My name is Andrea Furlan and I am pain specialist in Toronto Canada, today we're
going to talk about neuropathic pain. With my experience of 25 years working
in pain clinics and with patients who have chronic pain I can say that the
worst descriptions that I hear about pain and chronic pain are from
patients who have neuropathic pain. I remember a patient who had had a stroke
and he described his pain has burning oil on all the left side of his body.
burning oil constantly dripping on all of his left side of his body. I also
remember a patient who had diabetic neuropathy and the way he described his
pain was like ants crawling his legs all day long, constantly and he could not
do anything for those ants go away. A very well-known painter Frida Kahlo,
she had neuropathic pain and she painted her pain and if we see one of her
paintings. This is called the broken column it's a self-portrait from 1944. We
see that she painted her spine has a metal rod, she also painted her torso has
been a metal corset always squishing her back and her abdomen. And she
also painted some pins and needles all over her skin, and that was constantly
causing this tingling in her skin. So how do we define neuropathic pain?
Neuropathic pain is defined as pain that is caused by a disease or injury of the
nervous system and we know that the nervous system is composed of a
peripheral and a central nervous system the peripheral nervous system is formed
by the nerves, the peripheral nerves and the central
nervous system is basically the spinal cord and the brain. So neuropathic pain
can originate from the peripheral nervous system or the central nervous
system, the examples of some of the peripheral neuropathies that can cause
neuropathic pain are diabetic neuralgia, post-herpetic neuralgia, trigeminal
neuralgia, carpal tunnel syndrome, HIV neuropathy, and alcoholic neuropathy
The central neuropathies can be things caused by stroke like a central post
stroke pain or after brain injury, multiple sclerosis, spinal cord injury.
Those are some examples of Central Neuropathic pain.
We know that neuropathic pain affects 8% of the general population. How do
we make the diagnosis of neuropathic pain? So basically the diagnosis is by
examining the patient in talking to the patient and we call the signs and
symptoms. So some of these symptoms that the patients will complain that they
will tell us about pain. The pain descriptors are very characteristic of
neuropathic pain. These are usually described as tingling. Tingling is like
pins needles pricking. Like the patient that I mentioned to you that describe to
me the ants crawling in his skin that's what we call tingling. Patients
will also refer the pain as hot or burning they may also describe his shooting pain
or electrical shocks or they may talk about stabbing or cutting like a knife
entering the skin. Those are the descriptors of pain. Other sensations
also that are common and related to the neuropathic pain can be numbness or lack
of sensation in an area of the body. Also they may describe the touching that area
is painful so normally if we touch someone it doesn't cause pain but when
that happen we call that allodynia. Also they may
describe intolerance to cold to extreme cold. They can't tolerate cold applied to
the skin or even cold weather. When we examine the patient we are looking for
signs in the physical exam that will identifying some neuropathy and these
are typical signs in neuropathic pain so for example reduce sensations. If we
examine the patient's and they have reduced sensation to pain we call that
hypoalgesia, but they may also have reduced sensations they may not feel
pressure, heat, cold, touch, we call that hypoesthesia. Or there might be
augmented, elevated sensation they may feel more, we call that
hyperesthesia or hyperalgesia. Or there might be cross sensations, we may touch
the skin with a stimulus that cause touch and the patient may say this is
pain so that's a cross sensation and we call that allodynia. We may also
examine the rest of the nerve system we need to examine for the reflexes the
motor is strength to see if we can identify what is the underlying
neurological condition that is causing that neuropathic pain. And I have to say
that in many cases we can't find what is causing the neuropathic pain and those
are the difficult cases because it's if it's not diabetes if it's not post-
herpetic neuralgia, then it's hard even for us to treat but in many cases we can find a
cause for the neuropathic pain. In other cases we may also order all the tests
like skin biopsy, nerve biopsy or electromyography
in nerve conduction studies. So how do we treat neuropathic pain? We use a variety
of modalities: pharmacological, no pharmacological. We are going to talk a
little bit about those. In terms of drugs or pharmacological, we may use anti-
depressants like the tricyclic, antidepressants SNRI like duloxetine
venlafaxine. We may also use anticonvulsants like carbamazepine,
gabapentin, pregabalin. We may also use opioids like tramadol or a stronger
opioids. We may also use cannabinoids. And other things that we can also prescribe
are things like vitamins, especially vitamin B. We can also use the mo-
drugs like physical modalities such as what my patient found the warm water. We
can prescribe them like warm baths or TENS machines which is some electrical
stimulation to the skin. We can also prescribe topical creams things like
capsaicin or lidocaine or ketamine creams. We can also do some injections
botulinum toxin type A or nerve blocks. And also complementary and alternative
medicine things like acupuncture, manipulation, they work well for some
types of neuropathic pain especially peripheral nerves like carpal tunnel
syndrome. Other things are mind-body therapy like CBT, hypnosis, mindfulness
Those things are very helpful. And when we see a patient with neuropathic pain we have
to tell them there are many modalities not only medications that can help with
your neuropathic pain and you have to put them in a toolbox.
Remember the toolbox for treatment of chronic pain and you may have seen that
exercises is not in this toolbox of treatment of neuropathic pain. It's not
because I forgot it it's because exercise is usually not very helpful to
treat the neuropathic pain. Although we tell people to continue doing exercises
as tolerated, any kind of exercise that they like to maintain their body in
shape and also to avoid all the types of pain which can be myofascial pain that
could aggravate the neuropathic pain. Our first goal when we see someone with
neuropathic pain is to ask how they are sleeping, and we try to help their sleep
and we try to do this with medications or relaxation or mindfulness because
people with neuropathic pain is very common that they can't sleep well, and if
they can't sleep well they are always more stressed, they may gain weight they
are more anxious more depressed so we need to tackle the sleep problem right
away. And I like to mention also that there are some types of neuropathic pain
that can be prevented, things like vaccines for varicella-zoster or
reducing alcohol intake to avoid alcoholic neuropathy, controlling the
blood sugars in people who have diabetes is also a good idea, and things like
wearing helmets to avoid brain injury because I see some patients who had
neuropathic pain because of a traumatic brain injury. Remember that this video is
not intended to provide individual medical advice. If you think that you
have neuropathic pain and you need medical treatment please consult your
physician to get a treatment plan for you. This video is only for educational
purposes. And if you like this video don't forget to like it, to write your
comments, write your questions and I will prepare more videos in the future to
answer your questions I also have a tweet and Instagram account and a
Facebook page you can also contact me there. Thank you for watching. Bye