Misoprostol For Control Of Painful Tonic Spasms

Background: Painful tonic spasms may occur in association with multiple sclerosis (MS) and have recently been reported to occur even more frequently in people with neuromyelitis optica (NMO). Painful tonic spasms (PTS) are paroxysmal episodes associated with sustained abnormal tonic posture. The spasms are often triggered by movement but also occur after sensory stimulation or spontaneously.  They may be induced in some patients by hyperventilation. They usually begin in one limb and may spread to involve the other ipsilateral limb or the face. Spasms are usually under 2 minutes in duration, however they may occur numerous (sometimes > 50) times per day. These recurrent events are not only disabling but usually quite painful. They are commonly treated with anticonvulsant agents although baclofen and corticosteroids may also be tried. Although PTS may spontaneously subside, they may be long-standing and refractory to therapy. We present a case report describing use of the misoprostol with dramatic benefit.

Objectives: We describe use of misoprosol to control refractory painful tonic spasms in a patient with NMO.

Methods: Single case report

Results: The patient is a 59-year-old woman diagnosed with seropositive NMO in 2005. Her disease is currently under control on rituximab given every 3 months. She has experienced PTS throughout her disease course and has never achieved complete remission of the PTS. Her PTS usually involve her right leg and may spread to involve her  arm and cause her head to turn to the right. Tone may also become increased in her left leg. These events interfere with function and make it difficult for her to leave the home and function in the community.  Events would occur up to 60 times per day. She was initially treated with carbamazepine with a marked decrease but not total control of her events. Upward dose titration to 1800 mg per day was associated with ataxia. She was switched to oxcarbazepine without additional benefit (and developed hyponatremia). Prior treatment with gabapentin up to 1800 mg per day and levetiracetam up to 5000 mg per day also did not stop her events. Her best control was 5-6 episodes per day. These medications were associated with side effects including sedation. Prior courses of methylprednisolone were associated with transient reductions in PTS as well. Due to continue to disabling PTS, she was treated with misoprostol 200 mcg 3 times per day. Within one day of starting this agent fully expressed dystonic spasms had stopped which has continued unabated for 8 weeks now.  She continues to have an occasional episode of mild right foot dystonia.

Conclusions: This case demonstrates a marked benefit from using misoprostol for control of PTS. The agent was selected due to benefits experienced using it for trigeminal neuralgia, another type of ephaptic phenomenon seen in people with MS and related disorders. We will discuss possible mechanisms of action.