title: [Hypertrophic olivary degeneration. MR imaging findings and temporal evolution].
abstract: OBJECTIVE
  to describe the magnetic resonance imaging features of hypertrophic olivary degeneration (HOD) subsequent to lesion in the "Guillain-Mollaret triangle".
  
  
  METHODS
  15 cases of HOD were diagnosed at MR imaging in 12 patients (4 women and 8 men) with posterior fossa lesion. The time interval from the beginning of the disease to the MR examination was 3 weeks to 8 (1/2) years. Evaluation of the changes in signal intensity over time of the lesions was available in 6 patients.
  
  
  RESULTS
  Nine cases of HOD were unilateral and three were bilateral. HOD was associated to a lesion of the contralateral dentate nucleus in 8 cases, to a lesion of the ipsilateral central tegmental tract in 5 cases and to a lesion of the contralateral superior cerebellar peduncle in 2 cases. Hyperintensity and hypertrophy of the olive on proton density and T2-weighted images appeared as early as 3 weeks after the ictus. A curved central hyperintensity (CCH) could be observed 7 months after the initial presentation. Decrease in the signal intensity was observed after 3 (1/2) years and abnormal signal intensity could persist for up to 13 years. Palatal myoclonus at 5 months was associated with HOD in one case.
  
  
  CONCLUSIONS
  HOD is considered a trans-synaptic degeneration subsequent to lesions in the Guillain-Mollaret triangle. Hyperintensity and hypertrophy of the olive are observed, sometimes with palatal myoclonus.
authors.affiliation: Neuroradiologie Diagnostique et Interventionnelle, Hôpital G et R Laënnec, CHU Nantes.
authors.forename: E
authors.initials: E
authors.lastname: Auffray-Calvier
authors.forename: H A
authors.initials: HA
authors.lastname: Desal
authors.forename: E
authors.initials: E
authors.lastname: Naudou-Giron
authors.forename: S
authors.initials: S
authors.lastname: Severin-Fontana
authors.forename: H
authors.initials: H
authors.lastname: Cavenaile-Dolez
authors.forename: A
authors.initials: A
authors.lastname: Stefan
authors.forename: E
authors.initials: E
authors.lastname: Doury
authors.forename: A
authors.initials: A
authors.lastname: de Kersaint-Gilly
mesh_terms: D018450:Disease Progression; D005260:Female; D006801:Humans; D006984:Hypertrophy; D008279:Magnetic Resonance Imaging; D008297:Male; D009410:Nerve Degeneration / Q000473:pathology*; D009847:Olivary Nucleus / Q000473:pathology*