Chiari malformation and syringomyelia

Service detail


Chiari (previously called an Arnold-Chiari malformation) malformation is an abnormality of the posterior fossa (back of the skull) and top of the spine. There are different types. 

A Chiari involves the protrusion of the lowest part of the back of the brain (the cerebellar tonsils) into the top of the spinal canal and may be caused by the brain in this area being too big for the skull. This may cause no symptoms or may cause severe headaches that are often worse on coughing or sneezing. 

Chiari II and III malformations are associated with spina bifida (a congenital condition that may be associated with hydrocephalus and abnormalities at the base of the spine).  


Syringomyelia is a condition in which fluid filled cavities form within the spinal cord and can lead to pain, and loss of function (weakness or numbness). Some patients with a Chiari I malformation will develop a syrinx. Syrinxes can also occur after a spinal cord injury, meningitis, surgery, or if there is a tumour present. A syrinx is always caused by something else, and treatment is usually directed at the cause of the syrinx, rather than the syrinx itself.

The underlying cause of the problems may relate to alterations in the person’s normal fluid dynamics leading to pressure, blockage of flow, and in the cases of syringomyelia, damage to the spinal cord tissue itself. 


The treatment of Chiari malformations and syringomyelia can be difficult and may involve operating at the back of the head to enlarge the bony space, endoscopic third ventriculostomy (a fluid bypass procedure), placing drainage tubes (shunts) in the fluid spaces in the head or syrinx, exploring the spinal cord and enlarging the space available for fluid to flow, and untethering the spinal cord.

The Walton Centre has a number of surgeons with an interest in the treatment of patients with these conditions. 

There is a monthly specialist syringomyelia clinic where new patients or patients with complex Chiari or syringomyelia issues can be seen by up to three of the surgeons. 

Imaging of the complete neuroaxis, with flow studies where appropriate is routinely used to assess patients. Intracranial pressure monitoring can also prove helpful in deciding on the best treatment. Outcomes are examined with the spine tango database. 

Getting here

The Walton Centre - Main Hospital Building

The Walton Centre Main Building

This building hosts many of our in-patient services, including wards and theatres, and some outpatients services.


Lower Lane, Liverpool, L9 7LJ

Directions and map

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Patient leaflets

Chiari malformation patient information leaflet

Chiari Malformation

A Chiari Malformation (Hindbrain hernia) is a developmental abnormality which affects the cerebellum. This part of the brain lies at the back of the head, low down and at the top of the spinal canal. 

Chiari malformation and syringomyelia Consultants

Professor Andrew Brodbelt

Professor Andrew Brodbelt graduated from Liverpool Medical School before doing his basic surgical training in Merseyside and Manchester, and neurosurgical training at The Walton Centre. He did his PhD at the University of New South Wales, Sydney, Australia. 

Related Services


The Neurosurgical Division is one of the busiest neurosurgical units in the UK, seeing approximately 9,800 new patients, 3,800 elective patients, and 1,700 emergency inpatients every year.

Page last updated: 23 June 2021