PT  - JOURNAL ARTICLE
AU  - Z. Patay
AU  - J. Enterkin
AU  - J.H. Harreld
AU  - Y. Yuan
AU  - U. Löbel
AU  - Z. Rumboldt
AU  - R. Khan
AU  - F. Boop
TI  - MR Imaging Evaluation of Inferior Olivary Nuclei: Comparison of Postoperative Subjects with and without Posterior Fossa Syndrome
AID  - 10.3174/ajnr.A3762
DP  - 2014 Apr 01
TA  - American Journal of Neuroradiology
PG  - 797--802
VI  - 35
IP  - 4
4099  - http://www.ajnr.org/content/35/4/797.short
4100  - http://www.ajnr.org/content/35/4/797.full
SO  - Am. J. Neuroradiol.2014 Apr 01; 35
AB  - BACKGROUND AND PURPOSE: Posterior fossa syndrome is a severe postoperative complication occurring in up to 29% of children undergoing posterior fossa tumor resection; it is most likely caused by bilateral damage to the proximal efferent cerebellar pathways, whose fibers contribute to the Guillain-Mollaret triangle. When the triangle is disrupted, hypertrophic olivary degeneration develops. We hypothesized that MR imaging patterns of inferior olivary nucleus changes reflect patterns of damage to the proximal efferent cerebellar pathways and show association with clinical findings, in particular the presence or absence of posterior fossa syndrome. MATERIALS AND METHODS: We performed blinded, randomized longitudinal MR imaging analyses of the inferior olivary nuclei of 12 children with and 12 without posterior fossa syndrome after surgery for midline intraventricular tumor in the posterior fossa. The Fisher exact test was performed to investigate the association between posterior fossa syndrome and hypertrophic olivary degeneration on MR imaging. The sensitivity and specificity of MR imaging findings of bilateral hypertrophic olivary degeneration for posterior fossa syndrome were measured. RESULTS: Of the 12 patients with posterior fossa syndrome, 9 had bilateral inferior olivary nucleus abnormalities. The 12 patients without posterior fossa syndrome had either unilateral or no inferior olivary nucleus abnormalities. The association of posterior fossa syndrome and hypertrophic olivary degeneration was statistically significant (P < .0001). CONCLUSIONS: Hypertrophic olivary degeneration may be a surrogate imaging indicator for damage to the contralateral proximal efferent cerebellar pathway. In the appropriate clinical setting, bilateral hypertrophic olivary degeneration may be a sensitive and specific indicator of posterior fossa syndrome. HODhypertrophic olivary degenerationIONinferior olivary nucleuspECPproximal efferent cerebellar pathwayPFSposterior fossa syndrome