This post was written by Alexander Robitaille, DO, FAAPMR, Parkview Health.
Spasticity is a motor disorder that causes muscles to become tight or stiff. They may also sometimes jerk or spasm uncontrollably, interfering with an individual's ability to move, speak, walk or care for themselves. For many, this disorder poses a substantial challenge in maintaining quality of life. Due to spasticity's complexity and tendency to accompany other chronic conditions, finding the right treatment often involves trial and error. In this post, we dig into one modality, injectable neurotoxins, and how they can offer people with spasticity a practical approach to long-lasting relief.
What is spasticity?
Spasticity usually occurs because of damage to the part of the brain or spinal cord regions that control voluntary movement, often resulting from spinal cord or brain injuries or stroke. It can also occur as a secondary complication of conditions such as multiple sclerosis, cerebral palsy or amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease).
The primary treatments include physical therapy, occupational therapy, medications and various procedures to reduce muscle spasticity. Positioning aids or orthotics can also help prevent long-term complications, such as pain or contractures, which occur when spasticity is left untreated for an extended period, leading the muscles to become fixed in an abnormal position.
Expanding treatment
Most patients begin treatment with medications, but these often prove ineffective or cause undesirable side effects for many. Additionally, some individuals with widespread spasticity involving multiple muscles tend to need more than one modality to address their condition adequately.
Adding injection procedures for improved treatment is usually well-tolerated and has proven results. Administering botulinum toxin injections, commonly referred to as the brand name BOTOX®, into spastic muscles is one such option, but it may not be preferred depending on a patient's treatment goals.
I incorporate phenol injections and motor point blocks into my treatment approach to offer patients more options to relieve their spasticity. Phenol injections provide longer-lasting effects and are particularly useful in cases where botulinum toxin may not offer sufficient relief. Some studies have shown that phenol can effectively block nerve function, reduce muscle overactivity and help manage spasticity in a way that complements other treatment modalities.
They work well with other treatments such as oral antispasmodics, physical and occupational therapy, botulinum toxin injections and even intrathecal baclofen (baclofen pumps).
Phenol vs. botulinum toxin
While botulinum toxin has advantages, including minimal side effects and ease of application, most improvements only last 10-12 weeks and require repeated injections approximately every three months.
Phenol injections work by causing the nerve branch to die back. The effects only wear off if the nerve regrows into the muscle. These injections tend to last longer—up to a year or more in some cases—making them ideal for patients who need less frequent interventions. It is also generally more cost-effective, which is advantageous for individuals with a long-term need for symptom management.
Due to the immediate effects of phenol, most patients are shocked to see how much better they can move their joints after the procedure. This is very different from the slow onset of effects from botulinum toxin injections. Many appreciate the reduced frequency of treatments compared to other interventions. Some patients initially have concerns about potential discomfort, but overall satisfaction tends to be high.
Safety considerations
Phenol injections are not without risk. Unlike botulinum toxin, which providers inject directly into the muscles, phenol injections target nerve branches. Physicians need to precisely place the needle to avoid unwanted effects on nearby structures such as muscles, arteries and veins. Although done with care, this can make the procedure more uncomfortable for the patient. Some nerve branches can also contain sensory fibers that we must avoid to minimize discomfort and side effects.
Physiatrists previously administered phenol with electrical stimulation as the only form of needle guidance. Recently, improvements in ultrasound have allowed for better needle visualization and clearer pictures of surrounding nerves and branches. This increase in technical skill makes the procedure safer and more reliable.
Machines have become more compact with better image quality. The cost of these machines has also decreased, making bedside ultrasound more ubiquitous in many medical practices. Furthermore, many training programs have increased the time spent developing physician competence with ultrasound-guided procedures and patient assessment. Combining higher-quality ultrasound imaging with highly trained physicians reduces adverse outcomes during ultrasound-guided procedures such as phenol injections.
Assessing patient suitability
When planning spasticity management, I always consider a patient's treatment goals. Some patients may experience inadequate relief with Botulinum toxin injections, have too many muscles involved to be treated by Botulinum toxin injections alone, or are interested in less frequent injections. These patients may be good candidates for phenol injections.
Motor point blocks are one way of investigating if a patient is a good candidate for phenol injections. They utilize the same techniques for nerve branch localization as phenol injections; however, instead of injecting phenol, an anesthetic (such as bupivacaine) is injected. This causes the same effect as phenol but only lasts for a few hours, gives patients an idea of what to expect with phenol injections and allows for more fine-tuning of the treatment process before proceeding to phenol injections.
The frequency of phenol injections depends on the patient's needs, but on average, they may be performed once or twice a year due to their long-lasting effects. Eligibility criteria include the severity and location of spasticity, patient preference and previous treatment responses.
Patients with contractures will also not benefit from phenol or botulinum toxin injections. Sometimes, patients are misdiagnosed with contractures when, in reality, they have severe spasticity. Motor point blocks are also excellent for determining if a patient has true contractures.
Final thoughts
I foresee an increasing role for phenol injections in spasticity treatment as more practitioners become familiar with its benefits and advancements in technique. Ultrasound technology has contributed to renewed interest, making it a safer and more reliable option. Ultimately, spasticity will likely continue to require multimodal and multidisciplinary treatment plans that utilize an ever-growing toolbox of treatment options.
Learn more
Parkview Health has physical medicine & rehabilitation providers located in northeast Indiana and northwest Ohio. If you're interested in establishing care with one of our providers, call our 24/7 scheduling center at 206-785-2631.
