The utility of creatine kinase in status dystonicus and pre-status dystonicus

Background: Individuals with dystonia may experience acute exacerbations of symptoms. Objectives: We aimed to explore the role of serum creatinine kinase (CK) levels as a biomarker for dystonia severity during episodes of exacerbation. Methods: A retrospective review of admissions to a paediatric tertiary centre due to Status Dystonicus over a 5-year period. A comprehensive scoping review of the published literature for SD and pre-SD was also undertaken. Results: In total 58 admissions for 45 patients were identified. Dystonia Severity Action Plan (DSAP) was Grade 3 (pre-SD) for 41/58 admissions and Grade 4–5 (SD) for 17 admissions. Length of admission was significantly longer for SD (P < 0.005), with poorer outcomes (Fishers Exact test P < 0.001). CK levels were measured in 24/41 episodes of pre-SD, and 16/17 episodes of SD. Median peak CK levels were higher (729 IU/L) in the SD compared to pre-SD group (179.5 IU/L) (p = 0.009). For patients with SD, serial CK measurements tracked dystonia severity over time. Literature review identified 201 episodes of SD in 190 subjects. Note was made of CK measurement in 92/201 (45.8 %) episodes: pre-SD (DSAP 3) in 8 and SD in 84 [DSAP 4 (n = 30), and DSAP 5 (n = 54)] respectively, with a numerical value provided in in 73/90 episodes/cases. Median CK value was 4066 IU/L (884–22,105, 25th to 75th Centile). In the literature review, for 11 episodes serial CK measures were shown to correlate with severity of dystonic symptoms. Conclusions: serum CK levels represent a potentially useful biomarker for dystonia severity that differs between pre-SD and SD, and provide a measure to track dystonia severity at an individual patient basis.