Neuropsych. SWINNEN: WALKING & COGNITIVE FUNCTION IN PATIENTS WITH CNS DISORDERS
INTRO
DOES HUMAN WALKING REQUIRE COGNITIVE FUNCTION?
- “Walking has long been considered as an automatic or reflex controlled task requiring motor
responses to sensory stimuli, but requiring minimal cognitive resources”
Hoofdvraag
- gang≠ automatisch≠reflex
REFINEMENT OF THE RESEARCH QUESTION
Of course walking needs cognitive action ...
- Goal orientation
- Navigation
- Obstacle avoidance
- Environmental constraints
REFINED RESEARCH QUESTION
Need walking cognitive action?
- Does the act of walking per se
- i.e. the organisation and control of the walking movements, require cognitive capacity ?
WALKING AS AN AUTOMATED ACTION
Early studies (Sherrington (1910) & Brown (1911) on stepping movements in decerebrate & spinalized
cats:
- Sherrington suggested that walking could be produced entirely by a series of reflexes
- they supposed a neural mechanism in the lumbar part of the spinal cord
- wandelen trainen zelfs na SCI/hersenletsel
Barbeau & Rossignol (1987):
- Central pattern generator (CPGs)
Systeem in ruggenmerg spec. Voor generatie van dit patroon
- Recovery of locomotion after chronic spinalization in the adult cat.
1. CENTRAL PATTERN GENERATORS (CPGS)
Neural networks in the spinal cord are capable of producing rhythmic movements:
- breathing, swimming, walking, and hopping,
- even when isolated from the brain and sensory inputs !
stimulatie SCI/ brain leasion
Supraspinal inputs:
- play a role in initiating locomotion and in adapting the locomotor pattern to
environmental and motivational conditions
- input hersenen doorheen lichaam
Sensory afferents:
- involved in muscle and cutaneous reflexes have important regulatory functions in
preserving balance and ensuring stable phase transitions in the locomotor cycle
Neuromodulators:
- evoke changes in cellular and synaptic properties of CPG neurons, conferring flexibility to CPG circuits
2. 5 FUNCTIONS OF SUPRASPINAL AREAS IN THE CONTROL OF LOCOMOTION
activating spinal locomotor CPGs
controlling the intensity of CPG operation
maintaining equilibrium during locomotion
adapting limb movement to external conditions
coordinating locomotion with other motor acts
belangrijk voor het hertrainen van funcies na SCI/ brain leasion
Nala Melis Pagina 1
, Neuropsych. SWINNEN: WALKING & COGNITIVE FUNCTION IN PATIENTS WITH CNS DISORDERS
3. CPGS
CPGs do not operate in a vacuum
- but depend on the interplay of information between the brain and spinal cord
with final motor output shaped by sensory feedback from peripheral receptors &
reconfigured by neuromodulators
What is the nature of that supraspinal control ?
Does it imply cognitive action or is it completely automatic ?-->Volgende stap
TWO EXPERIMENTAL PARADIGMS
CORRELATIVE STUDIES
searching for a relation between two elements
1. STUDY 1
Duff et al. found a strong relationship between walking and global cognition
675 non-demented, community-dwelling older adults (65+)
- Nog actieve P
Walking speed: asked to walk on preferred walking speed 25 feet, turn around, and return (25 feet)
Cognition: Repeatable Battery for the Assessment of Neuropsychological Status (RBANS)
12 subtests
- list learning, story memory, figure copy, line orientation, picture naming, semantic fluency, digit span,
coding, list recall, list recognition, story recall, figure recall
- Total score and 5 index scores (attention, language, visuospatial/constructional abilities, immediate
and delayed memory)
The better the cognition, the faster the walking speed and vice versa (rp= .25, p<.01) in healthy elderly
- Correlatie tussen cognitive & wandelsnelheid
But, only 20 % of the variance of the walking speed was explained by cognition, even when including age,
gender, and education in the model
- there are also other element that could have an influence
- nog andere mogelijke verklaring voor ↑/↓ snelheid
2. STUDY 2
Holtzer et al. studied 186 cognitively normal elders (mean age 78 y)
- Beetje verschillend van vorige studie
Walking speed: measurement of the preferred walking speed using a 12-ft Gaitrite system
Neuropsychological tests: Test battery
- speed of information processing
- attention
- memory
- language
- executive function
Factor analysis yielded 3 significant neuropsychological factors:
1) verbal IQ
2) speed/executive attention
3) memory
- These neuropsychological factors were significant predictors of the walking velocity explaining 16 %
of the variance, even after adjusting for the effects of demographic variables, health condition and
clinical gait abnormality
=> at least in old age, walking is a complex task that requires the involvement of higher order
executive control processes
Niet enkel ruggenmerg dat wandelbeweging is geïnduceerd
CORRELATIVE STUDIES DON’T INDICATE THE DIRECTION OF THE RELATIONSHIP, NOR PROVE CAUSAL
EFFECTS !
Nala Melis Pagina 2
INTRO
DOES HUMAN WALKING REQUIRE COGNITIVE FUNCTION?
- “Walking has long been considered as an automatic or reflex controlled task requiring motor
responses to sensory stimuli, but requiring minimal cognitive resources”
Hoofdvraag
- gang≠ automatisch≠reflex
REFINEMENT OF THE RESEARCH QUESTION
Of course walking needs cognitive action ...
- Goal orientation
- Navigation
- Obstacle avoidance
- Environmental constraints
REFINED RESEARCH QUESTION
Need walking cognitive action?
- Does the act of walking per se
- i.e. the organisation and control of the walking movements, require cognitive capacity ?
WALKING AS AN AUTOMATED ACTION
Early studies (Sherrington (1910) & Brown (1911) on stepping movements in decerebrate & spinalized
cats:
- Sherrington suggested that walking could be produced entirely by a series of reflexes
- they supposed a neural mechanism in the lumbar part of the spinal cord
- wandelen trainen zelfs na SCI/hersenletsel
Barbeau & Rossignol (1987):
- Central pattern generator (CPGs)
Systeem in ruggenmerg spec. Voor generatie van dit patroon
- Recovery of locomotion after chronic spinalization in the adult cat.
1. CENTRAL PATTERN GENERATORS (CPGS)
Neural networks in the spinal cord are capable of producing rhythmic movements:
- breathing, swimming, walking, and hopping,
- even when isolated from the brain and sensory inputs !
stimulatie SCI/ brain leasion
Supraspinal inputs:
- play a role in initiating locomotion and in adapting the locomotor pattern to
environmental and motivational conditions
- input hersenen doorheen lichaam
Sensory afferents:
- involved in muscle and cutaneous reflexes have important regulatory functions in
preserving balance and ensuring stable phase transitions in the locomotor cycle
Neuromodulators:
- evoke changes in cellular and synaptic properties of CPG neurons, conferring flexibility to CPG circuits
2. 5 FUNCTIONS OF SUPRASPINAL AREAS IN THE CONTROL OF LOCOMOTION
activating spinal locomotor CPGs
controlling the intensity of CPG operation
maintaining equilibrium during locomotion
adapting limb movement to external conditions
coordinating locomotion with other motor acts
belangrijk voor het hertrainen van funcies na SCI/ brain leasion
Nala Melis Pagina 1
, Neuropsych. SWINNEN: WALKING & COGNITIVE FUNCTION IN PATIENTS WITH CNS DISORDERS
3. CPGS
CPGs do not operate in a vacuum
- but depend on the interplay of information between the brain and spinal cord
with final motor output shaped by sensory feedback from peripheral receptors &
reconfigured by neuromodulators
What is the nature of that supraspinal control ?
Does it imply cognitive action or is it completely automatic ?-->Volgende stap
TWO EXPERIMENTAL PARADIGMS
CORRELATIVE STUDIES
searching for a relation between two elements
1. STUDY 1
Duff et al. found a strong relationship between walking and global cognition
675 non-demented, community-dwelling older adults (65+)
- Nog actieve P
Walking speed: asked to walk on preferred walking speed 25 feet, turn around, and return (25 feet)
Cognition: Repeatable Battery for the Assessment of Neuropsychological Status (RBANS)
12 subtests
- list learning, story memory, figure copy, line orientation, picture naming, semantic fluency, digit span,
coding, list recall, list recognition, story recall, figure recall
- Total score and 5 index scores (attention, language, visuospatial/constructional abilities, immediate
and delayed memory)
The better the cognition, the faster the walking speed and vice versa (rp= .25, p<.01) in healthy elderly
- Correlatie tussen cognitive & wandelsnelheid
But, only 20 % of the variance of the walking speed was explained by cognition, even when including age,
gender, and education in the model
- there are also other element that could have an influence
- nog andere mogelijke verklaring voor ↑/↓ snelheid
2. STUDY 2
Holtzer et al. studied 186 cognitively normal elders (mean age 78 y)
- Beetje verschillend van vorige studie
Walking speed: measurement of the preferred walking speed using a 12-ft Gaitrite system
Neuropsychological tests: Test battery
- speed of information processing
- attention
- memory
- language
- executive function
Factor analysis yielded 3 significant neuropsychological factors:
1) verbal IQ
2) speed/executive attention
3) memory
- These neuropsychological factors were significant predictors of the walking velocity explaining 16 %
of the variance, even after adjusting for the effects of demographic variables, health condition and
clinical gait abnormality
=> at least in old age, walking is a complex task that requires the involvement of higher order
executive control processes
Niet enkel ruggenmerg dat wandelbeweging is geïnduceerd
CORRELATIVE STUDIES DON’T INDICATE THE DIRECTION OF THE RELATIONSHIP, NOR PROVE CAUSAL
EFFECTS !
Nala Melis Pagina 2
