Three-point sign in subacute combined degeneration of the spinal cord

Abstract

Rationale:Subacute combined degeneration (SCD) of the spinal cord has been reported to have distinctive characteristics on magnetic resonance imaging (MRI), such as an “inverted V sign”, a “pair of binoculars sign”, and a “dot sign”. We report a 3-point sign as a novel MRI characteristic, expanding the spectrum of imaging signs for SCD.Patient concerns:A 64-year-old female vegetarian presented with a 3-month history of progressive numbness and weakness in the lower extremities.Diagnosis:Laboratory examination showed a reduced serum vitamin B12 level. Spinal MRI showed hyperintensity within the posterior and lateral columns (appearing as a three-point sign) on T2-weighted imaging. Thus, the patient was diagnosed with SCD.Interventions:The patient was treated with intravenous cyanocobalamin and oral vitamin B12.Outcomes:After a follow-up period of 5 months, the symptoms were significantly improved.Lessons:Clinicians should be aware of this atypical MRI pattern, which may facilitate an early diagnosis.

A Case of Subacute Combined Degeneration of Spinal Cord Diagnosed by Vitamin B₁₂ Administration Lowering Methylmalonic Acid

“…Abnormalities on MRI of SCDS patients have been identified to include distinctive characteristics such as an "inverted V sign," a "pair of binoculars sign," and a "dot sign" [8]. However, Jain et al [9] reported that only 11.1-36.7% of patients with SCDS showed marked abnormalities on MRI.…”

Of dots and levels: a case of partial subacute combined degeneration

“…3 These may be the distinctive and prototypical 'inverted V' sign as well as the recently described 'three-point' sign. 3 However, isolated posterior column hyperintensity in the form of 'binocular sign' and 'dot' sign on MRI have also been described, albeit less commonly. 4 It is important to note that SACD may present with atypical clinical features.…”

“…Radiological features in SACD typically exhibit posterolateral signal change and are seen in 11%–37% of patients. 3 These may be the distinctive and prototypical ‘inverted V’ sign as well as the recently described ‘three-point’ sign. 3 However, isolated posterior column hyperintensity in the form of ‘binocular sign’ and ‘dot’ sign on MRI have also been described, albeit less commonly.…”

Recreational Nitrous Oxide-Induced Subacute Combined Degeneration

“…However, as observed in our patient, signal abnormalities are usually very distinctive when present. This often appears hyperintense on T2-weighted imaging but normal on T1-weighted imaging with an unremarkable or slight enhancement [ 6 ]. Other distinctive features such as an “inverted V sign,” a “pair of binoculars sign,” and a “dot sign” have also been identified on MRI [ 7 , 8 ].…”