Lesions, Levels, Sensory and Mobility

It's all about the letters and numbers.

For those not in the spina bifida world there are actually 2 sets of numbers and letters to work with (actually maybe 4), which represent that lesion (where the spine was damaged) or level. One is motor ability and the other is sensory ability. Then there is actual level and functional level. Am I confusing you yet?

Some basics: The spine is made up of vertebrae (bones) that have letters and numbers. From the top down we have 8 cervical vertebrae (C1-C8), 12 thoracic vertebrae (T1-T12), 5 lumbar vertebrae (L1-L5) and 5 sacral (S1-S5).

The spinal cord and nerves are protected by the bony vertebrae. The nerves send messages back and forth to/from the body and brain.
Sensory lets your brain know what different parts of your body is feeling
Motor function lets you brain tell your body, muscles what to do.

 

The lesion means that the protecting bony part of the spine did not develop and the nerves are exposed and damaged. Unlike a spinal cord injury - where there is usually a clear line of function versus no-function, spina bifida can be patchy with lesion levels that might not equal functional level.

So what does it mean?

Sensory level is easy to determine, it just means what does someone actually feel.
Does an infant, child or adult feel when you touch? When you tickle?

  

 You can see from both these pictures that it is not a straight line.

The nerves feed into different muscles and part of the body and it is different at the front and the back of the legs.
With Nickolas, I feel that he can feel down the front of his legs, and up the back of his calf, but nothing at the back of his thigh. So... that would give us about a S1 sensory level.

 Functional level is a little tricky.

Muscles get messages from different nerves - this is called innervation.
When I ask someone to give me a number and letter, they always tell me that it's their best guess. And with infants and children, it will take time to determine. There is also no clear-cut answer.

When scientists all got together in a room and drew all of these charts they had to draw a line in the sand and say 'this muscle = this vertebrae/nerve'
To get an idea of what I mean you can look at this medical illustration linked here.

The Spinal Hub website outlines exactly what function spinal nerves do to muscles. Also a powerpoint presentation here.

Vertebrae	Muscle	Function
C1
C2
C3	Diaphragm	Breathing
C4	Diaphragm/ Shoulder	Breathing/Shoulder shrug
C5	Deltoid/ Biceps	Lift arms, sideways/Bend elbow
C6	Wrist extensors	Lift wrist back
C7	Triceps	Straighten elbow
C8	Hands/Fingers	Grip object

Thoracic
T1	Hands/Fingers	Splay fingers apart
T2	Chest (intercostal)	Allow ribcage move/breathe
T3	Chest (intercostal)	Allow ribcage move/breathe
T4	Chest (intercostal)	Allow ribcage move/breathe
T5	Chest (intercostal)	Allow ribcage move/breathe
T6	Chest/ Abdomen	Ribcage move/Cough
T7	Chest/ Abdomen	Ribcage move/Cough
T8	Chest/ Abdomen	Ribcage move/Cough
T9	Abdomen	Cough, balance
T10	Abdomen	Cough, balance
T11	Abdomen	Cough, balance
T12	Abdomen	Cough, balance

Lumbar
L1	Hip	Bends hips
L2	Hip	Bend, flex hip joint
L3	Quadricep/Hip adductors	Straighten leg at knee
L4	Knee/Ankle	Bend ankle, draw foot back (dorsi-flexion)
L5	Ankle/Toe	Lift ankle/Lift big toe

Sacral
S1	Ankle/Toe	Bend ankle/Point toe (plantar flexion)
S2	Toes/Anal, bladder sphincter
S3	Anal, Bladder sphincter
S4	Anal, Bladder sphincter
S5	Anal, Bladder sphincter

When you start looking up things like this, it is almost like you need a separate textbook to understand what these pictures are telling you! One site that was very interesting in the amount of depth of information came from medical school notes, found here.
I love medical students that put their studying online like flashcards here.

Plain English please!

All of those muscles get confusing!

Especially when your physio talks about 'oh I think there is definitely ____ muscles, not sure about ____ mucles' and you are trying to remember grade 12 biology. So Glutes, quadracepts, and hamstrings are the ones that stick out for me on those pictures.

Muscle Ability	Muscle Group	Nerve Innervation
Thigh flexion		L1, L2, L3, L4
Thigh adduction		L2, L3, L4
Thigh abduction		L4, L5, S1
Extension of leg at hip	Gluteus maximus	L5, S1, S2
Extension of leg at knee	Quadriceps	L2, L3, L4
Flexion of leg at knee	Hamstrings	L4, L5, S1, S2
Dorsiflexion of foot		L4, L5, S1
Extension of toes		L4, L5, S1
Plantar flexion of foot		L5, S1, S2
Flexion of toes		L5, S1, S2
Anal wink		S2, S3, S4

Some sources for this chart here and here.

Muscles receive messages from a number of nerves. Can't anything be easy?!
So trying to determine what a level is by what someone can do or feel is not as easy as the colourful pictures lead you to believe. If you are trying to determine the functional level that your child has, I am just repeating what I found online as well as what our physiotherapist explained to us. I used alot of this information to try to decode or translate what we were told - not to diagnose. (OK maybe I tried to diagnose a little bit when I didn't like what I was being told)

I looked at a bunch of articles that talked about flexion and extension and abduction/adduction. Then I had to look up what all of those meant, and then I had to look up pictures.

Abduction

 Adduction

Knee extension

 

Knee flexion

Hip flexion



This is one of the most frustrating part when you are trying to imagine what you child will be able to do. All of this information and pictures and illustration will not let your child do something that their nerves will not allow them to do.
Labelling your child as a number and letter will not help anything (I can say this from experience and from fighting with myself about wanting a letter and a number). Being aware of what information is out there, and celebrating the achievements and abilities of your child and trying to educate yourself  is what I hope people get out of this information post.

Learning about SB: Beyond Walking

Will he walk? That is always the question that people ask when they learn about Spina bifida. And that is one of my first questions as well. We are lucky and everyone seems very confident that yes, he will walk. But how do we picture walking? Walking down the street like you and I walk? Walking with a limp? Walking with crutches and braces? Walking with a walker? All of those are walking. And if he needs to use a wheelchair – I’m ok with that (it’s easy to say that now – I’ve heard it’s very hard on the parents, but not so much on the children). Walking is NOT the be-all and end-all of life.

 I found this picture that I think helps to show how walking can be affected by nerve damage. Nerves do not progress all the way down; some nerves go to the front of the leg, some to the back. Spinal nerves are what carry the messages to and from the brain and muscles. Thoracic nerves go to the chest, back and stomach, upper lumbar nerves (L1-L3) to the hips and thighs, lower lumbar nerves (L4-L5) to the knee and front of the lower leg and sacral nerves (S1-S3) to the ankles, feet, back of legs, buttocks, bladder and bowels.

Walking involves more than just nerves, there is mobility and sensation. Here is a common table that explains level of Spina bifida and walking:

This chart came from Understanding Spina Bifida booklet from Spina bifida team at Bloorview MacMillan Centre

What is needed for walking? There are a variety of different things that need to be all lined up for someone to walk. Balance, range of motion, control and power. This is (something that I am learning about as well, so I'm sorry if it's a little dry)
1. Balance, is that center of gravity of the spine, pelvis, hip, knee and foot.
2. Range of motion of the joints, how they move and ‘step’, and the hip is the most important part of walking.
3. Control is needed. I could go into all the muscles that are important for control of the hips, but what the information I have is at least a page long, and I find it hard to follow with talking about different names of muscles – so I’m not going into it – but what I have came from Hip Function Fact Sheet from Spina Bifida Association of America http://www.sbaa.org/.
4. Finally we look at power. This is more than power to control joints, but to actually push and pull muscles. Calf muscles and hip extensors are used, and are sent messages from the sacral level. Power to move may not move forward, but side to side to move forward –the shifting that you see to move forward. Whatever works.

But this all takes a lot of energy, and some things are more important than walking. I’ll even say it again. There are some things more important than walking.

The next time you take a step, just one. Stop and think about all of the things that your body is doing. The nerve impulses, how you flex a muscle and a joint. And how you do it without any effort at all. THIS is what everyone takes for granted.

We are not here yet, and we won't be thinking about walking for a while yet, we are still getting control of Nick's trunk and rolling before thinking about crawling and being upright and standing before even thinking about walking. But the question that everyone has (including us) when we talk about spina bifida is will he walk? Well it doesn't have a simple answer.


Picture http://www.improve-education.org/id52.html
http://www.spinabifidaassociation.org/site/c.liKWL7PLLrF/b.2700279/k.91AF/Hip_Function_and_Ambulation.htm