(Black, L., Gaebler-Spira, D. 2016). The authors studied 12 patients with Dravet syndrome and SCN1A mutations, aged 2-17. All patients showed gait disturbances and fine motor delays, and those over the age of 6 had crouch gait and joint deformities. The authors studied how electrical signals travel along the muscles of the peripheral nervous system (arms/legs, vs. the central nervous system which involves the brain and spinal cord) by performing nerve conduction studies and electromyography. These tests send electrical signals down the muscle, and the time it takes to travel from one end to other coupled with the strength of the signal can determine whether the nerves are healthy or damaged, termed motor neuropathy in this case. Most patients had some evidence of motor neuropathy, and the authors suggest the neuron dysfunction may be due to SCN1A and may be a contributing factor to crouch gait.

Black, L., Gaebler-Spira, D. (2016). Crouch gait in Dravet syndrome. Pediatric Neurology Briefs. Nov; 30(11): 42. doi: 10.15844/pedneurbriefs-30-11-2 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5127818/