Presentation
History of pontine hemorrhage, 10 months prior. Now presents with all limb weakness, palatal myoclonus, gait disturbance (delivered to the study on wheelchair).
Patient Data
There are post hemorrhagic infarct changes in left pons/superior cerebellar peduncle/midbrain and the in the right caudate nucleus as well. The inferior olivary nucleus is larger and with increased T2 signal intensity bilaterally, but more evident on the left.
Axial T2 shows a linear hyperintensity focus with a T2-hypointense rim at the left pons, tends to lateral wall of 4th ventricle through left superior cerebellar peduncle. Same focus localized at right nucleus caudatus. Note enlarged hyperintense both inferior olivary nuclei. Also there are many confluent foci of T2 hyperintensity within anterior and posterior horns, both corona radiata, reflecting small vessel ischemia. Enlarged perivascular spaces in basal ganglia D=S.
Sagittal T1 shows hypointense lesions located at body of corpus callosum, right basal ganglia, left midbrain. Also empty sella is presented.
Axial FLAIR fat suppressed images demonstrate post-infarct changes in left pons, left superior cerebellar peduncle, right basal ganglia, body of corpus callosum, multiple confluent foci of T2-hyperintensity. Well-defined, hypertrophic, hyperintense inferior olivary nuclei.
Axial DWIs do not show acute diffusion restriction. ADC maps correspond DWI and does not show acute pathology
Coronal FLAIR images demonstrate well-defined post-infarct changes in left pons, superior cerebellar peduncle and right basal ganglia. Well seen both inferior olivary nuclei hypertrophy and increased T2-intensity. Multifocal small vessel brain ischemia involving body of corpus callosum.
Axial gradient shows many foci of susceptibility artifacts within the cerebellum, parietal, occipital and temporal lobes, basal ganglia, left pons, superior and inferior cerebellar peduncles, depicting hemosiderin deposition.
Case Discussion
This is a rare case of hypertrophic olivary degeneration (HOD) in a patient with previous history of pontine hemorrhagic infarct.
HOD is a rare condition characterized by a unique pattern of trans-synaptic degeneration caused by damage dentato-rubro-olivary pathway. This disease process is different from all other types of neuronal degeneration in that the main pathophysiology is hypertrophy of neurons.
Differential diagnosis:
- infarction
- neoplasms: primary or secondary
- demyelination
- infections