Table 2.

Summary of results of included studies in chronological order

Study	N	Cognitive assessment	Measures with significant differences (AOIFD v HC)	Measures with no significant differences (AOIFD v HC)	NIH QA score	QA comments
Leplow et al. 1994	18 CD 18 HC	Route walking test, body placing test, Ratcliff figures, Benton’s Line Orientation Task, dot localisation, draw-a-bicycle	CD worse than HC: Verbal IQ, route walking test, Draw-a-Bicycle (if Lezak scoring used)	CD v HC: personal orientation test, Ratcliff Figures, Dot Localisation, Benton Line Orientation, draw a bicycle (if Kolb and Wishaw scoring used)	Fair	Some evidence of selection bias Some evidence of information bias Lack of adjustment for multiple comparisons and small N
Hinse et al. 1996	15 CD 15 HC	Mehrfachwahl-Wortschatzest (German equivalent of NART), Hebb’s recurring-digits test, Corsi’s block tapping test, Judgement of the visual-vertical, Benton’s line orientation test, Route walking test, personal orientation test, Ratcliff’s mental re-orientation test, standardised road-map of direction sense.	CD worse than HC: Verbal IQ, road map test number of correct turns, body-scheme errors, route walking test correct turns, mental orientation test mean errors	CD v HC: recurring digits test, block tapping test, Line orientation test	Fair	Some evidence of selection bias Some evidence of information bias Lack of adjustment for multiple comparisons and small N
Rinnerthaler et al. 2006	12 BSP 20 CD 32 HC	MDRS, VOSP, FEEL	BSP + CD worse than HC: FEEL disgust	BSP + CD v HC: MDRS, VOSP, FEEL total score, FEEL: happiness, fear, surprise, sadness, anger BSP v CD: Feel disgust	Fair	Some evidence of selection bias Lack of statistical power
Hoffland et al. 2011	13 CD 29 HC	NART, A cancellation test of psychomotor speed, graded difficulty arithmetic test, Design Fluency (DKEFS)	CD worse than HC: more errors when copying meaningless gestures for both dominant, non-dominant hand, meaningless sequence with dominant hand, sig more errors on sequence task	CD v HC: NART, A Cancellation test, tapping task, graded difficulty arithmetic test, design fluency CD v HC: no significant differences in copying meaningful gestures with either hand, types of errors, meaningful sequence task with either hand, meaningless sequence performed with the non-dominant hand	Fair	Some selection bias Small N, not adjusted for multiple comparisons
Sitek et al. 2011	20 CD 23 HD 25 PDdys 21 PDndys	MMSE, AVLT, Stroop CWIT	CD better than HD: AVLT 1–5, ALVT delayed recall CD better than HD and PDdys: Stroop CWIT	AVLT % recall after a delay	Fair	Some selection and information bias
Sitek et al. 2013	20 CD 23 HD 25 aPD 21 mPD	MMSE, Stroop CWIT	CD better than aPD: Stroop CD less errors than aPD and HD	NR	Fair	Some selection and information bias
Dinkelbach et al. 2015	13 CD	Verbal Learning and Memory Test, DS forward, block span forward, NVLT, DOT, VF(lexical and semantic), TEA (elevator counting, elevator counting with distraction, elevator counting with reversal), Stroop, BJLOT, VOSP, graded difficulty arithmetic test, MWT-A	CD post DBS: sig. worse category fluency	CD post DBS: VLMT, DOT, WMS-R Block span, NVLT, DOT, RWT, TEA, FWIT, VOSP, BJLOT, Verbal IQ (MWT-A)	Good	Small N
Chillemi et al. 2018	23 CD 12 HC	Line bisection task	CD worse than HC: line bisection		Fair	Some evidence of selection bias Some evidence of measurement bias
Czekóová et al. 2017	CD 25 HC 26	WAIS-R (picture completion, Similarities, Digit-Symbol Coding, Arithmetic), WMS -III (Word list), Stroop test, TMT, Tower of London, phonemic and semantic VF, FPRT	CD worse than HC: Picture Completion, Arithmetic, Digit-Symbol Coding, TMT A, TMT-B, lexical fluency, semantic fluency, Tower of London, Immediate verbal memory, delayed verbal memory, FPRT +, FPRT + Cognitive inappropriateness, intentions, belief, FPRT + Affective detection, empathy, FPRT -	CD v HC: recognition memory, Stroop test	Fair	Some evidence of selection bias Small N, lack of statistical power and multiple comparisons
Bayram et al. 2018	30 PD 30 CD 30 HC	MMSE, VF (phonemic, semantic, action)	CD worse than HC: action verbs	CD v PD v HC: MMSE, Phonemic fluency, Semantic fluency, Action fluency, non-action word counts, action verb counts CD v PD: No between group differences on non-action and action word counts	Fair	Some evidence of selection bias
Foley et al. 2017	25 CD 13 generalised dystonia 50 HC	WAIS-III (prorated verbal and non-verbal abilities), NART, MMSE, Graded Naming Test, VOSP silhouettes/ incomplete letters, Recognition Memory Test, TEA (elevator counting), TMT-A, TMT-B, Modified Card Sorting Test, Brixton Spatial Anticipation Test, Hayling Sentence Completion Test, FAS VF	Combined dystonia worse than HC: TMT-A, TMT-B, TMT-B-TMT-A Combined dystonia: 31.58% (n = 12) impaired on at least of on the TMT-B, Stroop and Hayling tests	CD V generalised: NART, MMSE, Graded naming, VOSP, RMT, TEA, MCST, Brixton, FAS Combined dystonia v HC: NART, WAIS-III, memory	Good	Some evidence of selection bias Lack of statistical power
Yang et al. 2017	60 CD 60 BSP 60 HC	ACE-R	CD + BSP worse than HC: ACE-R total, orientation, memory, fluency, language, visuospatial 42.9% impaired on ACE-R (15 CD, 21 BSP)	CD v BSP: ACE-R total, ACE: orientation, memory, fluency, language, visuospatial	Fair	Some evidence of selection bias Large N but no a priori power calculation
Huh et al. 2018	12 CD	The Seoul Neuropsychological Screening Battery: DS forwards and backward, Korean BNT, RCFT (copy, immediate recall, delayed recall, and recognition), Seoul Verbal Learning test (immediate recall, delayed recall, recognition), COWAT, Korean Colour-Word Stroop, Korean MMSE	CD worse post DBS: Stroop word and colour reading correct responses	CD post DBS: DS, BNT, RCFT, Seoul Verbal Learning, COWAT, MMSE	Good	Small N
Bradnam et al. 2019	10 CD 11 HC	Line bisection, Bells Task, Landmark Task, Temporal Order Task, Walking Task	CD worse than HC: Walking task. n = 3 with at a neglect like pattern on at least one of the tests (n = 1 Line Bisection Task, n = 2 Temporal Order Task, n = 1 walking task)	CD v HC: Line Bisection, Bells Task, Landmark Task, Temporal Order Task, Walking Task	Fair	Some evidence of selection bias Small N, lack of statistical power
Maggi et al. 2019	26 CD 27 BSP	MoCA, MIST, Prose memory test, TMT, MCST	BSP worse than HC: time-based PM, recognition task of MIST CD worse than HC: time-based PM, recognition task of MIST	BSP/CD v HC: MoCA, MCST, TMT, recall of short story,	Fair	Some evidence of selection bias Lack of statistical power
Burke et al. 2020	46 CD 46 HC	TOPF-UK, RAVLT, Logical Memory I and II (WMS-IV), ROCFT, Lexical Fluency, DS, Stroop CWI Test, FAB^, RMET	CD v HC: Name Facial Affect, Name Emotional Prosody, LM encoding, LM delayed recall, LM recognition, LM % retention, RCFT Copy, RCFT immediate, RCFT Delay, RCFT Recognition, RAVLT recognition,	CD v HC: Fluency, Forward Digit Span, Reverse Digit Span, Stroop Colour Naming, Stroop Word Reading, Stroop Trial 3, RMET, Conflicting Emotional Prosody, Matching emotional faces to emotional prosody % retention of RAVLT, % retention of ROCFT	Good	A priori power calculation complete
Ellement et al. 2020	46 CD	Advanced clinical solutions for the WASI-IV & WMS-IV Affect Naming task, Prosody Face Matching task, Prosody Pair Matching task), Benton Facial Recognition Task, reality-known and reality-unknown false belief reasoning test	CD: 21.74% (n = 10) impaired on TOM impaired belief reasoning reality known, 4.35% (n = 2) based on reality-unknown test, 4.35% (n = 2) impaired on both reality known and reality unknown tasks. 10.37% (n = 5) inconclusive results on reality unknown belief reasoning. CD worse than HC: fearful affect naming. CD: sadness, anger, and surprise less well recognised than happiness and disgust, anger, and surprise less well recognised than neutral	Prosody Face Matching, Reality Unknown belief test, reality known belief test	Fair	Some evidence of selection bias Large N, although no power calculation
Herr et al. 2020	40 CD 40 HC	MoCA, TMT, DS, FAS VF	CD worse than HC: TMT	CD v HC: MoCA, DST, F-A-S VF	Fair	Some evidence of selection bias Lack of statistical power but large N relative to others
Lagravinese et al. 2021	35 CD 47 HC	MMSE, MoCA, Advanced Test of ToM (AT), Emotion Attribution Task (EAT)	CD v HC: MMSE, MoCA total scores	CD-NT v HC: MoCA visuospatial, CD-T v HC: MoCA, orientation CD-T & CD NT v HC: MoCA language, AT, EAT	Fair	Lack of statistical power but large N relative to others Controlled for multiple comparisons
Monaghan et al. 2021	46 CD	TOPF, WASI-II, WAIS-IV (digit span, coding), RAVLT, WMS LM, RCFT, BNT, DKEFS phonemic and semantic fluency, Stroop, ^FAB, RMET, Pegboard	CD worse than normative data: Coding, LM I, LM 2, RCFT Immediate, RCFT Delay, RCFT Recognition, FAB naming facial affect, FAB naming emotional prosody, FAB matching, FAB congruent	CD v normative data: TOPF-UK, WASI-II FSIQ, processing speed, BNT, Semantic fluency, RAVLT, RAVLT recall, Digit Span, Stroop Inhibition, letter fluency, RMET, FAB incongruent	Good	Based from previous case-controlled study (Burke et al., 2020) Controlled for multiple comparisons

Note: ACE-R = Addenbrooke’s Cognitive Assessment Revised, AOIFD = Adult Onset Idiopathic Focal Dystonia, BNT = Boston Naming Test, BSP = blepharospasm, BTX = Botulinum toxin, CD = cervical dystonia,, COWAT = Controlled Oral Word Association Test, CWIT = Colour Word Interference Test, DBS = Deep Brain Stimulation, D-KEFS = Delis Kaplan Executive Function System, DOT = Digit Ordering Test, DS = Digit Span, DS = Digit Span, FAB = Florida Affect battery, F-A-S = phonemic verbal fluency, FPRT = Faux Pas Recognition Test, HC = healthy controls, HD = Huntington’s disease, HFS = hemifacial spasm, JLOT = Judgement Line Orientation Test, JRS = Jankovic Rating Scale, LM = Logical Memory, MDRS = Mattis Dementia Rating Scale, MCST = Modified Card Sorting Test, MIST = Memory for Intentions Screening Test, MMSE = Mini Mental State Examination, MoCA = Montreal Cognitive Assessment, MWT-A = multiple choice vocabulary test, NART = National Adult Reading Test, NR = Not Reported, NVLT = Non Verbal Learning Test, PD = Parkinson’s disease, PM = Prospective Memory, PST = Prague Stroop Test, RAVLT = Rey Auditory Verbal learning Test, RCFT = Rey-Osterrith Complex Figure Test, RMET = Reading the Mind in the Eyes Test, RWFT = Regensburg’s Word fluency Test, TEA = Test of Everyday Attention, TMT-A = Trail Making Test A, TMT-B = Trail Making Test B, TOPF-UK = Test of Premorbid Function United Kingdom edition, VF = Verbal Fluency, VLMT = Verbal Learning memory Test, VOSP = Visual Object and Space Perception Battery, WAIS = Wechsler Adult Intelligence Scale, WASI = Wechsler Abbreviated Scale of Intelligence, WCST = Wisconsin Card Sorting Test, WMS = Wechsler Memory Scale