Submission to the Joint Committee on Health and Children
On
The Benefits of the Introduction of Deep Brain Stimulation
to Ireland
Dr. Richard Walsh MB, MD, MRCPI
Consultant Neurologist
Tallaght Movement Disorders Unit
Adelaide and Meath Hospital Dublin Incorporating the National Children’s Hospital
Professor Timothy Lynch MB, BSc., DCH, FRCPI, FRCP, ABPN
Consultant Neurologist
Mater Misericordiae Hospital
Dublin Neurological Institute
Mr Gavin Quigley MBChB, FRCS(Neurosurgery)
Consultant Neurosurgeon
Royal Victoria Hospital, Belfast.
Thursday 6th November 2014
1.0
Background
1.1
Parkinson’s disease
Parkinson’s disease is one of a family of disorders known as neurodegenerative
disorders. These are disorders that typically arise in adult life and result from a
slow and progressive loss of brain cells at a rate that is faster than expected in
normal ageing, disrupting the neural circuits that drive movement, cognition and
emotions. The specific features of each disease depend on which population of cells
are lost. Frustratingly, for physicians and patients alike, we have yet to identify an
effective way of protecting these neurons from premature loss in any of these
degenerative disorders and management is therefore centred on symptom control.
Parkinson’s disease is the second most common neurodegenerative disorder in
Ireland after Alzheimer’s disease. The disease affects almost all aspects of daily
living, although much of the disability in Parkinson’s disease relates to the loss of
cells that produce dopamine, a critical messenger in the brain that facilitates
normal movement. The loss of these cells leads to stiffness, slowness, tremor and
balance difficulty that becomes more prominent over time.
There was a revolution in the treatment of Parkinson’s disease in the 1960s with
the discovery of levodopa as a treatment that could be delivered orally in tablet
form. This drug is converted into the lost messenger dopamine. The use of this
drug was nothing short of miraculous in the way it transformed disability into
normal movement and therefore return normal function or close to normal function
for people with Parkinson’s disease.
For some people with Parkinson’s disease the striking benefit of levodopa treatment
diminishes in quality and quantity over time. Although the drug’s efficacy is never
lost, the brain’s ability to utilise it over time becomes erratic, unreliable and
unpredictable. People who enter this phase of their illness in which they have socalled ‘motor complications’ experience dramatic changes in their ability to move
from hour to hour. Pills have to be taken with increasing frequency and often
provide progressively diminishing periods of normal movement. These brief periods
of relative normality can be further contaminated by excessive involuntary writhing
movements known as dyskinesia, representing the other extreme of a roller coaster
of movement. The cost of Parkinson’s disease at this advanced stage increases
significantly, both directly due to drug costs and indirectly due to lost productivity,
reduced working time for carers and longer hospital stays (Findley, 2011).
1.2
Deep brain stimulation and Parkinson’s disease
Over the last 20 years, patients with disabling motor complications of their
Parkinson’s disease have experienced a second therapeutic revolution in the form
of deep brain stimulation. Deep brain stimulation involves the placement of
electrodes into specific parts of the brain by a team of neurosurgeons specifically
trained in functional neurosurgery. Unlike most forms of neurosurgery, which
involve removing abnormal brain tissue, functional neurosurgery aims to modulate
brain activity, using carefully targeted electrical impulses to restore function. Deep
brain stimulation thus allows us to fine tune abnormal circuits in the brain that
misbehave as part of a disease process such as Parkinson’s disease. Stimulation is
delivered via a ‘pacemaker’ battery placed under the skin that must be replaced
intermittently. This battery can be fine tuned according to the patient’s needs by a
team of doctors in the programming stage post-operatively. The critical difference
between deep brain stimulation and the standard oral medications we use in
Parkinson’s disease is the fact that the benefit stimulation provides is continuous
throughout a 24-hour period, reliable from day to day, and maintained in the long
term.
From an individual perspective, deep brain stimulation can be transformative,
returning to a patient hours of their day that previously were characterised by
disability and dependence on a carer. Many trials of deep brain stimulation versus
best medical therapy have shown the superiority of surgery over best medical
therapy for the small proportion of patients that meet criteria for surgery in
Parkinson’s disease (Hilarion, 2014). The wider benefits in terms on general well
being, restoration of normal relationships, a return to the workforce, reduced
hospital attendances and societal integration are less well measured but perhaps
more significant.
There are available alternatives to deep brain stimulation for people with
Parkinson’s disease who experience disabling fluctuations in their movement. Pump
therapies can deliver drugs under the skin (apomorphine) or through a tube passed
into the small bowel (levodopa-carbidopa intestinal gel). This continuous pumpbased delivery can relieve the symptoms of Parkinson’s disease in a more reliable
way than tablets taken intermittently can. These pump therapies have been used
successfully in many patients for a number of years and have an important place in
the war-chest we have at our disposal to restore movement in Parkinson’s disease.
Importantly, neither of these pump options can match the efficacy of deep brain
stimulation when indirectly comparing the data available. Furthermore, and of
greater importance from a societal point of view is the greater cost of these pump
therapies which carry a recurring year-on-year cost. Deep brain stimulation is
associated with a 50-60% reduction in medication requirements. After two years
the cost of the surgical episode and hardware are covered by this medication
saving, making it cost effective with respect to the alternatives (Valdeoriola, 2013).
Although economics does not come into individual choices of best therapy for a
given patient, this is an important consideration when planning for the future
therapeutic landscape for this increasingly common disease in our aging population
(Dams, 2013).
2.0
Other Conditions treatable by Deep Brain Stimulation
2.1
Essential tremor
Essential tremor is a common movement disorder characterised by disabling upper
limb tremor when an affected person attempts to use their arms in performing any
task. Prevalence statistics vary widely but conservatively it is estimated that 1% of
the population are affected and this rises to over 5% amongst people over 65
years. The resulting tremor can be mild or moderate and many people continue to
work and do not seek medical attention. For some people the tremor is severe and
incapacitating making the most simple of tasks impossible such as drinking from a
cup or glass, signing a cheque, doing up buttons or shaving. Medical options for the
treatment of essential tremor are very limited and often unsuccessful at best. Deep
brain stimulation, however, can abolish essential tremor and restore function where
it has been lost (Baizabal-Carvallo, 2014).
2.2
Dystonia
Dystonia is a less common movement disorder than Parkinson’s disease or
essential tremor but still may affect as many as 3000 people in Ireland. This
condition is characterised by sustained abnormal postures and twisting movements
of the neck and limbs produced by muscles contracting in an involuntary way.
Dystonia can be localised to a single body part or can be generalised where it is at
its most disabling, affecting the entire body which can make sitting or lying down
difficult. Dystonia is often painful and secondary problems with joint development
and breathing are seen in affected children who develop skeletal malformations as
a result of sustained muscle spasms. We unfortunately have no useful medicines
for the treatment of dystonia. Injections of botulinum toxin can reduce spasms but
are impractical where many muscles are involved and sometimes ineffective. Deep
brain stimulation can provide significant long-lasting (Fitzgerald, 2014; Walsh,
2013) improvements in focal and generalised dystonia by restoring normal neural
function capable of returning lost ability to walk, feed and perform self-care in
affected patients.
3.0
Current Service Provision of Deep Brain Stimulation
3.1
The patient experience
As things currently stand, deep brain stimulation is not available in the Republic of
Ireland and this is unusual by international standards in comparison to other
developed nations of our size. Our two neurosurgical centres in Dublin and Cork are
not currently resourced to offer deep brain stimulation for any of its indications and
at this point in time we do not have neurosurgeons with training or experience in
its provision. People with Parkinson’s disease must therefore be referred to centres
in the United Kingdom, and sometimes beyond, for assessment and surgery under
the Treatment Abroad Scheme. The complex decision making process that brings
physician and patient to the point of weighing up the risks and benefits of brain
surgery therefore marks only the start of a long and stressful process involving
multiple flights abroad for assessments, surgery and then programming. Notably,
for the patients who undertake this process, movement is so difficult that the
potential risks of brain surgery are outweighed by their desire for treatment
success. Negotiation of transport to one of our airports, travel and overnight stays
abroad with return trips if accepted are difficult, fraught with stress and anxiety
and without any comparator in medicine in Ireland that we aware of. In addition,
the cost of travel for the surgical candidate, one or two carers and hotel
accommodation must be added to the total cost of surgery abroad.
3.2
The treating neurologist’s experience
As neurologists treating patients who have travelled to the United Kingdom for
deep brain stimulation, the practicalities of management following surgery can be
challenging. Although our colleagues abroad are leaders in their field and provide
an excellent service to our patients, the geographical and therapeutic disconnection
can be frustrating and even dangerous at times when complications occur. We do
not have ease of access to operative targeting information or imaging, we do not
have access to data relating to the post-operative programming and we have no
MRI department that is equipped to scan these patients should they require one for
any reason due to their metal implants. Furthermore, and possibly of greater
therapeutic significance, is the post-operative programme required in a crosschannel approach. The careful and gradual reduction in oral drug therapy while
electrical stimulation is increased in the programming stage is optimal if done
locally and frequently over 5 to 7 visits taking place every one to two weeks. This is
accepted as best practice amongst experts in the field. Irish patients are very well
cared for abroad, but the challenges of travel mean a modified programme of
monthly programming over half the number of sessions is necessary. Many
neurologists in Ireland have had the experience of having a patient with deep brain
stimulation who has suffered a hardware malfunctions (e.g. battery failure, lead
fractures) or infection. These neurosurgical emergencies must be negotiated via
communication with busy neurosurgical centres in the United Kingdom and are
further complicated by the need to apply for travel approval for an increasingly
unwell and often suddenly disabled patient.
4.0
The benefits of a cross border solution for Ireland
There are therefore compelling reasons for the patient and their treating medical
team to look for an alternative to the status quo, i.e. the establishment of a
neurosurgical centre on this island to treat Parkinson’s disease and related
movement disorders. Such a centre will need to be run by a neurosurgical team
with access to the appropriate hardware, working in tandem with movement
disorders neurologists and adequate nursing support to guide patient selection and
post-operative treatment. Aside from the difficulties outlined that mitigate against
the retention of the current state of affairs, there are many strong positive factors
which additionally support the development of cross-border collaborative deep
brain stimulation service:

Access is key in healthcare. The accessibility of this service ‘locally’ in Ireland
will inevitably give rise to an expansion in numbers of patients opting for this
mainstream treatment which is currently viewed by many patients as a
curiosity experienced by the few willing and physically able to travel abroad
for it.

Deep brain stimulation is the most cost effective therapy for patients with
motor fluctuations in Parkinson’s disease. After 2 years the initial investment
in hardware and surgical costs are covered by the reduction in medication
possible post-operatively. Unfortunately, the up-front cost of establishing a
deep brain stimulation service in the Republic of Ireland proved to be
prohibitive in economically difficult times at the time of the HIQA Health
Technology Assessment in 2012. A cross border collaboration will allow
patients in the Republic of Ireland access an internationally recognised
facility in Belfast, avoiding this cost but at the same time reaping the
economic benefit of DBS in the medium and long term until such a time that
a unit in the South can be established. The likely patient demand would
support two centres.

On this island we now have an internationally trained quorum of neurologists
and neurosurgeons who are experts in this field and a total 32 county
population of sufficient size to develop one or two centres of excellence for
the delivery of a national deep brain stimulation service. This will break our
reliance on the financially and logistically inefficient treatment abroad
process and will ensure we can deliver local treatment in a safe way that
delivers both clinical outcomes and an acceptable patient experience.

The additional safety factor and related reassurance for patients and
physicians in knowing that a local neurosurgeon familiar with their case is
available with same-day access by car, train or ambulance for postoperative
complications is critical and invaluable. This is best appreciated by those of
us admitting these patients to general hospitals in the Republic while
urgently faxing forms and leaving messages in an effort to secure passage to
the United Kingdom under current arrangements.

In the Republic of Ireland we do not have a magnetic resonance imaging
(MRI) department which can perform MRI imaging on patients who have had
deep brain stimulation. This is for safety reasons, where knowledge of
implanted material is limited and where the necessary MRI hardware
designed to manage patients with implants in situ is not available. When
patients who have had deep brain stimulation present with headache or
stroke symptoms, we are limited to performing less detailed and less useful
CT scans. This can be a significant diagnostic limitation at times and one that
would not exist with a cross-border collaboration allowing access to specialist
MRI equipment or indeed if a centre evolves over time in the Republic.

The development of local deep brain stimulation expertise in Ireland is
essential for the training of future neurologists and neurosurgeons in the
rapidly expanding field of functional neurosurgery. There is a very real threat
that Irish patients with neurological disease in the future will be left behind
in the wake of a field of neuroscience that has grown exponentially in the
range of targets and conditions that may be amenable to treatment with
deep brain stimulation. We need to put in place the structures to harness
this rapid explosion of potential that has spread from the treatment of
tremor into surgical approaches for other disorders affecting brain circuitry
including drug resistant depression, Alzheimer’s disease and epilepsy. We
have the expertise on this island to do this but need the political will and
assistance to put the required framework in place.

There is enormous potential for academic medical centres on both sides of
the border to share data and participate in cutting edge neuroscience
research in the area of functional neurosurgery. We have a pool of hugely
talented researchers in the fields of neural engineering, neuropsychiatry,
neuroimaging and translational neuroscience in this country. Patients we are
sending abroad for deep brain stimulation who look to participate in research
are unable to provide any data to these researchers and there is therefore a
huge loss of research potential. A neurosurgical unit nested within an
academic centre on this island working in collaboration with colleagues
throughout the island to share preoperative, intra-operative and
postoperative data would open an exciting number of avenues in
neuroscience research.
Summary
Deep brain stimulation is now a well-established and evidence based treatment for
a number of chronic and disabling neurological conditions. In carefully selected
patients, for whom available alternative treatments fail to provide an acceptable
quality of life, surgery can provide significant symptomatic benefit. This benefit has
been clearly demonstrated using clinical outcome scales. The additional benefits to
the individual, society and the healthcare system are substantial in returning
patients to work and a productive role within their families and communities.
For many people with movement disorders in Ireland, deep brain stimulation in
inaccessible and for this reason many good candidates are unnecessarily
experiencing day-to-day disability. Ireland is almost unique amongst European
nations with a developed healthcare system in not being able to provide this
therapeutic option locally. The need to travel imposed on patients, some with
severe motor disability, is difficult to justify and warrants consideration of an
alternative approach until a surgical service can be established in the Republic of
Ireland.
We therefore fully support the establishment of Irish deep brain stimulation service
with our colleagues in Belfast to deliver the best available treatment to selected
patients in a manner that is acceptable to them, their carers and the doctors
managing their condition.
References:
Hilarion et al. Deep brain stimulation in Parkinson’s disease: meta-analysis
of randomized controlled trials.J Neurol 2014 (published online 2 Feb 2014)
Findley LJ, Wood E, Roeder C, Bergman A, Schifflers M. The economic burden of
advanced Parkinson’s disease: an analysis of a UK patient dataset.’J Med Econ
2011; 14(1): 130-9
Dams J et al. Cost-Effectiveness of Deep Brain Stimulation in Patients With
Parkinson’s Disease. Movement Disorders 2013;28(6)
Valldeoriola F, Puig-Junoy J, Puig-Peiro R, Workgroup of the SCOPE study. Cost
analysis of the treatments for patients with advanced Parkinson's disease: SCOPE
study.J Med Econ 2013;16(2):191-201. Epub 2012 Oct 29.
Fitzgerald JJ et al. Long-term outcome of deep brain stimulation in generalised
dystonia: a series of 60 cases. J Neurol Neurosurg Psychiatry 2014. (published
online April 2014)
Walsh R.A. et al. Bilateral pallidal stimulation in cervical dystonia: Blinded evidence
of benefit beyond 5 years. Brain 2013;136(3):761-769
Baizabal-Carvallo JF, Kagnoff MN, Jimenez-Shahed J et al.The safety and efficacy of
thalamic deep brain stimulation in essential tremor: 10 years and beyond. J Neurol
Neurosurg Psychiatry. 2014 May;85(5):567-72.