Download Intrathecal baclofen in children and adolescents with cerebral palsy

Intrathecal baclofen in children and
adolescents with cerebral palsy
Dr Ram Kumar
Consultant Paediatric Neurologist
Alder Hey, Liverpool
May 2012
Summary
• Case example: before and after ITB (short
term effects)
• Refresher on ITB and basics
• Another couple of case examples
demonstrating context of ITB use in teenagers
with CP
• Other issues particularly pain
• Useful references
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Case A: seen March 2011
15
HIE Grade 2 or 3
Athetoid dystonic 4 limb cerebral palsy
GMFCS Level 5; MACS 4
Good cognition, dysarthria
Minimal co-morbidities
Increasing dystonia
Previous hip surgery – pseudoarthrosis on left
Spine X-ray pre-ITB (6 months): 51 deg Cobb angle
Case A: Supine spine x-ray 51 deg Cobb angle
Previous adductor
tenotomies, botulinum toxin
lower limbs, bilateral hip
reconstruction surgery
Progress
• Main goals: voluntary upper limb control, pain
relief, improve flexibility of spinal curvature
• ITB test dose November 2011 – successful;
low pressure headache
• Proceed to ITB implantation Feb 2012
• Current dose ITB 180 mcg/day
?
Refresher on ITB
Titanium
40 ml capacity
175 g
8.8 cm diameter
7 year life except
at high infusion
rates
Connector
Opaque one-piece catheter
89 cm long; internal volume ~ 1 day’s worth of
infusion
Refill through the
central port
Programmer and wand
Various ways of programming infusion e.g. simple
continuous, variable rate continuous, complex bolus
dosing regime
Intrathecal baclofen itself
• ITB provides 1000 times the CSF concentration
compared to oral baclofen
• Rule of thumb 100mg/day of oral baclofen =
100mcg/day
• Acts on GABA-B receptor – but where?
• Volume and flow effects of IT baclofen
• Receptor downregulation and tolerance
• Overdose and withdrawal effects life-threatening
IT baclofen
• Concentration of 1000mcg/ml to 4000mcg/ml
• With 40ml pump reservoir, minimum volume of 3
mls
• 1000mcg/ml solution at 250mcg/day. Would
need refill every 4.5 months
• Alarm for low reservoir volume and nearing end
of life
• Can be removed – not permanent procedure
• Implications: 100% commitment and ability to
attend clinics
Usual process of assessment
Diagnosis and prognosis
Co-morbidities
Past, current and impending physical,
drug and surgical treatments
Other professionals involved
Non-medical factors
Physical examination at baseline
Questionnaire tools as appropriate
Follow-up:
Symptoms
Focussed physical examination
Other professionals involved/missing
from follow-up
Changes in non-medical situation
Questionnaire tool as appropriate
Response to previous changes in
treatment
Consensus on the appropriate use of ITB in paediatric spasticity. Eur J Paed Neurol 2009
The updated
European
Consensus
2009 on the
use of
Botulinum toxin
for children
with cerebral
palsy. Eur J
Paed Neurol
2009
Another case
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Case B: seen since 2008, now 17 years
4 limb spastic-dystonic CP
Prematurity 30 weeks
GMFCS 5; MACS 5
Learning difficulties, dysarthric, oral feeder
Perseverative, anxiety issues
Bilateral hip reconstruction in 2002 and 2008
Oral baclofen 100mg/day – ongoing hip pain and
general discomfort
Dec 2008:
Age 13
Mar 2010:
Age 15
Mar 2010:
Age 15
76 degree Cobb angle
Spine flexible under traction
March 2012: Age 17 years
ITB dose 210mcg/day
Posterior instrumentation ;
anterior approach not
required
Out of hospital within 9 days
Post-operative problems
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Headaches, flashing lights
Has the ITB pump stopped working?
Has the catheter been cut or blocked?
Neuropathic pain and behaviour change
ITB and pain
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Case C; now 17 year old male
CP due to neonatal meningitis
Asymmetric 4 limb spasticity, left worse
GMFCS 5; MACS 5
Severe intellectual disability, blind, VP shunt
Previous bilateral hip surgery ’03
Increasing pain 2 years – focal and general
CCHQ scores for Case C
7
6
5
4
Ease of cares
3
Positioning
Score
Comfort
2
Interaction
1
0
Pre-ITB
ITB 85mcg/day
ITB dose
ITB 90mcg/day
ITB infusion
dose
(mcg/day)
Pre-ITB, T-1
(9 months
prior to ITB
implantatio
n)
Pre-ITB
pump
implantatio
n, T0
T1 (2
months
postimplantatio
n)
T2 (27
months postimplantation)
-
0
90.0
182.0
Pain profile for hip pain
60
50
40
Pain score 30
PPP Pain A
(hip pain)
50
54
5
22
20
PPP Good
day
14
-
5
11
MAS
1.08
1.78
0.6
0.16
10
0
Oral
medications
Diclofenac
40mg tds,
Tramadol
50mg tds
Diclofenac
40mg tds,
Tramadol
50mg tds
Diclofenac
40mg tds,
Tramadol
50mg tds
Diclofenac
40mg tds,
intramuscular
botulinum toxin
injections
Phase
Patient
number
Co-morbidities
Medication related to tone or pain
management, at implantation
LD, EPILEPSY, SCOLIOSIS, VI, BEHAVIOUR
Codeine, Paracetamol,
Gabapentin Botulinum Toxin,
Baclofen
LD
Baclofen
LD, EPILEPSY, PEG, RESP, SCOLIOSIS, HIPS
Tramadol, Paracetamol,
Tetrabenazine
LD, EPILEPSY, PEG, SCOLIOSIS, VI
Dantrolene, Paracetamol,
Nitrazepam
LD, EPILEPSY, SCOLIOSIS, HIPS, VI
Diclofenac, Paracetamol,
Tramadol, Botulinum Toxin,
Baclofen
LD, SCOLIOSIS, VI
Diclofenac, Baclofen,
Trihexiphenidyl
LD, EPILEPSY, BEHAVIOUR
Diclofenac, Baclofen,
Trihexiphenidyl
LD, EPILEPSY, PEG, VI, BEHAVIOUR
Paracetamol, Baclofen
Age at ITB pump
implant
1
14
2
16
3
4
5
6
12
13
14
16
7
14
8
13
Findings
• Works for some types of pain (spasticity,
neuropathic) more than others (osteoarthritic,
visceral)
• In long-term, new sources of pain arise e.g.
scoliosis, GI dysmotility
• Other intervention modalities also have a role,
so not just about ITB “ITB is not a panacea”
Other specific issues
• Early and late complications: neurological,
regional and systemic
• Often difficult to identify catheter blockage vs
progression of underlying tone disorder vs
tolerance vs response shift and mission creep
• Problems specific to standing transfer and
indoor walkers (GMFCS 3 verging on 4)
• Athetoid-dystonic patients with and without
spasticity
Summary
• Patient selection and feasible goals important
• Medical and non-medical factors important
• ITB “success” vs “failure” only relevant to a 6
month time-frame
• ITB long-term success only makes sense in
context of wider rehabilitative approach
• Need help please – tall order for any single
service to do all of this
• Additional advances in hardware, software and
pharmaceutics should improve matters
References
• NICE Spasticity in children guidelines – due out soon
• Dan et al. Consensus on the appropriate use of intrathecal baclofen (ITB)
therapy in paediatric spasticity. Eur J Paediatr Neurol 2010 14(1): 19-28.
• Morton et al. Controlled study of the effects of continuous intrathecal
baclofen infusion in non-ambulant children with cerebral palsy. Dev Med
Child Neurol. 2011; 53(8):736-41.
• Pin et al. Use of intrathecal baclofen therapy in ambulant children and
adolescents with spasticity and dystonia of cerebral origin: a systematic
review. Dev Med Child Neurol. 2011;53(10):885-95.
• Heinen et al. The updated European Consensus 2009 on the use of
Botulinum toxin for children with cerebral palsy. Eur J Paediatr Neurol.
2010; 14(1):45-66.