What is a Chiari Malformation?
Chiari Malformation is an abnormal crowding at the base of the brain and in the brainstem, which results in the downward displacement of some of the brain's structures into the foramen magnum (the hole that exits the skull) and the spinal canal. Two of the lower parts of the brain are called the cerebellum and brainstem. The brainstem is the area inside the base of the skull, which transitions into the spinal cord. Just behind the brainstem, the cerebellum is made up of three major lobes which are composed of nerve fibers connecting to the brainstem. There are two small portions of cerebellar tissue, called the cerebellar tonsils, which normally lie within the posterior fossa of the skull.
While we are not doctors, this post discusses the topic of Chiari Malformations in peer reviewed medical journal articles and medical textbooks. For an evaluation, diagnosis and treatment options please consult with a licensed doctor in your area.
In 1891, Austrian Doctor Hans Chiari first identified the Chiari Type I malformation. What is now called a “Chiari Malformation” occurs when the area at the base of the skull (posterior fossa) and the hole that exits the skull into the spinal canal (the foramen magnum) is not properly formed and the brainstem, instead of sitting properly above the posterior fossa, is displaced downward, causing pressure on the lower part of the brain and the brain stem. There is also an obstruction of the normal flow of cerebral spinal fluid through this area because the cerebellum is stuffed into the foramen magnum, the main passage from the skull into the spinal canal.
For lack of a better description, this is like shoving part of the brain into the suction of a hole the size of a bathtub drain. In its most extreme form, this pressure (like the suction of a drain) can cause a “tonsillar herniation” or “downward cerebellar herniation” of the cerebellum into the foramen magnum, which is one type of brain herniation.
Chiari Malformations caused by Trauma
Historically, doctors have incorrectly believed that Chiari Malformations were never caused by trauma. That belief has now been discredited by scientific studies and new diagnostic imaging technology.
A traumatically induced condition, alternatively referred to as an “acquired Chiari” “Chiari II” or “traumatic tonsillar ectopia” are used for this condition in the medical literature. The medical literature now recognizes that Chiari Malformations can be caused by trauma, but most insurance defense doctors will not admit to that. The Portland personal injury lawyers at DeShaw Law Firm have experience handling litigation cases involving acquired Chiari Malformation caused by trauma such as auto or trucking collisions.
Information on Chiari Malformations
Chiari Malformations are usually described as Type I which consists of a downward displacement of the cerebellar tonsils out of the inferior opening of the skull into the spinal canal.
Type II malformations have greater displacement of brain structures into the spinal canal. In addition to the cerebellar tonsils, there is also displacement of the inferior vermis.
It is not unusual for the Chiari Malformations to have an associated accumulation of fluid, or increased pressure within the interior of the spinal column. This can cause a condition in which cerebral spinal fluid is forced into the spinal cord, creating a tear, or a fluid filled hole called a syringomyelia.
The most frequent symptoms of Chiari Malformation include headache with pain at the base of the skull and upper neck, progressive scoliosis, cerebral dysfunction (difficulty with balance, coordination, disequilibrium) and where there is compression of the lower brainstem, there can be an alteration in voice, frequent respiratory tract infections and coughing when swallowing foods and fluids.
The historical (and outdated) belief is that a Chiari Malformations was that the malformation was present at birth. [It has been suggested that during early embryo development of the brainstem and spinal cord, the malformation occurs.] While this condition may be non-symptomatic in many people, it can, over time, become symptomatic. It is noteworthy that Chiari I malformation occurs more often in women than in men.
While it is generally believed that Chiari Malformation occurs at birth, recent scientific research has shown that this condition, which may be non-symptomatic, can become symptomatic due to trauma. Also, there is a body of literature that recognizes that Chiari Malformation may be acquired as opposed to congenital.
One of the leading studies on the effects of trauma and Chiari Malformation found that 25 percent of the patients cited trauma as the precipitating factor for their symptoms. The most common mechanisms were whiplash injuries from auto accidents and trucking accidents, as well as direct blows to the head and neck. This finding raised the possibility that certain types of trauma accentuate tonsillar impaction or result in subarachanoid hemorrhage that destabilizes a marginally compensated CSF system.
This study was important as patients with traumatically symptomatic Chiari I malformation had found it exceedingly difficult to obtain reimbursement from auto insurance companies despite the onset of symptoms being caused by their collision. While insurers continue to attempt to mislead juries about the connection between trauma and Chiari Malformation, a number of studies have followed confirming that trauma can cause a traumatic chiari malformation or “tonsilar ectopia.”
Traumatic Chiari Malformation Lawyers
If you or a loved one have been sustained a traumatic chiari malformation, please contact DeShaw Law Firm today. We handle Chiari Malformation injury cases in Oregon and Washington, and will put our extensive resources and experience to work for you. Our attorneys will work hard to obtain the compensation necessary for you and your family against the party responsible for your injuries. Contact us for a free consultation at (503) 227-1233 to determine how you can receive compensation for medical treatment, lost wages, and physical pain and suffering as well as for changes in your quality of life.
Chiari Malformation Symptoms
Symptoms from the Chiari Malformation often develop in a slow and insidious manner. They do not happen immediately after trauma, as many insurance doctors will testify. Frequently, the symptoms are vague and progress over a number of years. Many people have symptoms for years before they are properly diagnosed. Some people develop symptoms after physical trauma. Examples include auto accidents, trucking accidents, or a blow to the back of the head.
Headaches
The most common symptom of the Chiari Malformation is headache. It usually begins at the back of the head and radiates behind one or both eyes to the top of the head or to the temples. The headache is often described as a pressure sensation but can be heavy, sharp or stabbing. For many, the pain varies between these and other sensations.
The headache is often made worse by straining activities (known as valsalva maneuvers) such as coughing, sneezing or even laughing or singing. Some patients report feeling as though "my head will explode" or "my head will pop off." Bending forward or looking up can worsen the headache. When the headache is intense, some patients note dizziness, blurring of vision, nausea or a feeling of being in a "mental fog."
Visual Symptoms
A variety of visual symptoms can occur with Chiari Malformation including double vision, decreased peripheral vision, seeing flickers of light ("fireflies"), visual loss, blind spots, photophobia (sensitivity to light), spasm of the eyelids (blepharospasm) and jerking of the eyes (nystagmus).
Dizziness & Auditory Symptoms
Dizziness is frequently seen in persons with Chiari Malformation. It is usually intermittent, often worse with the headache, and more noticeable when changing position. A sensation of spinning (vertigo), ringing in the ears (tinnitus), poor balance (disequilibrium) and decrease or loss of hearing may also occur.
Difficulty Swallowing & Hoarseness
People with Chiari Malformatino may develop difficulty swallowing (dysphagia), either with liquids or solid foods, or a feeling of "catching" in the throat when attempting to swallow. The progression of dysphagia may be rapid and result in aspiration (inhaling fluid or food products into the lungs). Change in voice character and timber are common complaints. Hoarseness is often noted first by a family member or friend. Some patients report the inability to modulate voice when singing or speaking loudly.
Pain
Persons may complain of neck or arm pain. Often the pain is worse with exertion, fatigue, or lifting. The pain may be dull and aching, or shooting and stabbing. It is usually present or worse on one side. Along with pain, some patients experience weakness of the hand or arm, or difficulty with fine movements of the fingers. If syringomyelia is present, the pain may be more widespread.
Numbness
Tingling, numbness, or pins and needles sensation often occur in the same areas as the pain. Numbness can progress over months to years and involve the lower extremities and trunk. These symptoms are usually more noticeable if a person has a syringomyelia (also called syrinx).
Problems Walking
Problems walking may be described as unsteadiness or listing to one side. Persons may report falling or bumping into walls or doors. Infrequently, patients may have spasticity (stiffness and jerkiness) of the legs, which occurs more commonly with syringomyelia.
Respiratory, Heart & Abdominal Symptoms
Effects of the Chiari Malformation on the respiratory and cardiovascular systems can cause shortness of breath, chest pain, episodes of rapid heart rate (tachycardia), black out spells, and hypertension. Abdominal symptoms may include nausea, abdominal pain, or vomiting.
General & Cognitive Symptoms
These include poor sleep (insomnia), fatigue and depression. Some note problems with memory, thinking, speech and difficulty with word finding. People may report the feeling of a "brain fog" with difficulty in thinking and concentration. Difficulty in finding the right word may occur.
Evaluation of a Chiari Malformation
Advanced Medical Imaging Studies
Chiari malformations are now definitively diagnosed by advanced diagnostic imaging using different studies performed on an MRI machine.
MRI Evaluation of Chiari Malformation
An MRI (Magnetic Resonance Image) of the brain and/or cervical spine is the test of choice for diagnosis of Chiari Malformation. An MRI scan creates an anatomical picture of the brain and spinal cord. In Chiari Malformation it can show the degree of crowding at the large opening at the bottom of the skull (called the foramen magnum). The MRI can show compression and/or distortion of the cerebellar tonsils, and can also analyze the shape and changes in the bony structures skull and upper cervical spine.
An MRI of the spine can also show the presence of syringomyelia (the collection of abnormal fluid in the spinal cord). Additional information about syringomyelia can be found under the realted disorder section. Tethered cord can be diagnosed with an MRI of the lumbar spine (read more under related disorders section).
A CINE flow study is an MRI study that evaluates the flow of spinal fluid through the area of the foramen magnum. The CINE MRI is performed in the MRI scanner- the same as a regular MRI. The test takes about 30 minutes. In some cases, the CINE shows obstruction of flow through the area.
Additional studies may be recommended, such as plain x-rays of the spine to show bone structure, or a 3-dimensional CT scan of the skull.
CSF Flow Studies or MR Ventriculography Study of CSF in Chiari Malformation
A “CSF Flow Study” or “MR Ventriculography Study of CSF” is an MRI of the brain or spine that evaluates the flow of cerebrospinal fluid around the brain, brainstem and/or spinal cord.
An Cerebral Spinal Fluid (CSF) Flow Study is an important tool that allows neuroradiologists to measure the velocity of cerebral spinal fluid as it flows from the cerebral ventricles (fluid reservoirs) inside the brain, down to the skull base via the cerebral aqueduct, and to the spinal canal via the fourth ventricle and foramen magnum. Cerebral spinal fluid is continually produced within the center of the brain, and is continually reabsorbed at a number of locations along the surface of the brain. CSF is circulated by movement of the body with cranial and cervical motion at the top part of the body, and the sacrum at the lower end of the spinal column. There are a number of injuries, that can significantly alter the normal flow of CSF. These changes are visible via the CSF waveform obtained through the MRI study. Abnormal CSF flow is seen with Chiari Malformations.
Neurologic Examination for Chiari Malformation
While diagnostic imaging shows most Chiari Malformations, it is helpful to also have a thorough neurologic examination. This allows a neurologist, neurosurgeon or other physician in making the diagnosis, but also helps determine the symptoms of the Chiari Malformation.
Treatment for Chiari Malformation
This page is not intended to provide medical advice. It should not be used in making treatment decisions for any condition. All medical diagnosis, advice and treatment methods must be decided and provided by a licensed doctor in your state. If you believe you have a Chiari malformation, please consult with a doctor in your state for examination, diagnosis and effective treatment options.
The following are common forms of treatment for Chiari Malformation based upon peer reviewed medical studies:
Decompression Surgery for Chiari Malformation
The procedure most commonly performed in patients with Chiari Malformation is a posterior fossa decompression, which is accompanied by reconstruction: the dura is opened and grafted. The surgery is customized for each patient based on an analysis of the morphology (shape and form) of the skull, neurological tissues and the findings during surgery.
During surgery, the patient is asleep under general anesthesia. An area of hair about two inches wide is shaved at the back of the head. An incision is created from the occipital area at the back of the head to upper neck. Bone is removed at the base of the back of the skull and from the back part of the cervical one (C1) vertebrae. In rare case, the lamina (roof bone) of C2 is also removed.
Once the bone in this area is removed, a tough membrane, called the dura matter, is seen. Ultrasound is then performed (called color doppler-ultrasonography), to show the tonsils, the degree of crowding, and most importantly, the location of the blood vessels in the area. This helps guide the opening of the dura membrane.
Once the dura membrane is opened, the position of the tonsils and the degree of crowding is assessed. In patients with a syrinx, it is important to look between the tonsils and make sure that a drainage path for spinal fluid, the foramen of Magendie, is open. Sometimes a thin veil is found over the foramen that must be opened to free spinal fluid flow.
In some cases, marked crowding is present despite the opening of the dura. In these cases, the tips of the cerebellar tonsils are shrunk with electrocautery, which is applied with a fine pincer forceps. No specific side effects have been described from this shrinkage. The important point is to create more room in the area, remove the crowding, and allow for normal flow of spinal fluid.
Next, a patch of tissue is sewn to the edges of the open dura to enlarge the dural sac. The patch material, called pericranium, is tissue obtained from underneath the scalp in the area just above the bony removal.
Once the patch is sewn in, a customized titanium plate is attached to the edges of the bony resection by very small titanium screws. The muscles that were previously attached to the bone in this area can now be stitched to the plate. This union allows for natural reconstruction and helps avoid the sunken defect that some people develop after posterior fossa decompression surgery.
Lastly, the tissues are closed with stitches. Staples are used to close the skin.
Chiari Malformation FAQ
Can a Chiari Malformation occur in people who are not born with the deformity?
Yes. This is called “acquired Chiari Malformation,” “secondary Chiari,” “Chiari II” or “traumatic tonsilar ectopia” and it can be caused by trauma from car accidents, trucking accidents and other traumatic injuries, which causes the brain to swell.
Does a Chiari Malformation cause disability?
Yes. Chiari I Malformation can cause temporary and permanent disabilities that are dependent on the individual. In legal cases the pre-existing condition is called a “prior infirm condition.” The fact that the person who injured you didn’t know that you had the Chiari malformation when they hurt you does not matter – they are responsible for the full extent of your injuries. That is what the law says in every state, and it is a basic rule of law in the United States. Someone who injures you shouldn’t be able to avoid personal responsibility for the consequences of their actions just because you were medically susceptible to a more serious injury.
Symptoms of trauma to someone with a Chiari Malformation may not be easily resolved, even with a surgery, and may take time and effort on the part of the injured person, and healthcare professionals. Ultimately, the goal is to solve the problems as well as possible so that you can get back to a normal lifestyle. Unfortunately, this is not always possible.
If Chiari Malformation is present at the time of birth, why do symptoms show up so much later?
This is still largely unknown. It may be that the nervous system can still function with certain amounts of pressure, on the brain and brain stem. But, with injury, and increased pressure on these structures, it makes the condition symptomatic. The scientific literature demonstrates that while the condition may be present since birth, many people report symptoms of Chiari Malformation only after an injury such as a motor vehicle accident, trucking accident or fall.
Why does crowding of the brain stem and cerebellum in the Foramen Magnum and poor Cerebrospinal Fluid (CSF) circulation cause symptoms?
The Cerebrospinal Fluid or “CSF” surrounds the brain and spinal cord and provides protection for the delicate nervous system structures, and circulates around them constantly. Most of the symptoms of Chiari Malformation can be attributed to obstruction of spinal fluid flow or compression of the lower brainstem and cranial nerves.
Hiring the Best Lawyer for a Chiari Malformation Claim
If you are looking for the best lawyer for a traumatic Chiari Malformation claim, it is important to understand that few personal injury lawyers will understand this injury. Our background with this injury is the result of our lead lawyer, Aaron DeShaw, being a former Doctor of Chiropractic who completed a 4000 hour doctorate degree before becoming a trial lawyer. It is closely related to our primary field of legal practice as traumatic brain injury lawyers.
When personal injury cases are highly complex, lawyers in Oregon, Washington and other states will refer the case to our firm. But you should choose our firm from the beginning or we may not be able to take over your case unless your lawyer is willing to allow you to move your case.
Traumatic Chiari Malformation is a much less common injury after trauma than spinal injuries such as a herniated disc, facet injury or spinal fracture. For this type of case you should be looking for a Portland spinal injury lawyer who has extensive experience and education in the most complex spinal injury cases.
If you or a loved one have been sustained a traumatic chiari malformation, please contact DeShaw Law Firm today. We handle Chiari Malformation injury cases in Oregon and Washington, and will put our extensive resources and experience to work for you. Our attorneys will work hard to obtain the compensation necessary for you and your family against the party responsible for your injuries. Contact us or call (503) 227-1233 for a free consultation to determine how you can receive compensation for medical treatment, lost wages, pain and suffering, as well as changes in your quality of life.
Research on Traumatic Chiari Malformations
Scientific studies demonstrating that Chiari Malformation can be caused by trauma are found in the following articles, and many more:
- Brain Inj. 2010;24(7-8):988-94. A case-control study of cerebellar tonsillar ectopia (Chiari) and head/neck trauma (whiplash.) Freeman MD, et al.
- Neurosurgery. 2008 Oct;63(4):748-53; discussion 753. Conversion to symptomatic Chiari I malformation after minor head or neck trauma. Wan MJ, et al.
- J Bone Joint Surg Br. 2009 Aug;91(8):1103-4. Simple whiplash? Uzoigwe CE et al.
- Neurol Clin. 2004 Feb;22(1):229-36. Tonsillar ectopia and headaches. Arnett BC
- J Neurosurg 1995 Sep;83(3):556-558 Acquired Chiari Malformation and syrin associated with bilateral chronic subdural hematoma. Case report. Morioka T, et al.
- J Neurosurg 1998 Feb;88(2):237-242 Acquired Chiari I malformation secondary to spontaneous spinal cerebrospinal fluid leakage and chronic intracranial hypotension syndrome in seven cases. Atkinson JL, et al. Department of Neurological Surgery, Mayo Clinic.
- Pediatr Neurosurg 1995;22(5):251-254 Acquired Chiari-I malformation and hydromyelia secondary to a giant craniopharyngio. Lee M, Rezai AR, Wisoff JH.
- "Acquired" Chiari I malformation. Case report. Huang PP, Constantini S. Department of Neurosurgery, New York University Medical Center, New York.
- Acta Neurochir (Wien) 1998;140(5):417-27; discussion 427-8. The acquired Chiari Malformation and syringomyelia following spinal CSF drainage: a incidence and management. Johnston I, et al. Department of Neurosurgery, New Children's Hospital, Australia.
- Neurology, v.30, #5, 758 (1992).4 W.C. Clivero and D.H. Dinh, A Case of a Temporary ACM/Syrinx, 28 year old female with a car accident head injury - when the injury healed the ACM/syrinx disappeared.