On Thursday 17 March 2022, Professor Marek Czosnyka and Doctor Zofia Czosnyka delivered a training seminar on cerebrospinal fluid (CSF) dynamics. The virtual seminar was part of a series provided to Scottish neurosurgical registrars.
An overview of cerebrospinal fluid dynamics
Prof. Czosnyka began the session with an overview of CSF dynamics. He explained that hydrocephalus is far more complex than simply a disorder of the CSF circulation, delving into the causes and effects of the condition and citing a number of important models and studies.
Carrying out infusion tests
Next, Dr Czosnyka explained how to carry out an infusion test, including the equipment needed. The infusion test is used to measure mean intracranial pressure (ICP), heart rate, pulse amplitude of ICP, and RAP index. The ICM+ neuromonitoring software developed by the Brain Physics Laboratory can generate reports to send these values to the patient’s consultant neurosurgeon, supporting them in diagnosing various CSF disorders.
Prof. Czosnyka continued the seminar with insights into the many shunt technologies that are used to treat hydrocephalus and other disorders. These can include membrane valves, programmable valves, and ball on spring valves. He compared the advantages and disadvantages of the various shunt types. For example, some programmable valves are sensitive to external magnetic fields and could therefore be re-adjusted by accident.
Shunt testing in vivo
Dr Zofia Czosnyka next talked about shunt testing in vivo, a minimally invasive test. After shunting, the model of CSF circulation changes. She therefore answered questions such as: how do ICP pulsations influence drainage through the shunt? How does the shunt influence ICP pulse pressure? Dr Czosnyka also explained how to test for shunt underdrainage, overdrainage and ventricular blockages.
Shunt testing saves Addenbrooke’s hospital an estimated £1m per year by avoiding unnecessary shunt revision surgery, making it an important part of ongoing patient care.
Prof. and Dr Czosnyka concluded the training seminar by answering questions from participants.