Cannabis derivatives therapy for a seronegative stiff-person syndrome: a case report

Stiff-person syndrome (SPS) is an uncommon and disabling disorder characterized by progressive rigidity and episodic painful spasms involving axial and limb musculature. SPS treatment is mostly based on benzodiazepines, baclofen, immunosuppressants and intravenous immunoglobulin. Cannabis derivatives [tetrahydrocannabinol (THC) and cannabidiol (CBD)] are available as an oromucosal spray (Sativex(®)), indicated as add-on treatment, for symptom improvement in patients with moderate to severe spasticity because of multiple sclerosis (MS). Our objective is to report a case of seronegative SPS successfully treated with THC-CBD oromucosal spray.

We report a case of a 40-year-old man presenting with progressive muscle stiffness and intermittent spasms for 6-years. The diagnosis of stiff-person syndrome was based on the clinical features and neuroelectrophysiologic findings of continuous motor unit activity. Glutamic acid decarboxylase autoantibodies was absent in our patient, in both serum and cerebrospinal fluid (CSF). Cannabis derivatives oromucosal spray was introduced after a series of unsatisfactory traditional medical treatments. After 14 months treated with THC-CBD oromucosal spray, improvement was verified in the eight dimensions of the scale of SF-36 quality of life questionnaire.

Clinical experience with cannabis derivatives in patients with multiple sclerosis is accumulating steadily, but there is no current literature about its efficacy for SPS. Because MS and SPS share some neurological symptoms such as spasticity and rigidity, it is thought that THC-CBC can be an option for SPS patient. Our case report suggests that THC-CBD oromucosal spray is an alternative treatment for patients with refractory SPS, and further validation is appropriate.