Cockayne syndrome

Cockayne syndrome is a rare autosomal recessive dysmyelinating disease. Cockayne syndrome is classified among the childhood leukodystrophies, and brain imaging findings are cardinal features suggesting the diagnosis of Cockayne syndrome. Previously published Cockayne syndrome imaging studies have described major brain atrophy (predominantly white matter), bilateral and symmetrical calcifications, and a lack of myelination of the white matter, but whether these findings are due to hypomyelination or demyelination remains unclear.

Clinical presentation

Clinical features include failure to thrive, neurodevelopmental delay, cutaneous photosensitivity, pigmentary retinopathy, sensorineural hearing loss, dental caries, and cachectic dwarfism.

The diagnosis is considered very likely if the first 2 clinical criteria and at least 3 of the other criteria mentioned above are present.

Pathology

AssociationsGenetics

• Cockayne syndrome is an autosomal recessive disorder due to mutations in genes encoding nucleotide excision repair proteins ERCC6 (CSA) and ERCC8 (CSB).

  Cockayne syndrome belongs to the group of nucleotide excision repair disorders that includes xeroderma pigmentosum

Radiographic features

CT

Cockayne syndrome is one of the causes of basal ganglia calcifications in a child. Calcification may also occur in cerebellar and cerebral cortical regions. CT may also show early atrophy.

MRI

There is atrophy which predominantly involves the supratentorialwhite matter, the cerebellum, the corpus callosum, and the brainstem ¹.

• T2: calcification may be seen as low signal in putaminal (most common), dentate nuclear and cortical regions 
• MRS: 
  • normal Creatine level
  • elevated Lactate level
  • decreased NAA/Cr ratio in white and gray matter
  • decreased Cho/Cr ratio in the white matter
  • normal or decreased Cho/Cr ratios in the gray matter

The combination of demyelination and basal ganglia calcification may, therefore, be helpful in the imaging of this entity ³.

History and etymology

This condition is named after Edward Alfred Cockayne, English physician (1880-1956).

Differential diagnosis

• Pelizaeus-Merzbacher: may show similar features in early stages, but no calcification occurs
• Mitochondrial diseases: the severe and progressive brain atrophy is more suggestive of Cockayne syndrome
• congenital cytomegalovirus infections: brain calcifications typically show a periventricular subependymal distribution
• Aicardi-Goutières syndrome: calcifications punctuate in basal ganglia, deep and periventricular white matter