Ears of the lynx sign (brain)

The ears of the lynx sign refers to abnormal T2/FLAIR cone-shaped hyperintensity at the tip of the frontal horn of the lateral ventricles in the region of forceps minor which resembles the tufts of hair crowning the ears of a lynx.

This sign is seen in hereditary spastic paraplegia with thin corpus callosum (HSP-TCC), a form of hereditary spastic paraplegia associated with mutations of the spastic paraparesis gene 11 (SPG11) on chromosome 15 ^1,2. The spatacsin vesicle trafficking associated (SPG11) gene, codes spatacsin. The sign may also be seen in SPG15, another of the hereditary spastic paraplegias, which is caused by a mutation in the zinc finger fyve domain-containing protein 26 (ZFYVE26) gene, encoding spastizin. This sign has also been described in Marchiafava-Bignami disease ³.

Differential diagnosis

• ependymitis granularis
  • a normal variant, commonly seen
  • can appear similar but usually less pronounced