Review Question - QID 740

The clinical presentation is consistent with a left thoracic curve with abnormal abdominal reflexes and therefore an MRI is indicated to look for abnormalities of the neural axis such as Chiari malformations and syringomyelia. One should recognize that right thoracic curves are more commonly seen in idiopathic scoliosis.

Spiegel et al performed a a retrospective radiographic review on 41 patients with scoliosis associated with a Chiari I malformation and/or syringomyelia. Approximately 50% of patients had an "atypical" pattern (left thoracic, double thoracic, triple, long right thoracic). They recommend that MRI should be considered in these patients.

Yngve et al reviewed the sensitivity of abnormal abdominal reflexes on physical exam. They found the finding of abdominal reflexes consistently present on one side and consistently absent on the other side did not occur in normal subjects. They recommend further workup with an MRI if found in a patient with scoliosis.

Illustration A shows the MRI of the patient presented in this question. It shows a large syringomyelia with dilatation in the lower cervical and upper thoracic area. Also noted was an Arnold-Chiari malformation. This patient was referred to a neurosurgeon and treated with a posterior fossa decompression.