Reliability of clinical diagnosis of dystonia.
BACKGROUND
There is only one small single-center study on the reliability of the diagnosis of focal dystonia. The aim of this study was to assess the inter-rater reliability of dystonia diagnosis among neurologists with different professional experience.


METHODS
Twenty-nine adults (18 with dystonia, 9 with other movement disorders, and 2 healthy controls) were videotaped while undergoing neurological examination and during the process of collecting information on the history of their condition. Each case was diagnosed by 35 blind raters (12 general neurologists, 21 neurology residents, and 2 experts in movement disorders) from different hospitals. Sensitivity and specificity were calculated confronting raters with the gold standard (the caring physician). Inter-rater agreement was measured by the Kappa statistic.


RESULTS
Specificity and sensitivity were 95.2 and 66.7%, 76.3 and 75.2%, 84.6 and 71.6% for experts, general neurologists, and residents, respectively. Kappa values on dystonia diagnosis ranged from 0.30 to 0.46. The agreement was moderate for experts and residents (0.40-0.60) and fair for general neurologists (0.20-0.40). Kappas were the highest among experts for cranial and laryngeal dystonia (0.61-1), but not for cervical dystonia (0.37).


CONCLUSIONS
The diagnosis of dystonia is difficult and only partially mirrors a physician's background.
Department of Neuroscience, IRCCS - Institute for Pharmacological Research 'Mario Negri', Milan, Italy.
Ettore
E
Beghi
Valentina
V
Regio
Annamaria
A
Papantonio
Anna Rita
AR
Bentivoglio
Alfonso
A
Fasano
Danilo
D
Fogli
Laura
L
Giordano
Roberto
R
Piolti
Giuseppe
G
Rinaldi
Pasqualino
P
Simone
Luigi M
LM
Specchio
Pietro
P
Tonali
Paola
P
Torelli
Michele
M
Zarrelli
Paolo
P
Messina
D000328:Adult; D004421:Dystonia / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D009460:Neurologic Examination; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity