Early Onset Hereditary Spastic Paraplegia in Childhood: A Remarkable Differential Diagnosis in Children with Gait Problems

Introduction: Gait disturbances are one of the most frequent reasons to refer a patient for further neuropediatric investigation. Differential diagnosis varies from CP, muscle and metabolic disorders to habitual toe walking. We report another rare cause of gait disturbances, which should always be kept in consideration.

Case Report: A 3-year-old boy was referred to our outpatient clinic for further investigation of gait disturbances and reduced resilience during exercise noticed from 18 months of age. Pregnancy and birth history were uneventful with no indication of intrauterine or perinatal hypoxia or asphyxia. Early motor milestones were achieved within the normal timeframe. From the age of 18 months, a significant discrepancy of the boy’s gait, strength and endurance compared with his peers in kindergarten were noted. He showed a tendency to fall and could not keep up with the other kids during exercise. Initially, the boy presented with muscular hypotonia and weakness, a slow and clumsy gait with a broad base and ataxic appearance, Gower sign was positive. Extensive clinical, laboratory, and imaging studies did not elicit any abnormality. Over the course of following year, his clinical situation deteriorated and signs of spasticity became apparent while cranial magnetic resonance imaging (MRI) remained unremarkable. Gait analysis showed a pattern similar to bilateral spastic hemiplegia left greater than right with premature muscle activation in swing and stance. Because of a family history of a grandfather and great-grandmother on the maternal side with an early onset of a foot deformity and despite a healthy mother and older sister, genetic testing for autosomal-dominant hereditary spastic paraplegia was initiated and confirmed a heterozygote missense mutation in the ATL 1 gene (c.1483C>T, p.Arg495Trp). The mutation has previously been reported in independent families with early-onset spastic paraplegia.

Conclusion: Hereditary spastic paraplegia is a rare, but important differential diagnosis for children presenting with gait disturbances and sign of spasticity similar to bilateral hemiplegia and normal MRI.