**2. Intrathecal baclofen pump**

Intrathecal baclofen pump placement is a cost-effective treatment modality in spasticity and dystonia management of patients with CP that are non-responsive to enteral pharmacological treatments [6]. Penn and Kroin were the first scientists using ITB to treat spasticity in patients with multiple sclerosis [7]. Baclofen is a chlorophenol derivative of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) [3]. Intrathecal administration of this product results in ten times the concentration after oral administration [3]. Direct administration of baclofen to central nervous system via intrathecal route minimizes dosage and decreases systemic side effects when compared with oral form of baclofen [6]. ITB disseminates into the superficial layers of the spinal cord and binds to GABAb receptor sites, and acts presynaptically. It inhibits the uptake of calcium and inhibits the release of excitatory neurotransmitters (i.e. glutamic acid and aspartic acid) [3]. A single dose of ITB reduces lower extremity muscle tone within 20–40 min, its maximum effect is seen in 4 h after administration. Its half-life is 5 h and a single dose is effective for 8–10 h. ITB treatment improves muscle tone, gait, and quality of life of patient with CP. Approximately 300 μg/day dose of ITB is mostly adequate in reducing lower extremity spasticity and diminishing muscle spasms [3]. ITB overdose results in coma, respiratory depression, and hypotonia [3]. These effects usually subside within 2–3 days. Intravenous physostigmine is the treatment of choice in ITB overdose, however severe overdoses are not reversed.

Continuous ITB is best achieved via a pump which delivers baclofen to the lumbar area of the spinal cord to reduce spasticity in the lower extremities [8]. The catheter is inserted through means of a 14-gauge Tuohy needle and enters the spinal canal at about L2, and the tip of the catheter is advanced to T10 for paraplegics, T5 for quadriplegics, and C5-T1 for complex movement disorders and dystonia [9]. Right lower quadrant of the abdomen is the usual side for subcutaneous pump placement. A catheter is passed from the pump into the intrathecal space. Baclofen

#### *Neurosurgical Treatment of Cerebral Palsy DOI: http://dx.doi.org/10.5772/intechopen.110258*

dose can be arranged via a radiofrequency wand which transmits information from a computer to the implanted pump [10]. Test dose is needed in the preimplantation period before the procedure. This will help physician to assess the potential effects of baclofen on symptoms and function. The initial continuous infusion dose is mostly twice the single ITB dose that shows a clinically prominent effect. The daily dose is slowly increased until desired clinical effects are present. Regular follow-up and percutaneous pump refill every three to six months is a requirement for this procedure. The pump is refilled by inserting a needle through the skin into the reservoir. Frequent monitoring and dose adjustment is a must after pump placement. Pump replacement is also a necessity at the end of battery life (4–6.5 years). The pump is similar to hockey pump, and the child must weigh approximately 15–18 kg to accommodate the pump. ITB affects both spasticity and dystonia and benefits both ambulatory and non-ambulatory children.

Shared decision-making between physician and patient and his/her caregivers is an important step. The adverse events include CSF leakage, infection, catheter disconnection or breakage, constipation, respiratory depression, baclofen withdrawal, and baclofen overdose [5, 10]. Highest complications rates for ITB therapy are around 36% [11]. Baclofen withdrawal symptoms include muscle spasms, dysesthesias, pruritus, agitation, and rhabdomyolysis. Treatment of this issue is restoring the ITB delivery [6]. Contraindications are baclofen sensitivity, inappropriate body size for reservoir placement, non-compliant patient, or any limitation that inhibits close follow-up. In patients with unilateral spasticity, ITB would probably also decrease muscle tone on the healthy side and ITB is not recommended for these patient group. Benefits and risks associated with ITB treatment should be cautiously evaluated; individual needs, expectations, and clear treatment goals should be agreed before procedure. Children with moderate to severe spasticity spectrum will benefit from ITB.
