My name is Rajeshwari Srinivasan. I will be talking about spasticity, hypertonia, dystonia, and rigidity. This is being recorded as part of the Pediatric Rehab Focus Board Review course. I have no financial disclosures. What is tone? Muscle tone refers to tension in the muscle at rest. Muscle tone is usually regulated by local spinal cord reflexes at the segmental level, innervating that muscle, and also by suprasegmental influences. Increase in tone is loosely referred to as hypertonia. Hypertonia refers to increase in tone in upper and lower extremities, causing stiffness and difficulty in movement caused by various factors. Rigidity, on the other hand, is a type of hypertonia in which the muscle spasms are increased by movement, where patients usually have exaggerated reflex responses. With evaluation of hypertonia, as part of the neural influences, lack of modulation of the stretch reflex is seen. With non-neural influences, there are peripheral biomechanical components where there is altered structure or properties of tendons and muscles that are seen, and impaired growth is also seen. Clinical evaluation of hypertonia includes utilization of some scales. Modified Ashworth scale is usually used. This ranges anywhere from 0 to 4. A modified Ashworth scale of 0 indicates no increase in tone. 1 indicates a slight increase with catch and release. 1 plus indicates slight increase followed by minimal resistance throughout the range of motion. 2 indicates more marked increase throughout range of motion, but affected part moves easily. 3, there is considerable increase in tone with difficulty in passive movement. 4, the affected part is rigid in flexion and extension. Continuing with clinical evaluation of hypertonia, the other scales that are also used are the Tardieu scale. The technique for this is the examiner should note the initial catch after a rapid stretch, which is R1, in relation to the full passive end range of motion of the joint, or R2. Interpretation of this is as follows. If there is a large difference in R1 to R2, this suggests a neural or a dynamic component. A small difference in R1 to R2 suggests fixed contracture. If R2 is less than normal, passive range of motion. Treatment options for specificity are variable. They consist of focal treatments, including chemo-denervation and serial casting, which also can be reversible, or general treatment options, which include oral medications, intrathecal baclofen, and deep brain stimulation as reversible options. Permanent options include selective dorsal rhizotomy and orthopedic surgery. Contracture management includes serial casting, where the tendon lengthening is stimulated by prolonged stretch. A joint is casted weekly with solid or bivalve casts until increased end range is obtained. If there is little or no improvement, then consider surgical intervention. For upper and lower extremity contractures, there are moderate to strong evidence. Orthotics and hand surgery, there is moderate evidence for upper extremity contractures. For skeletal malalignment, there is moderate evidence to support use of orthotics and orthopedic surgery to treat skeletal malalignment. Single event multi-level surgeries in the management of contractures has been shown to be beneficial, and for bony deformities like femoral and tibial portion, scoliosis management is with the assistance of bracing and with surgery. Treatment of spasticity, the generalized treatments include use of oral medications. The oral medications typically used are diazepam, which shows strong evidence, baclofen, which shows moderate evidence, and dantrolene. Selective dorsal rhizotomy shows strong evidence in the treatment of spasticity. Intrathecal baclofen shows moderate evidence. Focal choices include chemodenervation, including use of botulinum toxin with strong evidence and use of phenol as also a tool to treat spasticity using chemodenervation. Diazepam, mechanism of action is it acts on the presynaptic inhibition of the GABA-A receptors. Side effects usually seen are sedation, decreased motor coordination, impaired attention and memory. Dosing, it should be titrated to desired effect. It has a wide dosing range, has a quick onset of effect and a long half-life. One should be cautious while using diazepam as physiologic dependence can occur and this is a medication that one must wean as opposed to stopping abruptly. It is a good short-term treatment option. Baclofen acts by presynaptic inhibition of GABA-B receptors. Side effects, it causes sedation, fatigue and weakness. It should be titrated to effect as a short half-life so patient may need more frequent dosing. Use of baclofen should also be judicious and cautious. It should never be stopped suddenly. Sudden discontinuation can cause seizures or hallucinations. It is good for long-term management of spasticity. Tantraline, it inhibits skeletal muscle contraction by suppressing release of calcium. Side effects include weakness and nausea. As it causes potential hepatotoxicity, liver function tests should be periodically checked. The dosing is usually between three times a day to four times a day and one titrates the medication to the desired effect. It can be combined with CNS active medications. Botulinum toxin, the commercially available preparations in the United States include Unobotulinum toxin A, Abobotulinum toxin A and Remobotulinum toxin B. Until recently, these were being used as off-label use. However, recently FDA approval was obtained for two of the formulations. Abobotulinum toxin A is FDA approved for gastrocnemius and soleus muscle use in children more than two years. Unobotulinum toxin A is also FDA approved for children more than two years. Onset of action is between three to seven days and the duration of action can vary between three to six months. Side effects include commonly injection site discomfort and local weakness. However, rarely it can cause severe systemic adverse events. It has dose limitations as the dosing depends on body weight, on the functional level and pre-existing medical comorbidities. Phenol injections. Phenol acts by causing temporary partial demyelination of the nerve. It requires an e-stim machine to help localize the motor points. It does however have certain limitations. It can cause dysesthesias, particularly when the motor nerves or branches are injected as seen in musculocutaneous or obturator or peroneal nerve injections. It requires precise localization, needing for the child to be under anesthesia. Excessive doses over toxins can be that it has a longer duration of action and is inexpensive. Question. Safe dosing considerations for children with cerebral palsy undergoing botulinum toxin injections include all of the following except body weight, previous orthopedic surgery in the injected limb, functional mobility level, history of aspiration pneumonia. Answer. Previous orthopedic surgery in the injected limb. B. Commentary. Children with cerebral palsy may be at higher risk for rare but serious systemic adverse events. Because of this, the total dose of botulinum toxin is not determined by body weight alone. The current recommendations for dosing vary by functional level with lower dose ranges used for GMFCS 4 and 5. Consideration must also be given to pre-existing medical comorbidities such as history of swallowing problems and respiratory disease. Previous orthopedic surgery in the injected limb may affect choice of injection sites but does not directly impact safe dosing. Intrathecal baclofen. Indications are a clinically stable patient with generalized muscle overactivity. Or they have had suboptimal results with other interventions. They have adequate size and mass. Patient and caregiver goals are realistic. And family is committed to ongoing refills and replacement. The intrathecal baclofen pump is a programmable pump which is implanted in the abdomen and is attached to a catheter which extends from the pump to the intrathecal space. The advantages include it allows for a variety of patient-specific dosing. Disadvantages include it has a frequent follow-up needed for maintenance and has a high rate of complications in children more than in adults. Selective dorsal root rhizotomy. Indication, treatment of lower extremity spasticity. Technique includes identification of the most abnormal dorsal rootlets from L2 to S2 with intraoperative EMG. The rootlets are cut. It involves intensive follow-up therapy. Baseline may not be reached for 6 to 12 months. And this is a commitment that needs to be made by the family prior to the surgery. Candidate selection for selective dorsal root rhizotomy include patients with spastic diplegia, typically those with history of prematurity and history of periventricular leukomalacia. At AGM-FCS level 1 to 3, having AGM-FM score more than 60, age needing to be less than 10 years of age, the child should be intelligent and family should be committed. Contraindications include spasticity of spinal cord origin, other movement disorders, poor trunk control, and severe underlying weakness. Question, which of the following spasticity treatments is primarily indicated for ambulatory children with cerebral palsy? Deep brain stimulation, intrathecal baclofen, selective dorsal rhizotomy, Achilles tenotomy. Answer, C, selective dorsal rhizotomy. Commentary, selective dorsal rhizotomy has been shown to be beneficial in patients AGM-FCS levels 1 to 3. Intrathecal baclofen is primarily used to improve comfort and ease of caregiving. Deep brain stimulation is used in patients with cerebral palsy with severe secondary dystonia interfering with care and or comfort. Tenotomies are typically not done in patients with cerebral palsy because of the concern for weakness and overpull by muscle antagonists. Dystonia. Dystonia is a neurological disorder that causes excessive involuntary muscle contractions. These muscle contractions result in abnormal muscle movements and body postures, making it difficult for individuals to control their movements which may be painful. Dystonic movements are typically patterned and repetitive. Classification of dystonia can be based on age. Childhood onset is between ages 0 to age 12. Adolescent onset is when it occurs between ages 13 to 20 and adult onset is older than age 20. It can also be classified based on the body part affected and hence can be focal or segmental dystonia. It can be based on the cause idiopathic or secondary dystonia. Other tools used in management of hypertonia to evaluate include the hypertonia assessment tool or the HAT and the Barry Albright dystonia scale or the BADS. Hypertonia assessment tool is a seven-item clinical assessment tool to differentiate types of pediatric hypertonia which includes spasticity, dystonia, and rigidity. The Barry Albright dystonia scale or the BADS rates severity of dystonia on five-point scale. Rating for specific areas include the eyes, mouth, neck, trunk, and the four extremities. This is a flow diagram for an evidence-informed care pathway for dystonia in cerebral palsy and this is from the AACPDM website which goes over the treatment options and assessment stuff. This slide shows a flow diagram for an evidence-informed care pathway for dystonia management in cerebral palsy. This is from the American Academy of Cerebral Palsy and Developmental Medicine website and it looks at the steps involved in the assessment of dystonia determining the intervention goals including the rehab strategies and then trial of medications and what the ultimate treatment patterns include. It should be noted that intrathecal baclofen and deep brain stimulation are possibly or probably effective in the management of dystonia in cerebral palsy. Treatment of dystonia can be generalized or focal. Generalized treatment includes use of oral medications. Medications that affect the body overall include baclofen and trihexyphenidyl. Specific indications depending on presentation include benzodiazepines and flannidine which are usually used in management of storming and disturbed sleep. Gabapentin is used if there is associated pain. Other treatment options include intrathecal baclofen and deep brain stimulation. Focal treatment of dystonia includes use of botulinum toxin. Rigidity refers to increased muscle tone which means stiffness or inflexibility of the muscles. It is one of the symptoms of Parkinson's disease with tremor and slowness of movement also known as bradykinesia. Cogwheel rigidity refers to muscle rigidity where passive movement of limbs elicits start and stop movements through a range of motion of a joint as seen in Parkinson's disease. These are my references. Thank you.

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