Progressive Encephalomyelitis with Rigidity and Myoclonus

Abstract

Progressive encephalomyelitis with rigidity and myoclonus (PERM) is a rare autoimmune neurological condition. Antibodies targeting glycine receptors (GlyR) have been implicated in PERM. Because GlyR activity is enhanced by inhaled anesthetic drugs at clinically relevant concentrations, there is a theoretical possibility that these drugs may be less effective in the presence of GlyR antibodies. We describe a case of general anesthesia in a patient with PERM and GlyR antibodies. This patient did not demonstrate a clinically significant alteration in the behavioral effects of anesthesia using induction of anesthesia with sevoflurane and maintenance of anesthesia using sevoflurane and nitrous oxide.

A case report of rigidity and recurrent lower limb myoclonus: progressive encephalomyelitis rigidity and myoclonus syndrome, a chameleon

“…This condition is often associated with hyperekplexia due to brainstem dysfunction [ 3 , 10 – 12 ]. This brainstem dysfunction is manifesting in alteration of consciousness, cerebellar ataxia and respiratory insufficiency due to breathing and swallowing difficulties [ 6 , 13 , 14 ].…”

“…This condition has previously been associated with the glutamic acid decarboxylase (GAD), dipeptidyl-peptidase-like protein-6 (DPPX) antibodies and glycine receptor (GlyR) serum antibodies [ 3 , 14 , 22 ]. The latter is associated with a disruption of the inhibitory glycinergic synaptic transmission, which is prominent in the spinal cord and brainstem [ 5 , 13 ]. Abnormal cerebrospinal fluid (CSF) is seen and additional denervation on the electromyography (EMG) [ 2 , 3 , 6 , 11 , 18 , 23 , 24 ].…”

Editorial Commentary

“…Some antibodies such as those reactive to the N-methyl-d-aspartate (NMDA) receptor are strongly associated with cancer, while others such as antibodies to the voltage-gated potassium complex are less likely to be found with neoplasms. 4 The first case, from the United Kingdom by Papadopoulou et al, 1 involves a patient with progressive encephalomyelitis with rigidity and myoclonus (PERM). The patient had a rectal neoplasm that was accompanied by glycine antibodies and a clinical picture of PERM and required resection.…”

“…Two case reports in this issue provide information on anesthetic management of patients with recently described autoimmune encephalopathies. 1,2 These syndromes result from antibodies directed at neuronal cell surface targets. 3 Such encephalopathies are often but not always associated with cancer.…”