Long spinal cord lesions in a patient with pathologically proven multiple sclerosis

Pathological observations of a long spinal cord lesion in a patient with multiple sclerosis

We report an autopsy case of multiple sclerosis (MS) manifesting as a long spinal cord lesion. The patient was a Japanese woman. At the age of 59 years, she presented with a one-month history of progressive paraplegia, dysesthesia in the lower extremities, and urinary retention. Magnetic resonance imaging revealed a long, hyperintense lesion on T2-weighted images that extended from the inferior portion of the medulla oblongata to the cervical segments of the spinal cord and an isolated lesion at the T6 level. Cerebrospinal fluid (CSF) examination revealed the presence of oligoclonal bands and increased myelin basic protein levels (999 pg/mL). Serum antibody against aquaporin 4 (AQP4) was undetectable in this patient. She was diagnosed as having atypical MS and experienced symptom improvement following immunotherapy with corticosteroids and plasma exchange. She died of pneumonia and renal failure at the age of 62 years. Postmortem examination revealed a long demyelinating lesion that extended from the inferior portion of the medulla oblongata to the sacral segments of the spinal cord. The lesion was comprised of numerous demyelinating plaques with inflammatory cell infiltration. A long spinal cord lesion is usually indicative of neuromyelitis optica spectrum disorder (NMOSD), and there are limited reports of postmortem observations of long spinal cord lesions among patients with anti-AQP4 antibody-seronegative MS. Our findings suggest that the pathomechanisms of such long spinal cord lesion formation differ between anti-AQP4 antibody-seronegative MS and NMOSD.

Magnetic resonance imaging in neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disease of the central nervous system (CNS) associated with antibodies to aquaporin-4 (AQP4), which has distinct clinical, radiological and pathological features, but also has some overlap with multiple sclerosis and myelin oligodendrocyte glycoprotein (MOG) antibody associated disease. Early recognition of NMOSD is important because of differing responses to both acute and preventive therapy. Magnetic resonance (MR) imaging has proved essential in this process. Key MR imaging clues to the diagnosis of NMOSD are longitudinally extensive lesions of the optic nerve (more than half the length) and spinal cord (three or more vertebral segments), bilateral optic nerve lesions and lesions of the optic chiasm, area postrema, floor of the IV ventricle, periaqueductal grey matter, hypothalamus and walls of the III ventricle. Other NMOSD-specific lesions are denoted by their unique morphology: heterogeneous lesions of the corpus callosum, 'cloud-like' gadolinium (Gd)-enhancing white matter lesions and 'bright spotty' lesions of the spinal cord. Other lesions described in NMOSD, including linear periventricular peri-ependymal lesions and patch subcortical white matter lesions, may be less specific. The use of advanced MR imaging techniques is yielding further useful information regarding focal degeneration of the thalamus and optic radiation in NMOSD and suggests that paramagnetic rim patterns and changes in normal appearing white matter are specific to MS. MR imaging is crucial in the early recognition of NMOSD and in directing testing for AQP4 antibodies and guiding immediate acute treatment decisions. Increasingly, MR imaging is playing a role in diagnosing seronegative cases of NMOSD.