Diencephalon

Question 1

What structure is mainly involved in Wernicke-korsakoff syndrome? What function is principally impaired?

Answer 1

• degeneration of the dorsomedial nucleus of thalamus
• memory
• thiamine deficiency in alcoholics

Question 2

Cause and presentation of thalamic pain syndrome

Answer 2

• ventral nuclear group (VPL)
• burning, aching pain in contralateral limb or body, ⬆️ sensitivity to pain, contralateral loss of vibratory sense and gait ataxia
• resistant to analgesics

Question 3

What lesion in hypothalamus lead in starvation?

Answer 3

Lateral hypothalamic: feeding center

Question 4

What lesion in hypothalamus leads in hyperphagia, obesity, savage behavior?

Answer 4

Ventromedial: satiety center

Question 5

What lesion at hypothalamus leads in diabetes insipidus?

Answer 5

Supra optic and paraventricular: production ADH and oxytocin

Question 6

What lesion at hypothalamus leads in Wernicke encephalopathy? Cause and presentation

Answer 6

Mammillary bodies: input from hippocampus

• thiamine deficiency in chronic alcoholism
• korsakoff syndrome: anterograde and retrograde amnesia + confabulations

Question 7

What leads a lesion at anterior region of hypothalamus?

Answer 7

Hyperthermia: temperature regulation

Question 8

What lesion at hypothalamus leads in poikilothermia?

Answer 8

Posterior region: temperature regulation

Question 9

What does a lesion at preoptic area of hypothalamus lead?

Answer 9

• before puberty: arrested sexual development

- after puberty: amenorrhea or impotence

Question 10

What lesion at hypothalamus could yield galactorrhea and amenorrhea? Why?

Answer 10

• arcuate nucleus lesion

- because normally inhibit prolactin secretion from anterior pituitary

Question 11

What can a pineal tumor commonly cause?

Answer 11

• ⬆️ intracranial pressure: obstruction of CSF flow
• Parinaud syndrome: compression pretectal area and upper midbrain ▶️ impair conjugate vertical gaze and pupillary reflex abnormalities