Spasticity distribution and severity in individuals with HTLV-1-associated myelopathy/tropical spastic paraparesis

In individuals with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), spasticity is one of the main symptoms. The neurological signs of the disease are well defined, but details of how spasticity appears in these individuals have not been well explored. To describe spasticity location and severity of HAM/TSP individuals. Cross-sectional study with individuals older than 18 years, diagnosed with HAM/TSP and with lower limb spasticity. Pregnant women, individuals with other associated neurological diseases, and those using antispastic drugs were not included. Spasticity was assessed by the Modified Ashworth Scale (MAS), applied to the abductor, adductor, flexor, and extensor muscles of the hips, flexors, and extensors of the knees, dorsiflexors, plantiflexors, evertors, and inverters of the foot. Thirty participants were included. The plantiflexor muscles (90%), knee extensors (80%), knee flexors (63,3%), and adductors (50%) were most frequently affected by spasticity. Twenty-three (76.7%) individuals had mixed spasticity, 5 (16.7%) with distal spasticity and 2 (6.7%) with proximal spasticity. MAS was similar between the lower limbs in at least 6 of the 10 muscle groups of each individual. Spasticity was mostly mixed in the lower limbs, with more frequently mild severity. The individuals were partially symmetrical between the lower limbs. The most affected muscle groups were the plantiflexors, knee extensors and flexors and the hip adductors, consecutively, being predominantly symmetrical.