Table 4.

Summary of main clinical characteristics of common presentations of FD

FD
Type	Cranial dystonia	Fixed dystonia	Paroxysmal dystonia
Age at onseta	Fourth to sixth decade	Second to fourth decade	Third to sixth decade
Gender	F ≫ M	F ≫ M	F > M
Common phenotypic characteristics	Unilateral tonic downward lip pulling with ipsilateral platysma involvement	Lower limbs > upper limbs > neck/shoulder; fixed plantar flexion and inversion with toe curling; carpal flexion with prominent clawing of fourth and fifth fingers; tonic dystonic posturing of neck (latero/torticollis) with ipsilateral shoulder elevation	Attacks with variable phenomenology and duration; presence of paroxysmal episodes on a background of continual dystonic posturing; alterations of responsiveness during attacks possible; presence of atypical triggers and relieving maneuvers
Additional features	“Other Babinski sign”; asynchronous spasms of lower and upper facial muscles; bilateral tonic contractions of the lower face with unilateral spasm of the upper face	CRPS‐I common; spread to other extremities possible; absence of sensory tricks or overflow dystonia	Frequency and severity increase during examination; presence of additional movement disorders during paroxysmal episodes; atypical response to medication
Presence of pain	Common	Prominent	Common
Neurophysiology	Blink reflex recovery cycle and postexcitatory inhibition normal	Normal sensorimotor plasticity	—
Reference	43, 48, 91	27, 28, 38, 39, 63, 95	27, 28, 41

^aCases with onset in childhood/adolescence or older than sixth decade possible.

CRPS‐I, Chronic regional pain syndrome type I; F, female; M, male.