Neural Axis Abnormalities in Patients With Adolescent Idiopathic Scoliosis: Is Routine Magnetic Resonance Imaging Indicated Irrespective of Curve Severity?

Abstract

Objective Magnetic resonance imaging (MRI)-verified neural axis abnormalities (NAAs) have been described in adolescent idiopathic scoliosis (AIS), and several risk factors have been associated with the presence of NAAs in AIS patients. However, the clinical significance of these findings is unclear. The purpose of the present study was to determine the prevalence of NAAs in a large consecutive cohort of AIS patients and to evaluate the clinical significance of previously proposed risk factors. Methods We prospectively included AIS patients referred to a tertiary facility for evaluation. Full-spine MRI scans were performed on all included patients irrespective of curve magnitude or proposed treatment modality. MRI scans were prospectively analyzed by a neuroradiologist and the pathologic findings were confirmed by a second independent radiologist. Results NAA was observed in 34 of the 381 patients (8.9%): 32 patients had a syrinx, 1 patient had an arachnoid cyst, and 1 patient had a Chiari malformation. Four patients were referred for a neurosurgical evaluation but none received any neurosurgical treatment. No statistically significant difference was observed between the NAA and non-NAA groups in terms of sex, major curve size, thoracic kyphosis, left thoracic curve, curve convexity, curve progression, or level of pain (p>0.05). Conclusion In this prospective study examining the risk factors for NAA in AIS patients, we found that previously proposed risk factors could not predict the MRI outcomes. The finding of an NAA had no clinical implications and we do not support MRI scans as a routine diagnostic modality in all AIS patients.

An atypical case with chronic granulomatous disease and Kabuki syndrome

“…Of 381 patients with AIS, NAA was observed in 34 (8.9%). The 32 patients had a syrinx, one patient had an arachnoid cyst, and one patient had a Chiari malformation (6). Symptomatic Chiari I malformation is a very rare manifestation in KS I, which was detected in our case (3).…”

“…The neurological and skeletal findings in Arnold-Chiari type I can be confused with many other diseases. Scoliosis with Arnold-Chiari type I may also vary but is generally considered to be rare, and the genetic etiology of this malformation cannot be established, usually (3,6). Here, we presented a rare case of KS with scoliosis at the thoracolumbar axis and Arnold Chiari malformation I (Fig.…”

Does magnetic resonance imaging impact pre-operative plans in adolescent idiopathic scoliosis patients? A retrospective study

“…Correction of scoliosis in people with neural axis anomalies may cause neurological complications. [1,8,12] According to the different studies, the incidence of neural axis anomalies in AIS patients ranges from 2 to 26%. [3,6,7] According to Dewan et al, [8] 114 (14%) of 811 scoliosis patients showed aberrant neural axis, with no significant link with a left-sided thoracic curve, double thoracic curve, male gender, or scoliosis diagnosis before the age of 10.…”

Selection of Fusion Level for Adolescent Idiopathic Scoliosis Surgery : Selective Fusion versus Postoperative Decompensation

“…The King-Moe classification of idiopathic thoracic scoliosis is a long-standing system widely used to classify curve patterns and to recommend fusion levels. However, a limitation of this system is that it is based only on the coronal plane, lacks a defined isolated thoracolumbar curve type, and has relatively poor to fair inter-observer and intra-observer reliability [ 12 , 31 ].…”