Need to contact the physician

I would order head MRI to see if the hypothalamus or pituitary do not have a mass . Otherwise he could be hypogonadal due to less hypothalamus LH releasing factor. Then a stimulation test may be in order.

I would like to suggest to initially control LH level by a repeated blood test. Ask him for external testosterone replacement (e.g. nutritional supplement), especially as testosterone is normal, than proceed with MRI of the brain.

what to expect from brain MRI?? brain tumors will have clinically apparent symptoms and signs, besides that infarction or ischemia might have predisposing factors which absent in our patient....giving external testosterone may relief loss of his libido and ED but will lead to more inhibition of LH ....???

If feasible, collect information on his hormonal responses to romantic interactions with his partner -- compare with 'baseline'.

Decreased LH level with normal Testosterone level should not theoretically influence sexual response. You should check for psychological factor possibly influencing his mood.

Regarding to low LH level: There should be another testosterone source outside the hypothalamic pituitary axis. You should check for testosterone producing tumors or external testosterone source.

An external testosterone source is the most probable, but for how long it can affect LH secretion from the pituitary gland, and if serum testosterone reverted to normal level why LH remained low???

Dear Ahmed,

With an external source of testosterone the blood testostrone level is maintained without the need for testicular production from testes thus negative feedback on brain would decrease LH level continously. LH would only increase if testosteone level drops below normal.