Medicine & Research

Dolor. It’s the Latin word for pain. Medical students learn the Latin terms for many medical symptoms. During my training, medical students were also sometimes taught that MS was not directly associated with pain. This is one of the great myths of MS. Let’s take a look at some of the ways that MS can be directly linked to pain. As we look at MS and pain, please remember that having MS does not mean you cannot also have other health issues. There is a tendency for the medical community to want to blame all symptoms in a person living with MS on their MS. This can be just as frustrating (and potentially dangerous) as ignoring some of the hidden symptoms of MS.

Spasticity and spasms

Spasticity and spasms are common with MS and can be painful. Normally, our central nervous system finds a balance between muscles that flex and muscles that extend. MS upsets that normal balance and results in both spasticity and spasms. Spasticity is the state of continuous increased muscle tone, while spasms are sudden waves of increased muscle tone. Either can result in discomfort. Recognizing the signs and symptoms of spasticity and spasms is the first step in dealing with them.

A stepwise approach to treating spasticity and spasms is typically employed. We start with removing any noxious stimuli that might provoke spasms. This could be an awkward seating situation, a poorly fitted brace, or a UTI. Stretching and rehabilitation is the next step and should never be
overlooked.

Finally, we come to oral medications such as baclofen and tizanidine. Cannabinoids (medical marijuana) may also be useful. For more difficult situations, we may look at Botox injections and intrathecal baclofen pumps. A coordinated, comprehensive medical team offers the best way of managing spasticity. When treating spasticity, I like to get the physical therapists involved early. Ironically, not all spasticity is a bad thing. Some people with MS benefit from an increase in extensor tone in the legs, as it may help overcome weakness and aid in transfers. Similarly, when thinking about an intrathecal baclofen pump, a team approach is best.

Neuropathic pain

Central neuropathic pain is another cause for discomfort directly related to MS. Neuropathic pain may be burning in nature or cause hypersensitivity to touch. Some people have tingling, buzzing, or crawly sensations that become painful. These symptoms are due to disruptions in the normal sensory pathways in the spinal cord or brain from demyelination. While these symptoms can be quite like those caused by a peripheral neuropathy, the location of the sensory disruption is different between the two. Peripheral neuropathies, such as those seen in some people with diabetes, are because of damage in the peripheral nerves outside of the central nervous system. Again, the
symptoms and even the treatment can be similar between central neuropathic pain and a peripheral neuropathy.

Neuropathic pain may be managed with medications. Most of our therapy options fall broadly into one of two classes: anticonvulsant drugs or antidepressant drugs. Anticonvulsant drugs frequently work by decreasing abnormal electrical cross talk between nerve fibers. This makes them potentially useful for managing neuropathic pain. Options include gabapentin (Neurontin), pregabalin (Lyrica), carbamazepine (Tegretol), and oxcarbazepine (Trileptal). Neuropathic pain may also be attacked through the modulation of neurotransmitters like serotonin and norepinephrine. This is where antidepressant medications may help. Amitriptyline (Elavil), nortriptyline (Pamelor), duloxetine (Cymbalta), venlafaxine (Effexor), and desvenlafaxine (Pristiq) are some of the possible options.
Typically, any of these medications would be started at a low dose and slowly titrated up until the pain has improved, side effects are seen, or the maximum safe dose is achieved.

A curious phenomenon with pain in MS is that it is frequently worse at night. We see this with both spasms and with central neuropathic pain. This may mean that sleep is disrupted and daytime fatigue is magnified. Pain that occurs primarily at night also presents a possible treatment advantage in that, we don’t have to worry as much about sedation as a drug side-effect if the medication is only being used at bedtime. As with spasms, cannabis may be a treatment option for central neuropathic pain.

Neuralgias

Neuralgias represent a unique cause of pain for some living with MS. Trigeminal neuralgia (Tic Douloureux) is pain that travels along the trigeminal nerve or cranial nerve 5 into the face. This nerve has three branches – V1, V2, and V3 - supplying sensation to the forehead, cheek and jaw respectively. Trigeminal neuralgia typically affects V2 or V3.

The pain can be intense and debilitating. It is described as lightning bolts of shock-like pain shooting into the face. It can be worsened with talking, chewing, light touch, or even the wind blowing across the face. It may come in episodes lasting days, weeks, or months. It may remit, only to return in the future. Trigeminal neuralgia can occur in people without an MS diagnosis as well.

Carbamazepine and oxcarbazepine have been our standby therapies and can be quite effective. More refractory cases may need to be referred to a pain specialist or neurosurgeon to consider options such as phenol injections, gamma knife, radiofrequency lesions, or decompressive surgery.

Occipital neuralgia is another type of nerve pain we see in MS. Like trigeminal neuralgia, it can also occur in those without an MS diagnosis. This pain travels along the greater occipital nerve. This nerve exits the base of the skull and supplies sensation to the scalp on the back of the head. The pain can be similar to trigeminal neuralgia but is usually not as intense. It may also relapse and remit.

Carbamazepine and oxcarbazepine are used to manage this. It may also respond to an old anti-inflammatory medication called indomethacin (Indocin). Occipital nerve blocks are relatively simple and may provide relief that lasts for months.

Contrary to mythology, MS can cause pain. If you are suffering from pain, discuss it with your healthcare team. Your primary care doctor may help in determining whether there are non-MS explanations for the discomfort. Your MS team should be able to help sort this out as well and put you on the path to a better quality of life.