This presentation is about the role of cognition in vestibular system . Its pathways and mechanisms

1. Vestibulocognitive interaction
Presenter: Nahid Shamsi

2. Topics
 Vestibular system roles and cognitive?
 Vestibular pathways involved in cognition
 Vestibular cortical areas
 Pathways to cortex or exactly hippocampus??
 Cognition tasks : attention, memory..
 AD disease
 Vestibular rehabilitation and cognition

3. Vestibular
system
 Senses angular and linear acceleration of the head in three
dimensions
 Responsible for generating vestibulo-ocular and vestibulo-
spinal reflexes
 Stabilize the visual image on the retina and adjust posture
during head movement
 Role in maintaining gaze stability and balance via
reflexive mechanisms
 Its role in cognition

4. Vestibular
pathways involved
incognition:
(1) the vestibulo-thalamo-cortical pathway
(2) a pathway from the dorsal tegmental nucleus via the
lateral mammillary nucleus, the anterodorsal nucleus of
the thalamus to the entorhinal cortex
(3) a pathway via the nucleus reticularis pontis oralis,
the supramammillary nucleus and the medial septum to
the hippocampus
(4) a possible pathway via the cerebellum, and the
ventral lateral nucleus of the thalamus

5. Vestibular
pathways involved
incognition:
 Thalamo-cortical
pathway
 Theta pathway
 Cerebello-cortical
pathway
 Head direction
pathway

6. 4pathwaysto
cortexorexactly
hippocampus??

7. Hippocampus
 We know that the hippocampus is required for episodic
memory, but the role of spatial information, so obvious in
rodent recordings (for example, place cells), remains to be
clearly defined
 essential for :
1. spatial representation of environments
2. ability to remember specific events, or ‘episodic
memory/Spatial memory
3. Cognitive map

8. Vestibular
cortical areas(9)
 PARIETO-INSULAR VESTIBULAR CORTEX (PIVC) AND
TEMPORO-PARIETAL JUNCTION
 ANTERIOR PARIETAL CORTEX
 POSTERIOR PARIETAL AND MEDIAL SUPERIOR
TEMPORAL CORTICES
 CINGULATE GYRUS AND RETROSPLENIAL CORTEX
 HIPPOCAMPAL AND PARAHIPPOCAMPAL CORTICES

9. PARIETO-INSULAR
VESTIBULAR
CORTEX (PIVC)AND
TEMPORO-
PARIETAL
JUNCTION
 the superior temporal gyrus,
posterior insula, inferior
parietal lobule
 1/3 neurons
 receive proprioceptive input,
mostly during body movement
independent of head
movement

10.  PIVC
 TEMPORO-PARIETAL JUNCTION
 the superior temporal gyrus,
posterior insula, inferior parietal
lobule
 the area OP2 of the parietal
opercula
 Integrate with proprioceptive

11. ANTERIOR
PARIETAL
CORTEX

12.  ANTERIOR PARIETAL CORTEX
 anterior part of the intraparietal
sulcus(VIP) and primary somatosensory
cortex(ant parietal cortex)
 a center of integration of vestibular input
and somatosensory information from the
head, neck and upper limbs
 role in differentiating self from object
motion

13. POSTERIOR
PARIETALAND
MEDIALSUPERIOR
TEMPORAL
CORTICES

14.  POSTERIOR PARIETAL AND MEDIAL
SUPERIOR TEMPORAL CORTICES
 Inferior parietal lobule in area 39 and 40
 Brodmann area 37 of the middle temporal
gyrus
 a multimodal center
 a key role in spatial representation and encodes
precise self-motion and acceleration states
 integrates visual object location information
relative to the head
 suppress reflex movement during active
movement

15. CINGULATE
GYRUS AND
RETROSPLENI
AL CORTEX

16.  CINGULATE GYRUS AND
RETROSPLENIAL CORTEX
 anterior and posterior cingulate
gyrus
 retrosplenial cortex: navigation and
path integration
 Caloric stimulation
 transform a representation from
allocentric to egocentric

17. HIPPOCAMPAL
AND
PARAHIPPOCAMP
ALCORTICES

18.  HIPPOCAMPAL AND
PARAHIPPOCAMPAL CORTICES
 integrate cognitive maps
 based on place cells, border cells,
head direction cells (HD cells) and
grid cells

19. How itcancreatecognitive
maps?
1.Cells
2. Theta rhythm
3. Theta pathway

20. Placecellsand
HDcells
 an activity highly correlated with the location of the subject
in a specific area of the environment
 are associated with spatial view cells in the parahippocampal
region
 Vestibular input appears to be fundamentally important for
place and HD cells
 inactivation of the vestibular system leads to the disruption
of location-specific firing in hippocampal place cells and the
direction-specific discharge of thalamic and PoS HD cells

21. Gridcells
 grid cells do not fire in only one location but in multiple
specific locations forming an equilateral triangle grid-
like pattern

22. Thetarhythm
 Hippocampal theta rhythm (theta) is an oscillating
electrical signal within the 1-4 Hz frequency range found in
human
 Cognitive functions like spatial orientation or spatial
memory require theta rhythm in the hippocampus
 because theta establishes a subthreshold membrane
potential
 modulates the spiking activity of hippocampal, entorhinal,
and septal neurons

23. Thetapathway
Signal from PRO
Activate SUM
Convert to
rhytmiv pattern
Relay to
Gaba/cholin MS
Modulate the
interneuron of
hippocampus and
generation of
Theta

24. INFLUENCEOF
VESTIBULAR
INPUTONTHETA
 passive rotation of awake restrained rats : increases
theta power
 passive translation in rats: increases in theta
 vestibular lesions: decrease the power and the
frequency of theta
 Theta pathway

25. Evidence
 In humans, functional imaging during vestibular
stimulation demonstrates activation or inactivation of
the hippocampal and parahippocampal areas
 patients with chronic bilateral vestibular deficits
demonstrate bilateral hippocampal atrophy and spatial
memory impairment
 the fundamental role of vestibular inputs in
integrating different maps of the same environment in
the hippocampus
 Besides the spatial representation integrated in these
maps, place cells contribute to time representation of
the past (spatial memory) and the future.

26. Vestibular involvement
in cognition
Visuospatial ability, attention, executive function
and memory

27. 1.Visuospatial
ability
 How the mind organizes and understands two- and
three dimensional space
 Include:
1. spatial memory
2.mental imagery
3.Mental rotation
4. Distance and depth perception
5.Navigation
6.Visuospatial construction

28. Spatialmemory
 a complex construct that encompasses information about several
different components of one’s environment: including geometry,
relative position, distance, size, orientation, and coordinates
 virtual Morris Water Maze Task (vWMT)

29. Computerized
virtual Morris
Water MazeTask
(vWMT)

30. Results:
 The bilateral vestibular dysfunction (BVD) patients
1.significant decreases in hippocampal size (16.9%)
2. impaired performance on several aspects of the vWMT
including longer path length and decreased time spent in
the correct quadrant
3.no difference in intelligence or nonspatial memory
 not involve any vestibular inputs
 UVD leads only to mild or no changes in performance

31. CorsiBlock-
Tappingtest
 unilateral vestibular neuritis patients performed
significantly worse than controls,
 were also found to have higher co-morbid depression
and anxiety

32. Spatial
navigation
 Spatial navigation refers to the ability to move through
one’s environment
 head direction and path integration

33. Results
 clear evidence of navigational impairment in patients
compared to controls
 unilateral vestibular neuritis : required more time to walk on
a memorized square, circle, or triangular path with their eyes
closed, but not eyes open
 Surgical vestibular deafferentation :
increased numbers of turn errors and increased time required to
reach memorized targets when walking, particularly during eyes
closed
 Spatial navigation abilities may be improved by vestibular
rehabilitation/exercise

34. Mentalrotation
 measures visuospatial ability is mental transformation or
mental rotation
 vestibular patients : more errors and were slower on
mental rotation tasks
 Post-op and BVD patients : impaired in mental rotation
of three-dimensional objects and in mental scanning of
familiar and unfamiliar environments

35. Visuospatial
conclusions
 altered or absent vestibular input may lead to a fundamental
change in an individual’s mental representation of three-
dimensional space
 activate a broad cortical network, including the insula,
superior temporal gyrus, hippocampus, and the inferior
parietal lobule, among other regions

36. Visuospatial
conclusions
 these brain regions are part of a complex neural
network for visuospatial processing and memory
 decreased hippocampal volumes in association with
impaired spatial memory among BVD patients
 UVD patients: smaller volumes of the superior
temporal gyrus

38. 2.Attention
 Kahneman’s Capacity Model of Attention,an individual
has a set amount of attention and cognitiveresources
available to allocate to mental tasks
 Performance of tasks that require processing by
similar cognitive networks should decline in response
to the increased cognitive demand of the concurrent
task

39. Test
 Attention demand : such as asking the participant to
press a button in response to auditory stimuli or
counting backwards by three
 Balance is indeed demanding of cognitive resources
and is not simply reflexive

40. Results
 Both patients and controls’ performance : worsened during
eyes closed postural challenge
 posture and balance were similar between patients and
controls, but performance on cognitive tasks were not
 An ‘orientation-first’ principal, that orientation and posture
are prioritized and may draw attentional resources
 Attention deficit

42. 3.executive, and
memory function
 Patients with perilymph fistula syndrome:
1. deficits in memory (digit symbol, auditory recall, paired
associate learning tests)
2. Deficits in visuospatial ability (block design, picture
arrangement, paired associate learning, trail making tests)
3. deficits in executive function (digit symbol, picture
arrangement, trail making tests)
 lower scores on the arithmetic (executive function) and digit
span (memory, attention) portions of theWechsler Adult
Intelligence Scale
 short-term memory loss
 concentration problems
 difficulty with word retrieval
 reading problems
 inability to prioritize tasks
 dyscalculia

43. Effectofvestibular
manipulationoncognition
1. Microgravity and cognitive function
2. Vestibular stimulation

44. 1.Microgravity
andcognitive
function
 The otoconia dependent portions of the vestibular
system, the utricle and saccule, both require linear acceleration
to function
 Astronauts have anecdotally reported decreases in
1.cognitive and motor function
2. in executive function (judgement, arithmetic)
3. memory, and language (i.e. grammatical reasoning)
4. in visuospatial ability (tracking, spatial mental representation)
and attention

45. Thespace
stupid

46. Otolithlesions
 both the astronauts in space with reduced otolith input
and the vestibularly impaired patients appear to have
deficits in visuospatial ability and attention

48. 2.Vestibular
stimulation
 physical motion: decrease in latency of characteristic
EEG patterns in an auditory attention task
 caloric vestibular stimulation (CVS): paradoxical
results
 Galvanic vestibular stimulation (GVS): paradoxical and
worsen in imagery tasks

50. Galvanic and
caloricvestibular
stimulation
1.posterior insula (first
and second long insular
gyri)
2. retroinsular regions
[representing the PIVC
and the posterior
adjacent visual temporal
sylvian area]

51. Galvanic and
caloricvestibular
stimulation
 Activation of this cortical network during vestibular
stimulation is not symmetrical in the two hemispheres
 Activation was stronger in :
1. the nondominant hemisphere
2. Hemisphere ipsilateral to the stimulated ear
3. hemisphere ipsilateral to the slow phase of vestibular
caloric nystagmus

52. Galvanic and
caloricvestibular
stimulation

54. ADdisease

55. ADtheories
 Beta amyloid
 cerebrovascular deficiency
 lack of exercise
 head trauma
 diabetes

56. Vestibular
theoryof AD
1. Its role in cognition
2. more than any other sensory system, diffusely projects
to a variety of cortical and subcortical
3. an important and specific vestibular projection to the
medial-temporal cortex, including the hippocampus and
para hippocampal gyrus/parieto temporal, post cingulate
 horizontal semicircular canals (cholinergically)
 vestibular symptoms in AD
 d

57. Evidence of
Rehabilitation

58. Vestibular
rehabilitation
 In vestibular patients:
1. improvement in dizziness-related indexes and
psychological distress following vestibular rehabilitation
2.significant improvement in cognitive functions
including visuospatial ability, attention, and executive
function
 in older adults with and without mild cognitive
impairment:
implementation of a home-based virtual reality protocol
may be a safe option in order to ameliorate VOR,
postural control and the quality of life

60. References
 Vestibular involvement in cognition:Visuospatial ability, attention,
executive function, and memory ,Robin T. Bigelow∗ Department of
Otolaryngology, Head & Neck Surgery, Johns Hopkins University
School of Medicine, Baltimore, MD, US
 Vestibular pathways involved in cognition Martin Hitier1,2,3,4*,
Stephane Besnard1 and Paul F. Smith2 1 Inserm, U 1075 COMETE,
Caen, France
 Vestibular loss as a contributor to Alzheimer’s disease, Fred H. Previc
,Texas A&M University – San Antonio, One University Way, San
Antonio, TX 78224, United States
 From ear to uncertainty: vestibular contributions to cognitive function,
Paul F. Smith, Department Pharmacology and Toxicology, School of
Medical Sciences, and the Brain Health Research Centre, University of
Otago, Dunedin, New Zealand

61. Bibliography
 Functional brain imaging of peripheral and central vestibular
disorders Marianne Dieterich1 and Thomas Brandt2 ,University of
Munich, Munich,Germany
 Adolescent Hippocampal and Prefrontal Brain Activation During
Performance of the Virtual Morris Water Task ,Jennifer T. Sneider1,2*
 Challenges to the Vestibular System in Space: How the Brain
Responds and Adapts to Microgravity Jérome Carriot, 1Department of
Physiology, McGill University, Montreal, QC, Canada, 2Department of
Biomedical Engineering, Johns Hopkins University, Baltimore, MD,
United States