A rare case of hereditary spastic paraplegia: Case report

Hereditary spastic paraplegias represent a rare set of monogenic disorders encompassing 79 distinct genetic variations. The principal culprit behind recessive hereditary spastic paraplegia is frequently attributed to mutations in the spastic paraplegia gene, particularly type 11, closely followed by type 15. This category is typically characterized by nonspecific clinical features, including cognitive decline, which may precede the development of progressive lower limb weakness and spasticity. While the thinning of the spinal cord is recognized as the magnetic resonance imaging hallmark of hereditary spastic paraplegia, insights into specific subtypes can be gleaned from brain magnetic resonance imaging findings. Notably, thinning of the corpus callosum emerges as a prominent abnormality in almost one-third of recessive hereditary spastic paraplegias, providing pertinent diagnostic clues. Additionally, recent observations introduce a distinctive anomaly termed the "ears of the lynx" sign, primarily affecting the forceps minor of the corpus callosum. This sign is highly indicative of type 11 and 15 hereditary spastic paraplegias. We present the case of a patient diagnosed with hereditary spastic paraplegia type 15 through exome genetic testing, with the initial magnetic resonance imaging revealing the characteristic "ears of the lynx" sign.