Stiff-Person Syndrome: Seeing Past Comorbidities to Reach the Correct Diagnosis

Table 2

Most commonly used therapies for patients with stiff-person syndrome [13].

Most commonly used therapies for patients with stiff-person syndrome
Therapy	Dose per day	Presumed mechanism of action
GABA-enhancing drugs
Sedative anxiolytics
Diazepam	5–100 mg	Central GABAA agonist
Clonazepam	2.5–6 mg	Central GABAA agonist
Alprazolam	2–4 mg	Central GABAA agonist
Lorazepam	6 mg	Central GABAA agonist
Antiepileptic drugs
Vigabatrin	2–3 g	Irreversible inhibition of GABA-transaminase
Valproate	0.6–2 g	Augments GABA transmission
Gabapentin	3600 mg	Structurally related to GABA, but the mechanism of action is unknown
Levetiracetam	2000 mg	Facilitates inhibition of GABAergic transmission
Tiagabine	6 mg	Blocks GABA reuptake
Antispasticity agents
Baclofen	10–60 mg	GABAB agonist
Tizanidine	6 mg	Central α2-adrenergic action; inhibits norepinephrine release
Dantrolene	200–400 mg	Dissociates excitation-contraction coupling and blocks release of Ca^++ from the sarcoplasmic reticulum
Botulinum toxin A	—	NMJ blocking; prevents acetylcholine exocytosis
Immunotherapies
IV immunoglobulin	2 g/kg	Immunosuppression/modulation
Rituximab	2 g (in two divided doses)	B-cell depletion
Plasmapheresis	5–6 passes	Immunosuppression/modulation
Corticosteroids	Up to 60 mg	Immunosuppression/modulation
Immunosuppressive agents
Azathioprine	2.5–3 mg/kg	Immunosuppression/modulation
Methotrexate	15–20 mg	Immunosuppression/modulation
Mycophenolate	2–3 g	Immunosuppression/modulation
GABA = γ-aminobutyric acid, IV = intravenous, NMJ = neuromuscular junction