Localization of Hypothalamus issues Flashcards
Broad fnxl divisions of the hypothalamus
Anterior “PNS area”
Lateral “ drinking center”
Medial
Posterior “ SNS area”
Lesion of Anterior “PNS “ hypothalamus
Insomnia
Hyperthermia
Emaciation
Diabetes insipidus
Posterior “SNS” hypothalamus lesion
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
Medial hypo lesion
Hyperdipsia Diabetes insipidus SIADH obesity rage Amnesia Ipsilateral Horner's
Lateral “drinking center” lesion
Adipsia
Emaciation
Apathy
Dorsomedial nucleus
Responsible for emotion and mood. It also serves a function in memory.
Suprachiasmatic nucleus (anterior region) lesion
Insomnia will be the result. The suprachiasmatic nucleus functions to regulate circadian rhythm. Possible causes = lost of neurons in Alzheimer’s dz; shift-work
Anterior nucleus lesion
Hyperthermia. The anterior nucleus fnx to dissipate heat. Endogenous pyrogens (IL-1, PGE2) can cause fever
Media hypothalamus lesion
Lesion causes overeating –> obesity
The medial hypothalamus regulates feeding behavior(stops overeating)
Prader-Willis syndrome, craniopharyngioma
What are 3 neurons necessary to get to the eye via the SNS tract
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.
Cause of spastic bladder
Sp cd Lesion . So pt will be urinating all the time.
What is Pancoast tumor
Direct spread of tumor ( usually lung cancer) unto sympathetic chain.
Arterial dissection manifestations
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.
Cavernous sinus lesions
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.
CN3 lesion
Affected eye will not constrict in either direct or consensual light reflex.
Eye shows consensual eye response but not direct response
Not CN3 lesion but lesion of the nucleus before that
Horner’s
Ipsilateral:
Miosis = small pupil
Ptosis = weakness of superior tarsal muscle (Muller’s)
Anhidrosis = decreased sweating of face
Locating Horner’s lesion
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
Optic nerve lesion
Neither eye will constrict . However the affected eye will show consensual eye response when the other eye is shined on.
CN3 lesion or ciliary ganglion lesion
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.
Other CN3 lesion signs
Down and out eye, and ptosis.
Ciliary ganglion lesion
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
Bladder dysfunction caused by sympathetics lesion
Hyperactive bladder (“ spastic bladder”)
Underactive sphincter
TX: anti-cholinergics
Bladder dysfunction caused by PNS lesion
Hypoactive bladder ( “ flaccid bladder”)
Overactive sphincter –> incomplete emptying
TX: anti-adrenergics to rlx
