Bright Spotty Lesions in the Myelon: A Hallmark of AQP-4 Positive Neuromyelitis Optica Spectrum Disorders

A 15-year-old girl presented with pain and sensory impairment for temperature and pain of the right arm and later numbness in both lower extremities. Cerebrospinal fluid (CSF) analysis revealed pleocytosis (35 cells/μL; normal range, 0–5/μL), increased total protein (142 mg/dL; normal range, 15–46 mg/dL), while oligoclonal bands were absent. Serum aquaporin-4–immunoglobulin G (AQP4-IgG) was positive. Recent magnetic resonance imaging (MRI) showed increased signal throughout the right optic nerve ([Fig. 1A]), right thalamus ([Fig. 1B]), and longitudinal extensive transverse myelitis (LETM) involving cervical and dorsal cord ([Fig. 1C] and [D]). A LETM MRI pattern may occur in patients with different demyelinating disorders like multiple sclerosis, neuromyelitis optica spectrum disorders, acute disseminated encephalomyelitis (ADEM), or infections, especially by enterovirus-71, neoplastic and paraneoplastic diseases, spinal cord infarction, and traumatic spinal cord injury.[1] [2] [3] [4] Furthermore, a similar MRI pattern in particular in the myelon can be seen in the ADEM or LETM associated with oligodendrocyte glycoprotein antibodies.[5] In conclusion, this is a typical AQP4-IgG positive case of neuromyelitis optica spectrum disorders (NMOSD)[6] in which peculiar bright spotty lesions ([Fig. 1E]), which probably reflect intense damage of the cervical spinal cord,[2] are shown.

Fig. 1 Hyperintensity throughout the right optic nerve (A) and in the right thalamus (B) in T2-weighted images. Bright spotty lesions (white arrows) as part of LETM in sagittal postgadolinium T1 (C), T2 (D), and axial T2-weighted (E).

• References

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