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Updated: Jun 25, 2026
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Predicting the motor outcome of acute disseminated encephalomyelitis by apparent diffusion coefficient imaging: Two
Shoji Kawashima1, Noriyuki Matsukawa, Yoshino Ueki
1Department of Neurology, Nagoya City University Graduate School of Medicine. 1-40 Kawasumi, Mizuho-ku, Nagoya, Japan.
Abstract:
We present two cases of young adults with acute disseminated encephalomyelitis (ADEM) who developed severe conscious and motor disturbances. Despite their similar initial clinical course and MRI findings, their motor function outcomes were quite different. In both cases, fluid attenuated inversion recovery (FLAIR) sequenced MRI showed multiple symmetric hyperintense lesions in the internal capsule and the brainstem at the subacute stage. However, in case 1 the apparent diffusion coefficient (ADC) was pathologically decreased in the internal capsule, whereas the ADC for case 2 was normal. At the end of the examination period, severe motor disability (bedridden state) with brain atrophy apparent on MRI remained in case 1, whereas case 2 made an almost full recovery without brain atrophy. These two cases suggest that altered ADC in the internal capsules at the subacute stage may reflect a different pathogenesis between cytotoxic and vasogenic edema, and may be a valuable indicator for the prognosis of motor disturbance.
Insights
Acute disseminated encephalomyelitis (ADEM) in young adults can have varied outcomes. Altered apparent diffusion coefficient (ADC) on MRI may predict motor function prognosis in ADEM patients.
Area of Science:
- Neurology
- Radiology
- Pathophysiology
Background:
- Acute disseminated encephalomyelitis (ADEM) is an immune-mediated inflammatory demyelinating disease.
- ADEM typically presents with neurological deficits, including altered consciousness and motor disturbances.
- Early diagnosis and prognostic indicators are crucial for managing ADEM.
Observation:
- Two young adults with ADEM presented with similar initial clinical and MRI findings, including symmetric brainstem and internal capsule lesions on FLAIR sequences.
- Case 1 showed a decreased apparent diffusion coefficient (ADC) in the internal capsule, indicating cytotoxic edema.
- Case 2 had a normal ADC in the internal capsule, suggesting vasogenic edema.
Findings:
- Despite similar initial presentations, Case 1 experienced severe motor disability and brain atrophy.
- Case 2 achieved near-complete motor recovery without brain atrophy.
- The difference in ADC values correlated with distinct clinical outcomes.
Implications:
- Apparent diffusion coefficient (ADC) values in the internal capsule during the subacute stage may differentiate between cytotoxic and vasogenic edema in ADEM.
- ADC may serve as a valuable imaging biomarker for predicting motor prognosis in ADEM patients.
- Understanding these pathophysiological differences can guide therapeutic strategies and improve patient outcomes.
