Arnold Chiari One Malformation

By Agnes Starr, RDH, BS

Arnold what? Arnold Chiari One malformation is a serious neurological disorder where the bottom portion of the brain (the cerebellum) descends out of the skull (foramen magnum) and puts pressure on the brain and spinal cord. The herniated tissue blocks the cerebrospinal fluid in the brain and can lead to the formation of a cavity (syrinx) within the spinal cord. Chiari with the formation of a syrinx is known as Syringomyelia. Chiari was believed to affect approximately 1 in 1000 people. With the increased availability of magnetic resonance imaging, the number of reported cases has risen sharply and current estimates range from 200,000 to 2 million Americans with the condition. There is no cure for Chiari and surgery is usually the only option in treating the disorder in symptomatic patients. The surgery is invasive and involves removing part of the skull, vertebrae, and cutting into the dura covering the brain to release the cerebrospinal fluid.

How does it affect our patients and our treatment?

Symptoms of Chiari are many and vary from individual to individual. Our job is to keep the patient comfortable, recognize contraindications, be aware of conditions associated with Chiari, and symptoms that could affect treatment.

Symptoms: Most common are pain in the head upon coughing, sneezing, laughing, bending over, or looking up. Headache, neck pain, trouble swallowing, lack of or increased gag reflex, dizziness, vertigo, impaired balance, chronic nausea, vague pains throughout the body, poor memory, frequent urination, irritable bowel syndrome, ringing in ears or sensitivity to sounds, sensitivity to light, double vision, and the list goes on.

Related conditions: According to world renowned neurosurgeon, Dr. Paolo Bolognese, of the Chiari Institute in Great Neck, NY; patients with Chiari often have micrognathia (undersized jaw), overbite, and abnormal TMJ biomechanics. He finds that 18% of CM1 patients have Ehlers-Danlos Syndrome (EDS), in which enamel and gums are compromised. In rare cases, EDS X, problems with blood clotting can occur.

Contraindications: Patients with Chiari should avoid prolonged neck hyperextension while in the dentist chair. Prolonged hyperextension can exacerbate symptoms. Also fixed metal appliances such as braces may have to be put on hold or removed before necessary MRI imaging is performed.

Recommendations: When treating patients with Chiari you want to acknowledge the seriousness of their condition and tell them to let you know if they are uncomfortable and you will try your best to accommodate them. Many have a fear of the dentist knowing they will have to extend their neck for prolonged periods. A neck pillow or rolled up towel can help relieve pressure under the neck. Be patient and allow time for breaks. Leaning the chair back too far may cause pressure in the head or leaning the chair back too fast may affect dizziness and vertigo. You may want to let the patient sit up a minute before getting out of the chair to gather their bearings. Trouble swallowing and gag reflex may affect the use of a cavitron for prophy’s and you may want to handscale unless the patient can tolerate the water. Keeping a pair of sunglasses in the operatory for patients with light sensitivity can also aid in making the visit more tolerable. Disposable ear plugs can also help those with sensitivity to sounds and ear ringing.

Conclusion: I felt it was important to bring awareness to this condition after I was diagnosed myself. I do not remember ever hearing about this disorder in hygiene school, not in anatomy I, II, our labs, head and neck anatomy or pathology class. I did a lot of research after being diagnosed and found many informational web-sites and support groups. On the support groups I found people asking for advice and support on how to approach their dentist and explain the condition. Some didn’t want to go back after having a painful visit which aggravated their symptoms. As a hygienist I was dismayed to hear this and saw a need for greater awareness.
For more information, click here, here, here, or here.