Progressive encephalomyelitis with rigidity and
myoclonus (PERM) is a rare and disabling syndrome characterized by painful
spasms,
myoclonic jerks,
hyperekplexia, brainstem signs, and
dysautonomia, which is considered to be a severe form of stiff person spectrum disorder (SPSD) and is mostly associated with
glycine receptor antibodies. The PERM has an acute or subacute course, with complex and varied initial symptoms mainly manifest as stiffness and
pain. The authors present the case of a male patient admitted for intractable stiffness and paroxysmal
myoclonus of the lower extremities preceded by a 5-day history of facial weakness. After admission, his symptoms deteriorated rapidly. He developed progressive generalized hypertonia and painful
spasms, which quickly spread to the upper extremities, and he suffered frequent paroxysmal
myoclonus. Serum and cerebrospinal fluid (CSF) were tested by a cell-based assay, and both were positive for
glycine receptor antibodies (GlyR-Abs). The patient developed complications, such as crushed teeth, lumbar vertebral
compression fractures, and psoas major muscle
abscess, during rapid
disease progression, although he responded well after being treated with intravenous
methylprednisolone and
immunoglobulin. This report of PERM, initiated as
facial palsy followed by acute progression, helps to expand the clinical spectrum of this rare autoimmune disorder and raise awareness of the prevention of complications.