PMC6566138_01
Gadolinium-enhanced spinal magnetic resonance imaging (MRI) findings at the initial attack. The lower "A" represents "anterior" in (A). The "R" represents "right" in (K). (A-C) Post-contrast fat-suppression T1-weighted images showed multiple abnormal foci in the medulla and spinal cord at the initial attack. (D,E) T2-weighted images showed multiple abnormal foci in the medulla and spinal cord at the initial attack. (F-H) Post-contrast T1-weighted MRI of the cervicothoracic and lumbar spine after two courses of high-dose steroid pulse therapy. Abnormal enhancement was slightly decreased, but new enhanced lesions appeared in the spinal cord at the 3rd, 6th, and 7th levels of the cervical spine. (I,J) T2-weighted MRI of the cervicothoracic and lumbar spine after two courses of high-dose steroid pulse therapy. T2-weighted images showed patchy lesions with a marked increase in signals in the spinal cord at the 3rd and 6th levels of the cervical spine and at the 9, 10, and 12th levels of the thoracic spine. (K,L) Axial fat-suppression T1-weighted images showed enhanced lesions at the 9 and 12th levels of the thoracic spine at the initial attack. (M,N) After two courses of high-dose steroid pulse therapy, follow-up T1-weighted MRI showed that abnormal enhancement was decreased. (O,P) After three courses of high-dose steroid pulse therapy and 5 plasmapheresis treatments, follow-up MRI showed that the enhanced foci were diminished but still present.
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Gadolinium-enhanced magnetic resonance imaging (MRI) demonstrated multiple foci of abnormal signal intensities in the medulla and spinal cord (Figure 1). Post-contrast-enhanced spinal MRI demonstrated abnormal enhanced lesions at the C3 to C4 level (Figure 1). Because MRI showed that abnormal enhanced lesions remained in the medullary cone and cauda equina (Figure 1), the patient started a regimen of oral prednisolone (PSL; 20 mg/day; 0.5 mg/kg/day) after the second plasma exchange, on day 35 post-admission, and she was discharged on day 40 post-admission (Figure 3).
Nerve conduction study (NCS) in the right tibial nerve and the results of right side short-latency somatosensory evoked potentials (SSEPs). (A) The waveform of NCS findings at first admission. Conduction block was observed. (B) The waveform of NCS findings at 11 days after first admission. Normal NCS. (C) The waveform of NCS findings at the second admission. NCS revealed prolonged distal motor latency (DML) and decreased motor nerve conduction velocity (MCV). (D) The waveform of NCS at 14 days after second admission. Normal NCS. (E) The waveform of SSEPs in the right upper limb before treatment at the initial attack. Normal SSEPs. (F) The waveform of SSEPs in the right upper limb after two courses of high-dose steroid pulse therapy and four selective plasma exchanges at the initial attack. N13 and N20 were not evoked. (G) The waveform of SSEPs in the right lower limb before treatment at the initial attack. Normal SSEPs. (H) The waveform of SSEPs in the right lower limb after two courses of high-dose steroid pulse therapy and four selective plasma exchanges at the first attack. Central conduction time (N19-P35) was normal but prolonged from 20.4 (in the first SSEPs) to 23.9 ms (normal values: 24.2-25.2 ms). N13: negative peak recorded from the posterior column at the C7 level of the spinal cord ~13 ms after median nerve stimulation. N20: negative peak recorded from the contralateral scalp ~20 ms after median nerve stimulation. N19: negative peak recorded from the posterior column at the Th12 level of the spinal cord ~19 ms after peroneal nerve stimulation. P35: positive peak recorded from the cortex ~35 ms after peroneal nerve stimulation. N19-N35: inter-peak latency, central sensory conduction time.
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Conduction block was observed in the right tibial nerve (distal and proximal CMAPs: 10.7 and 1.9 mV, respectively; Figure 2). Short-latency somatosensory evoked potentials (SSEPs) and visual evoked potentials were normal (Table 2, Figure 2). Upon treatment with methylprednisolone pulse therapy (1,000 mg/day for 3 days, two times), RCF was observed in NCS (Table 3, Figure 2); however, the patient's muscle strength in the right upper limb was weakened on day 8 post-admission. SSEP) to 23.9 ms (normal values: < 28.3 ms), and right N13 and N20 negative peaks were not observed (Table 2, Figure 2). Selective plasma exchange (1.25 plasma volume exchange with 5% albumin replacement fluid; selective plasma exchange procedures were performed twice a week for 2 weeks) and additional methylprednisolone pulse therapy only improved muscle strength in the right upper limb. MCV of right tibial nerve and right peroneal nerve: 32 and 35 m/s, respectively; Figure 2). MCV was also decreased in the left tibial nerve (36 m/s). Following treatment with methylprednisolone pulse therapy (1,000 mg/day for 3 days, two times), muscle strength in both lower limbs improved, NCS was normalized (Table 5), and abnormal signal intensities were decreased on the follow-up MRI (Figures 2, 4).
Clinical course and IgG index. MMT, manual muscle testing; CSF, cerebrospinal fluid; IVMP, intravenous methylprednisolone pulse therapy; M, magnetic resonance imaging; N, Nerve conduction study.
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Because MRI showed that abnormal enhanced lesions remained in the medullary cone and cauda equina (Figure 1), the patient started a regimen of oral prednisolone (PSL; 20 mg/day; 0.5 mg/kg/day) after the second plasma exchange, on day 35 post-admission, and she was discharged on day 40 post-admission (Figure 3). Oral PSL (40 mg/day; 1 mg/kg/day) was initiated after high-dose methylprednisolone pulse therapy (Figure 3).
Gadolinium-enhanced spinal T1-weighted magnetic resonance imaging (MRI) findings at recurrence. The lower "A" represents "anterior" in (A). The "R" represents "right" in (F). (A) Sagittal MRI showed abnormal enhanced lesions in the epiconus to cauda equina. (B) After two courses of high-dose steroid pulse therapy, follow-up MRI showed decreased enhancement in the epiconus to cauda equina at recurrence. (C,D) Axial images showed abnormal enhanced lesions at the 9 and 12th levels of the thoracic spine. (E,F) After two courses of high-dose steroid pulse therapy, follow-up MRI showed decreased enhancement at the 9 and 12th levels of the thoracic spine.
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Gadolinium-enhanced MRI demonstrated multiple foci of abnormal signal intensity from the epiconus to the cauda equina (Figure 4). Following treatment with methylprednisolone pulse therapy (1,000 mg/day for 3 days, two times), muscle strength in both lower limbs improved, NCS was normalized (Table 5), and abnormal signal intensities were decreased on the follow-up MRI (Figures 2, 4).