Abstract
To clarify the relationship between clinical manifestations and MRI findings in the early diagnosis of medullary infarction (MI), the present study was undertaken on 114 consecutive patients with MI who were admitted at the acute stage between 1991 and 2006. The MRI findings were classified into medial (MMI, n=53) and lateral (LMI, n=59) groups. According to the horizontal localization, LMI was then subclassified into 5 categories: dorsal (DS), postero-ventral (PV), antero-ventral (AV), extensive ventral (EV), and antero-lateral (AL) lesions, and MMI was subdivided into large and small lesions. The mean age was significantly older in MMI than in LMI (68.3 vs. 63.1 years, P<0.05). Alternative hemihypesthesia was observed more frequently in the MMI group. The patterns of sensory disturbance differed within the LMI group: a combination of ipsilateral face and contralateral body was most frequent in PV lesions (55.6%), whereas isolated ipsilateral face disturbance was mainly noted in DS lesions (41.2%). The lesions were predominantly located in the rostral portion in MMI (66.0%) and in the middle portion in LMI (66.1%). Sensory disturbance (54.1%), Horner's sign (58.1%) and hiccups (66.7%) were more frequently observed in patients with middle lesions. The responsible lesions were not visualized on the diffusion-weighted image (DWI) in 18 patients within 48 hours of onset, and these false negative findings were predominantly located in the rostral portion (83.3%, P<0.01). Since a combination of facial palsy and hiccups in addition to hemihypesthesia may imply MI, MRI should be performed repeatedly at the acute stage, even though the initial DWI is negative for MI.
