Introduction: While Chiari I malformations are well described in the literature, there are no studies that directly investigate the role of race, gender, and socioeconomics on presentations and outcomes.
Methods: The authors retrospectively reviewed the charts of 638 adult patients with the diagnosis of Chiari 1 malformation. Of these, 287 patients were included in the study. Race, gender, insurance status, individual symptoms, combinations of symptoms, depth of cerebellar tonsillar herniation, and presence of syringomyelia were examined as covariates in multivariate logistic regression models to identify independent predictors of presentation and outcome.
Results: Patients with public insurance tended to be older (P=0.01), were more likely to be African American (P<0.01), and had a longer length of stay in the hospital (P=0.01). There were a higher proportion of males who presented with upper extremity weakness (P=0.01), lower extremity weakness (P=0.040), and cranial nerve findings (P=0.02). Males also had shorter onset to diagnosis times (P=0.02), worse tonsillar herniation (P=0.03), and more severe symptoms (P=0.05). Caucasians more frequently presented with back pain (P=0.03), and African Americans more frequently presented with lower extremity weakness (P=0.01). African American patients were also found to have worse tonsillar herniation (P<0.01) and were more likely to present with syringomyelia (P=0.01). A multivariate regression analysis revealed that back pain (P<0.01), upper extremity weakness (P=<0.01), upper extremity paresthesias (P<0.01), and upper with lower extremity paresthesias (P=0.04) were significant predictors of syringomyelia. Predictors of operative intervention included typical headache (P<0.01), typical headache with upper extremity paresthesias (P=0.01), typical headache with neck pain (P=0.02), upper and lower extremity paresthesias (p=0.04), typical headache with dizziness (P=0.02), and worse tonsillar herniation (P<0.01). The only independent predictor of outcome was size of tonsillar herniation (P=0.03).
Conclusions: Significant differences in the presentation of Chiari 1 malformation due to gender, race, and insurance status were quantified for the first time.
Patient Care: Helping patients with Chiari malformations can be challenging because of uncertainty regarding how presenting symptoms may or may not relate to tonsillar herniation. It can be difficult to predict which patients might improve after surgical decompression and which ones will not. To the best of our knowledge, there have been no adult studies that examine racial or socioeconomic factors that may account for some of the variability in clinical presentation. Ideally, this study will help inform physicians when advising Chiari patients regarding presentation, prognosis, and treatment options.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) describe the importance of gender, race, and socioeconomic status on the presentation and outcomes of adult Chiari malformations; 2) discuss in small groups how these results can be explained and whether current assessment and management strategies should be altered; and 3) identify ways to improve current treatment plans for patients with adult Chiari 1 malformations
References: 1) Chiari H: Concerning alterations in the cerebellum resulting from cerebral hydrocephalus. (Translated by Radkowski A). Pediatr Neurosci 13:3–8, 1987
2) Mueller DM1, Oro' JJ. Prospective analysis of presenting symptoms among 265 patients with radiographic evidence of Chiari malformation type I with or without syringomyelia. J Am Acad Nurse Pract. 2004 Mar;16(3):134-8.
3) Meadows J, Kraut M, Guarnieri M, Haroun RI, Carson BS. Asymptomatic Chiari type I malformations identified on magnetic resonance imaging. J Neurosurg.2000;92(6):920-926
4) Aboulezz AO, Sartor K, Geyer CA, et al: Position of cerebellar tonsils in the normal population and in patients with Chiari malformation: a quantitative approach with MR imaging. J Comput Assist Tomogr 9:1033–1036, 1985.
5) Barkovich AJ, Wippold FJ, Sherman JL, et al: Significance of cerebellar tonsillar position on MR. AJNR 7:795–799, 1986
6) Kalb S, Perez-Orribo L, Mahan M, Theodore N, Nakaji P, Bristol RE. Evaluation of operative procedures for symptomatic outcome after decompression surgery for Chiari type I malformation. J Clin Neurosci. 2012 Sep;19(9):1268-72. doi: 10.1016/j.jocn.2012.01.025.
7) Klekamp J. Surgical treatment of Chiari I malformation--analysis of intraoperative findings, complications, and outcome for 371 foramen magnum decompressions. Neurosurgery. 2012 Aug;71(2):365-80; discussion 380. doi: 10.1227/NEU.0b013e31825c3426.
8) Vakharia VN1, Guilfoyle MR, Laing RJ. Prospective study of outcome of foramen magnum decompressions in patients with syrinx and non-syrinx associated Chiari malformations. Br J Neurosurg. 2012 Feb;26(1):7-11. doi: 10.3109/02688697.2011.578771.
9) Dones J1, De Jesús O, Colen CB, Toledo MM, Delgado M. Clinical outcomes in patients with Chiari I malformation: a review of 27 cases. Surg Neurol. 2003 Aug;60(2):142-7; discussion 147-8.
10) Arnautovic A1, Splavski B, Boop FA, Arnautovic KI. Pediatric and adult Chiari malformation Type I surgical series 1965-2013: a review of demographics, operative treatment, and outcomes. J Neurosurg Pediatr. 2015 Feb;15(2):161-77. doi: 10.3171/2014.10.PEDS14295.
11) Baisden J1. Controversies in Chiari I malformations. Surg Neurol Int. 2012;3(Suppl 3):S232-7. doi: 10.4103/2152-7806.98580.
12) Levy WJ, Mason L, Hahn JF: Chiari malformation presenting in adults: a surgical experience in 127 cases. Neurosurgery 12; 377–390, 1983.
13) Chavez A1, Roguski M1, Killeen A1, Heilman C1, Hwang S2. J Clin Neurosci. Comparison of operative and non-operative outcomes based on surgical selection criteria for patients with Chiari I malformations. 2014 Dec;21(12):2201-6. doi: 10.1016/j.jocn.2014.06.009.
14) Elster AD, Chen MYM: Chiari I malformations: clinical and radiologic reappraisal. Radiology 183:347–353, 1992.
15) Krishna V1, McLawhorn M2, Kosnik-Infinger L2, Patel S2. High long-term symptomatic recurrence rates after Chiari-1 decompression without dural opening: a single center experience. Clin Neurol Neurosurg. 2014 Mar;118:53-8. doi: 10.1016/j.clineuro.2013.12.016.
16) Parker SL1, Godil SS, Zuckerman SL, Mendenhall SK, Wells JA, Shau DN, McGirt MJ. Comprehensive assessment of 1-year outcomes and determination of minimum clinically important difference in pain, disability, and quality of life after suboccipital decompression for Chiari malformation I in adults. Neurosurgery. 2013 Oct;73(4):569-81; discussion 581. doi: 10.1227/NEU.0000000000000032.
17) Duddy JC1, Allcutt D, Crimmins D, O'Brien D, O'Brien DF, Rawluk D, Sattar MT, Young S, Caird J. Foramen magnum decompression for Chiari I malformation: a procedure not to be underestimated. Br J Neurosurg. 2014 Jun;28(3):330-4. doi: 10.3109/02688697.2013.841847.
18) Greenberg JK1, Ladner TR, Olsen MA, Shannon CN, Liu J, Yarbrough CK, Piccirillo JF, Wellons JC 3rd, Smyth MD, Park TS, Limbrick DD. Complications and Resource Use Associated With Surgery for Chiari Malformation Type 1 in Adults: A Population Perspective. Neurosurgery. 2015 Apr 23.
19) Shweikeh F1, Sunjaya D, Nuno M, Drazin D, Adamo MA. Pediatr Neurosurg. 2015;50(1):31-7. doi: 10.1159/000371659. National trends, complications, and hospital charges in pediatric patients with Chiari malformation type I treated with posterior fossa decompression with and without duraplasty.
20) Stevens JM1, Serva WA, Kendall BE, Valentine AR, Ponsford JR. Chiari malformation in adults: relation of morphological aspects to clinical features and operative outcome. J Neurol Neurosurg Psychiatry. 1993 Oct;56(10):1072-7.
21) Killeen A1, Roguski M1, Chavez A1, Heilman C1, Hwang S2. Non-operative outcomes in Chiari I malformation patients. J Clin Neurosci. 2015 Jan;22(1):133-8. doi: 10.1016/j.jocn.2014.06.008. Epub 2014 Jul 28.
22) McGirt MJ1, Attenello FJ, Atiba A, Garces-Ambrossi G, Datoo G, Weingart JD, Carson B, Jallo GI. Symptom recurrence after suboccipital decompression for pediatric Chiari I malformation: analysis of 256 consecutive cases. Childs Nerv Syst. 2008 Nov;24(11):1333-9. doi: 10.1007/s00381-008-0651-3. Epub 2008.
23) Chotai S1, Medhkour A2. Surgical outcomes after posterior fossa decompression with and without duraplasty in Chiari malformation-I. Clin Neurol Neurosurg. 2014 Oct;125:182-8. doi: 10.1016/j.clineuro.2014.07.027.
24) Chotai S1, Kshettry VR2, Lamki T1, Ammirati M3. Surgical outcomes using wide suboccipital decompression for adult Chiari I malformation with and without syringomyelia. Clin Neurol Neurosurg. 2014 May;120:129-35. doi: 10.1016/j.clineuro.2014.02.016.