Onion-bulb patterns predict acquired or inherited demyelinating polyneuropathy

Jennifer A. Tracy, Peter J. Dyck, Christopher J. Klein, Ja Nean K. Engelstad, Jane E. Meyer, P. James B. Dyck

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Introduction: Onion-bulbs (OB) are concentrically layered Schwann-cell processes, surrounding nerve fibers, occurring in both inherited and acquired demyelinating polyneuropathies. We investigated whether OB patterns (generalized, mixed, or focal) correlate with acquired or inherited neuropathies. Methods: One hundred thirty-one OB-rich nerve biopsies were graded for OB pattern and inflammation without knowledge of clinical history. We classified inherited (n = 49) or acquired (n = 82) neuropathies based solely on clinical history. Results: Fifty-one biopsies had generalized (34 inherited vs. 17 acquired, P < 0.001), 54 mixed (48 acquired vs. 6 inherited, P < 0.001), and 26 focal/multifocal (inherited [n = 9], acquired [n = 17]) OB. Inflammation occurred more frequently in acquired (n = 54) than inherited (n = 14) neuropathy (P = 0.004). Discussion: Generalized OB correlates with inherited neuropathy; mixed OB with acquired. Inflammation occurs more in acquired neuropathy cases. OB patterns are best explained by ubiquitous Schwann-cell involvement in inherited and multifocal Schwann-cell involvement in acquired neuropathies and predict the electrophysiology of uniform demyelination in inherited and unequal demyelination in acquired neuropathies. Muscle Nerve 59:665–670, 2019.

Original languageEnglish (US)
Pages (from-to)665-670
Number of pages6
JournalMuscle and Nerve
Issue number6
StatePublished - Jun 2019


  • chronic inflammatory demyelinating polyradiculoneuropathy
  • demyelinating neuropathy
  • hypertrophic neuropathy
  • inherited neuropathy
  • onion bulbs
  • peripheral neuropathy

ASJC Scopus subject areas

  • Physiology
  • Clinical Neurology
  • Cellular and Molecular Neuroscience
  • Physiology (medical)


Dive into the research topics of 'Onion-bulb patterns predict acquired or inherited demyelinating polyneuropathy'. Together they form a unique fingerprint.

Cite this