The Blood-Brain Barrier (BBB)

The blood-brain barrier plays a vital role in protecting brain tissue from harmful substances in the bloodstream, while allowing essential nutrients through. It keeps the brain’s internal environment stable and healthy.

Historically, the existence of the BBB was used to dismiss the idea of a drainage system in the brain. However, modern research has revealed at least seven areas of the brain where the barrier is either absent or more permeable, allowing larger molecules, including potential toxins, to pass through under certain conditions.

Circumventricular Organs (CVOs)

Circumventricular organs are specialised areas in the brain where the blood-brain barrier is naturally more permeable. They allow hormones and other large molecules – which would otherwise be too big to pass through – to enter and exit the brain.

These organs help regulate essential processes like hormone signalling, particularly in the hypothalamus, which is a major control centre for many bodily functions.

Biofeedback and Hormonal Regulation

The hypothalamus monitors and regulates hormone levels through a process called biofeedback. For example, if blood glucose levels rise, the hypothalamus sends a signal to the pancreas to release more insulin.

This system relies on the ability of CVOs to allow hormones to bypass the blood-brain barrier. However, this also opens a pathway for larger toxic molecules to potentially enter the brain – disrupting normal function and contributing to symptoms seen in ME/CFS and related illnesses.

The Glymphatic System

Back in 1989, Dr Perrin hypothesised the existence of a waste clearance system in the brain – something that was initially dismissed due to the belief that the blood-brain barrier made it impossible.

In 2013, scientists officially identified the glymphatic system – named for its dependence on glial cells and its similarity to the body’s lymphatic system. This network helps clear toxins from the brain, supporting the foundations of The Perrin Technique.

The Central Nervous System (CNS)

Made up of the brain and spinal cord, the central nervous system controls virtually everything – from conscious thought and emotional regulation to movement and organ function.

The cerebrospinal fluid (CSF) surrounding the CNS helps remove waste, moving toxins through specific drainage channels into the lymphatic system.

Brain Drainage Pathways

Toxins from the brain are carried through two main channels:

• Paravascular spaces (alongside blood vessels)

• Perivascular spaces (within arterial walls)

From here, toxins pass through small openings in the skull and along the cranial nerves – including the olfactory (nose), optic (eye), auditory (ear) and trigeminal (face) nerves – and down the spinal cord, entering the body’s lymphatic drainage system.

The Lymphatic System

The lymphatic system is a crucial part of the immune system. It consists of tissues, lymph vessels, and organs connected by a network of lymph nodes, which help fight infection and remove waste.

Lymph fluid carries white blood cells and transports bacteria, viruses, and toxins to the lymph nodes, where they are broken down by lymphocytes.

How the Lymphatic System Pumps

The movement of lymph through the body is powered by vessels with unique structures – similar to gills – that engulf and expel waste products. These are eventually filtered by the liver and processed out of the body.

The thoracic duct, located in the spine, is the main pumping station of the lymphatic system. It is regulated by the sympathetic nervous system.

Sympathetic Nervous System (SNS) Breakdown

The sympathetic nervous system, part of the autonomic nervous system, originates in the thoracic and upper lumbar spine. It manages involuntary functions such as heart rate, breathing, and the “fight or flight” stress response.

Under chronic stress or illness, this system can become dysregulated, disrupting the lymphatic pump. In some cases, it may even reverse the flow of lymph, allowing toxins to recirculate and build up – especially around the brain and spinal cord.