Transcript thalamus

Diencephalon
Diencephalon
• Thalamus  dorsal thalamus
• Hypothalamus
pituitary gland
• Epithalamus
habenular nucleus and commissure
pineal gland
• Subthalamus  ventral thalamus
subthalamic nucleus (STN)
field of Forel
Diencephalon
dorsal surface
Diencephalon
ventral surface
Diencephalon
Medial Surface
THALAMUS
Classification of Thalamic Nuclei
I.
Lateral Nuclear Group
II.
Medial Nuclear Group
III. Anterior Nuclear Group
IV. Posterior Nuclear Group
V.
Metathalamic Nuclear Group
VI. Intralaminar Nuclear Group
VII. Thalamic Reticular Nucleus
Classification of Thalamic Nuclei
LATERAL NUCLEAR GROUP
Ventral Nuclear Group
Ventral Posterior Nucleus (VP)
ventral posterolateral nucleus
ventral posteromedial nucleus (VPM)
ventral posteroinferior nucleus (VPI)
LATERAL NUCLEAR GROUP
Ventral Lateral Nucleus (VL)
Ventral Anterior Nucleus (VA, L.po.)
LATERAL NUCLEAR GROUP
Prefrontal
SMA
MI, PM
SI
Ventral
Nuclear Group
TTT
SNr
GPi
Cbll
ML, STT
LATERAL NUCLEAR GROUP
Dorsal or Lateral Nuclear Group
Lateral Dorsal Nucleus (LD, D.sf.)
Lateral Posterior Nucleus (LP, D.im. & Z.im.)
Pulvinar (P, Pu.)
LATERAL NUCLEAR GROUP
cingulate gyrus,
precuneus
Somesthetic
Association
Area
HF
SC, Pretectal
Visual
Association
area
MEDIAL NUCLEAR GROUP
Dorsomedial Nucleus (MD)
- pars magnocellularis
- pars parvocellularis
Midline Nuclear Group
ANTERIOR NUCLEAR GROUP
anteroventral nucleus (AV, A.pr.)
anterodorsal nucleus (AD, A.d.)
anteromedial nucleus (AM, A.m.)
POSTERIOR NUCLEAR GROUP
suprageniculate nucleus (SG, Li.)
nucleus limitans (Lim, Li.)
posterior nucleus (PO, Li.por.)
MEDIAL & ANTERIOR NUCLEAR GROUP
MB, HF
cingulate
gyrus
Prefrontal Frontal
Cortex
Eye Field
Basal
forebrain
Medial
Frontal
Gyrus
SNr, SC, RF
METATHALAMIC NUCLEAR GROUP
Medial Geniculate Nucleus (MG)
ventral nucleus
dorsal nucleus
medial nucleus
Lateral Geniculate Nucleus (LG)
dorsal nucleus
ventral nucleus
INTRALAMINAR NUCLEAR GROUP
Rostral Intralaminar Nuclei
central lateral nucleus,
central medial nucleus,
paracentral nucleus,
Caudal Intralaminar Nuclei
(CM-PF nuclear complex)
centre median nucleus,
parafascicular nucleus,
THALAMIC RETICULAR NUCLEUS
Cerebral Cortex
Thalamic
Reticular
Nucleus
Thalamocortical
Neuron
Subcortical Structure
Summary of Thalamic Connectivity
I.
Sensory Input
general sensation
special sensation
taste, equilibrium, hearing, vision
II. Motor Input
cerebellum, basal ganglia
III. Reticular Formation
IV. Limbic System
mammillary nucleus
hippocampal formation
Sensory Input
(1) General Sensation
1. Medial lemniscus
VPLc ----------- S I, S II
2. Spinothalamic tract
VPLc ----------- S I, S II
POm ----------- retroinsular cortex
Sm ------------- frontal lobe(?)
CL ------------- diffuse cortical areas
3. Trigeminothalamic tract
VPM ------------- S I, S II
Sensory Input
(2) Taste sensation
VPM pc ------- gustatory area (Brodmann area 43)
(3) Sense of equilibrium
VPLo ---------- S I
(4) Auditory sensation
MGv ----------- A I (Brodmann area 41, 42)
MGd ----------- A II
(5) Vision
LGd ---------- V I (Brodmann area 17)
Pi, Pl ---------- V I, V II (Brodmann area 17, 18, 19)
Motor Input
(1) Cerebellum
VLc, VPLo, - M I (Brodmann area 4), Premotor area
(2) Basal ganglia
1. GPi (internal segment of globus pallidus)
-------- SMA (supplementary motor area)
------- frontal cortex
2. SNr (pars reticularis of substantia nigra)
- fronal cortex
--------- medial frontal cortex
---------- frontal eye field (Brodmann area 8)
Reticular Formation & Limbic System
Reticular formation
rostral intralaminar nuclei (CL, Cem, PC), Rh
----- diffuse cortical areas
thalamic reticular nucleus (R), LGv
----- adjacent thalamic nucleus
Limbic System
Mammillary Body
AV, AD, AM ----- cingulate gyrus
Hippocampal Formation
AV, AD, AM ----- cingulate gyrus
LD ------------------ cingulate gyrus, precuneus
Re ------------------- medial cortex, entorhinal cortex
Clinical Syndromes of the Thalamus
Posterolateral thalamic syndromes
sensory disorders
Thalamic (Dejerine-Roussy) syndrome
----- VP nucleus - pain
Medial thalamic syndromes
disorders of consciousness
thalamic neglect, thalamic amnesia,
akinetic mutism
Anterolateral thalamic syndromes
motor disorders
paresis, ataxia, motor incoordination, dysphagia
Thalamic (Dejerine-Roussy) Syndrome
Joseph Jules Dejerine
(1849-1917)
Gustave Roussy
(1874-1948)
Visual (Optic) Pathway
Modality: Vision
Receptor: Photoreceptor Cell of Retina
Cranial Nerve: II (Optic nerve)
1st Neuron: Bipolar Cell
2nd Neuron: Ganglion Cell
optic nerve
optic chiasm
optic tract
3rd Neuron: Lateral Geniculate Nucleus
optic radiation
Termination: Visual Areas (V I, V II)
Brodmann area 17 (V I), 18, 19 (V II)
RETINA - Pars Nervosa
1. Pigment Epithelium
- retinal detachment
2. Neuronal Layer
(1) Photosensitive Cell Layer
Rod Cell, Cone Cell
(2) Bipolar Cell Layer
Bipolar Cell
Horizontal Cell
Amacrine Cell
(3) Ganglion Cell Layer
Ganglion Cell
Optic Nerve (II)
Visual
Pathway
1. Optic nerve
2. Optic chiasm
3. Optic tract
4. Lateral
geniculate
body
5. Optic radiation
6. Visual cortex
Visual (Optic) Pathway
Visual Pathway
dorsolateral
Lateral Geniculate Nucleus (LGd)
Dorsal Nucleus (LGd)
Magnocellular Part
1, 2
Parvocellular Part
3, 4, 5, 6
contralateral afferents
1, 4, 6
ipsilateral afferents
2, 3, 5
Ventral Nucleus (LGv)
ventromedial
part of thalamic
reticular nucleus
Optic Radiation (Geniculocalcarine Tract)
Meyer’s loop
Clinical Features of Visual Pathway Lesion
1. optic nerve
2. optic chiasm
3. optic tract
4. 5. optic radiation
A. unilateral blindness
B. bitemporal hemianopsia
C. left homonymous
hemianopsia
D. left inferior homonymous quadranopsia
E. left superior homonymous quadranopsia
Signs of Visual Pathway Lesion
Optic nerve
- ipsilateral blindness
Optic chiasm
- bitemporal hemianopsia
Optic tract
- contralateral homonymous hemianopsia
Optic radiation
- contralateral homonymous quadranopsia
- intact light reflex
Visual Cortex
- contralateral homonymous quadranopsia
- macular sparing
Visual Field Defect
left inferior optic radiation lesion
right superior quadranopsia
Hypothalamus  Limbic System
Epithalamus  Limbic System
Habenular Nucleus
Medial Habenular Nucleus
Lateral Habenular Nucleus
Habenular Commissure
Pineal Gland
Subthalamus  Basal Ganglia
Subthalamic nucleus
zona incerta
Field of Forel
H ansa lenticularis
H1 thalamic fasciculus
H2 lenticular fasciculus