[Hypertrophic olivary degeneration. MR imaging findings and temporal evolution].
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.
Auffray-Calvier
E
E
Neuroradiologie Diagnostique et Interventionnelle, Hôpital G et R Laënnec, CHU Nantes.
Desal
H A
HA
Naudou-Giron
E
E
Severin-Fontana
S
S
Cavenaile-Dolez
H
H
Stefan
A
A
Doury
E
E
de Kersaint-Gilly
A
A
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*