Purpose or Case Report: Introduction: Hereditary spastic paraplegias (HSP) are heterogeneous neurodegenerative disorders causing progressive lower limb spasticity. MRI findings are variable but crucial for differential diagnosis. Classic radiological features include spinal cord atrophy (most common), corpus callosum thinning, and T2/FLAIR hyperintensities in the corticospinal tracts, such as the posterior limb of the internal capsule and the " ears of the lynx" sign (periventricular frontal signal). We present a case demonstrating both typical and significant atypical MRI findings.
Case Report: A 16-year-old male patient presented to our clinic with a three-year history of "finger-tip walking." Neurological examination revealed mild mental retardation, increased deep tendon reflexes (DTR) in the lower extremities, and mild spasticity in the feet. The patient's history indicated normal developmental milestones, and there was no known family history of neurological disease. Clinical findings were primarily consistent with HSP, and radiological evaluation was planned.
Radiological Findings: Cranial MRI showed findings typical for HSP: symmetric T2 hyperintensities in the posterior limbs of both internal capsules and in the frontal periventricular white matter (the " ears of the lynx" sign). The corpus callosum was markedly thin, especially the genu and body. Atypical findings were also present: diffuse symmetric T2 signal changes in the bilateral temporoparietal white matter and prominent cerebral sulcal spaces (cerebral atrophy) for his age.
Discussion and Conclusion: This case highlights the classic radiological triad of complicated HSP: corpus callosum thinning, posterior internal capsule signal changes, and the "ears of the lynx" sign, all reflecting corticospinal tract involvement. However, the presence of significant cerebral atrophy and widespread temporoparietal white matter abnormalities are atypical. These atypical features expand the differential diagnosis, necessitating clinical correlation to rule out overlapping conditions such as periventricular leukomalacia (PVL) sequelae or a hypomyelination disorder. This case underscores that while MRI can reveal characteristic signs of HSP, it may also present a mixed picture with unexpected findings, emphasizing its role in characterizing the full scope of white matter pathology..
Methods & Materials:
Results:
Conclusions: