Neurosurgery notes/Functional/Spasticity/Medical spasticity

Medical spasticity

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Spasticity
Medical management of spasticity (including rehabilitation, physiotherapy, and occupational therapy)

The MDT managing spasticity should include a

  • Rehabilitation physician
  • Physiotherapists,
  • Occupational therapy,
  • Variety of surgeons
    • Neurosurgery,
    • Plastic surgery,
    • Orthopaedic surgery

Aim of management

  • Protect function and avoid/ reduce the harmful effects of the spasticity and disability as a whole.
    • Carefully balance the control of spasticity against any side effects of doing so.
      • The spastic stiffness in a patient’s legs may counteract the underlying weakness and allow them to walk; removing this spasticity may render them immobile.

Functional help

  • Communication aids
  • Splints,
  • Customized walking frames
  • Customized wheelchairs.

Physiotherapy

  • Aim
    • Maintain flexibility
    • Avoid the progression of muscle/ tendon contracture formation.

Occupational therapy and orthotic reviews

  • To
    • Protect skin
    • Optimize splints and supports,
    • Maximizing function
    • Preventing pressure sore development.

Good bladder care

  • Is also vital to prevent recurrent infections
    • UTI is very common cause of spasticity exacerbation).

Medical interventions

Aim to

  • Improve tone,
  • Alleviate spasms
  • Control gastrointestinal effects,
  • Control bladder function.

Antispasticity medications

  • Side effects
    • Drowsiness,
    • Weakness,
    • Fatigue,
    • Sedation
    • Memory impairment.

Baclofen

  • Mainstay of spasticity treatment
  • Especially in cerebral palsy and spinal cord lesions.
  • Mechanism
    • Activate pre- and postsynaptic GABAB receptors → reducing excitatory transmission of the α- motor neuron and decreasing nociception.
  • Pharmacokinetics
    • Good GI- tract absorption
    • Poor transfer across the BBB.
      • High doses may be required before clinical effects are seen, creating a higher risk of side effects
  • Maximum dose: 100 mg per day in three to four divided doses
  • Side effects
    • Sedation
    • Behavioural changes
    • Confusion
    • Ataxia
    • Urinary frequency
    • Insomnia
  • Dosage
    • Start low and gradually increased until benefits are maximized or side effects become troublesome.
  • Withdrawal symptoms: Withdrawal must be done gradually
    • Seizures
    • Rebound hyper-spasticity
    • Hallucinations.
  • Over dose causing side effects can be reverse with physostigmine
    • Inhibit acetylcholinesterase → reverse central nervous system depression → reduce respiratory depression and Coma
    • Physostigmine use is reduced with IT baclofen.

Dantrolene

  • Is used for treatment of spasticity, cramps, and spasms.
  • Mechanism
    • Reducing depolarization- induced calcium influx into sarcoplasmic reticulum of striated muscle.
    • Its GI absorption is incomplete, slow but consistent.
  • Maximum dose 400 mg per day in three divided doses.
  • Side effects include
    • Muscle weakness (making mobility more difficult)
    • Sedation
      • Due to it being peripherally acting
    • Hepatitis

Tizanidine

  • Indicated if baclofen is not tolerated or ineffective
  • Mechanism
    • A central α2 - adrenergic agonist → decreasing the release of excitatory neurotransmitters at the spinal interneuron level → It reduces spasticity
  • It is commonly used
    • For spasticity in MS, stroke, and spinal cord injury.
  • Well tolerated
  • Maximum dose: 36 mg per day in four to five divided doses.
  • Pharmacokinetics
    • Shortacting, with peak effects 1– 2 h after administration;
    • Wears off by 3– 6 h.
      • As a result, it is generally reserved for particular activities and times when relief of spasticity is most important.
    • Its pharmacokinetics differ between different preparations and also when taken with/ without food, being better when taken under fasting conditions (>3 h after food).
    • Its dose can be gradually increased over several days, and withdrawal should be similarly gradual.

Benzodiazepines

  • Eg: diazepam and clonazepam
  • Mechanism
    • Activates GABAA receptors → increase the postsynaptic inhibition of α- motor neurons
  • Indication
    • Treatment spasticity and muscle spasms.
    • It is most useful in patients with complete spinal cord injuries.
  • Pharmacokinetics
    • Doses should be increased or decreased incrementally.
    • When used for more than one week, problems with drug- dependency can occur.
    • Abruptly stopping may cause
      • Depression
      • Seizures
      • Acute withdrawal syndrome
  • Side effects
    • Weakness
    • Sedation and cognitive impairment
      • Associated with prolonged use
      • Not recommended for prolonged use
    • Poor stamina

Gabapentin

  • Can be used alone or in combination with other oral medications.
  • Indicated
    • Spasticity
    • Relieve painful muscle spasms.
  • Side effects
    • Sedation
    • Weight gain.

Clonidine

  • Can be useful in reducing spasticity,
  • But its use in clinical practice is limited due to its side effects

Injection therapy

Botulinum toxin A therapy

Indication

  • Upper limb spasticity in adults
    • It is widely used for upper and lower limb spasticity in children but is unlicensed for these purposes.
  • Bladder instability
  • Overactive bladder
  • Cervical dystonia.

Best used in combination with

  • Stretching
  • Serial casting
  • Muscle re- education
  • Strengthening
  • Orthotic adjustments

Aim

  • Improve function and mobility
    • Improved sitting posture, walking further with fewer falls, or increased tolerance of splints which aid function
  • Pain relief:
  • Prevent contractures and deformity
  • Facilitate care and handling: In some cases, reducing spasticity can make it easier for caregivers to dress the patient and perform other daily care tasks

Mechanism

  • A neurotoxin,
  • Permanently binds to the presynaptic terminal at the neuromuscular junction → inhibition of acetylcholine release → functionally denervating the treated muscle

Administration is via direct injection,

  • Often with ultrasound guidance to improve accuracy and duration of effect
  • The effects of botulinum toxin last for three to six months and repeat injections are needed
  • The effects can be enhanced by localizing the muscle under electromyography (EMG) or ultrasound guidance.

Pharmacokinetics

  • The effects are seen within 3– 7 days and it lasts up to 16 weeks;
  • Wearing off as new neuromuscular junctions grow from sprouting nerve rootlets.
    • If used too frequently, it can become less effective due to antibody formation.
  • Care must be taken over the dose;
    • The benefits can be limited if too little is used,
    • But overdose can also occur, leading to systemic effects and widespread muscle paresis.

Phenol nerve and motor point blocks

  • Useful alternative to botulinum toxin injections.
  • Phenol
    • A neurolytic agent
    • Can be used in 3– 7% aqueous solutions.
    • Needle electric stimulation is required to localize the nerve and the motor points.
    • Effects of phenol last for more than six months
    • Can be repeated as required.
    • Can be used with botulinum toxin injections
    • Side effects
      • Bruising,
      • Swelling,
      • Bleeding,
      • Neuropathic pain.