
Figure 1
PRISMA flowchart.

Figure 2
Density plots of tremor frequency for isolated (blue) and non-isolated (orange) OT.
Table 1
Clinical spectrum of OT cases according to the MDS classification.
| PARAMETER | PRIMARY OT | OT PLUS | PSEUDO OT | UNCLASSIFIABLE (FLUCTUATING FREQUENCY) | UNCLASSIFIABLE (>18 Hz) |
|---|---|---|---|---|---|
| N | 127 | 39 | 61 | 12 | 5 |
| Age (SD) | 64.13 (11.25) | 64.41(13.55) | 58.56 (16.03) | 61.67 (17.48) | 61.80 (13.05) |
| Sex (M/F) | 50/77 | 14/25 | 25/36 | 4/8 | 3/2 |
| Mean Tremor Frequency in Hz (SD) | 15.58 (1.26) | 15.46 (1.41) | 6.82 (2.36) | 13.12 (1.17) | 18.92 (0.71) |
| Familial history of OT | 13 | 2 | 2 | 0 | 0 |
Table 2
Clinical spectrum of OT cases based on isolated/non-isolated phenotype.
| PARAMETER | ISOLATED OT | NON-ISOLATED OT |
|---|---|---|
| N | 148 | 96 |
| Age (SD) | 63.97 (11.35) | 60.51 (15.96) |
| Sex (M/F) | 60/88 | 36/60 |
| Mean Tremor Frequency in Hz (SD) | 14.80 (2.82) | 11.03 (4.81) |
| ≥13 Hz/<13 Hz | 129/19 | 49/47 |
| Familial history of OT | 12 | 5 |
Table 3
Disorders associated with OT.
| ASSOCIATED DISORDERS | TOTAL NUMBER | <13 Hz N (%) | ≥13 Hz N (%) | MEAN TREMOR FREQUENCY | SD | MINIMUM FREQUENCY | MAXIMUM FREQUENCY |
|---|---|---|---|---|---|---|---|
| Parkinson’s disease/Parkinsonism/PSP | 38 | 22 (57.9) | 16 (42.1) | 10.07 | 5.171 | 3 | 18 |
| Essential tremor | 10 | 3 (30) | 7 (70) | 13.50 | 3.752 | 6.5 | 19 |
| Cerebellar disorders/lesions | 10 | 2 (20.0) | 8 (80.0) | 12.73 | 3.382 | 4.5 | 15 |
| Brainstem lesions | 6 | 2 (33.3) | 4 (66.7) | 12.37 | 5.258 | 4.25 | 17.5 |
| Hyperthyroid states | 5 | 3 (60.0) | 2 (40.0) | 10.50 | 4.213 | 6 | 15 |
| Musculoskeletal injury | 2 | 1 (50) | 1 (50) | 10.75 | 7.425 | 5.5 | 16 |
| Hereditary spastic paraplegia | 3 | 1 (33.3) | 2 (66.7) | 14.00 | 4.583 | 9 | 18 |
| Stiff person syndrome | 2 | 0 (0.0) | 2 (100.0) | 16.00 | 0.000 | 16 | 16 |
| Dementia | 2 | 0 (0.0) | 2 (100.0) | 15.00 | 2.828 | 13 | 17 |
| Miscellaneous | 18 | 13 (72.2) | 5 (27.8) | 8.98 | 4.502 | 3.5 | 16 |
| Isolated OT | 148 | 19 (12.8) | 129 (87.2) | 14.80 | 2.821 | 3.5 | 20 |
| SL NO | AUTHOR | YEAR OF PUBLICATION | AGE | SEX | FREQUENCY (HZ) | ISOLATED/NON-ISOLATED | ASSOCIATED CONDITION | MDS CLASSIFICATION |
|---|---|---|---|---|---|---|---|---|
| 1 | Tseng et al. [20] | 2025 | 34 | Male | 3 | Non-isolated | Butane induced encephalopathy, Parkinsonism | Pseudo OT |
| 2 | Swinnen et al. [21] | 2022 | 57 | Female | 4–5 | Isolated | - | Pseudo OT |
| 3 | Grobe-Einsler et al. [22] | 2020 | 53 | Female | 14–16 | Isolated | - | Primary OT |
| 4 | Verriello et al. [23] | 2020 | 82 | Male | 15–16 | Isolated | - | Primary OT |
| 77 | Male | 15–16 | Isolated | - | Primary OT | |||
| 5 | Yoshii et al. [24] | 2020 | 62 | Female | 5–6 | Isolated | - | Pseudo OT |
| 6 | Yoo et al. [25] | 2020 | 69 | Female | 4–6 | Isolated | - | Pseudo OT |
| 7 | Chaithra et al. [26] | 2019 | 72 | Female | 15–16 | Non-isolated | Parkinson’s disease | OT Plus |
| 8 | Wadhwa et al. [27] | 2019 | 62 | Female | 17–18 | Isolated | - | Primary OT |
| 9 | Iovino et al. [28] | 2019 | 23 | Male | 10.5 | Isolated | - | Pseudo OT |
| 10 | Santus et al. [29] | 2019 | 73 | Female | 17 | Non-isolated | Frontotemporal dementia | OT Plus |
| 11 | Mousele et al. [30] | 2018 | 66 | Male | 11–12 | Isolated | - | Pseudo OT |
| 12 | Yoo et al. [31] | 2019 | 48 | Male | 4–6 | Non-isolated | Parkinson’s disease | Pseudo OT |
| 13 | Wuehr et al. [32] | 2018 | 62 | Male | 14.5 | Isolated | - | Primary OT |
| 55 | Female | 14 | Isolated | - | Primary OT | |||
| 75 | Male | 17.5 | Isolated | - | Primary OT | |||
| 75 | Male | 14 | Isolated | - | Primary OT | |||
| 56 | Female | 17 | Isolated | - | Primary OT | |||
| 75 | Female | 16.5 | Isolated | - | Primary OT | |||
| 66 | Female | 14 | Isolated | - | Primary OT | |||
| 75 | Male | 13.5 | Isolated | - | Primary OT | |||
| 76 | Male | 15 | Isolated | - | Primary OT | |||
| 14 | Evidente et al. [33] | 2018 | 73 | Male | 10–14 | Isolated | - | Unclassifiable(fluctuating) |
| 68 | Male | 5–12 | Non-isolated | Essential Tremor | Pseudo OT | |||
| 15 | Shirai et al. [34] | 2018 | 60 | Male | 4–5 | Non-isolated | Machado-Joseph disease | Pseudo OT |
| 16 | Ruiz-Julián et al. [35] | 2018 | 75 | Female | 14 | Isolated | - | Primary OT |
| 17 | Lehn et al. [36] | 2017 | 68 | Male | 16 | Isolated | - | Primary OT |
| 18 | Larrosa Campo et al. [37] | 2019 | 81 | Male | 14–16 | Non-isolated | Thyrotoxicosis | Primary OT |
| 19 | Chiang et al. [38] | 2017 | 74 | Female | ~16 | Isolated | - | Primary OT |
| 73 | Male | ~16 | Isolated | - | Primary OT | |||
| 20 | Vidailhet et al. [39] | 2017 | 46 | Female | 17 | Isolated | - | Primary OT |
| 21 | Schöberl et al. [40] | 2017 | 56 | Female | 17.2 | Isolated | - | Primary OT |
| 64 | Female | 16 | Isolated | - | Primary OT | |||
| 72 | Male | 14 | Isolated | - | Primary OT | |||
| 73 | Male | 16.7 | Isolated | - | Primary OT | |||
| 68 | Female | 15.5 | Isolated | - | Primary OT | |||
| 74 | Male | 14.2 | Isolated | - | Primary OT | |||
| 73 | Male | 13.5 | Isolated | - | Primary OT | |||
| 73 | Female | 16.5 | Isolated | - | Primary OT | |||
| 73 | Male | 14.5 | Isolated | - | Primary OT | |||
| 73 | Female | 14.2 | Isolated | - | Primary OT | |||
| 22 | Benito-Léon et al. [41] | 2016 | 74 | Female | 16–18 | Isolated | - | Primary OT |
| 64 | Female | 10–12 | Isolated | - | Pseudo OT | |||
| 57 | Male | 16–18 | Isolated | - | Primary OT | |||
| 68 | Female | 16–18 | Non-isolated | Parkinson’s disease | OT Plus | |||
| 78 | Female | 16–18 | Non-isolated | Parkinson’s disease | OT Plus | |||
| 62 | Female | 12–16 | Isolated | - | Unclassifiable(fluctuating) | |||
| 37 | Female | 16–18 | Isolated | - | Primary OT | |||
| 76 | Female | 12–16 | Isolated | - | Unclassifiable(fluctuating) | |||
| 75 | Female | 12–16 | Non-isolated | Parkinson’s disease | Unclassifiable(fluctuating) | |||
| 77 | Female | 12–16 | Non-isolated | Parkinson’s disease | Unclassifiable(fluctuating) | |||
| 38 | Male | 16–18 | Isolated | - | Primary OT | |||
| 81 | Female | 12–16 | Non-isolated | Parkinson’s disease | Unclassifiable(fluctuating) | |||
| 65 | Female | 16–18 | Isolated | - | Primary OT | |||
| 57 | Female | 16–18 | Isolated | - | Primary OT | |||
| 23 | Blahak et al. [42] | 2016 | 58 | Female | 15 | Non-isolated | Diabetic neuropathy | Primary OT |
| 72 | Male | 14 | Isolated | - | Primary OT | |||
| 73 | Female | 17 | Isolated | - | Primary OT | |||
| 67 | Male | 17 | Isolated | - | Primary OT | |||
| 24 | Coleman et al. [43] | 2016 | 61 | Female | 14 | Isolated | - | Primary OT |
| 74 | Female | 13–18 | Isolated | - | Primary OT | |||
| 25 | Athauda et al. [44] | 2017 | 46 | Female | 16 | Isolated | - | Primary OT |
| 73 | Male | 16 | Isolated | - | Primary OT | |||
| 66 | Male | 17 | Non-isolated | Parkinsonism | OT Plus | |||
| 26 | Contarino et al. [45] | 2015 | 70 | Female | 16 | Isolated | - | Primary OT |
| 27 | Erro et al. [46] | 2014 | 63 | Female | 15 | Non-isolated | Hereditary spastic paraparesis | OT Plus |
| 28 | Mazzucchi et al. [47] | 2014 | 70 | Female | 8 | Non-isolated | Graves’ disease | Pseudo OT |
| 29 | Adebayo et al. [48] | 2014 | 57 | Female | 16 | Isolated | - | Primary OT |
| 30 | Vetrugno et al. [49] | 2013 | 77 | Female | 16 | Non-isolated | Stiff Person Syndrome | OT Plus |
| 55 | Female | 16 | Non-isolated | Stiff Person Syndrome | OT Plus | |||
| 31 | Bhattacharyya et al. [50] | 2013 | 12 | Male | 15–16 | Non-isolated | Poliomyelitis | Primary OT |
| 7 | Male | 14–15 | Non-isolated | Essential tremor | OT Plus | |||
| 32 | Coffeng et al. [17] | 2013 | 86 | Male | 10–11 | Isolated | - | Pseudo OT |
| 33 | Lin et al. [51] | 2013 | 26 | Male | 8–9 | Non-isolated | Graves’ disease | Pseudo OT |
| 34 | Lyons et al. [52] | 2012 | 75 | Male | 13 | Isolated | - | Primary OT |
| 35 | Virmani et al. [53] | 2012 | 79 | Male | 13.5 | Isolated | - | Primary OT |
| 75 | Female | 13.3 | Isolated | - | Primary OT | |||
| 36 | Lee et al. [54] | 2012 | 64 | Male | 11–13 | Non-isolated | Spinal Schwannoma | Unclassifiable(fluctuating) |
| 37 | Lee et al. [55] | 2011 | 81 | Female | 4–9 | Non-isolated | Parkinson’s disease | Pseudo OT |
| 38 | Kumar et al. [56] | 2011 | 60 | Male | 16 | Isolated | - | Primary OT |
| 39 | Hegde et al. [57] | 2011 | 69 | Male | 3–4 | Isolated | - | Pseudo OT |
| 40 | Yaltho et al. [58] | 2011 | 78 | Male | 14 | Isolated | - | Primary OT |
| 41 | Magariños-Ascone et al. [59] | 2010 | 68 | Female | 12–18 | Isolated | - | Unclassifiable(fluctuating) |
| 42 | Williams et al. [60] | 2010 | 70 | Female | 9 | Non-isolated | Cerebellar atrophy | Pseudo OT |
| 43 | Vetrugno et al. [61] | 2010 | 58 | Female | 16 | Non-isolated | Left midbrain lesion | OT Plus |
| 44 | Raudino et al. [62] | 2009 | 59 | Male | 13–14 | Isolated | - | Primary OT |
| 45 | Baker et al. [63] | 2009 | 38 | Female | 8–15 | Non-isolated | Multiple Sclerosis | Unclassifiable(fluctuating) |
| 46 | Kang et al. [64] | 2009 | 61 | Female | 6 | Non-isolated | Parkinson’s disease | Pseudo OT |
| 60 | Female | 6–7 | Non-isolated | Parkinson’s disease | Pseudo OT | |||
| 61 | Female | 4–5 | Non-isolated | Parkinson’s disease | Pseudo OT | |||
| 45 | Female | 3–4 | Non-isolated | Parkinson’s disease | Pseudo OT | |||
| 47 | Female | 16–17 | Non-isolated | Parkinson’s disease | OT Plus | |||
| 47 | Ramtahal et al. [65] | 2008 | 78 | Male | 13–14 | Isolated | - | Primary OT |
| 65 | Male | 15–16 | Isolated | - | Primary OT | |||
| 65 | Female | 15 | Isolated | - | Primary OT | |||
| 48 | Wegner et al. [66] | 2008 | 61 | Male | 16–18 | Isolated | - | Primary OT |
| 61 | Female | 16–18 | Isolated | - | Primary OT | |||
| 49 | Espay et al. [67] | 2008 | 73 | Female | 15 | Isolated | - | Primary OT |
| 67 | Female | 15 | Isolated | - | Primary OT | |||
| 50 | Guridi et al. [68] | 2008 | 55 | Female | 16 | Isolated | - | Primary OT |
| 51 | Trocello et al. [69] | 2008 | 49 | Male | 16 | Isolated | - | Primary OT |
| 76 | Female | 17 | Isolated | - | Primary OT | |||
| 55 | Female | 17 | Isolated | - | Primary OT | |||
| 66 | Male | 16 | Isolated | - | Primary OT | |||
| 66 | Female | 15 | Isolated | - | Primary OT | |||
| 49 | Female | 15 | Isolated | - | Primary OT | |||
| 75 | Female | 16 | Isolated | - | Primary OT | |||
| 62 | Female | 16 | Isolated | - | Primary OT | |||
| 74 | Female | 16 | Isolated | - | Primary OT | |||
| 78 | Female | 17 | Isolated | - | Primary OT | |||
| 70 | Female | 18 | Isolated | - | Primary OT | |||
| 70 | Male | 15 | Isolated | - | Primary OT | |||
| 52 | Stich et al. [70] | 2009 | 57 | Female | 17.5 | Non-isolated | Demyelinating lesion involving the right brainstem, Biclonal gammopathy of undetermined significance | OT Plus |
| 53 | Tan et al. [71] | 2008 | 50 | Female | 14–16 | Non-isolated | Graves’ disease | Primary OT |
| 54 | Leu-Semenescu et al. [72] | 2007 | 72 | Female | 18 | Non-isolated | Parkinson’s disease | OT Plus |
| 77 | Female | 16 | Non-isolated | Parkinson’s disease | OT Plus | |||
| 79 | Male | 13.5 | Non-isolated | Parkinson’s disease | OT Plus | |||
| 75 | Female | 17 | Non-isolated | Parkinson’s disease | OT Plus | |||
| 76 | Female | 7.5–9 | Non-isolated | Parkinson’s disease | Pseudo OT | |||
| 85 | Female | 5 | Non-isolated | Parkinson’s disease | Pseudo OT | |||
| 57 | Female | 5–6 | Non-isolated | Parkinson’s disease | Pseudo OT | |||
| 54 | Female | 4.3–5 | Non-isolated | Parkinson’s disease | Pseudo OT | |||
| 55 | Fischer et al. [73] | 2007 | 69 | Male | 16–17 | Isolated | - | Primary OT |
| 68 | Male | 16–17 | Isolated | - | Primary OT | |||
| 63 | Male | 16–17 | Isolated | - | Primary OT | |||
| 56 | Thomas et al. [10] | 2007 | 47 | Female | 6–7 | Non-isolated | Parkinsonism | Pseudo OT |
| 52 | Male | 6–7 | Non-isolated | Parkinsonism | Pseudo OT | |||
| 52 | Male | 6–7 | Non-isolated | Parkinsonism, Kearns-Sayre syndrome | Pseudo OT | |||
| 26 | Female | 6–7 | Non-isolated | Parkinsonism | Pseudo OT | |||
| 57 | de Bie et al. [74] | 2007 | 67 | Female | 16–17 | Non-isolated | Progressive supranuclear palsy | OT Plus |
| 58 | Krauss et al. [75] | 2006 | 58 | Female | 15–16 | Isolated | - | Primary OT |
| 72 | Male | 14 | Isolated | - | Primary OT | |||
| 59 | Contarino et al. [76] | 2006 | 68 | Male | 13 | Isolated | - | Primary OT |
| 68 | Male | 13 | Isolated | - | Primary OT | |||
| 60 | Gilhuis et al. [77] | 2005 | 55 | Female | 3–5 | Non-isolated | Small cell carcinoma of lung | Pseudo OT |
| 61 | Karlberg et al. [78] | 2005 | 46 | Female | 12 | Isolated | - | Pseudo OT |
| 36 | Male | 8.5 | Isolated | - | Pseudo OT | |||
| 63 | Female | 12.5 | Isolated | - | Pseudo OT | |||
| 64 | Female | 15.5 | Isolated | - | Primary OT | |||
| 73 | Female | 18 | Isolated | - | Primary OT | |||
| 62 | Bacsi et al. [79] | 2005 | 59 | Female | 15.9 | Isolated | - | Primary OT |
| 73 | Male | 17.3 | Isolated | - | Primary OT | |||
| 50 | Female | 15.2 | Isolated | - | Primary OT | |||
| 57 | Female | 16.5 | Isolated | - | Primary OT | |||
| 64 | Female | 18.1 | Isolated | - | Unclassifiable(>18 Hz) | |||
| 68 | Female | 17.3 | Isolated | - | Primary OT | |||
| 51 | Female | 17.3 | Isolated | - | Primary OT | |||
| 69 | Female | 16.8 | Isolated | - | Primary OT | |||
| 75 | Female | 15.6 | Isolated | - | Primary OT | |||
| 66 | Male | 15.7 | Isolated | - | Primary OT | |||
| 63 | Rodrigues et al. [12] | 2005 | 68 | Female | 19 | Isolated | - | Unclassifiable(>18 Hz) |
| 70 | Female | 14 | Isolated | - | Primary OT | |||
| 74 | Female | 16 | Isolated | - | Primary OT | |||
| 53 | Male | 15 | Isolated | - | Primary OT | |||
| 63 | Female | 14 | Isolated | - | Primary OT | |||
| 65 | Female | 13 | Isolated | - | Primary OT | |||
| 64 | Trip et al. [80] | 2003 | 43 | Female | 16 | Isolated | - | Primary OT |
| 65 | Apartis et al. [81] | 2001 | 75 | Female | 18 | Non-isolated | Parkinson’s disease | OT Plus |
| 66 | Finkel et al. [13] | 2000 | 76 | Male | 18–19 | Isolated | - | Unclassifiable(>18 Hz) |
| 67 | Cavallazi et al. [14] | 2000 | 42 | Female | 16 | Isolated | - | Primary OT |
| 41 | Male | 20 | Isolated | - | Unclassifiable(>18 Hz) | |||
| 59 | Female | 17 | Isolated | - | Primary OT | |||
| 48 | Female | 15 | Isolated | - | Primary OT | |||
| 68 | Benito-Leon et al. [82] | 2000 | 68 | Male | 15 | Non-isolated | B12 deficiency | OT Plus |
| 69 | Manto et al. [83] | 1999 | 49 | Male | 14 | Non-isolated | Pancerebellar atrophy | OT Plus |
| 62 | Female | 15 | Non-isolated | Pancerebellar atrophy | OT Plus | |||
| 64 | Female | 14 | Non-isolated | Pancerebellar atrophy | OT Plus | |||
| 70 | Wills et al. [84] | 1999 | 74 | Male | 14.5 | Non-isolated | Parkinson’s disease | OT Plus |
| 71 | Sander et al. [85] | 1998 | 79 | Female | 15–17 | Isolated | - | Primary OT |
| 64 | Male | 15–17 | Isolated | - | Primary OT | |||
| 72 | Setta F et al. [86] | 1998 | 48 | Male | 14 | Non-isolated | Cerebellar atrophy | OT Plus |
| 63 | Female | 14 | Non-isolated | Cerebellar atrophy | OT Plus | |||
| 61 | Female | 15 | Non-isolated | Cerebellar atrophy | OT Plus | |||
| 73 | Tsai et al. [87] | 1998 | 58 | Female | 16 | Isolated | - | Primary OT |
| 68 | Female | 16 | Isolated | - | Primary OT | |||
| 74 | Benito-Leon et al. [88] | 1997 | 49 | Female | 7–8 | Non-isolated | Right pontine lesion | Pseudo OT |
| 39 | Male | 14–15 | Non-isolated | Left pontine lesion | OT Plus | |||
| 75 | Hanna et al. [89] | 1997 | 33 | Female | 17.5 | Isolated | - | Primary OT |
| 76 | Poersch et al. [90] | 1994 | 60 | Female | 14 | Isolated | - | Primary OT |
| 77 | Britton et al. [91] | 1992 | 63 | Female | 16–18 | Isolated | - | Primary OT |
| 25 | Female | 8–16 | Isolated | - | Unclassifiable(fluctuating) | |||
| 68 | Male | 16–17 | Isolated | - | Primary OT | |||
| 57 | Female | 15–16 | Isolated | - | Primary OT | |||
| 47 | Female | 16–18 | Isolated | - | Primary OT | |||
| 64 | Male | 15–16 | Isolated | - | Primary OT | |||
| 78 | Willeit et al. [92] | 1991 | 77 | Male | 14–16 | Isolated | - | Primary OT |
| 57 | Male | 14–16 | Isolated | - | Primary OT | |||
| 79 | FitzGerald et al. [15] | 1991 | 60 | Male | 18–20 | Non-isolated | Essential tremor | Unclassifiable(>18 Hz) |
| 46 | Male | 12–14 | Non-isolated | Essential tremor | Unclassifiable(fluctuating) | |||
| 70 | Male | 12 | Non-isolated | Essential tremor | Pseudo OT | |||
| 56 | Female | 14 | Non-isolated | Essential tremor | OT Plus | |||
| 80 | Walker et al. [93] | 1990 | 79 | Male | 15 | Isolated | - | Primary OT |
| 81 | Gabellini et al. [94] | 1990 | 68 | Female | 14–16 | Isolated | - | Primary OT |
| 56 | Female | 14–16 | Isolated | - | Primary OT | |||
| 45 | Female | 14–16 | Isolated | - | Primary OT | |||
| 75 | Female | 6–7 | Isolated | - | Pseudo OT | |||
| 64 | Male | 6–7 | Isolated | - | Pseudo OT | |||
| 66 | Male | 6–7 | Isolated | - | Pseudo OT | |||
| 59 | Male | 6–7 | Non-isolated | Aqueduct stenosis hydrocephalus | Pseudo OT | |||
| 47 | Female | 6–7 | Non-isolated | Chronic relapsing radiculopathy | Pseudo OT | |||
| 82 | Oda et al. [95] | 1989 | 79 | Female | 4 | Non-isolated | Vascular Parkinsonism | Pseudo OT |
| 83 | Uncini et al. [96] | 1989 | 73 | Male | 8–10 | Isolated | - | Pseudo OT |
| 64 | Female | 16 | Isolated | - | Primary OT | |||
| 84 | Papa et al. [97] | 1988 | 63 | Female | 16 | Non-isolated | Essential tremor | OT Plus |
| 72 | Female | 16 | Non-isolated | Essential tremor | OT Plus | |||
| 68 | Female | 16 | Non-isolated | Essential tremor | OT Plus | |||
| 85 | Thompson et al. [9] | 1986 | 55 | Male | 8–16 | Isolated | - | Unclassifiable(fluctuating) |
| 86 | Kim et al. [98] | 2023 | 18 | Male | 5–6 | Non-isolated | Knee contusion | Pseudo OT |
| 87 | Park et al. [99] | 2020 | 79 | Female | 4–4.5 | Non-isolated | Right pontine lesion | Pseudo OT |
| 78 | Female | 6.5 | Non-isolated | Parkinsonism | Pseudo OT | |||
| 74 | Female | 8 | Non-isolated | Brain lesion | Pseudo OT | |||
| 46 | Female | 9 | Non-isolated | Parkinson’s disease | Pseudo OT | |||
| 63 | Male | 13.5–14 | Non-isolated | Restless leg syndrome | OT Plus | |||
| 62 | Female | 6 | Non-isolated | Drug induced parkinsonism | Pseudo OT | |||
| 59 | Male | 5–6 | Non-isolated | Tardive dyskinesia | Pseudo OT | |||
| 68 | Female | 15 | Isolated | - | Primary OT | |||
| 49 | Male | 4–5 | Non-isolated | Arteriovenous malformation | Pseudo OT | |||
| 65 | Female | 4 | Non-isolated | REM sleep behaviour disorder | Pseudo OT | |||
| 67 | Male | 8–8.5 | Non-isolated | Parkinsonism with Normal Pressure hydrocephalus | Pseudo OT | |||
| 58 | Female | 16 | Isolated | - | Primary OT | |||
| 72 | Male | 13 | Non-isolated | Dementia | OT Plus | |||
| 61 | Male | 13 | Isolated | - | Primary OT | |||
| 56 | Female | 13 | Isolated | - | Primary OT | |||
| 72 | Male | 8 | Non-isolated | Parkinson’s disease with Essential Tremor | Pseudo OT | |||
| 68 | Male | 6–7 | Non-isolated | Essential tremor | Pseudo OT | |||
| 65 | Female | 4–4.5 | Non-isolated | Parkinson’s disease | Pseudo OT | |||
| 88 | Comolli et al. [100] | 2024 | 65 | Female | 6 | Non-isolated | Graves’ disease | Pseudo OT |
| 89 | Li et al. [101] | 2022 | 22 | Male | 6–8 | Non-isolated | Hyperphenylalaninemia | Pseudo OT |
| 90 | Lv et al. [102] | 2022 | 67 | Male | 16 | Non-isolated | Primary malignant melanoma of the spinal cord | OT Plus |
| 91 | Bhattacharyya et al. [103] | 2003 | 70 | Male | 18 | Isolated | - | Primary OT |
| 92 | Jones et al. [104] | 2011 | 65 | Male | 16 | Isolated | - | Primary OT |
| 93 | Manrique-Huarte et al. [105] | 2012 | 65 | Female | 14–16 | Isolated | - | Primary OT |
| 69 | Female | 2–9 | Non-isolated | Psychogenic dizziness | Pseudo OT | |||
| 45 | Female | 10 | Isolated | - | Pseudo OT | |||
| 63 | Female | 8 | Non-isolated | Migraine with aura | Pseudo OT | |||
| 94 | Yague et al. [106] | 2011 | 47 | Female | 16 | Non-isolated | Surgery to left meniscus following trauma | Primary OT |
| 95 | Sanitate et al. [107] | 1993 | 72 | Female | 14–15 | Non-isolated | Head trauma, demyelinating lesions in the periventricular region and subcortical white matter, Ischemic changesin the right pons and the right cerebellar hemisphere | OT Plus |
| 96 | Marechal et al. [108] | 2024 | 73 | Male | 14 | Non-isolated | Restless leg syndrome, PSP | OT Plus |
| 97 | Myers et al. [109] | 2003 | 72 | Female | 16 | Isolated | - | Primary OT |
| 98 | Sarva et al. [110] | 2016 | 81 | Male | 13.8–15.9 | Non-isolated | Cerebellar degeneration | OT Plus |
| 57 | Male | 13 | Non-isolated | Spinocerebellar ataxia | OT Plus | |||
| 99 | Picillo et al. [111] | 2017 | 74 | Female | 18 | Non-isolated | Hereditary spastic paraplegia (SPG31) | OT Plus |
| 30 | Female | 9 | Non-isolated | Hereditary spastic paraplegia (SPG15) | Pseudo OT | |||
| 100 | Brotman et al. [112] | 2000 | 65 | Male | 3–4 | Non-isolated | Neurosyphillis | Pseudo OT |
