112 Neuromyelitis Optica

Xiaohong Si and Robert Hemdon

Fig. 112.1 Magnetic resonance imaging of spine with findings of multilevel increase signal and suggest edema on T2-weighted images within the spinal cord. (A) Sagittal and (B) axial T2-weighted images are demonstrated. The longest extends just below obex to the C5 level. There is second region of increased signal extending from the superior to the inferior margin of the T2 vertebra. (C) Sagittal T1-weighted MRI with contrast: this is a postcontrast view of the same lesion in (A). Note the contrast enhancement at level of C3–C4.

Clinical Presentation

A 20-year-old African American woman presented with blurred vision and headaches a few years ago.

She was then diagnosed with optic neuritis and had a suspected diagnosis of multiple sclerosis (MS).

At this time, magnetic resonance imaging (MRI) of the brain showed two small periventricular lesions on T2-weighted images.

She was treated with interferon β-1a (Avonex, Biogen Idec, Cambridge, MA) without significant improvement.

At the age of 25, she presents now with muscle weakness and numbness in her legs.

MRI of cervical spine demonstrates multilevel increase signal suggesting edema on T2-weighted images within the spinal cord (Fig. 112.1). This abnormal signal within the cervical cord was more prominent with contrast enhancement.

Questions

What is the differential diagnosis?

Her condition declined steadily over the last decade to the extent that she lost the ability to communicate and ambulate.

What is the next step in your assessment?

Her medical history is remarkable for systemic lupus erythematosus. Physical examination reveals some disorientation, unintelligible speech, with some limitations, as she was not following commands. Her reflexes were increased with ankle clonus.

What imaging and other diagnostic studies would you like to obtain?

MRI of the brain showed mild cerebral atrophy with two small nonspecific periventricular lesions on T2-weighted images. Electromyography and nerve conduction studies (EMG/NCS) performed on proximal and distal muscles in the upper and lower extremity show myopathic motor units with poor and irregular recruitment. The changes in muscles were interpreted as most likely from disuse and upper motor neuron disorder. Visual evoked potentials show anterior visual pathway dysfunction from the right eye. Findings are normal from the left eye.