A Diagnostic Approach to Myelopathy Based on Prognostic Factors in Patients With Lower Extremity Symptoms

Manabu Tsukamoto, MD, PhD; Eiichiro Nakamura, MD, PhD; Kenichiro Narusawa, MD, PhD; Kenji Shimizu, MD, PhD; Hajime Otomo, MD, PhD; Hirotoshi Yamane, MD, PhD; Teppei Muramoto, MD; Shinji Yamada, MD; Akinori Sakai, MD, PhD

Disclosures

Spine. 2020;45(13):E792-E798. 

In This Article

Abstract and Introduction

Abstract

Study Design: Case-control study.

Objective: We aimed to identify predictors for latent myelopathy and to develop a diagnostic protocol based on these factors.

Summary of Background data: There is no diagnostic protocol for latent myelopathy to avoid misdiagnosis in patients complaining only of lower extremity symptoms.

Methods: This case-control study identified 791 patients discussed at conferences from April 2006 to August 2012. Overall, 460 patients complaining only of lower extremity symptoms and who underwent spine surgery were included as participants; 54 underwent surgery involving the cervical and thoracic vertebrae and were assigned to the cervical-thoracic group (C-T group); 406 underwent lumbar surgery and were assigned to the lumbar group (L group).

Results: By univariate analysis, age ≥67 years, patellar tendon (PT) hyperreflexia, Achilles tendon (AT) hyperreflexia, spastic gait, and gait inability were more common in the C-T group than in the L group. By multivariate analysis, age ≥67 years (OR, 8; P = 0.001), AT hyperreflexia (OR, 20.5; P < 0.001), spastic gait (OR, 225; P < 0.001), and gait inability (OR, 64; P < 0.001) were significant predictive factors. In patients with age ≥67 years, PT hyperreflexia, and/or AT hyperreflexia, the sensitivity for myelopathy diagnosis was 98%. In patients with spastic gait or gait inability, the specificity of myelopathy diagnosis was 96%.

Conclusions: We analyzed factors that predict latent myelopathy in patients complaining only of lower extremity symptoms. We believe a diagnostic protocol based on the predictors shown in this study would contribute to the accurate diagnosis of latent myelopathy.

Level of Evidence: 4

Introduction

It is important to make an accurate neurological diagnosis prior to spine surgery. Generally, neurological findings are used to determine the specific location of the disability and imaging findings are used to confirm this determination. False-positive findings from spine images are common, particularly in the elderly.[1] The determination of the surgical site depends on accurate neurological diagnosis. Misdiagnosis and inappropriate surgery adversely affect the functional prognosis, and patient dissatisfaction can lead to lawsuits.[2] As the surgeons always require accurate preoperative diagnoses, various diagnostic techniques for neurological examinations have been reported.[3–5] Nevertheless, the diagnosis of a specific segment may sometimes be difficult. Lu et al[6] reported that 7 patients underwent surgery for lumbar canal stenosis, but the surgeons failed to detect myelopathy; thus, they had to undergo another operation.

In many cases, when a patient complains of lower extremity symptoms, the cause is a lumbar-related disease. However, there are also cases caused by diseases located in the cervical or thoracic vertebrae. Thus, deliberate care is required for an accurate diagnosis. However, the location of the disease might be misdiagnosed when a patient complains of lower extremity symptoms and magnetic resonance imaging (MRI) reveals lumbar canal stenosis, even though myelopathy is present. There is no diagnostic protocol for avoiding misdiagnosis in such cases.

At our hospital, all patients scheduled for invasive therapy were required to undergo neurological examinations conducted by spine surgeons from which clinical data and neurological findings were maintained in a database. Using this database, we identified factors useful in predicting a diagnosis of latent myelopathy in patients complaining only of lower extremity symptoms, with the intention of creating a diagnostic protocol based on these factors.

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