Thalamus and Hypothalamus

Question 1

thalamus

Answer 1

collection of subcortical grey matter and part of the diencephalon (along with the hypothalamus) involved in relaying information between different functional regions of the CNS
borders the dorsal part of the third ventricle and functions as part of the lateral wall of the ventricle

Question 2

thalamic nuclei

Answer 2

relay, association, and nonspecific nuclei

Question 3

relay thalamic nuclei

Answer 3

distinct inputs and outputs
includes: ventral posterior lateral (VPL) nucleus, ventral posterior medial (VPM) nucleus, lateral geniculate body/nucleus (LGN), medial geniculate body/nucleus (MGN), ventral anterior (VA) nucleus, ventral lateral (VL) nucleus

Question 4

association thalamic nuclei

Answer 4

receive majority of their input from the cortex and project fibers to the other cortical regions
includes mediodorsal/dorsomedial nuclei, anterior nucleus, pulvinar

Question 5

nonspecific thalamic nuclei

Answer 5

broadly project to numerous cortical regions
include reticular nucleus

Question 6

ventral posterior lateral (VPL) nucleus

Answer 6

relay center for sensory information for the BODY
output is to the postcentral (sensory) gyrus

Question 7

ventral posterior medial (VPM) nucleus

Answer 7

relay center for sensory information of the FACE
output is the postcentral (sensory) gyrus
VPM is also the relay center for taste

Question 8

lateral geniculate nucleus (LGN)

Answer 8

relay center for vision. receives input from the retina with output to the primary visual cortex via optic radiations
optic radiations from the upper visual world travel through the temporal lobe and optic radiations from the lower visual world pass through the parietal lobe

Question 9

medial geniculate nucleus (MGN)

Answer 9

relay center for hearing. receives input from the inferior colliculi and projects to the primary auditory cortex

Question 10

ventral anterior (VA) nucleus

Answer 10

conveys motor information from basal ganglia to the premotor cortex
it plays a role in the initiation of movement

Question 11

ventral lateral (VL) nucleus

Answer 11

conveys motor information from both the cerebellum and basal ganglia to the primary motor cortex

Question 12

thalamic nuclei mnemonic

Answer 12

VPL: ‘very pretty LEGS’ (body)
VPM: ‘very pretty MOUTH’ (face)
LGN: ‘LOOKS good naked’ (vision)
MGN: ‘makes good NOISE’ (hearing)

Question 13

mediodorsal/dorsomedial nuclei

Answer 13

receives input from the amygdala, subthalamic nucleus, and temporal lobe with output to the frontal cortex. it is involved in motivation and memory

Question 14

lesions to mediodorsal nuclei

Answer 14

amnesia, behavioral issues, and executive dysfunction

Question 15

anterior nucleus

Answer 15

receives input from the mammillary bodies with output to the cingulate gyrus. it is important for limbic function and memory formation

Question 16

pulvinar

Answer 16

receives input from the superior colliculi as well as the association cortex and has outputs to many different regions in the cortex. it is involved in visual attention and is located in the posterior medial aspect of the thalamus

Question 17

damage to the pulvinar

Answer 17

neglect and attention deficits
preferentially affected in patients with CJD

Question 18

reticular nucleus

Answer 18

receives input from many cortical regions and projects directly onto other thalamic nuclei. it is the only thalamic nucleus that does not project to the cortex
thought to play a role in sleep-wake cycles

Question 20

thalamic vascular supply

Answer 20

four major vessels:
- polar (tuberothalamic) artery
- paramedian (thalamic-subthalamic) artery
- thalamogeniculate (inferolateral) artery
- posterior choroidal artery -

Question 21

polar (tuberothalamic) artery

Answer 21

originates from the posterior communicating artery (PCOM)
supplies anterior portion of the thalamus

Question 22

anterior circulation stroke affecting thalamus

Answer 22

anterior circulation strokes can present with anterior thalamic involvement due to the polar artery arising from the PCOM - all other thalamic strokes arise from posterior circulatory system
lead to wide range of neuropsychiatric changes

Question 23

paramedian (thalamic-subthalamic) artery

Answer 23

originates from the P1 segment of the posterior cerebral artery (PCA) and supplies the dorsomedial nucleus

Question 24

infarction of paramedian (thalamic-subthalamic) artery

Answer 24

infarction has a range of neuropsychiatric symptoms
unilateral lesions can lead to language (dominant hemisphere) or visuospatial problems (non-dominant)
bilateral infarction can result in akinetic mutism. a top-of-the-basilar occlusion can commonly cause a bilateral infarction due to an anatomic variant known as the Artery of Percheron, where both paramedian arteries arise form a single pedicle on the P1 portion of PCA

Question 25

posterior choroidal artery

Answer 25

arises from the P2 segment of the posterior cerebral artery (PCA) supplies the lateral geniculate nucleus (LGN) and pulvinar among other nuclei

Question 25

thalamogeniculate (inferolateral) artery

Answer 25

originates from the P2 segment of the posterior cerebral artery (PCA) thalaMoGENICULATE artery supplies multiple nuclei including the Medial GENICULATE nucleus (MGN)

Question 26

lesions to posterior choroidal artery

Answer 26

vision changes, variable sensory loss, weakness, and memory impairment

Question 27

thalamic dysfunction can cause wide range of symptoms and syndromes

Answer 27

generally lesions to a nucleus of the thalamus lead to dysfunction of that relay arc (e.g. lesion of the VPL leads to numbness of the contralateral body)

Question 28

Dejerine-Roussy Syndrome

Answer 28

thalamic pain syndrome contralateral hemisensory loss of all modalities followed by body pain

Question 29

akinetic mutism

Answer 29

can develop with thalamic lesions, presumably with the involvement of the reticular nucleus can also be seen in bilateral prefrontal lobe lesions or caudate lesions as well

Question 30

artery of Percheron stroke

Answer 30

vascular anatomic variant where one artery supplies both paramedian regions of the thalamus clinically manifests with a decreased level of consciousness, hypersomnolence, aphasia/dysarthria, and oculomotor abnormalities

Question 31

what restricts diffusion in thalamus on MRI brain

Answer 31

status epilepticus and cerebral hypoxic ischemic injury

Question 32

hypothalamus

Answer 32

coordinating center of the endocrine system that helps maintain homeostasis containing several nuclei with various functions including autonomic function, body temperature regulation, and water balance

Question 33

lateral nucleus of the hypothalamus

Answer 33

activates hunger/thirst lesion: aphagia/adipsia

Question 34

medial preoptic nucleus of the hypothalamus

Answer 34

releases gonadotropic releasing hormone (GnRH)

Question 35

anterior nucleus of the hypothalamus

Answer 35

temperature regulation lesion: hyperthermia

Question 36

supraoptic and paraventricular nuclei of the hypothalamus

Answer 36

produces ADH and oxytocin (stored and released by posterior pituitary) lesion: diabetes insipidus and impaired lactation

Question 37

suprachiasmatic nucleus (SCN) of the hypothalamus

Answer 37

circadian (24hr) pacemaker

Question 38

ventromedial nucleus (VMN) of the hypothalamus

Answer 38

satiety center lesion: hyperphagia

Question 39

dorsomedial nucleus of the hypothalamus

Answer 39

aggression lesion: may lead to docility

Question 40

posterior nucleus of the hypothalamus

Answer 40

heat conservation lesion: poikilothermia

Question 41

mammillary bodies

Answer 41

memory formation poor long term memroy formation