<unk>  refers to a decreased pressure<unk>  of the<unk>  pressure.
It may be generated during the treatment of hydrocephalus.
"Spontaneous<unk> " (SIH), also known as a spontaneous low CSF (Cerebrospinal fluid) pressure headache, usually presents without any preexisting trauma or known violation of the epidural or thecal space.
Intracranial hypotension
Normotension
Heat syncope
Cough syncope
Hyperglycemic crises
Respiratory arrest
Cardiac arrest
Micturation syncope