Idiopathic spinal cord herniation: an imaging diagnosis with a significant delay

Abstract

Background context

Idiopathic spinal cord herniation (ISCH) is an underrecognized entity that is often underappreciated by the neurosurgery and neuroradiologic communities. This leads to delayed diagnosis, multiple imaging studies, other diagnostic tests, inappropriate surgeries, and repeat office visits.

Purpose

To evaluate common associations between ISCH and patient demographics/clinical presentation and to analyze the potential for delayed diagnosis.

Patient sample

Patient sample included those diagnosed with ISCH on imaging at our institution from June 20, 2005 to December 3, 2012.

Outcome measures

These were based on the patient improvement/stability/decline based on the patients' most recent clinic/office visit when compared with initial presentation.

Methods

A retrospective search of radiology reports was performed using Illuminate software from June 20, 2005 to December 3, 2012, using the search term “idiopathic spinal cord herniation.” Clinical data were reviewed including patient's age, sex, presenting clinical symptoms, number and type of imaging studies performed as part of the workup, other diagnostic tests, pain procedures, surgeries, and time between original presentation and diagnosis of ISCH on imaging.

Results

A total of 55 patients had the search term “idiopathic spinal cord herniation” included in their radiology report, of which 37 patients were found to meet the imaging and clinical diagnosis of ISCH. The median time from presentation to imaging diagnosis was 20 months in patients younger than 60 years and 5 months in those 60 years or older (p=.02). Of the 37 patients evaluated, 27 (73%) had no change in symptoms, 5 patients (14%) experienced worsening of symptoms, and 5 (14%) experienced symptom improvement from original presentation to most recent office visit. Among all patients evaluated, three underwent repair of the ventral dural defect in ISCH, resulting in clinical improvement. There was a median of nine outpatient office visits, three magnetic resonance images (MRIs), and one electromyography (EMG) per patient presenting with ISCH. The most frequent complaints were neck/upper back pain in 70%, upper/lower extremity numbness/paresthesias/weakness in 49%, hyperreflexia in 22%, and burning chest pain in 22%.

Conclusions

Prolonged time to diagnosis and subsequent treatment of ISCH protracts patient symptoms and is associated with redundant diagnostic tests and patient visits. Earlier use of MRI in younger patients (younger than 60 years) may be warranted in those with a clinical presentation suggestive of Brown-Sequard symptomatology. Increasing recognition of ISCH in imaging and surgical communities would lead to improved patient care.

Introduction

Evidence & Methods

The authors seek to document associations between idiopathic spinal cord herniation (ISCH) and presentation/demographic factors. The authors maintain that this is an increasingly misdiagnosed clinical entity with substantial delays in proper recognition.

The authors present their experience with 37 instances of ISCH. The authors advocate early use of MRI in young patients with a clinical picture that warrants concern for ISCH, especially those that present with idiopathic Brown-Sequard syndrome.

As a retrospective review, this study can only deal with the clinical experiences and radiographic features of a small sample of patients with ISCH treated at the authors' center. The reader and the authors cannot have access to the details of patients with ISCH who presented elsewhere for care or those who may have had ISCH but failed to be diagnosed with this clinical entity at the authors' own institution. These potentials for confounding limit the capacity for generalizing the guidelines proposed by the authors. Nonetheless, given the rarity of this condition, the findings presented here may be used to increase sensitivity for ISCH although they likely cannot be considered specific to the condition.

—The Editors

Idiopathic spinal cord herniation (ISCH) was first described by Wortzman et al. [1] in a 1974 case report involving herniation of the thoracic spinal cord resulting in neurologic symptoms. Idiopathic spinal cord herniation is classically described as occurring in middle-aged adults with a preponderance of women [2]. Most cases describe symptoms of Brown-Sequard syndrome, characterized by ipsilateral paralysis, loss of vibratory and position sense, contralateral loss of pain and temperature sensation, or other myelopathic sequelae [3]. Symptoms are typically unilateral from herniation of the lateral funiculus of the spinal cord in ISCH [3].

Recognition of ISCH in the literature has increased over the past decade, likely because of improvements in technique and utilization of spine magnetic resonance imaging (MRI); however, much of this is based on case reports and small series of patients. As such, the entity remains underrecognized and poorly understood, particularly outside of the surgical spine and neuroradiology communities, leading to a significant delay in clinical diagnosis with few cases undergoing surgical repair. One of the major reasons for delay in diagnosis is a wide spectrum of nonspecific and minor symptoms at patient presentation. These delays, in turn, can lead to redundant diagnostic testing, ineffective therapies, and repeat health care visits because of ongoing symptoms. Currently, there is increased focus on improving the quality of health care delivery, with the goal to improve patient outcome and avoid ineffective medical practices. Therefore, increased awareness and appropriate management of underrecognized entities such as ISCH is an efficient way to improve patient care.

Failure to suspect and recognize ISCH can result in delayed diagnosis and unnecessary use of medical resources. The purpose of this study was to evaluate common associations between ISCH and patient demographics and clinical presentation and to analyze potential causes for delayed diagnosis. The goal of this study was to increase awareness of ISCH as a cause of myelopathy, which can be effectively treated, leading to improvement or at least an arrest of patient symptoms.