Assess upper limb function in pediatric hereditary spastic paraparesis (HSP)

HSP is a heterogenous, inherited disorder characterized by lower extremity weakness and spasticity. The impact of the condition on upper limb function is not reported.

100 participants (M=57, F=43), mean age 9yrs 11mo (11mo-23yrs 4mo) met inclusion criteria. Identified genes included SPG4 (n=36), SPG3A (n=18), and 46 other known HSP SPG subtypes. Over half of the HSP cohort (63%, n=63/100) presented with upper limb involvement, including increased tone (n=16/98), decreased strength (n=23/92), diminished sensation[AS1] [AS2]  (n=26/65), and decreased motor coordination (n=18/69). In those with serial exams, 14% (n=14/100) demonstrated a deterioration in upper limb function over serial visits.

Chi-square tests were used to analyze associations. There were no statistically significant associations between upper limb involvement and gene type [X² (18, N=100) =15.84, p=0.60] or strength and gene type [X² (18, N=92) =26.26, p=0.09]. There were statistically significant associations between spasticity and gene type [X² (18, N=98) =38.42, p=0.003] and Gross Motor Function Classification System (GMFCS) equivalency levels and upper limb involvement [X² (4, N=84) =15.05, p=0.005]. All the individuals with lower gross motor abilities (IV and V) exhibited upper limb impairments. 57% GMFCS equivalent I-III showed upper limb involvement, primarily characterized by decreased motor coordination, leading to challenges with functional tasks such as handwriting, fastening buttons, tying shoes, and manipulating small objects.