1. Motor symptoms of ADHD

Author: Ulrich Brennecke
Review: Dipl.-Psych. Waldemar Zdero

Hyperactivity is a common symptom of ADHD, but not all people with ADHD are hyperactive.

In children, hyperactivity manifests itself in constant fidgeting, standing up or running around.
In adults, hyperactivity decreases, but restlessness of movement and certain behaviors such as finger drumming, foot tapping or nail biting may still occur. Motor hyperactivity may decrease over time, while inner restlessness may remain or become more visible. It is debated whether restlessness is a separate symptom and whether it is related to drive problems.

Men with and without ADHD show higher provoked hyperactivity than women in the Quantified Behavioral Test. Both men and women with ADHD have a doubled basal and a tripled provoked hyperactivity compared to non-affected persons.¹

Conclusion: These results suggest that women with ADHD suffer from hyperactivity to the same extent as men, challenging the assumption that hyperactivity is gender-dependent. This could lead to more accurate and timely diagnoses and reduce the burden and comorbidities associated with ADHD in females.

Hyperactivity and inner restlessness are also symptoms of stress. Stress hormones such as CRH can cause restlessness of movement. Gross motor problems such as clumsiness and coordination problems are common in ADHD-HI and ADHD-C. Fine motor problems such as poor handwriting and difficulties with fine motor tasks can also occur. It is unclear whether fine motor problems can be improved by ADHD medication.

The data from the ADxS.org symptom test showed that motor hyperactivity decreased with age, while restlessness and attention problems persisted.

While it has been recognized that attention problems in ADHD are primarily a motivational problem (lack of self-motivability), as intrinsically interesting topics can arouse attention while intrinsically non-interesting topics cause attention problems, it is largely unknown that this also applies to motor restlessness. A Time-lapse video showing a person with ADHD watching a video that is intrinsically interesting for him and one that is intrinsically uninteresting for himillustrates that hyperactivity problems are caused just as motivationally as attention problems.

• 1.1. Hyperactivity
  • 1.1.1. Motor hyperactivity as an ADHD symptom
  • 1.1.2. Manifestations of motor hyperactivity
  • 1.1.3. Age-related decline in motor hyperactivity
  • 1.1.4. Hyperactivity as a stress symptom
• 1.2. Gross motor problems with ADHD
• 1.3. Fine motor problems with ADHD
• 1.4. Motor development disorders
  • 1.4.1. Developmental coordination disorder (DCD, dyspraxia)
  • 1.4.2. Persistent (primitive) reflexes (RPR)
    • 1.4.2.1. Asymmetric tonic neck reflex (ATNR)
    • 1.4.2.2. Symmetrical tonic neck reflex (STNR)
    • 1.4.2.3. Moro reflex
    • 1.4.2.4. Galant reflex

1.1. Hyperactivity¶

Motor hyperactivity is a very common symptom of ADHD. However, hyperactivity is not a mandatory symptom of ADHD. There are people with ADHD who suffer greatly from their symptoms, who were/are neither hypermotoric as children nor full of inner restlessness as adults.

1.1.1. Motor hyperactivity as an ADHD symptom¶

Motor overactivity is a characteristic of ADHD-HI and ADHD-C. Hyperactivity is less pronounced in the ADHD-I subtype (predominant attention problems).²
Hyperactivity often subsides in adolescence. The specialist literature describes that hyperactivity in adults usually turns into a form of inner restlessness. This will need to be discussed.

The fidgeting and constant movement could be understood as an internal correction of vigilance (internal basic tension) and low dopamine levels. Movement increases the dopamine level.³⁴ People with ADHD who are forced to sit still are (even) more likely to give incorrect answers than when they are allowed to move.³ Similarly, sports before school (to act out motor restlessness) increases learning success.³
Children with ADHD showed a shorter reaction time in the Stroop test and improved self-efficacy with simultaneous exercise (cycling). In children without ADHD, the result was unchanged.⁵ The authors concluded that hyperactivity in ADHD may be a compensatory mechanism to upregulate hypoarousal in the PFC to support executive functions and self-efficacy.

1.1.2. Manifestations of motor hyperactivity¶

• for small children:
  • Extended childish defiant phase
  • Possibly with excessive, veritable, real tantrums
• for children:
  • Constant fidgeting with hands and feet or sliding around on the chair (DSM IV/5)
  • Is frequently present in class and other situations where sitting is expected (DSM IV/5)
  • Frequently runs around or climbs excessively in situations where this is inappropriate (in adolescents or adults this may be limited to a subjective feeling of restlessness) (DSM IV/5)
  • Often has difficulty playing quietly or engaging quietly in leisure activities (DSM IV/5)
  • Is often “on the move” or often acts as if he/she is “driven” (DSM IV/5)
  • Often talks excessively (DSM IV/5; categorized as impulsivity in ICD-10). Speech diarrhea can also be observed in some adults
• for adults:
  • Hyperactivity (external/physical) decreases by up to 60 % in adults⁶
  • Physical restlessness in adults, possibly only to a lesser extent
    • Foot tapping with high frequency (or impulse to do so, which is deliberately suppressed)⁷
    • Finger drumming (or impulse to do so, which is consciously suppressed)⁷
    • Chew nails⁸
    • Biting lips
    • Knot legs / wrap around chair leg to limit movement⁸

1.1.3. Age-related decline in motor hyperactivity¶

The data from the ADxS.org symptom test show the following changes in the age groups:

Age group	Motor hyperactivity	Inner restlessness	Attention problems
5- 9 years (n = 9)	0.70	0.80	0.75
10 - 14 years (n = 15)	0.72	0.68	0.83
15 - 19 years (n = 48)	0.45	0.62	0.81
20 - 29 years (n = 373)	0.49	0.70	0.81
30 - 39 years (n = 492)	0.49	0.74	0.83
40 - 49 years (n = 301)	0.46	0.74	0.78
50 - 59 years (n = 158)	0.46	0.72	0.80
60 - 75 years (n = 32)	0.42	0.74	0.72
Men (n = 630)	0.52	0.73	0.81
Women (n = 823)	0.45	0.72	0.80

As at June 2020. The values given reflect the severity of the symptoms relative to each other.
Limitations of informative value:

• There are few data sets with test persons under 20 years of age and far too few data sets with test persons under 10 years of age for a reliable statement.
• There was no separation of ADHD-I and ADHD-HI, so the (random) ratio of ADHD-I to ADHD-HI may skew the data for small group sizes.
• Only the data sets in which the symptom test found indications of existing ADHD were evaluated.
• This is a non-validated online self-test (screening).

The data can be discussed in relation to the thesis that attention problems in children up to the age of 15 are not yet fully developed and that motor hyperactivity diminishes in adulthood. However, they indicate that hyperactivity does not transform into inner restlessness, but that inner restlessness also exists in children and merely recedes to a lesser extent than hyperactivity. After the regression of motor hyperactivity, inner restlessness merely appears to become more visible.

Inner restlessness could be described as the “little brother” of hyperactivity.

1.1.4. Hyperactivity as a stress symptom¶

Hyperactivity and fidgeting are known to be typical symptoms of severe stress, as is the fact that thoughts concentrate on the stressor (circling thoughts, rumination).
Stress symptoms from the hyperactivity spectrum are:

• Restlessness¹⁰¹¹
  Inner restlessness is a typical symptom of the approaching final state of burnout.¹²
• Restlessness¹³¹⁴
• Restlessness of movement¹⁵

The stress hormone CRH, which is released by the hypothalamus in the first increment of the HPA axis, directly mediates an urge to move. Increased locomotor activity is a direct effect of the stress hormone CRH.^1617181511

Symptoms that are directly mediated by stress hormones themselves can nevertheless also be ADHD-specific symptoms. Chronic stress such as ADHD mediate their symptoms through a lack of dopamine and noradrenaline in the brain.

1.2. Gross motor problems with ADHD¶

Gross motor skill problems are a symptom of ADHD.^{1920212223242526} They are already present in young children and correlate with sleep problems in children. More than half of people with ADHD are said to have gross and fine motor problems.^27282930
Gross motor and fine motor disorders should be considered separately from motor hyperactivity.

Forms of appearance:

• Clumsiness
  • Frequently bump into/stay stuck
• Many accidents (clumsiness meets hectic pace)
  • Frequent injuries (esp. ADHD-HI)
  • Bruises
• Coordination problems (dyscoordination)
  • E.g. learning to ride a bike at the age of 6
  • E.g. difficulty maintaining balance or standing on one leg³¹³²³³
    • Balance and bilateral coordination (including manual dexterity) are the most commonly reported areas of motor impairment in ADHD³⁴
• Difficulties with force dosage

Initial data from the ADxS.org online symptom test (as of October 2018) suggests that gross motor problems are far more common in ADHD-HI with hyperactivity than in the ADHD-I subtype. Studies prove the connection between gross motor problems and hyperactivity/impulsivity.³⁵

It is possible that motor problems in the form of deficits in interpersonal (automatic) (motor) synchronization contribute to the development of social problems. Interpersonal synchronization requires good motor control and is also important in the development of mother-child relationships³⁶
Interpersonal synchronization plays an important role in the acquisition of social cognitive skills in development.³⁷³⁸ In ADHD, the extent of interpersonal synchronization between mother and child correlates with the level of functioning of preschool children with ADHD.³⁹
Another hypothesis suspects a connection between impaired eye control (gaze control and gaze saccades (eye movements)) and ADHD symptoms such as attention problems and impulsivity.⁴⁰

Gross motor symptoms related to ball catching/throwing and balance are said to be higher in ADHD-I > ADHD-C > ADHD-HI > than in non-affected individuals.⁴¹

1.3. Fine motor problems with ADHD¶

Fine motor problems are a symptom of ADHD.²¹⁴²⁴³ More than half of people with ADHD are said to have gross and fine motor problems.²⁹
Fine motor and gross motor disorders should be considered separately from motor hyperactivity.

4- and 5-year-old children with ADHD were more likely to have developmental delays in fine motor skills than in gross motor skills, more so in the 4-year-olds than in the 5-year-olds.
Among 5-year-olds, poorer fine motor skill development was more strongly associated with ADHD severity than gross motor skill development.⁴⁴

Forms of appearance:
Activities that require precise hand-eye coordination are made more difficult

• Handwriting problems⁴⁵
  • Scrawly handwriting⁴⁶⁴⁷
  • Disproportionately increasing with dictation under time pressure⁴⁸
• Problems with
  • Drawing
  • Children find it difficult to color pictures neatly⁴⁸
  • Dressing (children)
  • Eating with cutlery and other
  • Straight cuts with scissors (children)
  • Inserting small screws

Fine motor problems should

• be stronger in younger children (6 to 9 years) than in older children (10 to 13 years)⁴⁹
• be more common in ADHD than in ODD/CD⁵⁰
• be more common with ADHD-I²⁹
• with ADHD-I stronger than with ADHD-C stronger than with ADHD-HI stronger than with non-affected persons⁴¹
• be about equally common in ADHD-HI and ADHD-I⁵¹
• be more common in ADHD-C than in ADHD-I and ADHD-HI⁴⁹
• be gender-independent⁴⁹
• occur with dominant and non-dominant hand⁴⁹

Between 28% and 67% of people with ADHD also showed improvements in their fine motor skills with ADHD medication²⁹⁵²

Using the Functional Dexterity Test (FDT) to measure manual fine motor skills, children and adolescents with ADHD between the ages of 7 and 17 showed lower processing time for the dominant hand and the non-dominant hand, higher processing speed in the Pegboard Test, higher total errors and higher FDT time. Although ADHD children were faster, they were at a disadvantage in terms of processing errors and total processing time.⁵³

1.4. Motor development disorders¶

1.4.1. Developmental coordination disorder (DCD, dyspraxia)¶

An online survey of German parents (n = 149) found a significantly higher prevalence of DCD (over 50%), even if the parents had never heard of DCD.⁵⁴ A larger study (n = 755) found Developmental Coordination Disorder (DCD, dyspraxia) in 34% of boys and 29% of girls with ADHD.²⁶

1.4.2. Persistent (primitive) reflexes (RPR)¶

In CNS ontogeny, later developed functions tend to replace older ones when higher increments of CNS development have been successfully achieved.⁵⁵ So-called primitive reflexes, including the Asymmetric Tonic Neck Reflex (ATNR) and the Symmetric Tonic Neck Reflex (STNR), are early childhood (primitive/primary) reflexes that are replaced by more advanced functions during normal development and then regress.
It is true that many healthy children also show persistent (retained) primitive reflexes (RPR).⁵⁶ However, RPR often correlate with developmental delays and

• ADHD^{57 58 59}
• ASS^{5758 60 61}
• Dyslexia⁵⁷
• Tourette⁵⁷
• Learning disability⁵⁷
• sensory processing disorders⁵⁷
• Cerebral palsy⁶²⁶³
• Parkinson’s disease⁶⁴
• Zika virus syndrome⁶⁵
  • Children with congenital Zika virus syndrome showed abnormal persistence of primitive reflexes (94.7%), impaired cognitive development (95.1%), delayed neuropsychomotor development (between 92.8% and 100%), hypertonia (between 74.7% and 90.1%) and impaired language development (between 68.42% and 100%).⁶⁶showed abnormal persistence of primitive reflexes⁶⁵ (94.7 %), impaired cognitive development (95.1 %), delayed neuropsychomotor development (between 92.8 % and 100 %), hypertension (between 74.7 % and 90.1 %) and impaired language development (between 68.42 % and 100 %).⁶⁶
• other neurobehavioral disorders.⁶⁷ RPR appear to be associated with maturational delays and neuronal developmental disorders ⁵⁷⁶⁸
• Premature births⁶⁹

ATNR and STNR can still be measured in adulthood.⁷⁰ Primitive reflexes even appear to increase again in old age.

• persistent primitive reflexes were found⁷¹
  • at 47 to 51 % at the age of 25 to 45 years
  • 73 % to 75 % between the ages of 65 and 85
  • no correlation was found with cognition
• Palmomental reflex found⁵⁷
  • in 6% to 27% of young adults aged 20-50 years
  • 28 % to 60 % of people over 60 years of age
• Snout reflex⁵⁷ (also orbicularis-oris reflex; is triggered by lightly tapping the closed lips in the midline and manifests itself in a contraction of the lip muscles (pout, protrusion of the lips reminiscent of a beak or snout).
  • in 13 % of people aged 40-57 years
  • 22% to 33% of the over-60s
• Sucking reflex, which is also associated with frontal lobe disorders⁵⁷
  • in more than 6% of normal people aged 73 to 93 years

Persistent primitive reflexes (ATNR, STNR, Moro) caused significantly lower success rates in technical and tactical moves in soccer players (average age 17.5 years), including a 15.5 % to 31.8 % lower pass success rate and significantly worsened defensive actions and duels.⁷² Of high performance youth soccer players, two-thirds showed active primitive reflexes. Among those who played one age group higher than their age, the rate of non-integrated primitive reflexes was higher.⁷³

RPR can also (re)occur in old age, e.g. due to degeneration (dementia, Parkinson’s disease)⁷⁴⁷⁵ , a lesion of the frontal lobe or damage to the corticospinal tract.⁵⁷

Training the primitive reflexes improved eye control.⁷⁶ Even in adults, a retraining of primitive reflexes is still possible with a daily effort of 5 minutes over one to one and a half years.⁵⁸

One study found an increased presence of persistent reflexes in n = 14 children with learning problems:⁷⁷

• ATNR 100 %
• STNR 100 %
• Tonic lateral reflex (TNR) 100 %
• Moro reflex 92.8 %
• Spinal galant reflex 64.2 %
• Search reflex (root reflex, rooting) 64.2 %
• Palmar reflex 64.2 %
  • light pressure is exerted by stroking the palm horizontally. An existing palmar reflex leads to closing the palm or forming a fist.
• Suction reflex 57.1 %

In ASD, in which there is abnormal lateralization, long-range underconnectivity, a greater ratio of functional qEEG connectivity between left and right, and short-range overconnectivity, a reduction in persistent primitive reflexes (RPRs) (two of the group Asymmetric tonic neck reflex, Symmetrical tonic neck reflex, Spinal Galant, Babinski, Palmer Grasp, Search reflex and Tonic neck reflex) by unilateral transcutaneous electrical nerve stimulation (TENS) correlated with a change in the qEEG in the Bete, Delta, Theta and Gamma bands towards normalization of the U-curve typical in ASD.⁷⁸
In ASD, there was an increased persistence of the snout reflex and the visual search reflex, but not of the tactile search reflex, sucking reflex and grasping reflex.⁷⁹

A reduction in persistent reflexes is in line with the therapeutic goals for developmental delays. Persistent reflexes could be a biomarker for developmental disorders⁸⁰

A case study of 3 individual cases reports resolution of persistent primitive reflexes in three adult alcoholics by the NDMA antagonist acamprosate.⁸¹

1.4.2.1. Asymmetric tonic neck reflex (ATNR)¶

ATNR:⁸²

• Turning the head to the side is followed by a reflex
  • Stretching the limbs (arm and leg) on the side of the face
  • Flexion of the limbs (arm and leg) on the back of the head
  • Test: The test person (blindfolded so that visual orientation does not distort the result) gets down on their hands and knees. The subject’s head is placed in the center line, with the face parallel to the floor. Knees and hips are bent as far as possible. were. The subject should relax and then keep their arms straight and not bend their elbows. The flexion of the elbows is measured with the head in a neutral position, with the head positioned to the right and left by the examiner.
• Training in the 16th to 18th week of pregnancy⁸³
• Purpose:
  • prenatal
    • Building up the muscle tone
    • Reduction of oxygen demand by shutting down the circulation in the event of oxygen deficiency⁵⁸
  • Support for active birth process (rotation)
    • Press contractions cause oxygen deficiency and trigger ATNR⁵⁸
  • Support for eye-hand coordination that begins after birth
• is gradually integrated in the 3rd to 9th month of life by crawling on the stomach⁸³
• should have completely disappeared by the end of the 1st year of life, otherwise signs of developmental delay

The Children’s Primitive Reflex Integration Measurement Scale (CPRIMS) was developed to measure ATNR and STNR, among other things.⁸⁴
Failure to regress ATNR and STNR increased the risk of motor⁸³ and psychological⁵⁵ problems.

Excessive reflex responses and persistence of the ATNR are considered a pathological sign of brain damage (e.g. cerebral hypoxia in newborns) and hinder normal motor development.⁸⁵
Possible signs of ATNR developmental delay (usually several):⁸²

• lack of development of laterality
  • lack of laterality / homolateral (equilateral) movement patterns
  • changing preference for guide hand / leg
    • ADHD correlates with an increased frequency of non-right-handedness (left-handedness, mixed handedness)⁸⁶
  • unfixed guide eye
    • possible Consequences (increased under stress):
      • lack of following eye movement
      • impaired or confusing visual perception
      • LRS (reading and spelling difficulties)
  • undefined guide ear = lack of definition of the ear = change of the preferred ear when listening
    • possible Consequences (increased under stress):
      • Problems with sound processing
      • auditory sequence problems
      • Mixing up and omitting letters, numbers and arithmetic symbols
      • LRS
• Right/left weakness (confusing right and left)
• mirror image writing
• mirror image reading (confusing b and d or p and q)
• Handwriting
  • Child compensates for the pressure on the pen, which impairs handwriting
  • spidery
  • very narrow and small
  • Difficulties keeping to lines
  • Turning the page while writing
• Reclined sitting posture
• Scoliosis⁸³⁸⁷
• Disorders of eye-hand coordination⁸⁵
• visual perception and fixation disorders⁸⁵
• Coordination disorder, especially when crossing the midline of the body (movement, posture and writing disorders)⁸⁵
• Balance problems⁸⁸
  • when the head is turned to the side
  • Learning to ride a bike more difficult
• Dyslexia
• Reading and spelling difficulties
• Difficulties in math

Studies have found a correlation between a persistent ATNR and

• ADHD^83899088
• LRS^91929394
• Hearing problems⁹²
• Difficulty reading the time⁹⁵
• motor problems⁸³
• neurological problems⁹⁶

In children (8 to 11 years) with persistent ATNR and LSR, ATNR features were reduced by mimicking reflex movements.⁹⁷

1.4.2.2. Symmetrical tonic neck reflex (STNR)¶

STNR:

• Reflex pattern consists of two movements
  • child kneels on hands and knees and head is raised, arms are straight and one is bent
  • head is lowered, arms are bent and legs are stretched
• When the head is moved forwards (chin to chest) or backwards (head to neck), the following reflex occurs⁸²
  • Counter movement of the upper half of the body to the lower half
  • Stretching the upper half of the body causes flexion of the lower half and vice versa
  • Bend head forward -> arms bend, legs stretch
  • Bend head backwards -> arms stretch, legs bend

The STNR influences the further integration of the tonic labyrinthine reflex. It strengthens the back and neck muscles and is important for correct posture.

If the STNR is not sufficiently integrated, the child moves on its bottom by sliding or sitting until it learns to walk. Children who have never crawled on all fours usually have an active STNR.

The STNR is crucial for the development of vision, the sense of balance and eye-hand coordination.

STNR⁸²

• develops from the tonic labyrinth reflex, which becomes visible at the beginning of the 9th week of pregnancy
• STNR is particularly pronounced from the 6th to 8th month of life⁸³
• close connection to the vestibular system
• important transition phase to crawling
• trains accommodation (distance adjustment of the eyes)

The STNR should be integrated in the 9th to 11th month of life and be completely replaced by more mature movement coordination in the further course of life⁸³

The Children’s Primitive Reflex Integration Measurement Scale (CPRIMS) was developed to measure ATNR and STNR, among other things.⁸⁴
Failure to regress ATNR and STNR increased the risk of motor⁸³ and psychological⁵⁵ problems.

Motor immaturity in the form of movement patterns from persistent STNR correlates with⁸²

• ADHD symptoms
  • Hyperactivity
  • Attention problems
  • Concentration problems
  • Organizational problems
  • poorly developed sense of time
  • Sequence problems (for practical requirements or more complex work instructions)
  • motor problems⁸³
• difficult rhythmically coordinated movements
• Fluid affected by movements that⁹⁸
  • require vertical eye movement
  • Require control of sitting posture
• Reading and writing posture impaired
• Difficulty coordinating upper and lower body movements, e.g. swimming, forward/backward roll
• Push-ups are more difficult because stretching the arms triggers the bend reflex in the legs
• Catching balls made more difficult by
  • lack of eye-hand coordination
  • Difficulty estimating distance and time
• Muscle tone
  • weak
  • stiffened
• Balance problems
• Poor posture
• Problems keeping the back straight
• Weak upper arm strength
• Sitting in the W position or wrapping your legs around the legs of the chair
• When reading or writing, the child remains lying over the book and supports their head with their hand
• Lack of/barely any crawling (toddlers)
• Difficulties with accommodation and visual focusing at different distances (impairs reading ability)
• Perceptual difficulties
  • visual
  • spatial

1.4.2.3. Moro reflex¶

The Moro reflex (startle reflex) responds to sudden, startling stimuli in the 2nd to 4th month of life by spreading out and then pulling the arms and legs back in, which is often supported by a cry.

Trigger: Sudden movements, loud noises, change of position, bright light
Reaction: Spreading of the arms and legs, followed by tightening and often screaming, increase in pulse, activation of the sympathetic nervous system
Meaning: activates the first breath after birth; helps the baby to hold on or protect itself in case of danger
Inhibition: Usually between 2 and 4 months of age, but may persist longer in some children

A small study found an increased prevalence of a persistent Galant reflex in ADHD⁹⁹
A persistent Moro reflex is an indication of neurological problems.⁹⁶

An excessive, persistent Moro reaction can trigger excessive startle reactions. This is more common in people who have an increased openness to stimuli, as is typical with ADHD.⁵⁸
An individual case reports of an 18-year-old woman in whom a massive anxiety and panic disorder correlated with a still fully developed Moro reflex. Treatment to regress the Moro reflex showed an improvement in the anxiety symptoms.⁵⁸

1.4.2.4. Galant reflex¶

One small study found an increased prevalence of a persistent Galant reflex in ADHD.⁹⁹