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Published on: November 4, 2017
Histopathological Investigation of Progressive Encephalomyelitis with Rigidity and Myoclonus: An Autopsy Case
Hiroyuki Yabata1,2, Ryutaro Nakamura1, Seiji Sugiyama1
1Department of Neurology, Shiga University of Medical Science, Japan.
Abstract:
Progressive encephalomyelitis with rigidity and myoclonus (PERM) is a rare disease associated with the presence of anti-glycine receptor (GlyR) antibodies. We herein report an autopsy case of an 80-year-old man diagnosed with anti-GlyR antibody-positive PERM who presented with symptoms of oculomotor dysfunction and autonomic failure. Despite intensive immunotherapy, the neurological symptoms showed almost no improvement, and the patient succumbed to aspiration pneumonia and bacterial translocation. Postmortem pathology revealed mild inflammatory changes and neuronal loss that were disproportionate to a severe clinical presentation. These results suggest that the clinical symptoms of PERM may result from antibody-mediated GlyR internalization, leading to neuronal disinhibition, rather than a neuroinflammatory signature.
Insights
Progressive encephalomyelitis with rigidity and myoclonus (PERM) is linked to anti-glycine receptor (GlyR) antibodies. This case suggests PERM symptoms stem from antibody-mediated GlyR internalization, not inflammation.
Area of Science:
- Neurology
- Immunology
- Pathology
Background:
- Progressive encephalomyelitis with rigidity and myoclonus (PERM) is a rare neurological disorder.
- PERM is characterized by the presence of anti-glycine receptor (GlyR) antibodies.
- Clinical presentation often includes rigidity, myoclonus, and autonomic dysfunction.
Purpose of the Study:
- To report an autopsy case of anti-GlyR antibody-positive PERM.
- To investigate the pathological basis of severe clinical symptoms in PERM.
- To explore the mechanism underlying neurological dysfunction in anti-GlyR antibody-associated PERM.
Main Methods:
- Autopsy case report of an 80-year-old male with anti-GlyR antibody-positive PERM.
- Clinical assessment including oculomotor dysfunction and autonomic failure.
- Postmortem neuropathological examination to evaluate inflammatory changes and neuronal loss.
Main Results:
- The patient presented with severe neurological symptoms, including oculomotor dysfunction and autonomic failure.
- Despite intensive immunotherapy, neurological symptoms showed minimal improvement.
- Postmortem findings revealed mild inflammatory changes and neuronal loss, disproportionate to the clinical severity.
- Antibody-mediated GlyR internalization leading to neuronal disinhibition is proposed as the pathogenic mechanism.
Conclusions:
- Clinical symptoms in anti-GlyR antibody-positive PERM may be primarily due to antibody-mediated GlyR internalization and subsequent neuronal disinhibition.
- The findings challenge the notion that severe clinical manifestations are solely driven by a prominent neuroinflammatory signature.
- This case highlights a potential non-inflammatory mechanism contributing to the pathogenesis of PERM.
