Table 1.

References addressing sensorimotor integration in patients with cervical dystonia (CD), focal hand dystonia (FHD), benign essential blepharospasm (BEB), and DYT1 dystonia (DYT1). The number after the year reflects position in the reference list. Under Participants, N_D, N_C, and N_O respectively denote dystonia, control, and other non-dystonic movement disorder sample sizes, R denotes age range, M denotes mean (standard deviation), and D denotes duration of symptoms, all in years.

Author/Year	Participants	Type	Technique / Design	Key Findings
Anastasopoulos, 1998 [29]	ND: 10, NC: 12, M: 43.0 (13.9), D: 4–16	CD	Perception of ‘visual straight ahead’ (VSA)	VSA shifted to trunk under head/trunk misalignment. Mechanisms suggested: (i) central compensation restoring VSA, (ii) reference frame shift to more stable trunk coord. system
Anastasopoulos, 2003 [58]	ND: 12, NC: 12, M: 43.8 (10.7), D: 6.1 (3.4)	CD	Neutral head position estimation after head/trunk displacement	Patients use neck proprioception, but lack head posture knowledge, suggesting an offset of a non-sensory setpoint.
Anastasopoulos, 2013 [50]	ND: 8, NC: 10, R: 42–72, D: 2–10	CD	Peripheral target foveation and trunk kinematic assessment	Prevalence of hypometric gaze saccades and trunk bradykinesia in neck dystonia.
Anastasopoulos, 2014 [64]	ND: 13, NC: 23, R: 20–61, D: 3–16	CD	Measured resistive torques to passive head/trunk/head+trunk movements	Resistive torques higher in patients than controls and independent of torticollis direction, suggesting impaired proprioceptive feedback.
Avanzino, 2013 [45]	ND: 14, NC: 17, M: 42.3 (12.3), D: 9.6 (7.4)	FHD	Temporal expectation task: video of hand motion or inanimate obj.	More timing error in patients when viewing hand motion vs. inanimate object motion, suggesting planning deficits.
Avanzino, 2018 [85]	ND: 20, NC: 17, M: 60.3 (11.5)	CD	Catching a ball with unpredictable mass	Adaptation to heavier mass similar between patients and controls, but the anticipatory adjustment to impact reduced for patients, suggesting cerebellum’s role in predictive control is abnormal in CD.
Bove, 2004 [114]	ND: 12, NC: 12, M: 59 (15.1), D: 9.4 (5.5)	CD	Postural balance and stepping in place w/wo vibration to neck	Reference frame for body orientation progresses to different egocentric reference as disease advances.
Brugger, 2018 [23]	ND: 35, NC: 16, Older adults, D: ~16 (12.5)	CD	Quiet stance posture analysis during neck vibration with/without effective sensory trick	Patients with effective sensory trick responded similarly to controls during vibration; those without had little change in posture. Effectiveness of sensory trick may require an intact ability to preserve proprioceptive gain.
De Pauw, 2017 [57]	ND: 24, NC: 70, No ages listed, D: 13 (8.7)	CD	3D motion tracking of return-to-neutral head position	Larger positional errors in patients than in controls, and tendency to overshoot return to neutral head position.
De Pauw, 2018 [116]	ND: 23, NC: 36, M: 59.4 (14.6), D: 13 (8.7)	CD	Seated postural control	Postural instability was increased in patients, with center of pressure correlating to impairments in cervical sensorimotor control.
Filip, 2013 [41]	ND: 30, NC: 30, M: 52 (13.7), D: 3–38	CD	Virtual projectile intercept task	Visual input - predictive motor control integration problem, suggesting impairment to the cerebellar anticipatory timing function and ability to integrate visual and motor information.
Frima, 2003 [24]	ND: 21, NC: 18, R: 29-72	CD	Tendon vibration inducing illusion of elbow joint movement	Perception of movement increased in patients, suggesting subnormal muscle spindles elasticity.
Frima, 2008 [25]	ND: 30, NC: 19, R: 29–75, incl. parents, siblings, children	CD	Same as Frima 2003	Higher prevalence of abnormal perception in 1st degree relatives, suggesting trait heritability.
Hoffland, 2014 [97]	ND: 26, NC: 10, M: 56.5 (8.2)	CD, FHD, BEB	Split-belt gait adaptation with 3D motion capture	Gait adaptation impairment in BEB and FHD, but not CD patients, suggesting different cerebellar pathologies.
Hubsch, 2011 [51]	ND: 14, NC: 14, M: 31.8 (15.1)	DYT1	Reactive saccade adaptation	Less adaptation in patients than controls, suggesting cerebellar dysfunction in DYT1 dystonia (myoclonus).
Inzelberg, 1995 [67]	ND: 8, NC: 6, R: 19–43, D: 2–27	non-specific	Temporal and spatial analysis of unimanual reaching w/wo vision	Velocity profiles in patients less symmetric than in controls, longer deceleration phase, similar to PD. Impairments were more prevalent during ‘closed-loop’ control suggesting abnormalities in integrating feedback into subsequent motor commands.
Kägi, 2013 [38]	ND: 32, NC: not specified, M: 56.4 (9.9), D: 12.5 (8.5)	CD	Temporal discrimination to visual, tactile, and visuotactile stimuli	Visuotactile discrimination improvement with sensory tricks, particularly in patients with shorter disease duration, suggesting a progressive loss of adaptive mechanisms.
Karnath, 2000 [63]	Case study of 48 y/o female	CD	3D tracking of head position before/after vibration	More improvement after vibration than TENS or haptics, suggesting impaired central processing of neck muscle afferents.
Katschnig-Winter, 2014 [69]	ND: 12, NC: 11, M: 58.8 (9.6), D: 6–36	CD	Center-out reaching: motor reference task, sequence learning, motor adaptation	Higher peak velocities, longer movement times in patients, normal sequence learning and motor adaptation.
Lekhel, 1997 [22]	ND: 19, NC: 12, M: 33.8, R: 24–49	CD, FHD, BEB	Postural sway analysis, with vibration of neck muscles	Decreased postural sway in patients, possibly due to vestibular signal - neck muscle spindle signal integration.
Müller, 2004 [32]	ND: 28, NC: 28, M: 49.5 (14.3), D: 0.5–43	CD	Subjective straight-ahead task, BORB battery, VOSP battery	Intact allocentric but compromised egocentric spatial abilities in patients; reliance on proprioceptive neck inputs.
Naumann, 2000 [37]	ND: 10, R: 28–76, D: 1–19	CD	PET recording in response to sensory trick application	Sensory tricks normalizing head position shift egocentric midline reference to opposite side of head turn, decreasing M1 activation.
Pelosin, 2009 [72]	ND: 10, NC: 10, M: 50.5, R: 35-65, D: 1-10	CD	Center-out reaching before/after botulinum toxin treatment	Botox improved spatiotemporal control of reaching, possibly improving proprioceptive feedback by relaxation of muscle spindles.
Putzki, 2006 [26]	ND: 23, NC: 13, R: 42–64, D: 0.5–24	CD, BEB	Passive finger movement detection and discrimination	Patients were less sensitive to movement, with poorer directional discrimination, suggesting contribution of defective sensory processing to dystonic symptoms.
Rome, 1999 [20]	ND: 24, NC: 18, NO: 21, R: 30–77, D: 1–33	CD, FHD	Arm position matching, with/without tendon vibration	Contralateral joint position perception impaired in dystonia, but not PD. Botox injections did not recover function.
Sadnicka, 2018 [84]	ND: 10, NC: 12, M: 43.9 (14.3), D: 2–58	DYT1	Center-out reaching with visuomotor perturbation	Increased baseline task-dependent variability predicted poor adaptation in patients. Specifically, variability in feedforward component of movement was most predictive, suggesting unwanted noise affects planning, but not online corrective actions.
Sedov, 2019 [52]	ND: 12, R: 22–68, D: 2–17	CD	In-vivo single-unit neuron recording in basal ganglia and EMG of trapezius	Malfunction of neural integrator results from impairments to cerebellar, basal ganglia, and feedback converging on integrator. Asymmetry in pallidal activity correlated with degree and direction of head turning.
Vacherot, 2007 [31]	ND: 12, NC: 11, M: 63 (4.7)	CD	Balance testing, assessing subjective visual vertical	Whole body stabilization not affected in patients, but head stabilization reliant on referencing the trunk.
van der Steen, 2014 [46]	ND: 15, NC: 15, M: 36.5 (12), D: 1–20, prof. musicians	FHD	Temporal perception and motor task battery	Musician’s dystonia not associated with sensory deficits; likely a highly task-specific disorder.
Yoneda, 2000 [21]	ND: 29, NC: 15, M: 57.7, R: 29–79, D: 11.5	CD, FHD, BEB	Arm position matching, with/without tendon vibration	Abnormal perception of tonic vibration reflex in patients suggests abnormal muscle spindle afferent processing. Despite localized motor deficits, authors suggest FHD is a systemic disorder.