In this case report,1 the authors describe the case of a 27-year-old woman who sustained a minor injury to her neck in a low energy motor vehicle accident. Note that at the time of her initial injury no advanced imaging was obtained, no abnormal neurological findings were identified, and she was counselled and brought back for routine follow-up. Just prior to her follow-up she has another low energy neck injury while driving her car. She describes increasing pain and new symptoms of paresthesiae in the left upper extremity. At this time an MRI is obtained which demonstrates a type I Arnold-Chiari malformation. On this basis the patient is sent for neurosurgical consultation with an eye towards foramen magnum decompression.
The authors make an important point that it is important for the orthopaedic surgeon evaluating patients with trauma to the cervical spine to be aware of craniocervical abnormalities such as an Arnold-Chiari malformation. However, in many patients such an observation may be an asymptomatic `incidental finding’. Furthermore, type I Arnold-Chiari malformations are often followed and do not need surgical decompression. Although there have been reports in the neurosurgery literature of patients becoming symptomatic from their Arnold-Chiari malformations2,3 it is not clear in this case report whether the new symptoms in the left arm which develop after the second accident are directly related to the Arnold-Chiari malformation. It should be kept in mind that following cervical spine trauma and whiplash type mechanisms, patients will often develop upper extremity paresthesiae in the absence of compressive or craniocervical pathology. The presence of increased tone is not unusual in a young lady, and it is not clear from the serial examinations that this was different to that at the time of her initial presentation approximately two months earlier. Furthermore, there is no documentation of other physical findings such as abnormalities in gait or the presence of a Hoffman’s or Babinski sign or myoclonus at the ankle, all of which are other important stigmata associated with ongoing spinal cord compression and dysfunction.4
While this paper provides an important reminder to orthopaedic surgeons that craniocervical pathology can be associated with neurological findings that might be associated with an injury to the cervical spine, it also is a reminder that many radiological findings may be incidental and not causally related to symptoms with which a patient presents. This demonstrates once more, that it is important for orthopaedic surgeons to investigate by careful history and physical examination whether there are physical findings that can be correlated with a patient’s symptoms and thereby make a decision as to whether abnormal radiographic findings are in fact clinically relevant. In the situation of their case report, it would be important to establish through symptoms and physical findings that the patient had symptoms consistent with cervical myelopathy prior to making the assumption that the Arnold-Chiari malformation is the cause of the patient’s new left arm pain and that referral for foramen magnum decompression might be warranted.
1. Uzoigwe, CE, Shabani F, Chami, G. Simple Whiplash? J Bone Joint Surg [Br] 2009;91-B:1103-1104.
2. Wan M, Nomura H, Tator C. Conversion to symptomatic Chairi I malformation after minor head or neck trauma. Neurosurgery 2008;63:748-753.
3. Murano T, Rella J. Incidental finding of Chiari malformation with progression of symptoms after head trauma: case report. J Emerg Med 2006;30:295-298.
4. Emery SE, Bohlman HH, Bolesta MJ, Jones PK. Anterior cervical decompression and arthrodesis for the treatment of cervical spondylotic myelopathy. J Bone Joint Surg [Am] 1998;80-A:941-951.
Rothman Institute, Philadelphia, Pennsylvania, USA