title: Hourglass-like constrictions of peripheral nerve in the upper extremity: a clinical review and pathological study.
abstract: BACKGROUND
  The development of an hourglass-like constriction in the nerve is rare, and its origin is unknown. Its clinical manifestations are not well documented, and the treatment protocol has not been established.
  
  
  OBJECTIVE
  To identify the cause, presentation, and possible treatment for patients with nerve palsies secondary to an hourglass-like constriction in the affected nerves.
  
  
  METHODS
  Patients presenting with peripheral nerve palsy caused by an hourglass-like constriction of nerves were retrospectively investigated in 2 hand centers. The patients' presentation and neurological findings were reviewed, and the immunohistochemistry of excised specimens was studied.
  
  
  RESULTS
  Forty-two patients who presented with 47 nerve palsies were examined. Forty-one patients experienced a sudden onset of pain in the upper limb, followed by flaccid paralysis in the affected muscles. Ten patients had multiple nerve involvement. Surgical exploration found 1 or more hourglass-like constrictions in the nerve. The treatments included internal neurolysis, neurorrhaphy, and nerve grafting. Thirty-one of 42 patients (36 nerves) were followed up for a mean of 48 months (range, 8-157 months). Fifteen of 16 nerves treated by neurolysis, 10 of 13 nerves treated by neurorrhaphy, and 4 of 7 nerves treated by nerve grafting had good recovery. CD8-positive T-lymphocyte infiltration was observed in all the excised specimens.
  
  
  CONCLUSIONS
  The clinical presentation of patients with hourglass-like constrictions in their nerves is similar to that of patients with neuralgic amyotrophy. Histochemical analysis suggests that the pathogenesis may be immunological in origin. The role of surgery in this condition is uncertain.
authors.affiliation: *Department of Hand Surgery, Beijing Jishuitan Hospital, Beijing, China; ‡Department of Pathology, Peking University Health Science Center, Xueyuan Rd, Haidian District, Beijing, China; §Department of Orthopaedics and Traumatology, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, Hong Kong SAR.
authors.forename: Yongwei
authors.initials: Y
authors.lastname: Pan
authors.forename: Shufeng
authors.initials: S
authors.lastname: Wang
authors.forename: Danfeng
authors.initials: D
authors.lastname: Zheng
authors.forename: Wen
authors.initials: W
authors.lastname: Tian
authors.forename: Guanglei
authors.initials: G
authors.lastname: Tian
authors.forename: Pak Cheong
authors.initials: PC
authors.lastname: Ho
authors.forename: Hi-Shan
authors.initials: HS
authors.lastname: Cheng
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Zhong
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003251:Constriction, Pathologic / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D010243:Paralysis / Q000601:surgery; D010525:Peripheral Nerves / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies; D034941:Upper Extremity / Q000294:innervation; D055815:Young Adult