Radiology Teaching Files > Case 22803664

Contributed by: bala chandiran, Radiologist, govt.general hospital,pondicherry, India.
Patient: 42 year old male
History: A forty two years old male was referred for evaluation of cerebellar signs.

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Findings: MR-TIW axial and sagittal showed a well defined hypointense lesion in the right inferior cerebellum.The T2W axial and coronal and FLAIR axial showed hyperintense signal in the same area.The DWI showed increased signal and ADC decreased signal in the right inferior cerebellum indicating recent infarct.Predictably there was no contrast enhancement.
Diagnosis: Cerebellar infarct due to PICA involvement.

The posterior inferior cerebellar artery (PICA) territory includes all of the posteroinferior cerebellum, the ipsilateral cerebellar tonsil, and the ipsilateral inferior vermis. The PICA also frequently supplies the posterolateral medulla and infarction in this location results in the lateral medullary syndrome or the so-called Wallenberg syndrome. The clinical manifestations and structures affected in Wallenberg's syndrome include:
-preganglionic Horner syndrome (descending reticulospinal tracts to cord sympathetics)
-ataxia (cerebellum, inferior peduncle)
-facial pain, numbness, impaired sensation (CN V nucleus, spinal tract)
-dysphagia, hoarseness, diminished gag reflex (CN's IX and X)
-diminished taste (CN IX nucleus and solitary tract)
-vertigo, nausea, vomiting (vestibular nuclei and connections)
-nystagmus, diplopia, oscillopsia (restiform body, inferior and medial vestibular nuclei)
-numbness, decreased pain and temperature in trunk and extremities (spinothalamic tract)
The variability in vascular supply of the cerebellum and medulla is reflected by PICA infarcts. Sometimes a PICA infarct produces the classic Wallenberg syndrome described above while others may spare the medulla. Single PICA branch occlusions can affect a very small area.
PICA Infarctions.-Infarction in the distribution of the PICA typically encompasses the posteroinferior surface of the cerebellar hemisphere and ipsilateral vermis The lateral medulla may or may not be involved with PICA infarctions . The extent of a PICA territory infarction and the amount of deep white matter involvement depend on the variability of the PICA distribution and on the reciprocal and balanced supply of this regionby the AICA and the SCA

References: 1. PeterJ. Cormier, Eugene R. Long, EricJ. Russell, MR Imaging of Posterior Fossa Infarctions: Vascular Territories and Clinical Correlates, RadloGraphics 1992; 12:1079-1096
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Additional Details:

Case Number: 22803664Last Updated: 2011-01-26
Anatomy: Cranium and Contents   Pathology: Vascular
Modality: MRAccess Level: Readable by all users
Keywords: mri in cerebellar infarct

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