Thalamus Flashcards
Arteries serving thalamus (4)
- Thalamogeniculate**
- Thalamoperforating
- Posterior choroidal
- Tuberothalamic (Polar)
Lesion to anterior portion of dorsal thalamus (Tuberothalamic A.)
- lose anterior nucleus, dorsolateral nucleus
- memory, limbic, emotion
Lesion - Paramedian region
- lose dorsomedian nucluss (amyglada, intralaminar nuc)
- neuropsych issues - arousal.memory
Lesion - inferolateral area (thalamogeniculate arteries)
-contra loss somatic sensations (not pain)
Lesion - posterior limb of internal capsule
- contra hemiplegia (corticospinal)
2. Contra somasthetic sensation (touch, pressure, proprio)
Epithalamus (contents - 3)
=roof of 3rd ventricle
- habenula, pineal body (melatonin), stria medularis
- link from flimbic(forebrain) and other parts of brain
Thalamus formed from _____
alar plates of neural tube
prosencephalon –> diencephalon
Subthalamus
border btw thalamus and midbrain, rostral to subs. nigra
- important for regulating movements produced my skeletal ms.
- actually part of basal ganglia
Hypothalamus
homeostasis, behavior
Dorsal thalamus
=thalamus proper
Pineal Body
- secretes melatonin
- regulates sleep/wakefulness, sexual maturity, mating season
Habenula
- nucleus projecting to midbrain
- thought to release dopamine, NE, serotonin
3 Major function
- relay/integrate sensory info
- effect consciousness and helps with focusing attention
- relay/integration of motor info
- dictates what we perceive
Association Nuclei (3)
dorsomedial, pulvinar, lateral posterior
Dorsomedial Nuclei
- parvo cellular - lesion = flat affect, transient memory loss, anterograde amnesia
- Magno cellular - smell relay
Pulvinar
vision
Lateral posterior
links btw subcortical visual areas & association cortical visual areas
Medial Group - blood
thalamic A, post cerebral A
Posterior Group – blood
Posterior cerebral A, post choroidal A
Lateral Group – Blood
Post choroidal, thalamogeniculate, polar
Anterior Group – Blood
tuberothalamic A
Anterior Area Lesion - Tuberothalamic A.
-peronsality changes (withdrawn, disoriented, euphoria, lack of insight, apathy, etc), memory impairment (new memory)
Paramedian Lesion
- dorsomedian nucleus
- probs with arousal, memory
- confusion, agitation, aggression, apathy
- speech probs (hypophnia - soft speech, dysprosody - pitch/timing control)
- schizo-like
Inferolateral Lesion - Thalamogeniculate A
- ataxia (VA, VL)
- somatosensory sensation (VP)
- most common lesion
Posterior Lesion
- hypoesthesia (decr sensitivity to light, other sensations)
- spatial neglect
- homonymous horizontal sectoranopsia (LGB) = loss of vision in a portion of the visual field
Thalamic Syndrome (Dejerine Roussy)
- blockage in thalamogeniculate going to post-ventral thalamus
- numbness-> burning/tingling on affected side, dysasthesias/allodynia
- sometimes severe ongoing pain w little/no stimuli
- can have motor problems
Internal Capsule – Anterior limb
anterior thalamic radiation, frontopontine and other corticofugal fibers
Internal Capsule – genu
corticobulbar, head
Internal Capsule – post limb
corticopontine, superior thalamic radiation, corticospinal tract
