Table 2.

Data extraction Table

First author/year of publication	Design	Population, n = age, gender and dementia type	Definition/Clinical criteria	Diagnosis and assessment	Pathogenesis	Therapy and interventions	Critical appraisal score Items positive/total items
Bautmans et al. (2008) [28]	RCT	n = 15, age range: 77–98, male n = 6, severe AD	Form of hypertonia characterized by an active unintentional resistance against passive movement. Based on consensus definition by Hobbelen et al. 2006 [47].	Presenting paratonia with altered neck posture (cervical antero-position, extension or kyphosis) and known dysphagia.	–	Cervical spine mobilization, caused by postural head and cervical neck changes due to paratonia, to improve swallowing capacity.	10/13
Benassi et al. (1990) [33]	Cross-sectional	n = 398, age range: 67–87, dementia (n = 27, male n = 14)	Primitive reflex.	Limp placement maneuver, examiner passively lifts the patients arm with the instruction to relax. When the arm stays elevated this indicates paratonia.	Cortical disinhibition sign.	–	3/7
Bennet et al. (2002) [32]	Cohort, 5.8 years	n = 77, age range: 60–86, male n = 58, VaD	–	–	Frontal system dysfunction.	–	8/9
Beversdorf and Heilman (1998) [11]	Cross-sectional and test	n = 25, age mean: 70.1(8.7), male n = 9, AD (n = 20), FTD (n = 2), LBD (n = 1), pseudodementia (n = 1), isolated memory impairment (n = 1)	Alteration of tone to passive movement, divided into oppositional paratonia (Gegenhalten) and facilitory paratonia.	Subjective impressions of both assistance and resistance offered to passive flexion and extension about the elbow versus Modified Kral procedure; With this procedure the patient is in seated position. The examiner will flex and extend the right arm between full flexion and 90 degrees of extension three times with the patient instructed to relax completely. At the end of the third cycle, the patient’s arm will be released at the level of the patient’s leg and the examiner’s hand withdrawn. The patient’s response must be scored as follows: 0 = no movement; 1 = right arm flexes, but insufficiently to raise the hand off of the leg; 2 = right arm flexes, lifting the arm off of the leg but less than halfway to full flexion;3 = right arm flexes at least halfway, but not fully; 4 = right arm flexes fully, or repeated cycles of flexion and extension occur.	Frontal lobe dysfunction.	–	3/7 Score on Test accuracy appraisal; 7/9
Critchley (1956) [22]	Narrative review	–	Gegenhalten. A uniform resistance to passive manipulations, especially in limbs and the neck. Often with a “mental” component, i.e., rigidity may vary directly with the amount of force used by the examiner or the subject is not relaxing.	–	Cerebrovascular degeneration.	–	5/6
Damasceno et al. (2005) [34]	Cross-sectional	n = 174, AD (n = 30, age: mean 70.9 (9.1), male n = 11	Primitive reflex, Gegenhalten.	Subjective impressions of resistance to passive, irregular extension and flexion of arms and legs.	Cortico-subcortical neuronal loss.	–	5/7
Drenth et al. (2017) [40]	Prospective study, 6 months on psychometric properties test	n = 152, age: mean 83.5 (8.2), dementia	Form of hypertonia with an involuntary variable resistance during passive movement. Based on consensus definition by Hobbelen et al. 2006 [47].	MyotonPro (handheld device objectively measuring muscle properties) versus MAS-P, PAI, passive movement of extremities. Following criteria must be met;-An involuntary variable resistance during passive movement-No clasp-knife phenomenon-Resistance to passive movement is in any direction-Resistance must be felt in either one limb in two movement directions or in two different limbs-Degree of resistance correlates with the speed of movement (e.g., a low resistance to slow movement and a high resistance to fast movement).	Peripheral biomechanical muscle changes due to AGEs.	–	10/10
Drenth et al. (2017) [30]	Cohort, one-year	n = 144, age: mean 80.7 (7.7), AD or AD/VaD	Form of hypertonia characterized by an active unintentional resistance against passive movement. Based on consensus definition by Hobbelen et al. 2006 [47].	PAI; passive movement of extremities (see above) MAS-P.	Peripheral biomechanical muscle changes due to AGEs.	Preventing or postponing paratonia by decreasing AGE formation and accumulation through glycemic control (physical activity, diet)	9/9
Duret et al. (1989) [29]	RCT	n = 14, age: range 56–83, male n = 6, dementia	Rigidity, extrapyramidal sign.	Modifies Columbia rating scale for rigidity.	Lewy bodies, neuronal loss or gliosis in substantia nigra. Rigidity in AD differs pharmacologically from Parkinson rigidity.	–	11/13
Franssen et al. (1991) [35]	Cross-sectional	n = 135, age: mean 72.6 (9.5), male n = 45, no memory impairment n = 27, mild cognitive impairment n = 20, AD n = 88	Primitive reflex. Paratonic rigidity defined as stiffening of a limb in response to contact with the examiner’s hand and an involuntary resistance to passive changes in position and posture.	Graded with the amount of passive force necessary to elicit stiffening.	Cortical inhibition loss.	–	6/7
Franssen et al. (1993) [46]	Case series	n = 56, age: mean 74.6 (9.6), male n = 16, AD	Primitive reflex, paratonic rigidity or Gegenhalten. Defined as a sudden increase in muscle tone of an extremity in reaction to an external perturbation of that extremity, resulting in an involuntary resistance to passive movement.	Resistance elicited with sudden passive changes in position and/or speed and regularity of movement of the upper extremity.	Frontal lobe pathology.	–	89
Hobbelen et al. (2003) [25]	Pilot RCT	n =  15, age: range 70–9, male n = 1	Oppositional paratonia a form of hypertonia in late stage dementia.	Middelveld-Jacobs criteria; passive movement of extremities, trunk and head. Following criteria must be met:-Increase in muscle tone during passive movement of the extremities, head or trunk-Occurring at flexion and extension, independent of the starting position of the joints-Increasing with rapid movement-Decreasing slow movement-Ranging from light tovery fierce. MAS-P.	–	- Passive movement therapy-Stabilizing cushions	11/13
Hobbelen et al. (2006) [47]	Delphi procedure for consensus definition	–	Paratonia is a form of hypertonia with an involuntary variable resistance during passive movement. The nature of paratonia may change with progression of dementia (e.g., from active assistance to active resistance). The degree of resistance depends on the speed of movement.The degree of paratonia is proportional to the amount of force applied and increases with progression of dementia. The resistance to passive movement is in any direction and there is no clasp-knife phenomenon.	–	–	–	6/6
Hobbelen et al. (2008) [42]	Cross-sectional on psychometric properties test in 3 phases	Phase 1: n = 79, age: range 67–99, male n = 17, AD/VaD (n = 57), VaD (n = 17), LBD (n = 4), other (n = 1)Phase 2: n = 86, age: range 65–96, male n = 26, AD/VaD (n = 60), VaD (n = 22), LBD (n = 2), other (n = 2)Phase 3: n = 24, age: range 78–95, male n = 4, AD/VaD (n = 16), VaD (n = 6), other (n = 1)	Consensus definition Hobbelen et al. 2006 [47].	PAI passive movement of extremities (see above).	–	–	6/6
Hobbelen et al. (2011) [14]	Cohort, one year	n = 204, age: mean 79.8 (7.5), male n = 93, AD (n = 91), VaD (n = 50), AD/VaD (n = 36), LBD (n = 14), other (n = 13)	Consensus definition Hobbelen et al. 2006 [47].	PAI passive movement of extremities (see above).	Unclear-Frontal lobe pathology-Substantia nigra pathology-Peripheral biomechanical changes-Anti psychotic medication may induce paratonia-like rigidity.-Diabetes and vascular damage are risk factors	–	10/10
Hobbelen et al. (2012) [26]	RCT	n = 102 (intervention n = 48, control n = 54), age: range 67–98, male n = 19, AD (n = 64), VaD (n = 18), AD/VaD (n = 11), LBD (n = 4), other (n = 5)	Consensus definition Hobbelen et al. 2006 [47].	PAI passive movement of extremities (see above). MAS-P.	–	Passive movement therapy.	12/13
Jenkyn et al. (1977) [21]	Cross-sectional	n = 76, age: range 16–80, male n = 43, cognitive impaired; mild (n = 25), moderate (n = 23), marked (n = 10), no impairment (n = 18)	Primitive reflex, Gegenhalten. Paratonia can be differentiated from the full range, regular rigidity, or cog-wheeling of Parkinsonism and theclasp-knife phenomenon of spasticity.	Passive extension and flexion of the limbs.An irregular opposition to the examiner’s movementsafter instructions to relax resulted in a ‘catching’sensation is considered abnormal.Limp placement maneuver, examiner passively lifts the patients arm with the instruction to relax. Any delay in dropping of the arm was considered abnormal after Parkinsonian rigidity and spasticity had been excluded.	Cerebral dysfunction, cortical inhibition loss.	–	7/7
Kleiner-Fisman et al. (2014) [27]	RCT	n = 10 (intervention n = 5, control n = 5 with crossover), age: mean 85.3 (8.0), male n = 1, AD (n = 9), FTD (n = 1)	Increasing muscle resistance reflexively when a limb is moved passively (severity can fluctuate depending on level of relaxation), unto constant muscle contraction in advanced stages.	PAI passive movement of extremities (see above). Severity by joint range of motion.	Originate in the central nervous system.	Botulinum toxin injection	12/13
Kurlan et al. (2000) [12]	Narrative review/ Viewpoint	–	In paratonic rigidity, there is resistance to passive movement of a limb whereby the degree of resistance varies depending on the speed of movement. Resistance increases when the limb is moved more rapidly and decreases or even disappears when it is moved more slowly. Cogwheeling can occur with parkinsonian or paratonic rigidity and does not help to distinguish the two types of rigidity. The presence of mitgehen suggests that the quality of rigidity is paratonic.	–	–	–	6/6
Marinelli et al. (2017) [43]	Cross-sectional on psychometric properties test	n = 10, age: range 63–84, male n = 6, MCI (n = 7), AD (n = 1), AD/VaD (n = 1), Fld (n = 1)	Oppositional (Gegenhalten) with resistance to passive movement or facilitory (mitgehen) occurring when the action is in the same direction of passive movement.	Paratonia scale; subjective impressions of both assistance and resistance offered to passive flexion and extension about the elbow.Modified Kral procedure (see above) versus electromyography.	Defective response inhibition associated with frontal lobe lesions.	–	8/10
O’Keeffe et al. (1996) [36]	Cross-sectional	n = 110, age: mean 78 (5)AD (n = 55, male n = 21) Control (n = 55)	Primitive reflexParatonic rigidity (Gegenhalten).	Presence or absence of Gegenhalten noted during irregular passive extension and flexion of the elbow and wrist joints.	Frontal lobe pathologyExtrapyramidal neural loss.	–	6/7
Paulson and Gottlieb (1968) [23]	Narrative review	n = 85, age: mean 62.3 (?), dementia	Primitive reflex.Increase in rigidity in both the motor and psychological areas. Paratonic rigidity (Gegenhalten). Marked increase in tone which the examiner may think is voluntary, but usually is not consciously determined.Hypertonus is accentuated by rapid passive movements of the limb and distinguished it from spasticity (clasp-knife) as well as from cogwheel rigidity of Parkinsonism.	–	Central nervous degeneration by age and disease.	–	5/6
Peralta and Cuesta. (2017) [50]	Narrative review	AD	Gegenhalten. Catatonia like sign. Motor abnormality of severe mental disorder.	–	–	–	6/6
Pauc and Young (2012) [48]	Narrative review	Dementia	Involuntary resistance to passive movement (Gegenhalten).A primitive reflex occurring naturally in neonates which should disappear as the brain develops.	–	Neuronal loss occurring with normal ageing and the onset of dementia.	–	3/6
Ries (2018) [49]	Narrative review	AD, VaD, AD/VaD, LBD, PDD, FTD	Consensus definition Hobbelen et al. 2006 [47].	PAI passive movement of extremities (see above).	–	Facilitating the movement by giving some counterpressure in the direction of the movement that the patient must move into	6/6
Risse et al. (1990) [31]	Cohort until death	n = 28, male n = 28, (probable) AD	Resistance to movement with increased muscle tone throughout the range of motion while not on antipsychotic drugs. Gegenhalten, patient appears to be actively resisting passive movement in any direction.	–	No neuro-pathologic (substantia nigra neural loss) evidence for Parkinson disease.	–	4/9
Souren et al. (1997) [16]	Narrative review	AD	Type of rigidity that occurs on contact. Changing resistance to passive alterations in position and posture. The degree of paratonia increases when the patient is repeatedly urged to relax. Can be elicited or augmented by state of anxiety, anger and agitation.	Moving passively an extremity (usually the forearm) repeatedly, first slowly and evenly, and, subsequently in a more rapid, brusque and irregular fashion.	Symptom of congenital or acquired diffuse brain damage.Resembles primitive reflex in healthy infants, therefore can be considered as the return of an infantile stabilization reflex mechanism, parallel to the patient’s motor function decline.	Paratonia serves as a physiologic and psychological stabilizing mechanism, protecting the patient against overwhelming external stimuli. Approach and behavioral advice are given, such as gentle movements, eyes and voice contact to reduce anxiety and agitation.Active physical activity to prevent or postpone contractures.	6/6
Tyrell and Rossor. (1988) [38]	Cross-sectional	n = 10, age; range 53–82, male n = 2, AD (n = 4), AD/VaD (n = 1), Progressive dyspraxia (n = 3), CVD (n = 2)	Paratonic rigidity (Gegenhalten) an increase in muscle tone which occurs in response to passive movement, proportional in degree to the stimulus applied.	Rigidity detected on passive movement of the limb, occurring in absence of cogwheeling or a spastic catch, that is not exacerbated by movement in the contralateral fist.Limb placement maneuver (see above).	–	–	3/7
Tyrell et al. (1990) [37]	Cross-sectional	n = 20, age: mean 59.1 (8.5), AD	Extrapyramidal sign, rigidity.	–	No evidence for dopaminergic nigrostriatal dysfunction.	–	4/7
Van Deun et al. (2016) [41]	Cross-sectional on psychometric properties test	n = 16, age: mean 85.5 (6.8), male n = 3, dementia with paratonia	Consensus definition Hobbelen et al. 2006 [47].	PAI passive movement of extremities (see above).MAS-P.MyotonPro (handheld device objectively measuring muscle properties).	–	–	9/10
Van Deun et al. (2018) [45]	Survey	Physiotherapists in nursing homes (n = 242)	Consensus definition Hobbelen et al. 2006 [47].	–	–	Positioning and soft passive mobilization were most applied.Key points for paratonia approach were relaxation, positioning, active movement stimulation.	7/9
Van Deun et al. (2018) [39]	Cross-sectional	Healthy control (n = 60, age: mean 82.07 (5.53), male n = 30). Mild dementia (n = 31, age: mean 80.48 (4.87), male n = 15). Moderate dementia (n = 31, age: mean 87.81 (4.94), male n = 3)	Consensus definition Hobbelen et al. 2006 [47].	PAI passive movement of extremities (see above).MyotonPro (handheld device objectively measuring muscle properties).	–	–	7/8
Van Deun et al. (2019) [44]	CT with AB/BA crossover	n = 22, age: mean 84.8 (7.3), AD (n = 10), VaD (1), FTD (n = 1), other (n = 10)	Consensus definition Hobbelen et al. 2006 [47].	PAI passive movement of extremities (see above).MAS-P.MyotonPro (handheld device objectively measuring muscle tone).	–	-Harmonic movement techniques.-Supporting cushions	6/9
Vahia et al. (2007) [13]	Prevalence study	n = 80, age: mean 75.5 (7.0), male n = 17, AD	External stimulus dependent increase in muscle tone that is absent at rest.	Graded with the amount of passive force necessary to elicit stiffening.	Disorder of frontal lobe origin.	–	4/9
Villeneuve et al. (1974) [24]	Cross-sectional	n = 155, Organic brain syndrome (including dementia) (n = 56), age: mean 76 (7.2), male n = 56, Functional psychoses (n = 51), age: mean 70.9 (5.8), male n = 33, Schizophrenia (n = 16), age: mean 76.3 (8.8), male n = 0, Healthy controls (n = 32), age: mean 83.2 (4.9), male n = 11	Primitive reflex. Gegenhalten, a particular form of rigidity, also called negativism or opposition hypertonia.The marked increase in tone is not consciously determined and is accentuated when a rapid movement is imparted to a limb. It is different form spasticity (clasp-knife) and from cogwheel rigidity of Parkinsonism.	Any resistance of the forearm to passive movement from the examiner is considered as a hypertonic manifestation.	Central nervous degeneration by age and disease (frontal lobe, metabolic, vascular cerebral, deep coma)	–	5/8

AD, Alzheimer Disease; AGE, advanced glycation end-products; CVD, cardiovascular disease; FTD, frontotemporal dementia; LBD, Lewy body dementia; MAS-P, Modified Ashworth Scale for paratonia severity; MCI, mild cognitive impairment; PAI, Paratonia Assessment Instrument; PDD, Parkinson’s disease dementia; RCT, randomized controlled trial; VaD, vascular dementia.