Progressive Encephalomyelitis with Rigidity and Myoclonus Resolving after Thymectomy with Subsequent Anasarca: An...

Area of Science:

• Neurology
• Immunology
• Pathology

Background:

• Progressive encephalomyelitis with rigidity and myoclonus (PERM) is a rare autoimmune disorder affecting the central nervous system.
• PERM is often associated with thymoma, a tumor of the thymus gland.
• Glycine receptor antibodies are implicated in some cases of PERM.

Observation:

• A 75-year-old woman presented with classic PERM symptoms, confirmed glycine receptor antibody positivity, and a concurrent thymoma.
• Following surgical removal of the thymoma (thymectomy), her neurological deficits showed significant improvement.
• Unexpectedly, the patient developed severe anasarca (generalized edema) with massive pleural effusions and dangerously low albumin levels (hypoalbuminemia).

Findings:

• Autopsy revealed pleural edema and mononuclear cell infiltration, but notably lacked the characteristic neuropathological findings of PERM.
• The patient's death was attributed to the complications arising from the anasarca and pleural effusions.
• While thymectomy reversed the encephalomyelitis signs, the subsequent development of anasarca suggests a complex, potentially autoimmune, post-thymectomy process.

Implications:

• This case highlights that effective treatment for PERM may resolve neurological manifestations.
• The development of anasarca post-thymectomy warrants further investigation into potential autoimmune mechanisms.
• Understanding the link between thymoma, PERM, and systemic edema is crucial for improving patient outcomes.