Through the Beckley Foundation’s continued collaboration with Prof. Yuri Moskalenko, one of the world’s leading experts on cerebral circulation, we are learning more and more about a vital measure of cerebral functioning:
cranial compliance. Cranial compliance is a measure of the functioning of the cranial system as a whole: the skull, the brain tissue, and all the liquids that flow through and around this complex system, and is determined by the interaction of all these components. What our investigation is making increasingly clear is that a better understanding of cranial compliance is of crucial importance for healthier brains and improved cognitive functioning throughout the whole of one’s life.
The research has focused on the two fluid systems of the brain, the blood and CSF systems, and particularly, how these two fluid systems interact, how the functioning of these systems change with age and how such changes relate to deteriorations in mental health and cognitive functioning. This investigation has already produced some striking results, particularly, that cranial compliance which starts declining in the 20s, reaches its lowest point between 40 and 50, after which age, due to the death of brain cells, cranial compliance increases. This decline is correlated with a decline in cognitive functioning, and the severity of the decline is parallel to the severity of dementia in those suffering from that condition. This is important new knowledge as it identifies for the first time a link between cranial compliance and the quality of mental health and cognitive functioning. It also highlights the need for much closer attention to be paid to the role of CSF in shaping our cerebral functioning, something that has been traditionally overlooked by focussing solely on blood circulation in neuroscientific investigations. It is the cerebrospinal fluid which removes the large waste products from the brain and also is integrally involved in the movement of the blood.
With an instrument complex developed by Prof. Moskalenko et al., we can for the first time easily and non-invasively assess both cranial compliance and blood and CSF circulation as part of routine medical examinations, and thereby enable the identification of those at risk of suffering future deteriorations in cognitive functioning and implement measures to counteract this risk. This could be vital as a means to combat the predicted increase in age-related disorders in a progressively ageing population.
One such measure our research has already identified is that the ancient surgical procedure of trepanation (the removal of apiece of bone from the skull – there records of it being done 10,000 years ago) increases cranial compliance, improves cerebral circulation and may counteract the age related declines in these measures.This lead to the publication in 2007 of a paper entitled: ‘The Effect of Craniotomy on the Intracranial Hemodynamics and Cerebrospinal Fluid Dynamics in Humans’.
For many people, the practice of drilling holes in heads is objectionable or simply barbaric. However, trepanation is an unavoidable consequence of some operations. Moskalenko found that when the holes in the skull were left open after an operation, the brain received a better supply of blood. He also demonstrated that an increase in the skull’s capacity of only 1-2ml invigorates the movement of CSF and ensures that the brain receives a more abundant supply of blood.
We have just completed the first phase of the research, and this has already yielded some exciting results and possibilities.
The major findings:
1) Trepanation acts to restore the elasticity of the cranial system to the healthy levels associated with youth. This is the result of an average 20% increase in the complex tensibility of the skull, leading to a change in the distribution of arterial and venous blood, as well as CSF, and ensures there is sufficient capacity to accept a pulse increase in arterial pressure (i.e. reduces the likelihood of an increase in blood pressure leading to an increase in intracranial pressure). It also leads to an increase in cerebral blood flow during the diastolic (relaxation) phase of the heart beat.
2) The pulse stroke volume (the volume of blood entering the skull with each heart beat) is almost doubled, leading to an 8-10% increase in cerebral blood flow. This means an 8-10% increase in the delivery of oxygen and nutrients and so the working capacity of the brain.
3) The pattern of CSF movement within the brain changes so it acts as a more effective deliverer of nutrients and remover of toxic waste products. This is due to a decrease in the volume of CSF flowing from the brain to the spinal cord, and an increase in the volume of CSF moving through its cranial compartments and into the sub-arachnoid spaces, from where it is drained. As one analogy puts it, if CSF acts as the brains washing machine, then Trepanation acts to turbo charge the machine. This increase in CSF mobility is of particular importance as various age-related disease states such as dementia and Alzheimers have been linked to a decrease in CSF mobility. So trepanation acts as a direct countermeasure to these changes. Moreover, at an earlier age, trepanation may act to prevent the development of Alzheimers by increasing the removal via the CSF of large, toxic beta-amyloid particles, whose accumulation is associated with the first stages of Alzheimers.
4) This change in CSF movement leads to an increase in the compensatory potential of the cranial system i.e. increases in blood volume or pressure have a lesser impact on increasing ICP as the CSF more easily absorbs the force of these changes.
5) The increased CSF movement also leads to an increase in the force with which venous blood drains from the skull, as more CSF movement leads to more pressure being exerted on the venous system, a further facet of improved cerebral circulation.
6) Trepanation increases the effect that external influences, such as respiratory movements, have on the cerebral fluid systems (blood and CSF) and so could be used in conjunction with other therapeutic techniques such as Yoga or meditation to further enhance the beneficial effects of these practices.
7) Perhaps most importantly of all, trepanation is safe to the extent that none of these changes exceed the normal limits of cerebral circulation.
These findings therefore open up the possibility of developing craniotomy as a therapeutic treatment for the significant number of diseases of the brain that result from disorders of cerebral blood or CSF flow, which result in disrupted oxygen distribution to brain cells. In the next phase of research we will continue our investigation into craniotomy, as well as explore the effects that deep breathing, Yoga and meditation have on the cranial system, to determine why these techniques have the effects they do, and what, if any, their therapeutic potential might be. We also hope to determine how the size and location of the trepanation hole influence the effects it has, as well as assess the effects of trepanation, if any, on cognitive functioning (and particularly the restoration of cognitive functioning in those suffering from age-related declines in these faculties).
http://www.beckleyfoundation.org/2010/12/06/investigating-cerebral-circulation-and-cranial-compliance/