RT Journal Article
SR Electronic
T1 Progressive encephalomyelitis with rigidity and myoclonus
JF Neurology
JO Neurology
FD Lippincott Williams & Wilkins
SP 1521
OP 1528
DO 10.1212/WNL.0000000000000372
VO 82
IS 17
A1 Balint, Bettina
A1 Jarius, Sven
A1 Nagel, Simon
A1 Haberkorn, Uwe
A1 Probst, Christian
A1 Blöcker, Inga Madeleine
A1 Bahtz, Ramona
A1 Komorowski, Lars
A1 Stöcker, Winfried
A1 Kastrup, Andreas
A1 Kuthe, Martin
A1 Meinck, Hans-Michael
YR 2014
UL http://n.neurology.org/content/82/17/1521.abstract
AB Objective: To describe a novel and distinct variant of progressive encephalomyelitis with rigidity and myoclonus (PERM) associated with antibodies directed against dipeptidyl peptidase-like protein 6 (DPPX), a regulatory subunit of the Kv4.2 potassium channels on the surface of neurons.Methods: Case series describing the clinical, paraclinical, and serologic features of 3 patients with PERM. A recombinant, cell-based indirect immunofluorescence assay with DPPX-expressing HEK293 cells was used to detect DPPX antibodies in conjunction with mammalian tissues.Results: All patients presented with a distinct syndrome involving hyperekplexia, prominent cerebellar ataxia with marked eye movement disorder, and trunk stiffness of variable intensity. Additional symptoms comprised allodynia, neurogenic pruritus, and gastrointestinal symptoms. Symptoms began insidiously and progressed slowly. An inflammatory CSF profile with mild pleocytosis and intrathecal immunoglobulin G synthesis was found in all patients. High DPPX antibody titers were detected in the patients' serum and CSF, with specific antibody indices suggestive of intrathecal synthesis of DPPX antibodies. Response to immunotherapy was good, but constant and aggressive treatment may be required.Conclusion: These cases highlight the expanding spectrum of both PERM and anti-neuronal antibodies. Testing for DPPX antibodies should be considered in the diagnostic workup of patients with acquired hyperekplexia, cerebellar ataxia, and stiffness, because such patients might benefit from immunotherapy. Further studies are needed to elucidate both the entire clinical spectrum associated with DPPX antibodies and their role in pathogenesis.DPPX=dipeptidyl peptidase-like protein 6; EOG=electrooculography; FDG=[18F]-fluorodeoxyglucose; GAD=glutamic acid decarboxylase; Ig=immunoglobulin; IVIg=IV immunoglobulin; PERM=progressive encephalomyelitis with rigidity and myoclonus; SPS=stiff person syndrome