Diagnostic and Prognostic Value of Conventional Brain MRI in the Clinical Work-Up of Patients with Amyotrophic Lateral Sclerosis.

Giovanni Rizzo,Vincenzo Donadio,Ilaria Bartolomei,Silvia De Pasqua,Rocco Liguori,Rossella Infante,Luca Albini Riccioli,Stella Battaglia,Anna Marliani,Fabrizio Salvi,Patrizia Avoni,On Behalf Of The Boreals Group ,Massimiliano Passaretti,Veria Vacchiano

doi:10.3390/jcm9082538

Abstract

Clinical signs of upper motor neuron (UMN) involvement are important in the diagnosis of amyotrophic lateral sclerosis (ALS) though are often difficult to analyze. Many studies using both qualitative and quantitative evaluations have reported abnormal Magnetic Resonance Imaging (MRI) findings at the level of the pyramidal pathway in patients with ALS. Although the most interesting results were obtained by quantitative studies using advanced MR techniques, the qualitative evaluation of MRI images remains the most-used in clinical practice. We evaluated the diagnostic and prognostic contribution of conventional 3T-MRI in the clinical work-up of ALS patients. Two neuroradiologists retrospectively assessed 3T-MRI data of 93 ALS patients and 89 controls. The features of interest were corticospinal tract (CST) T2/FLAIR hyperintensity, motor cortex (MC) T2*/SWI hypointensity, and selective MC atrophy. All MRI features were significantly more prevalent in ALS patients than in controls. The simultaneous presence of CST FLAIR hyperintensity and MC SWI hypointensity was associated with the highest diagnostic accuracy (sensitivity: 70%; specificity: 81%; positive predictive value, PPV: 90%; negative predictive value, NPV: 51%; accuracy: 73%) and a shorter survival (HR: 6.56, p = 0.002). Conventional 3T-MRI can be a feasible tool to detect specific qualitative changes based on UMN involvement and to support clinical diagnosis of ALS. Importantly, CST FLAIR hyperintensity and MC SWI hypointensity are predictors of shorter survival in ALS patients.

Highlights

Amyotrophic lateral sclerosis (ALS), is a degenerative motor neuron disease, characterized by a progressive weakness of bulbar, limb, thoracic, and abdominal muscles [1].The diagnosis of amyotrophic lateral sclerosis (ALS) is based on the detection of clinical signs of upper motor neuron (UMN) involvement, clinical and electrophysiological signs of lower motor neuron (LMN) impairment, and the exclusion of ALS mimics according to the revised El Escorial criteria [2].While electromyography (EMG) can be used to detect signs of LMN impairment, signs related to UMN involvement can be difficult to detect since they can be masked by the signs of LMN impairment
The simultaneous presence of corticospinal tract (CST) FLAIR hyperintensity and motor cortex (MC) susceptibility-weighted images (SWI) hypointensity was associated with the highest diagnostic accuracy and a shorter survival (HR: 6.56, p = 0.002)
The diagnosis of ALS is based on the detection of clinical signs of upper motor neuron (UMN) involvement, clinical and electrophysiological signs of lower motor neuron (LMN) impairment, and the exclusion of ALS mimics according to the revised El Escorial criteria [2]

Summary

Introduction

While electromyography (EMG) can be used to detect signs of LMN impairment, signs related to UMN involvement can be difficult to detect since they can be masked by the signs of LMN impairment This has led to a need to identify biomarkers that are sensitive and specific to UMNs. In terms of clinical presentation and survival, ALS is known to be extremely heterogeneous [3]. The most interesting results were obtained in studies using advanced MR techniques that are able to detect subtle changes in the motor cortex or the corticospinal tract (CST). These techniques are not yet ready for use in clinical practice. Such features seem to be more detectable using high-field scanners

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