Characteristics of Spontaneous Spinal Cord Infarction and Proposed Diagnostic Criteria

Abstract

Importance: Spinal cord infarction (SCI) is often disabling, and the diagnosis can be challenging without an inciting event (eg, aortic surgery). Patients with a spontaneous SCI are often misdiagnosed as having transverse myelitis. Diagnostic criteria for SCI are lacking, hindering clinical care and research.

Objective: To describe the characteristics of spontaneous SCI and propose diagnostic criteria.

Design, setting, and participants: An institution-based search tool was used to identify patients evaluated at Mayo Clinic, Rochester, Minnesota, from January 1997 to December 2017 with a spontaneous SCI. Patients provided written consent to use their records for research. Participants were 18 years and older with a diagnosis of spontaneous SCI (n = 133), and controls were selected from a database of alternative myelopathy etiologies for validation of the proposed diagnostic criteria (n = 280).

Main outcomes and measures: A descriptive analysis of SCI was performed and used to propose diagnostic criteria, and the criteria were validated.

Results: Of 133 included patients with a spontaneous SCI, the median (interquartile range) age at presentation was 60 (52-69) years, and 101 (76%) had vascular risk factors. Rapid onset of severe deficits reaching nadir within 12 hours was typical (102 [77%]); some had a stuttering decline (31 [23%]). Sensory loss occurred in 126 patients (95%), selectively affecting pain/temperature in 49 (39%). Initial magnetic resonance imaging (MRI) spine results were normal in 30 patients (24%). Characteristic MRI T2-hyperintense patterns included owl eyes (82 [65%]) and pencil-like hyperintensity (50 [40%]); gadolinium enhancement (37 of 96 [39%]) was often linear and located in the anterior gray matter. Confirmatory MRI findings included diffusion-weighted imaging/apparent diffusion coefficient restriction (19 of 29 [67%]), adjacent dissection/occlusion (16 of 82 [20%]), and vertebral body infarction (11 [9%]). Cerebrospinal fluid showed mild inflammation in 7 of 89 patients (8%). Diagnostic criteria was proposed for definite, probable, and possible SCI of periprocedural and spontaneous onset. In the validation cohort (n = 280), 9 patients (3%) met criteria for possible SCI, and none met criteria for probable SCI.

Conclusions and relevance: This large series of spontaneous SCIs provides clinical, laboratory, and MRI clues to SCI diagnosis. The diagnostic criteria proposed here will aid clinicians in making the correct diagnosis and ideally improve future care for patients with SCI. The validation of these criteria supports their utility in the evaluation of acute myelopathy.

Figure 1.. Magnetic Resonance Imaging T2-Hyperintensity Patterns in Spinal Cord Infarctions

Typical patterns of T2-hyperintense signal seen in spinal cord infarction (SCI) include owl eyes associated with noncontiguous anterior pencil-like hyperintensity (A); anteromedial spot confirmed with short anterior pencil-like hyperintensity on sagittal view (B); residual cystic myelomalacia with very bright T2-hyperintensity and associated T1-hypointensity seen longer than 1 month after SCI (C); anterior pencil-like hyperintensity with associated anteromedial T2-hyperintensity (D); anterior U/V with associated anterior pencil-like hyperintensity on sagittal view (E); hologrey pattern with associated edematous T2-hyperintensity on sagittal view (F); and holocord pattern with associated edematous T2-hypertensity extending through the conus on sagittal view (G).

Figure 2.. Confirmatory Magnetic Resonance Imaging Findings and Typical Gadolinium Enhancement Pattern in Spinal Cord Infarctions

Confirmatory spinal cord infarction (SCI) findings are shown, including vertebral body infarction on short-τ inversion recovery imaging with associated gadolinium enhancement of the vertebral body infarct, SCI, and anterior cauda equina (A); cervical artery dissection with significantly decreased left vertebral flow with confirmed intramural hematoma shown on T1-fat suppression imaging (B) adjacent to SCI; and diffusion restriction on diffusion-weighted imaging with correlation on apparent diffusion coefficient (C). Spinal cord infarction gadolinium enhancement demonstrated with a typical craniocaudal linear strip on sagittal views (D) and corresponding anterior predominant gray matter and anteromedial spot (E) patterns on axial views, highlighting the predominant areas of ischemia.