title: Hypertrophic olivary degeneration and holmes' tremor secondary to bleeding of cavernous malformation in the midbrain.
abstract: BACKGROUND
  Hypertrophic olivary degeneration (HOD) is a rare phenomenon, probably related to transsynaptic degeneration of the inferior olivary nucleus. It usually occurs as a response to primary injury of dento-rubro-olivary pathways.
  
  
  METHODS
  A young man developed Holmes' tremor 7 months after a cavernous malformation bleed in the midbrain. Typical findings of HOD were observed in the magnetic resonance images: bilateral and asymmetric hypertrophy of the olivary nucleus with slight hypersignal in T2-weighted images. Because of the striking disability related to drug-resistant tremor, the patient underwent stereotactic thalamotomy (nucleus ventralis intermedius of the thalamus/zona incerta) with pronounced functional improvement over time.
  
  
  CONCLUSIONS
  Disruption of circuits in the Guillain-Mollaret triangle classically results in palatal myoclonus, however midbrain (Holmes') tremor can also occur, as we now describe.
authors.affiliation: Division of Functional Neurosurgery of the Institute of Psychiatry of the Hospital das Clinicas of the University of São Paulo.
authors.forename: Djalma F S
authors.initials: DF
authors.lastname: Menéndez
authors.affiliation: Abnormal Movements Unit of the Hospital das Clinicas of the University of São Paulo.
authors.forename: Rubens G
authors.initials: RG
authors.lastname: Cury
authors.affiliation: Abnormal Movements Unit of the Hospital das Clinicas of the University of São Paulo.
authors.forename: Egberto R
authors.initials: ER
authors.lastname: Barbosa
authors.affiliation: Discipline of Neurosurgery of the São Paulo University Medical School.
authors.forename: Manoel J
authors.initials: MJ
authors.lastname: Teixeira
authors.affiliation: Discipline of Neurosurgery of the São Paulo University Medical School.
authors.forename: Erich T
authors.initials: ET
authors.lastname: Fonoff
keywords: Olivary nucleus/pathology; central nervous system vascular malformations; magnetic resonance imaging; stereotaxic surgery; tremor/etiology