To develop a scale to guide treatment strategies during autonomic crises in FD.

Patients with FD experience recurrent episodes of paroxysmal sympathetic overactivity known as autonomic crises (AC).  Signs and symptoms can include tachycardia, hypertension, psychomotor agitation, akathisia, severe nausea, retching, vomiting, skin flushing, blotching, and sweating. A reliable scale is essential to assess the effectiveness of treatment.

We prospectively identified and rated the severity of hemodynamic and behavioral changes during and after habitual treatment (benzodiazepines and clonidine) of self-reported autonomic crises in patients with FD. We documented the duration and all reported features of ongoing crisis and crisis resolution, as determined by the patient and caregiver. Each feature was ranked on a Likert-type scale, with a higher score indicating greater severity. Data are described as mean ± standard deviation or median and interquartile range, as appropriate.

We evaluated 43 autonomic crises in 4 patients with FD (2 males and 2 females, age 32 ± 8) with increased blood pressure and heart rate, skin flushing or blotching, sweating, nausea/retching/vomiting, and psychomotor changes. The magnitude of blood pressure and heart rate rise were graded from 0 to 4, while for the remaining variables, the score ranged from 0 to 2, adding up to a total score ranging from 0 to 16. The median total score when patients were first identified as in crisis was 5 (3-7) points and 1.0 (0-2) when resolved, whereas in patients with ongoing crisis, the median score was 4 (4-6) points (p<0.001). A score greater than 2.5 points distinguished ongoing crisis from crisis resolution, with a sensitivity of 100% and specificity of 91%.  

The development of the Autonomic Crisis Scale (ACS) is a first step in standardizing assessments for autonomic crises, providing a reliable method to evaluate symptom severity.