Kotaro MORINO, Yukihiro YONEDA, Kensaku SHIBASAKI, Yasushi KITA, Masayasu TABUCHI

Neurology Service, Hyogo Brain and Heart Center at Himeji

(Received 8 November 2002; accepted 28 April 2003)

Abstract: [Purpose] To evaluate long-term outcomes after lower spinal cord infarction. [Subjects] Two adults (66- and 63-years-old females) with lower spinal cord infarction manifesting acute anterior spinal artery syndrome and paraplegia. [Methods] Spinal MRI and neurophysiological studies were sequentially performed. Neurological signs were assessed by ASIA (American Spinal Injury Association) motor score for the lower extremities (full score; 50 points) and daily activity was evaluated by the Barthel Index (BI). [Results] In both patients, T2-weighted MRI demonstrated areas of high signal intensity in the gray and white matter of the conus medullaris and epiconus in the acute phase. In the subacute phase at a few weeks from onset, areas of high signal were localized in the bilateral anterior horns of the gray matter in patient 1, and high signals were located in the whole white matter and partially in the posterior column in patient 2. In patient 2, the intramedullary lesions were enhanced after a Gd-DTPA injection, and the cauda equina and the ventral roots of the lumbar nerves were enhanced in both patients. Although both patients demonstrated an absence of an F wave with normal peripheral nerve conduction velocity on the posterior tibial nerve stimulation at the acute phase of illness, the F wave was evoked 3 weeks later in patient 1 and 7 weeks later in patient 2. The somatosensory evoked potentials on tibial nerve stimulation was evoked on the 8th day in patient 1, whereas they were not been evoked at all in patient 2. The ASIA motor score of patient 1 improved from 2 points at onset to 33 points at 12 months, and from 23 to 28 points for patient 2. Similarly, for patient 1, BI improved from 15 points to 85 points, and for patient 2 it improved from 25 points to 65 points. [Discussions] The extent of MRI lesions at the subacute phase of illness, the number of days until F wave appearance after onset, and presence of SEP may be the prognostic factors of long-term outcome, rather than neurological severity and MRI lesions at the acute phase.

Key words: spinal cord infarction, magnetic resonance image, electrodiagnosis, outcome