Stiff person syndrome: When a rare disorder hits the headlines
Treatment options
Because of wide variability in signs and symptoms of the disorder, treatment of SPSD is a highly individualized cocktail of interventions, which might include immunotherapy and GABA-ergic agonists, as well as nonmedication treatments. The response to these agents can be difficult to quantify.
Benzodiazepines (diazepam, clonazepam, baclofen) along with other oral symptomatic treatments are often recommended as first-line therapy because of their ability to enhance GABA.4
First-line immunotherapy is usually intravenous immunoglobulin, steroids, or plasmapheresis. Second- and third-line agents include rituximab, mycophenolate mofetil, azathioprine, cyclophosphamide, and combination immune treatments.
Dr. Newsome and Dr. Dalakas have independently published a step-by-step therapeutic approach to SPSD.3,5 But in patients with paraneoplastic stiff person syndrome, eradication of their cancer is critical, although, per Dr. Newsome, “this does not always cure SPS and most of these patients still have residual disability.”
But immune-based therapies are only part of what should be a multipronged treatment approach, said Dr. Newsome. He also strongly advocates for non-pharmacological interventions, such as selective physical therapy (stretching, ultrasound, and gait and balance training), heat therapy, aquatherapy, deep-tissue massage or myofascial techniques, osteopathic or chiropractic manipulation, acupuncture, and acupressure.3
Because SPSD is considered a progressive disorder for some, a reasonable goal of treatment is to prevent worsening, said Dr. Newsome. This can take time: “We don’t expect the treatments to work overnight. It involves consecutive months and, sometimes, a couple of years of immune treatment before you start to see it impact the person’s life favorably.”
Patients who are not well informed about the long-term goal of treatments might be tempted to abandon the treatments prematurely because they don’t see immediate results, Dr. Newsome added. Encouraging realistic expectations is also important, without dashing hopes.
“I have patients who were marathon runners, and they want to get back to doing marathons. I would love nothing more than for people to get back to their pre-SPSD levels of function. But this may not be a realistic goal. However, this does not mean that quality of life can’t be helped.”
Nevertheless, Dr. Newsome encourages clinicians to reassess regularly, especially because lack of disease biomarkers makes it hard to objectively monitor the impact of therapy.
“It’s always a good rule of thumb, especially in the rare disease space, to step back and ask: ‘Are we on the right treatment path or not?’ If we’re not, then it is important to make sure you have the correct diagnosis. Even when you have a patient who fits the textbook and you, yourself, diagnosed them, it is important to continue to re-evaluate the diagnosis over time, especially if there is consideration of changing treatments. It is also important to make sure there is not something else on top of the stiff person syndrome that is working in parallel to worsen their condition.”
Be alert for comorbidity
Undiagnosed comorbid conditions that can complicate SPSD include Parkinson’s disease or myasthenia gravis, to name a couple, which Dr. Newsome has seen more than once. “We’ve seen a few people over the years who have both SPSD and another autoimmune or degenerative neurological condition.”
