Localization of Hypothalamus issues

Question 1

Broad fnxl divisions of the hypothalamus

Answer 1

Anterior “PNS area”
Lateral “ drinking center”
Medial
Posterior “ SNS area”

Question 2

Lesion of Anterior “PNS “ hypothalamus

Answer 2

Insomnia
Hyperthermia
Emaciation
Diabetes insipidus

Question 3

Posterior “SNS” hypothalamus lesion

Answer 3

Hypothermia
Poikilothermia ( fluctuatio of the body temp of 2 to 3 degrees throughout the day. So u will be unable to REGULATE your own body temp).
Hypersomnia, coma
Narcolepsy
Apathy
Ipsilateral Horner syndrome = ptosis, miosis, anhydrosis

Question 4

Medial hypo lesion

Answer 4

Hyperdipsia
Diabetes insipidus
SIADH
obesity
rage
Amnesia
Ipsilateral Horner's

Question 5

Lateral “drinking center” lesion

Answer 5

Adipsia
Emaciation
Apathy

Question 6

Dorsomedial nucleus

Answer 6

Responsible for emotion and mood. It also serves a function in memory.

Question 7

Suprachiasmatic nucleus (anterior region) lesion

Answer 7

Insomnia will be the result. The suprachiasmatic nucleus functions to regulate circadian rhythm. Possible causes = lost of neurons in Alzheimer’s dz; shift-work

Question 8

Anterior nucleus lesion

Answer 8

Hyperthermia. The anterior nucleus fnx to dissipate heat. 
Endogenous pyrogens (IL-1, PGE2) can cause fever

Question 9

Media hypothalamus lesion

Answer 9

Lesion causes overeating –> obesity
The medial hypothalamus regulates feeding behavior(stops overeating)
Prader-Willis syndrome, craniopharyngioma

Question 10

What are 3 neurons necessary to get to the eye via the SNS tract

Answer 10

1) Descending hypothalamic fibers that come down to the IML cell column in the spine - travel laterally in the brainstem along with the spinothalamic tract for pain of the body
2) The preganglionic fiber that extends from the IML column to the superior cervical ganglion-cell body in the IML, enters the sympathetic chain via the gray rami to get to the SCG
3) The postsynaptic fiber that extends from the SCG to the actual pupillary dilator muscle- the post ganglionic nerve travels up the outside of the ICA and peels off in the cavernous sinus to get to the eye. Remember that the PNS input to the eye is through CN3.

Question 11

Cause of spastic bladder

Answer 11

Sp cd Lesion . So pt will be urinating all the time.

Question 12

What is Pancoast tumor

Answer 12

Direct spread of tumor ( usually lung cancer) unto sympathetic chain.

Question 13

Arterial dissection manifestations

Answer 13

If there is arterial disection
the carotid artery can dissect, so the layers of the artery can separate, and if this happens the postganglionic SNS fibers that are travelling on the outside of the artery can be injured, and u can have an ipsi Horner’s . Because the artery is innervated by nerves, the experience is hella painful, so neck pain associated with this.
Because of the tumor the lumen of this vessel will become larger and the flow will be turbulent…bruits will be heard.

Question 14

Cavernous sinus lesions

Answer 14

Concominant Ipsi Horner’s and CNIII, IV,V1,V2 and VI also ICA issues. EOM issues. Pituitary tumors can cause local inflammation in the cavernous sinus. Inflammation like chronic sinusitis can also cause inflammation in the cavernous sinus.

Question 15

CN3 lesion

Answer 15

Affected eye will not constrict in either direct or consensual light reflex.

Question 16

Eye shows consensual eye response but not direct response

Answer 16

Not CN3 lesion but lesion of the nucleus before that

Question 17

Horner’s

Answer 17

Ipsilateral:
Miosis = small pupil
Ptosis = weakness of superior tarsal muscle (Muller’s)
Anhidrosis = decreased sweating of face

Question 18

Locating Horner’s lesion

Answer 18

Anywhere on the IPSI side since sns is all ipsi. It could be DHF, superior cervical canglion, along the carotid etc.

If a pt with Horner’s has ipsi neck pain then they have an artery dissection. This can result in ipsi forebrain stroke. This is rare unless MARFANS or Ehlers Danlos

Question 19

Optic nerve lesion

Answer 19

Neither eye will constrict . However the affected eye will show consensual eye response when the other eye is shined on.

Question 20

CN3 lesion or ciliary ganglion lesion

Answer 20

Efferent pupillary defect, and therefore you will see that one eye will NEVER CONSTRICT regardless if the light is shined in it or the other. The other eye will ALWAYS CONSTRICT because the consensual light reflex is still intact on the contra side.

Question 21

Other CN3 lesion signs

Answer 21

Down and out eye, and ptosis.

Question 22

Ciliary ganglion lesion

Answer 22

Swinging light reflex will show that the affected eye will NEVER CONSTRICT while the unaffected eye will ALWAYS CONSTRICT. The swinging light reflex is the only way to isolate the Ciliary ganglion lesion

Question 23

Bladder dysfunction caused by sympathetics lesion

Answer 23

Hyperactive bladder (“ spastic bladder”)
Underactive sphincter
TX: anti-cholinergics

Question 24

Bladder dysfunction caused by PNS lesion

Answer 24

Hypoactive bladder ( “ flaccid bladder”)
Overactive sphincter –> incomplete emptying
TX: anti-adrenergics to rlx