The Effects of Chemotherapy-Induced Peripheral Neuropathy on Functional Balance in Children: Preliminary Results
Katie Schuelke, SPT and Elizabeth Waltner, SPT
(Click on image to expand)
Katie Schuelke, SPT and Elizabeth Waltner, SPT
(Click on image to expand)
USD PT Research 
Did you document/consider if the child was still undergoing chemotherapy treatment versus if treatment had stopped within the past 2.5 years, or how recently it had been stopped? Do you believe it could have influenced your results or yielded different results if there had been some kids that had undergone more chemotherapy treatment than other kids? Or if some kids were undergoing chemotherapy treatment at the time of testing?
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Good questions Tiffany. We had parent’s fill out a questionnaire about their child’s chemotherapy treatment and where they were at in their treatment process. It definitely could have influenced results, but at the same time we were also found research that showed that children with CIPN were showing impairments years down the road. This led us to believe that although there may be some healing that could interfere with our results, there is still likely to be impairments in balance with those children even years after treatment. Likewise, in children who are currently undergoing treatment there can be a certain delay in the damage to the nerves that might not peak until after treatment is done. There is likely to be a correlation between amount of chemotherapy treatment needed and balance function, but that was a little too specific for our small population size as well as too much variation from child to child as treatment is based on many factors.
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What do you think accounted for the improvement in neuropathy scores from time of previous research? Are these time-related changes or related to a variable that could be influenced by PT? Thanks!
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Thanks for the question, Abby. We discussed that our sample population may have demonstrated less neuropathy (or improved neuropathy scores) secondary to differences in chemotherapy agents that used to treat subjects from previous research studies we read. Also, our small sample size makes it difficult to confidently say why our subjects displayed better scores, with only 4 children 1 had been finished with chemo treatment for over 2.5 years, 2 had finished almost a year prior, while 1 had received treatment in the year 2018.
From the previous research we read in time some adult patients saw a resolve of symptoms. Patients who sought physical therapy demonstrated improvements in functional measures, but not necessarily neuropathy scores. We hypothesized that chemotherapy affecting the somatosensory system, PT can help train the vestibular and visual systems to help compensate for the deficits.
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Similarly to the previous question, I too am curious about why the investigated sample population demonstrated significantly lower scores on the neuropathy scale in comparison to the referenced article. I see from the reply above that you considered the possibility of this being attributed to differences in chemotherapy agents. This raises my question of if in your reviewing of literature; did you come across any research that took into consideration the chemotherapy agents utilized? Also, with the 1 patient who had received chemotherapy treatment in 2018, did her neuropathy scores more closely replicate that of the referenced article?
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Thanks for the question Cole. In our research population the most common cancer is acute lymphoblastic leukemia (ALL), and the treatments typically involve vincristine or cisplatin. Three of our four participants received vincristine, two within 2018. These participants had ALL, our fourth participant had non-Hodgkin’s Lymphoma and likely had a different treatment protocol. The referenced article with the scores from that study’s population was looking at participants that had received treatment with vincristine and/or cisplatin. The participant that had most recent undergone chemotherapy treatment still had very little evidence of neuropathy, as noted from her ped-mTNS scores that were below the average from the referenced study.
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Katie and Elizabeth, you did a great job with your poster! My question is about the balance assessments that you used. Were the BOT-2, PRT, and SEBT selected because they were used in the literature or did you select them for another reason? Also, did you do anything to address inter-rater and intra-rater reliability between the patients? Overall, this looks like a great preliminary study, and it will be interesting to future results with a bigger population! Great job!
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Thanks for the questions and compliments, Jen. The balance assessments we chose are valid and reliable outcome measures. The SEBT has excellent reliability and high sensitivity to detecting balance deficits, which could help us determine if there were even any small changes to balance. The PRT is a simple and objective measure valid in the pediatric population. The BOT-2 is norm-referenced for pediatrics ages 4-21 and gives a good comprehensive view of motor development.
As far as inter-rater reliability both Elizabeth and I administered the same portions of the tests to all subjects, so there was no change in that. Intra-rater reliability was not directly addressed other than for both the PRT and SEBT subjects were allowed 3 trials and the best was used, although typically the average is used for the PRT.
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I was wondering why you chose the age group 4-12 and not maybe 4-17 if you were looking at a pediatric population? Also for this study all participants were about the same age could this mask potential differences you might see if you had participants of different ages? I thought this was a very well thought out and interesting study!
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Brittany, thank you for the questions. We discussed originally wanting an age range from 4-21 since this is the norm-referenced population for the BOT-2 and we considered we may get more participants this way. However, with further discussion we decided that a range more like 4-12 helps eliminate some changes that potentially occur with puberty. We wanted to decrease the possibility that older children may skew our data from younger subjects, because as we know kids start sports anywhere from 8 and older but they may not have developed and improved coordination/balance as a 17 year old would have.
It is unfortunate that we were unable to get participants of different ages, and yes this could mask potential differences for some of the same reasons I discussed above. As we know, children develop according to exposure in their environment and having varying ages may have presented subjects with more experience training balance or less.
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Outstanding study. I was wondering why specifically you decided to test DF strength?ROM. You state that “ankle DF strength and ROM are critical to maintaining balance throughout the gait cycle.” How is DF strength/ROM bio-mechanically more relevant to balance than say, hip strength or hamstring strength? I understand that that ankle DF are commonly affected in this pathology. I wonder why specifically the pretibials are affected in this condition and not, say, the plantarflexors? Is there something with the treatment that follows a certain myotomal type pattern?
Again, wonderful study. Keep up the great work.
Sincerely,
James
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You are right James, we chose to test DF strength and ROM because previous research demonstrated it was one of the most commonly affected muscle groups. This is likely due to the use of vincristine, because it affects axonal transport, which is most detrimental with long axons like in the pretibials. Cisplatin also affects axonal transport and may also cause apoptosis in the dorsal root ganglion. Again, we focused on dorsiflexion because of findings in previous research that demonstrated significant impairments in a similar population. Although hip and knee strength and ROM are also vital for gait, ankle pretibials are going to be the first strategy utilized to maintain balance with small backward sways. In addition, catching a toe due to limitations in DF strength is a common cause of tripping in all populations. To sum it up, there were a variety of reasons we chose to focus on DF strength and ROM specifically, but plantarflexion strength and ROM may also be affected in some cases of chemotherapy-induced peripheral neuropathy. Thanks for the questions James.
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This was a very interesting topic; thank you for sharing! I am curious if there is any research regarding potential treatment techniques to combat this chemotherapy-induced peripheral nephropathy? Chemotherapy seems to be the gold standard cancer treatment, so it wouldn’t make sense to find an alternative treatment for cancer that does not induce this nephropathy in the first place, but it does seem to have a post effect on balance and gait. I’m curious if anyone has attempted ROM and strength training for the DFs and wrist extensors in this population after the cessation of chemo to determine a care guideline for these patients specifically with regards to balance and gait.
Again, thank you for the read!
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Good question Elizabeth! We also were curious to see what kind of treatment options were out there for those affected. We found that there was some success with utilization of TENS to treat any neuropathic pain patients may be experiencing. For muscle weakness or paralysis, the most utilized treatment would be a custom ankle foot orthotic (AFO). This allows the patient the quickest return to a more normalized gait pattern. As this is a condition that is caused as a result of damage to the nerves, solely focusing on increasing DF strength is not always a reasonable option. Over time, with regeneration or an increase in existing motor unit size, there have been some cases of patients experiencing improvements in DF strength and function. This may take many years however, as previous research demonstrated impairments in a population that was an average of 7 years s/p treatment. As for ROM, prolonged passive positioning efforts are likely to be successful. However, if positioning efforts are discontinued, any gains made are likely to be lost if the patient is still unable to actively utilize full range of motion.
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Awesome study! I really found this a great read as neuropathy is heavily present in patients who have received chemotherapy. I have had the opportunity to experience data collection with this age group of kids and found it to be extremely difficult! For tasks such as the star excursion balance test specifically I felt it near impossible to be 100% confident on my readings as the children would have difficulty understanding exactly what I needed them to do. What types of things did you try to do to reduce error with this age group and data collection?
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Thanks for commenting Brooke, we felt the same way when we started testing. Working through a pilot study on an unaffected child was helpful to get the hang of adjusting our instructions to the pediatric population. We attempted to decrease error by demonstrating, then allowing a practice wherein we would cue them on how to perform the motion correctly. If it appeared our instructions were too confusing it was just a matter of us tailoring our instructions to that child while being as similar to the base instructions as possible. I think in the future it may be beneficial to put something on the child’s toe that when they touch down it sticks to the tape or leaves a mark where they touched.
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First off, I think your poster is really well formatted- it is very clean and easy to read. Raw curiosity here, and this may be answered in future classes for me, but is there a difference in balance characteristics between boys and girls? And then, subsequently, do you two think that having only females was a strength to the study, played a role, or maybe is not of value?
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Good question, Stephanie, and thank you for the compliments. As far as balance characteristics between boys and girls, girls typically mature more quickly than boys and may reach motor milestones sooner. With that being said, there is also a large proponent of balance and overall development that can be attributed to a child’s exposure to tasks and their environment as they grow. For example, a child with greater interaction with his/her environment and experiencing a variety of learning opportunities will usually attain milestones sooner, when compared to a child who has not been exposed to as much stimuli or interaction. Basically, it comes down to their experience with balance, not necessarily gender.
We would have liked to have a more heterogenous sample of children, and I don’t feel we can confidently say if having only girls was a strength. I think it is of value to keep that in mind when moving forward with our current findings that the population was only female.
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