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.

Keywords: Delayed diagnosis; Dural defect; Health care costs; ISCH; Idiopathic spinal cord herniation; Overutilization.