From the Guidelines

Yes, a patient with hypertension can cause an intracranial hemorrhage by performing a Valsalva maneuver (bearing down) during defecation.

The Valsalva maneuver can increase intracranial pressure, which can lead to intracranial hemorrhage in patients with hypertension 1.
Hypertensive encephalopathy, which can occur in patients with markedly elevated blood pressure, can cause cerebral edema, microscopic hemorrhages, and infarctions 1.
The rate of blood pressure increase appears to be more important than the absolute blood pressure value in the development of hypertensive emergencies, including intracranial hemorrhage 1.
Patients with pre-existing hypertension are at increased risk of developing intracranial hemorrhage, especially if they have uncontrolled or poorly controlled blood pressure 1.

The Valsalva maneuver increases intrathoracic pressure, which can lead to an increase in intracranial pressure 1.
This increase in intracranial pressure can cause damage to the blood vessels in the brain, leading to hemorrhage.
Patients with hypertension are already at increased risk of developing intracranial hemorrhage due to the increased pressure on the blood vessels in the brain.

Patients with hypertension should be advised to avoid performing the Valsalva maneuver, especially during activities such as defecation or heavy lifting 1.
Patients with uncontrolled or poorly controlled hypertension should be closely monitored for signs of intracranial hemorrhage, including headache, visual disturbances, and focal neurological symptoms 1.
In patients with suspected intracranial hemorrhage, immediate medical attention is necessary to prevent further damage and improve outcomes 1.

From the Research

The relationship between hypertension and intracranial hemorrhage is complex, with studies suggesting that hypertension can contribute to the risk of hemorrhage, but the exact mechanisms are not fully understood 2, 3.
A study published in 2019 found that patients with pre-existing hypertension had higher admission systolic blood pressure and more severe bleeding, suggesting that hypertension may worsen reactive hypertension in the setting of intracerebral hemorrhage 4.
Another study found that elevated intracranial pressure and inadequate cerebral perfusion pressure were associated with poor outcomes in patients with hypertensive intraventricular hemorrhage, highlighting the importance of managing blood pressure in these patients 2.

There is limited direct evidence on the specific relationship between the Valsalva maneuver and intracranial hemorrhage in patients with hypertension.
However, a study published in 1989 found that moderate arterial hypertension did not precipitate spontaneous hemorrhage of intracranial arteriovenous malformations, suggesting that hypertension alone may not be sufficient to cause hemorrhage 5.
The Valsalva maneuver, which involves bearing down and increasing intrathoracic pressure, can increase blood pressure and may potentially increase the risk of hemorrhage in patients with pre-existing vascular malformations or weaknesses.

A study published in 2011 identified several risk factors for early death in patients with hypertensive intracerebral hemorrhage, including age, GCS score, systolic pressure at admission, and hematoma volume 6.
Effective prevention of hypertension and adequate reduction of blood pressure at admission are recommended as major measures to improve the prognosis of hypertensive intracerebral hemorrhage 6.
The relationship between the Valsalva maneuver and intracranial hemorrhage in patients with hypertension is not well-established, and further research is needed to fully understand the potential risks and mechanisms involved.