Primary lateral sclerosis:(PLS) is a rare motoneuronal disease resulting in pyramidal and bulbar syndrome. The clinical pattern mimics amyotrophic lateral sclerosis (ALS). Nevertheless, PLS evolution resembles hereditary spastic paraplegia and most of the patients have a good life expectancy. Spasticity is a major symptom of the disease. Despite the rarity of the disease, many patients with PLS are referred to our department. This study describes spasticity management and outcome in patients with PLS using botulinum toxin injections.

Between 2009 and 2015, 55 patients suffering from PLS with either paraparesis or tetraparesis were referred to the specialized consultation in physical rehabilitation medicine department in Hospital Pitié-Salpêtrière in Paris, in order to manage their spasticity. Their medical charts were retrospectively analyzed, to determine the effects of botulinum toxin therapy.

Among the 55 patients, 44 patients received botulinum toxin injections, preceded by motor block for 16 patients. Injections were mostly performed in lowers limbs in order to ameliorate comfort, or ambulation. The treatment was uncomplicated. Among the 44 patients treated with botulinum toxin injections, 28 patients (63.6%) were satisfied by the treatment. Twenty-two patients (50%) underwent botulinum toxin therapy for at least a year, 6 patients (13.6%) for more than 3 years.

This study confirms the interest of botulinum toxin for the treatment of spasticity in patients with PLS as it provided clinical improvement of spasticity in almost two thirds of our patients. PLS evolutes slowly, this treatment could be reiterated in a long-term approach.