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Neuroradiology Case of the Week

Case 248

Virendra Kumar, MD, Guruprasad Srinath, MD, and P-L Westesson, MD, PhD, DDS

Clinical Presentation: A 2-year old cerebral palsy child presented with an episode of mild fever with vomiting and coughing, followed by  seizures. The child was unresponsive for the duration of the seizures.
     Past history: The child was born at 23 weeks gestation following premature rupture of membranes. He weighed 1 lb 9 oz at delivery and spent 6 weeks on a ventilator and then 6 weeks in NICU. He had a Grade 4 IV hemorrhage which did not require shunting.

Imaging Findings: Left cerebral atrophy with loss of white matter, especially in the temporal and parietal lobes. Gliosis in the left para-ventricular region and significant atrophy of the right cerebellum, middle cerebellar peduncle and right side of pons with thinning of the corpus callosum.

Diagnosis: Crossed cerebellar diaschisis

Discussion: Crossed cerebellar diaschisis refers to hypometabolism in a cerebellar hemisphere contralateral to a cerebral hemispheric lesion. The location of the lesion is a critical factor in producing this effect as lesions located in the motor cortex, anterior corona radiata, and thalamus produce the most marked suppression of the contralateral cerebellar cortical metabolism. The cerebellar hemispheric hypometabolism is thought to be secondary to disconnection of cerebro-ponto-cerebellar pathways, which leads to decreased oxygen and glucose utilization and, hence, decreased CO₂ production, which results in local arterial constriction (decreased cerebellar blood flow). The causes of crossed cerebellar diaschisis include stroke, brain tumor, and sickle cell disease.
     The cause of cerebral volume loss in this patient appears to be most likely vascular secondary to prematurity, and subsequent Grade 4 IV hemorrhage.

References:

1. Chakravarty A. Crossed cerebral - cerebellar diaschisis : MRI evaluation. Neurol India. 2002 Sep;50(3):322-5. [Medline]