Answer:
HYPERTROPHIC OLIVARY DEGENERATION
Findings:
Focal T2/FLAIR hyperintensity in left anterolateral medulla with minimal expansion, corresponding to inferior olivary nucleus FLAIR hyperintensities seen in both superior cerebellar peduncles. There is relative atrophy of left cerebral peduncle. Lacunar infarcts noted in both paramedian pons. There were also infarcts in left temporal and both frontal lobes.
Discussion:
Hypertrophic Olivary Degeneration is a rare transsynaptic degeneration seen at around 3 weeks following an injury to dentato-rubro olivarypathway (DROP) (The Guillain– Mollaret triangle. Lesions could be seen in ipsilateral red nucleus, the inferior olivary nucleus (which has connections through the central tegmental tract) and the contralateral dentate nucleus The causes could be Ischemic infarction, Demyelination, Hemorrhage (hypertensive disease or diffuse axonal injury). Clinically this condition may present as Palatal myoclonus or Ocular myoclonus or Dentatorubral tremors. The presence of both hyperintensity and expansion indicates the injury could be between 6 months and 3-4 yrs. it is Unique in that Hypertrophy and enlargement of the inferior olivary nuclei (ION) occurs in contrast to the atrophy usually observed. The other differentials would be Infarcts or Demyelinating Plaques . However the territories involved in infarcts are commonly lateral , posterior or anteromedial in contrast to Hypertrophic Olivary Degeneration which is anterolateral.
Contributed By:
Dr. Babu Peter MD, DNB
Associate Professor, Barnard Institute of Radiology, Chennai
Senior Consultant Radiologist, Aarthi Scans, Chennai
HYPERTROPHIC OLIVARY DEGENERATION
Findings:
Focal T2/FLAIR hyperintensity in left anterolateral medulla with minimal expansion, corresponding to inferior olivary nucleus FLAIR hyperintensities seen in both superior cerebellar peduncles. There is relative atrophy of left cerebral peduncle. Lacunar infarcts noted in both paramedian pons. There were also infarcts in left temporal and both frontal lobes.
Discussion:
Hypertrophic Olivary Degeneration is a rare transsynaptic degeneration seen at around 3 weeks following an injury to dentato-rubro olivarypathway (DROP) (The Guillain– Mollaret triangle. Lesions could be seen in ipsilateral red nucleus, the inferior olivary nucleus (which has connections through the central tegmental tract) and the contralateral dentate nucleus The causes could be Ischemic infarction, Demyelination, Hemorrhage (hypertensive disease or diffuse axonal injury). Clinically this condition may present as Palatal myoclonus or Ocular myoclonus or Dentatorubral tremors. The presence of both hyperintensity and expansion indicates the injury could be between 6 months and 3-4 yrs. it is Unique in that Hypertrophy and enlargement of the inferior olivary nuclei (ION) occurs in contrast to the atrophy usually observed. The other differentials would be Infarcts or Demyelinating Plaques . However the territories involved in infarcts are commonly lateral , posterior or anteromedial in contrast to Hypertrophic Olivary Degeneration which is anterolateral.
Contributed By:
Dr. Babu Peter MD, DNB
Associate Professor, Barnard Institute of Radiology, Chennai
Senior Consultant Radiologist, Aarthi Scans, Chennai