Are Herniated Cerebellar Tonsils the Main Culprit of Chiari Malformation Type I Symptoms? The Brainstem Compression Hypothesis seems to be Re-Elucidated and Revised.

AIM: The Chiari Malformation I (CM I) and the tethered cord syndrome (TCS) are both congenital abnormalities whose mechanisms are still not fully understood. The association of CM I and TCS has been reported only a few times previously.

MATERIAL AND

METHODS

This retrospective study included 7 patients who were diagnosed with CM I and TCS, managed by cutting of the filum terminale.

RESULTS

The mean follow-up period was 21 months and 28 days. Although all patients underwent an untethering surgical procedure by cutting the filum terminale only, all patients reported significant early postsurgical resolution of CM I symptoms and symptoms related to TCS as well.

CONCLUSION

Patients with symptomatic CM I, even if lumbar MRI is normal and the patient asymptomatic for TCS, may have tethered spinal cord at the same time. It seems it would be worthwhile to investigate CM I patients for occult TCS with spinal somatosensory evoked potentials.