Intense Sensations to Manage Muscle Cramps
Sensory Modulation Brisbane often discusses the effectiveness of sensory input as a pain competitor, to more effectively manage pain and improve functioning. For example, using temperature, deep pressure or intense scent. It is understood that the application of sensory input interferes with the transmission of pain signals, thus dialling down the intensity.
In 2017, Dr Bruce Bean (acclaimed Neurobiologist at Harvard) commenced extensive research into muscle cramps, which for some people is an incredibly painful and debilitating experience. Dr Bean was interested in why people experience cramps and more effective ways to manage them.
Many theories exist around why people have muscle cramps, including a lack of electrolytes, dehydration, lack of potassium, increased presence of lactic acid and poor fitness levels/reduced training. However many of these theories lack sufficient evidence and/or had been discredited. He understood this to be true also in part due to personal experience. Some years earlier he and a colleague participated in a deep ocean canoeing trip, and despite both men training extensively prior to the trip and maintaining their fluid & electrolyte levels, both still experienced severe muscle cramps.
Dr Bean hypothesised that muscle cramps are less to do with the muscle itself, and more to do with hyper-excitability of the motor neurons (present in the spinal cord) that control the muscle. This is a likely explanation for other related and debilitating conditions including Restless Legs Syndrome (RLS)
An Old Wives’ Tale Spearheads Research
Prior to Dr Bean’s research, in 2009 Kevin Miller (an Exercise Physiologist from the US) investigated the practice of drinking pickle juice to quickly ease muscle cramps. Mr Miller found that it was a highly effective and fast acting intervention. It was deduced that the speed of response (less than 1 minute) was not indicative of a chemical or metabolic change within the muscle, but rather a ‘neurally mediated reflex’ in the oropharyngeal region which inhibited the firing of alpha motor neurons (Miller, et al, 2009)
Dr Bean’s research built on the findings of Mr Miller. He demonstrated that the acetic acid (active ingredient in pickle juice) stimulated discrete sensory neurons in the mouth, stomach & oesophagus. These neurons were connected to/activated TRP (transient receptor potential) channels. TRP channels feed into multiple neural circuits, such as the Vagus nerve and other areas of the brain including the brainstem, which have a strong influence over spinal cord circuitry. Other neurotransmitters (dopamine, serotonin, acetylcholine etc) are also released in this process, which all have input into the spinal cord.
The changes in these neural pathways serve to dampen down the excitability in the motor neurons innervating the muscles, which reduces the experience of cramping. Sensory neurons in the stomach, mouth and oesophagus also have some direct input into the spinal cord, and so could act as an additional modulator of muscle excitation.
Intense Sensations (Taste) Shown to Reduce Muscle Cramps
A variety of strong sensory inputs (taste) have been shown to help reduce muscle cramping by activating TRP channels, including
· Vinegar flavours (pickle juice, yellow mustard)
· Chili peppers
· Bitter flavours (tonic water)*
· Wasabi
· Horse radish
· Cinnamon
· Ginger
* Quinine (used for treating malaria) has historically been promoted as preventing leg cramps despite the lack of robust evidence. People are now warned against using quinine for cramps or muscle pain, due to it increasing the risk of haemorrhage heart arrythmias. Tonic water contains a minimal amount of quinine, and thus the effect is due to the bitter taste and not the quantity of quinine.
Intense Sensations in Dissociation
Intense Sensations have also been used as a grounding strategy in dissociation and as an alternative to self harm in Dialectical Behaviour Therapy and in Sensory Modulation. We are wondering if intense sensations work due to a similar mechanism proposed in cramps. (Possibly the activation of the neutrally mediated reflex in the oropharyngeal region decreases dissociation?) . If there are any scientists reading this blog please let us clinicians know!
The intense taste sensations in the Sensory Modulation Resource Manual include:
· Lemon
· Strong mint
· Warhead or other sour lollies.
· Mouthwash gargling
· Chilli
· Garlic.
We have now updated the intense sensations worksheet to include:
· Wasabi
· Tonic water
· Pickle juice
The updated worksheet is available for downloading (free) at Sensory-Modulation-Brisbane.com and further information is available in the Sensory Modulation Resoruce Manual and the Using Sensory Modulation course.
Resources:
O’Sullivan, J & Fitzgibbon, C (2018) Sensory Modulation Resource Manual Sensory Modulation: Resource Manual eBook: Julie O' Sullivan, Carolyn Fitzgibbon: Amazon.com.au: Kindle Store
Using Sensory Modulation Online Course https://courserebel.com/coursedetailnew.aspx?courseid=264&page=/health
Chaffey, L (2019) Rewiring Pain: a new way to reclaim your life Rewiring pain: A new way to reclaim your life eBook: Chaffey, Lisa J: Amazon.com.au: Kindle Store
Show 1054: The Scientific Explanation for a Weird Remedy (Ar... | The People's Pharmacy
The first 30 minutes of this podcast has an interview with Dr Bean explaining his research into muscle cramps
