What will be effect on TSH in stalk effect?

What will be effect on TSH in stalk effect?

In one place you taught as hypothyrodism will not be seen in hypopituitarism because T3,T4 can be produced even in absence of TSH

In other place given as TSH not involved

In lymphophysitic hypophysitis you told manifestations are due to stalk effect,then why TSH level is low ?please clarify it sir