Comparison of Brain Morphology for Chiari I Malformation Subjects With and Without Ehlers-Danlos Syndrome. Talk presented at the second international CSF Flow meeting.

Click through to conference website.

Click through to conference website.


2nd Annual CSF Flow Meeting


Background. Many patients with Chiari malformation type I (CM) also have Ehlers-Danlos syndrome (EDS). EDS is characterized as a connective tissue disorder with patients diagnosed demonstrating joint hypermobility and recurrent joint dislocations. Our Chiari1000 database shows that 9.4% of the CM subjects also have EDS (CM+EDS).  In addition, 26% score high (>4) on a hypermobility index (Beighton Scale). While there are differences between the biomechanical properties of connective tissue for people with CM+EDS and CM without EDS (CM-EDS), it is unclear if this translates to differences between brain morphology for CM+EDS compared to CM-EDS.

Methods. Midsagittal morphological characteristics of CM+EDS patients were evaluated by comparing 50 morphological measurements (MMs) within the intracranial and craniocervical regions on 245 adult female CM subjects with (n=31) and CM-EDS (n=214). Morphological differences were determined using a two-tailed independent t-test and a Mann-Whitney u-test.

Results. Cerebrospinal fluid area (CSF) below the foramen magnum anterior and posterior to the brainstem was 14% and 24% larger respectively in CM+EDS compared to CM-EDS (p < 0.001, Cohen’s d > 0.5).  Average tonsillar position was smaller for CM+EDS compared CM-EDS (5.3 and 7.8 mm, respectively with p < 0.05, Cohen’s d > 0.47). However, 35 of the 50 MMs showed less than 3% difference between the two groups.

Discussion and Conclusions. While most of the 50 MMs were not different between CM+EDS and CM-EDS groups, a trend was observed of reduced crowding in CM+EDS patients within the craniocervical region compared to CM-EDS. Overall, the morphometrics for CM+EDS subjects was not markedly different when compared to CM-EDS cases.


Maggie S. Eppelheimer, Dipankar Biswas, Jayapalli Rajiv Bapuraj, James R. Houston, Dorothy M. Loth, Richard Labuda, Philip A. Allen, Francis Loth