Spectrum of Management of Spasticity--Intrathecal baclofen pump insertion

1. DR AMIT KUMAR GHOSH
Consultant Neurosurgeon
Institute of Neurosciences Kolkata

2. Spasticity
Greek Spastikos - “to draw or tug”
 Velocity-dependent increased resistance to passive
stretch
 Exaggerated tendon jerks
 Hyperexcitability of the stretch reflex
- James Lance (1980)

3. Neurosurgical Treatments
Neurodestructive Procedures
 Selective Dorsal Rhizotomy (SDR)
 Rhizotomy
 Neurectomy
 Myelotomy
 Cordectomy

4. Other surgical Intervention
Ortho-Plastic
 Tendon Lengthening - preferred method
 Allow full passive range with some residual muscle tension.
 Muscle must be immobilized under tension.
 Tendon Transfer - used on children (Shriner’s)
 Gait analysis with dynamic electromyographic monitory helps reduce
common errors associated with this procedure.
 Osteotomy - for skeletal deformity
 Restore boney architecture, muscle-length can be improved.
 Used along with tendon lengthening.
 Artrhodesis - joint fusion
 When the above are prohibited.
 Stabilize unstabel joints (subtalar, thumb, wrist).
 Tenotomy
 Myotomy

5. Spectrum of
Management of Spasticity
Injection
Therapy
Neurosurgery
Orthopedic
Treatments
Rehabilitation
Therapy
Prevent
Nociception
Intrathecal
Baclofen
(ITB™)
Therapy
Oral
Drugs
Patient

6. Traditional Step-Ladder Approach
to Management of Spasticity
Neurosurgical
Orthopedic
Oral medications
Rehabilitation Therapy
Remove noxious stimuli

7. -

8. Selection Criteria
Severe Spasticity (Mod. Ashworth >3),
Refractary to Oral medications or intolerable side effects.
Causing Pain.

9. POTENTIAL BENEFITS OF ITB THERAPY
Reduction in spasticity, spasms, pain
Facilitates rehabilitation!!
Functional improvements
Independence
Ease of Care
Programmability
Reversibility

10. Bolus injection of Baclofen Intrathecal—
A small test dose of Baclofen Intrathecal is injected into the patient’s
intrathecal space (i.e., area where fluid flows around the spinal cord) via
a lumbar puncture and assess patient’s response to the test dose
ITB Therapy Screening Test
Preparation for the Screening Test
Screening tests should not be conducted on patients who have an
active infection.
A monitored environment is essential for screening test---
A fully equipped setting to monitor the respiratory and cardiovascular systems of
the patient (an apnea monitor or pulse oximeter)
A fully staffed setting to monitor a patient’s vital signs
Resuscitative equipment
Intravenous (IV) drug physostigmine should be considered to
treat symptoms of baclofen overdose

11. ITB Therapy Screening test----Bolus Injection of Baclofen Intrathecal into the
Intrathecal Space

12. Clinical Response to the Medication
The desired clinical response to the screening test ------
Decrease in muscle tone (i.e., one point for spasticity of cerebral
origin or two points for spasticity of spinal origin on the
Mod. Ashworth Scale) or a decrease in spasms.
Baclofen Intrathecal begins to act 30–60 minutes after the injection.
Peak effect occurs approximately four hours after the bolus dose and
effects may continue for 4–8 hours

13. Insertion of the Tuohy needle at mid or upper lumbar space in an oblique,
paramedian trajectory and negotiation into intradural space.
positioning of the catheter tip at levels according to therapeutic indication
Approximately placement of the tip of the intrathecal catheter at the T1–2 level
for spastic quadriplegia, the T6–10 level for spastic diplegia, and in the
midcervical region for generalized secondary dystonia.
Subcutaneous tunnelling for connecting tube
Subfascial pump placement
Programming
Albright, A., Turner, M., & Pattisapu, J. V. (2006). Best-practice surgical techniques for intrathecal baclofen therapy, Journal of
Neurosurgery: Pediatrics PED, 104(4), 233-239. Retrieved Aug 16, 2020, from https://thejns.org/pediatrics/view/journals/j-
neurosurg-pediatr/104/4/article-p233.xml
PUMP IMPLANTATION

21. Programming
1) Daily dose
2) Mode
3) Infusion rate

24. Pediatric Patients: Use same dosing recommendations for patients with
spasticity of cerebral origin. Average daily dose for patients under 12 years was
274 mcg/ day, with a range of 24 to 1199 mcg/ day. Dosage requirement for
pediatric patients over 12 years does not seem to be different from that of adult
patients..
Maintenance dosage for long term continuous infusion of
BACLOFEN INTRATHECAL has ranged from 22 mcg/ day to 1400 mcg/ day,
with most patients adequately maintained on 90 micrograms to
703 micrograms per day.
Spasticity of Cerebral Origin Patients:
Maintenance Therapy:
Spasticity of Spinal Cord Origin Patients:
Maintenance dosage for long term continuous infusion of
BACLOFEN INTRATHECAL has ranged from 12 mcg/day to 2003 mcg/ day,
with most patients adequately maintained on 300 micrograms to
800 micrograms per day. There is limited experience with daily doses
greater than 1000 mcg/day.

25. Complications more specific to ITB include---
1) risk of infection around the device, and
2) risk of device malfunction.
3) Drug related complication
Baclofen withdrawal (from abrupt interruption of the delivery of
baclofen via the pump) and
baclofen overdose (usually as a result of human error) have also
occurred with ITB.
Serious complications from ITB are infrequent, and in most cases
reversible as long as they are diagnosed and treated in a timely
fashion.

26. The following effects are signs of overdose and can vary in severity:
•Drowsiness
•Light-headedness
•Dizziness
•Somnolence
•Respiratory depression
•Seizures
•Rostral progression of hypotonia (loss of muscle tone
progressing from the site of injection at the lumbar region to
the head)
•Loss of consciousness progressing to coma

27. Imaging Evaluation of Intrathecal Baclofen Pump-Catheter System
malfunction
1) X-ray of abdomen, LS spine, thorax—AP and Lateral to see the catheter kink, disconnection
,migration
2) Fluoroscopy----Intrinsic pump function (eg, pump rotor/roller function) can also be obtained if
radiographs are performed both before and after a programmed rotation of the rotor. An angular
rotation of 90° or 120° is expected for the SynchroMed EL and SynchroMed II devices,
respectively. Failure to observe rotor or roller movement usually indicates a rotor/roller malfunction
3) Contrast study--Injection of contrast into the catheter via the accessory pump port should always
be preceded by aspiration of 2–3 mL of fluid from the accessory pump port (which will clear any
residual baclofen from the accessory port and the catheter) to avoid acute baclofen
overdose. there can be a limited ability to detect catheter-tip loculations, catheter migrations,
microscopic perforations/leaks, and some larger leaks. CT appears to be more sensitive than
fluoroscopy in identifying some of these abnormalities
4) CT—particularly postcontrast (ie, postinjection of contrast material through the accessory pump
port)
5) Nuclear Scintigraphy--Radionuclide flow studies of the ITB delivery system may be indicated if a
more complete functional evaluation of the device is warranted or if prior imaging findings are
inconclusive. In DTPA is typically the preferred radiopharmaceutical due to its long half-life, which
allows radioactivity to be monitored for ≤7 days as it travels through the catheter and into the
subarachnoid space

28. SDR: Procedure
 Multilevel laminectomy vs. minimally invasive
approaches
 L1 – S1 sensory roots are identified and divided into 3-5
rootlets
 Each rootlet is stimulated and responses are measured
via EMG
 Rootlets with the most abnormal signal are cut
 Surgery takes about 4 hours

29. SDR: Procedure…

30. SDR: Procedure…
Nerves that have abnormal increased response are selectively sectioned.
Generally not more than 60% of rootlets at a given level

31. Pathophysiology of Spasticity
Theory
 Imbalance between excitatory and inhibitory impulses
to the alpha motor neuron
 Due to a lack of descending inhibitory input to the
alpha motor neuron
Descending
Inhibition
Sensory
Excitation

32. Pathophysiology of
Cerebral Origin Spasticity
Inhibitory signals
modulate reflex
signals–tone
remains normal
Lack of neural
inhibition leads to
spasticity
Normal brain
delivers inhibitory
neural signals to
the spinal cord
Damaged brain
fails to generate or
sends inadequate
inhibitory signals

33. Pathophysiology of
Spinal Origin Spasticity
Inhibitory signals
modulate reflex
signals–tone
remains normal
Lack of neural
inhibition leads to
spasticity
Inhibitory neural
signals sent to the
alpha motor
neuron
Damaged spinal
cord fails to relay
adequate inhibitory
signals
Normal Damaged

34. Factors aggravate spasticity
Age and Ageing 2013; 42: 435–41.

35. Causes
BMJ 2014;349:g4737 doi: 10.1136/bmj.g4737 (Published 5 August
2014)

36. Characteristics of Spasticity
 Hyperactive stretch reflex
 Increased resistance to passive movement
 Posturing of extremities
 Stereotypical movement synergies
Spasticity of arm showing excessive flexion
of elbow, wrist, and fingers
BMJ 2014;349:g4737 doi: 10.1136/bmj.g4737 (Published 5 August 2014)

37. Clinical features of spasticity
 Clonus
 Involuntary rhythmic contractions triggered by stretch; these can interfere with
walking, transfers, sitting, and care
 Spasms
 Sudden involuntary movements that often involve multiple muscle groups and
joints in response to somatic or visceral stimuli
 Spastic dystonia
 Tonic muscle overactivity without any triggers owing to the inability of motor
units to cease firing after a voluntary or reflex activity; results in characteristic
limb postures and contractures
 Spastic co-contraction
 Inappropriate activation of antagonistic muscles during voluntary activity due
to lack of reciprocal inhibition causing a loss of dexterity and slowness in
movements
BMJ 2014;349:g4737 doi: 10.1136/bmj.g4737 (Published 5 August

38. Possible Advantages of Spasticity
 Maintains muscle tone
 Helps support circulatory function
 May prevent formation of deep vein thrombosis
 May assist in activities of daily living

39. Consequences of Spasticity
 May interfere with mobility, exercise, joint range of
motion
 May interfere with activities of daily living
 May cause pain and sleep disturbance
 Can make patient care more difficult

40. Measuring Spasticity
 Ashworth and Modified Ashworth scales
 Spasm and reflex scales
 Passive quantitative tests
 Active tests of movement

41. Differential diagnosis
 Contractures
 Rigidity
 Catatonia

42. Pharmacological Intervention
Oral Medications
 Baclofen
 Dantrolene Sodium
 Tizanidine
 Gabapentin
 Diazepam

43. Pharmacological Intervention
Oral Drugs
Diazepam Brainstem reticular formation and
spinal polysynaptic pathways
Fatigue; reduced motor coordination, intellect,
attention, memory
Dantrolene Sodium Skeletal muscle calcium stores Hepatotoxicity, generalized muscle weakness
Oral Baclofen GABA-b receptors Drowsiness, confusion, headache, lethargy
Tizanidine Hydrochloride a2-adrenergic receptors Dizziness, sedation, dry mouth
Intrathecal Drugs
Intrathecal Baclofen Gaba-b receptors Pump malfunction/ dislocation
Focal Drugs
Phenol Injection Neuromuscular junction Causalgia with sensory nerve injury, pain at injection
site, hematoma
Botulinum Toxin Nerve Injection site pain, muscle weakness in injected
muscle, hematoma, muscle necrosis, phlebitis
•[Gallichio, (2004)]
Drug Site of Action Adverse
Effects

44. Rehabilitation Therapy
 Stretching
 Weight bearing
 Inhibitory casting
 Vibration of the
antagonist
 Pool therapy
 EMG biofeedback
 Electrical stimulation
 Positioning and rotary
movements

45. Thank
you