Background: Wallerian degeneration (WD) of bilateral middle cerebellar peduncles
(MCPs) can occur following pontine infarction, but its characteristics have not yet been clarified because of the low incidence.
5 In MSA-P the degenerative changes predominantly affect the basal ganglia, particularly the putamen seen as hyperintense rim at the putaminal edge, atrophy and hypointensity of putaminal body on T2WI while in MSA-C changes predominantly affect infratentorial structures like pons and cerebellum, seen as atrophy and hyperintense signals in pons, cerebellum and middle cerebellar peduncles
with pontine hyperintensity (hot cross bun sign) on axial image,4 which was seen in both of our patient's MRI.
Caption: Figure 4: Magnetic resonance imaging cerebellar peduncles
showing "molar tooth appearance"
Caption: Figure 1: Axial (a) and coronal (b) noncontrast computed tomography (CT) of the head demonstrates hemorrhage in the region of the inferior right cerebellar peduncle
, which appeared intraparenchymal, with extension into the fourth ventricle.
First patient with weakness of both legs, had hyperintensities in subcortical and periventricular white matter, internal capsule, pons and cerebellar peduncle
When the lesion is in the dentate nucleus or superior cerebellar peduncle
, the olivary degeneration is contralateral.
The radiologist reported findings that are representative of multiple sclerosis, with involvement of the right cerebral peduncle, left middle cerebellar peduncle
, medulla oblongata, anterior brainstem at the level of the pontomedullary sulcus in the region of the VI cranial nerve origins, and within the upper cervical cord.
The diagnosis of probable or possible MSA-C was established based on the second consensus criteria:[sup] (1) a sporadic, progressive, and adult (>30 years) onset disease characterized by a cerebellar syndrome (gait ataxia with cerebellar dysarthria, limb ataxia, or cerebellar oculomotor dysfunction), and (2) at least one of the additional features as follows: parkinsonism (bradykinesia and rigidity); atrophy of putamen, middle cerebellar peduncle
, or pons on magnetic resonance imaging (MRI); hypometabolism on fluorodeoxyglucose-positron emission tomography (FDG-PET) in putamen; and presynaptic nigrostriatal dopaminergic denervation on single photon emission computed tomography (SPECT) or PET.
Radiologically, posterior fossa and brain stem anomalies are seen such as cerebellar vermian dysgenesis, expanded 4th ventricle, and thickened strained superior cerebellar peduncle
Magnetic resonance imaging (MRI) demonstrated that intradural extension resulted in brainstem compression and created an intimate relationship between the lesion and both the vertebral artery and the cervicomedullary junction (figure 1, B); the tumor also extended rostrally to the middle cerebellar peduncle
(figure 1, C).
The increased signal intensity in the middle cerebellar peduncle
(MCP) has been incorporated in the diagnostic criteria for "definite" FXTAS (2,3,4).
The fibers then course deep through the pons and exit from the central nervous system between the olive and the inferior cerebellar peduncle