in Interventional Orthopedics and the clinical use of bone marrow concentrate for orthopedic injuries. He is board certified in Anesthesiology and Pain Medicine and underwent fellowship training in both. Dr. Schultz has extensive experience with same day as well as culture expanded bone marrow concentrate and sees patients at the CSC Broomfield, Colorado Clinic, as well the Regenexx Clinic in Grand Cayman. Dr. Schultz emphasis is on the evaluation and treatment of thoracic and cervical disc, facet, nerve, and ligament injuries including the non-surgical treatment of Craniocervical instability (CCI). Dr. Schultz trained at George Washington School of…

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More Resources

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    The knee joint is the largest compound synovial joint of the human body. The joint has bones, cartilage, muscles, and bursae that are held together by ligaments and tendons. Damage to any of these structures can give rise to knee pain. The location of knee pain can be very telling, and can help narrow down…

  • Craniocervical Instability and Vagus Nerve Compression

    Craniocervical instability (CCI) occurs when the supportive muscles and ligaments in the upper cervical spine become ‘loose’ or ‘lax’. The importance and complexity of the vagus nerve is highlighted in its name. Vagus is the Latin word for ‘wandering’ and, as the name suggests, the vagus nerve travels widely throughout the body, resembling the root…

  • Transverse Cervical Artery

    The transverse cervical artery (TCA) is a branch of the thyrocervical trunk, which itself is a branch of the first part of the subclavian artery. These arteries are part of the larger arterial network that supplies blood to the head, neck, and upper limbs. Understanding the anatomy and function of arteries like the TCA is…

  • Everything You Need to Know about Hip Ligaments

    The hip joint is a large ball and socket joint that’s important for lower extremity movement. The joints consist of the articulation of the femur (upper thigh bone/ball) and the acetabulum (the socket). The bones are lined with cartilage and the acetabulum is lined with a fibrocartilage called the labrum. The hip joints, as with…

  • Neck X-Ray

    The neck is a vital and complex part of the human anatomy, supporting the head and facilitating essential functions like movement, breathing, and communication. When neck pain, injuries, or other symptoms arise, healthcare providers often turn to diagnostic tools such as neck X-rays to assess the condition of the cervical spine and surrounding structures. Healthy…

  • Why Does My Neck Hurt?

    Neck pain can result from various factors, including poor posture, muscle strain, injury, or underlying medical conditions. It can be treated effectively when diagnosed properly. Treatment options may include physical therapy, pain management, exercise, and lifestyle changes to address the root causes of the pain and significantly improve your comfort and quality of life. If…

1.Fernández AA, Guerrero AI, Martínez MI, et al. Malformations of the craniocervical junction (Chiari type I and syringomyelia: classification, diagnosis and treatment). BMC Musculoskelet Disord. 2009;10 Suppl 1(Suppl 1):S1. Published 2009 Dec 17. doi:10.1186/1471-2474-10-S1-S1

2.Shah AH, Dhar A, Elsanafiry MSM, Goel A. Chiari malformation: Has the dilemma ended?. J Craniovertebr Junction Spine. 2017;8(4):297-304. doi:10.4103/jcvjs.JCVJS_138_17

3.Abd-El-Barr MM, Strong CI, Groff MW. Chiari malformations: diagnosis, treatments and failures. J Neurosurg Sci. 2014 Dec;58(4):215-21. PMID: 25418275.

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