Klinik für Neurochirurgie

What causes SIH?

Spontaneous intracranial hypotension is caused by the loss of cerebrospinal fluid (CSF) at the spine. There are various ways this loss can occur (leak types). What they all have in common is that the loss of fluid disrupts the regulation of the system. You can learn about the different types of possible spinal CSF leaks here.

While the pressure between spine and head is still balanced when lying down, standing up (orthostasis) leads to a shift of the fluid from the head to the spinal compartment. This creates low pressure inside the head and can result in a variety of symptoms and complications. The most common complaint from patients is headaches.

What are the symptoms of SIH?

Most patients with SIH complain of headaches, often in the back of the head and neck. These headaches occur or worsen when they stand up. When lying down, the symptoms significantly improve or even disappear completely.

In addition, there are many different accompanying symptoms, including nausea, vomiting, dizziness, hearing and vision disturbances, sensory disturbances, sensitivity to noise and light, "brain fog", concentration difficulties, and many more. Symptoms often change over time and may not be equally severe every day.

Is SIH common?

Current estimates of the incidence rate are around 4 per 100,000 per year (Schievink et al., Cephalalgia 2022).

However, we believe there is a significantly higher number of undiagnosed cases. Patients are often not diagnosed or are misdiagnosed and treated as migraine, fatigue, or somatization disorder.