Cushings triad
Cushings triad is a clinical triad variably defined as having:

Irregular, decreased respirations (caused by impaired brainstem function)
Bradycardia
Systolic hypertension (widening pulse pressure)

History
Cushings reflex is named after Harvey Williams Cushing (1869–1939), an American neurosurgeon. Cushing began his research in Bern, Switzerland studying abroad with Emil Theodor Kocher. A month into his trip, Cushing received a formal proposition from Emil Theodor Kocher to begin testing how compression of the brain affected blood vessels. Cushing also enlisted the aid of Hugo Kronecker, a known blood pressure researcher. Utilizing Kroeneckers assistance and resources, Cushing began his research. Cushing left Bern in 1901 to work in Turin, Italy with Angelo Mosso, a previous student of Kroenecker. He continued to work on the same research project, while also simultaneously improving his methods of recording coincidence of blood pressure and ICP. In June 1901 Cushing published his first paper through Johns Hopkins Hospital Bulletin entitled "Concerning a definite regulatory mechanism of the vasomotor centre which controls blood pressure during cerebral compression". Between 1901 and 1903, Cushing published five papers pertaining to his research on the vasopressor response. These papers were published in German and English, and one was authored by Emil Theodor Kocher. Experimental setup and results
Cushing began experimenting once he obtained approval from Kocher. His experimental setup was a modified version of  Leonard Hills model to similarly test the effects of brain pressure on sinus pressure, cerebrospinal fluid pressure, arterial and venous blood pressure. Like Hill, Cushing used dogs for his experiments.
Some researchers have reported apnea, while others have reported increased respiratory rates. Other researchers have found that increases in respiratory rate follow ICP decreases, while others say it is a response to ICP increase. One must also take into account the use of anesthetics in early experimentation. Research was initially performed on animals or patients under anesthesia. The anesthesia used in experiments have led to respiratory depression, which might have had effect on the results. Early experiments also put animal subjects under artificial ventilation, only allowing for limited conclusions about respiration in the Cushing reflex. The use of anesthetics proposes ideas for future research, since the creation of the Cushing response has been difficult to create under basal conditions or without anesthesia.Some researchers have also suggested a long-term effect of the Cushing reflex. Thus far it has only been observed as an immediate acute response, but there has been some evidence to suggest that its effects could be prolonged, such as a long-term raise in blood pressure. Heightened sensitivity of neurological response systems leading to arterial hypertension is also possible, but has not been examined.Although the Cushing reflex was primarily identified as a physiological response when blood flow has almost ceased, its activity has also been seen in fetal life. This activity has not been thoroughly investigated, so there is a need for more research in this area.