CSI 6 - Back pain Flashcards
What is a common cause of back pain?
Injury like a pulled muscle (strain)
What are some medical conditions that can cause back pain? (3)
- slipped disc
- sciatica (trapped nerve)
- ankylosing spondylitis
Very rarely, what can back pain be the sign of?
A serious problem e.g. broken bone, cancer or infection
Back pain usually improves on its own within …?
Within a few weeks
What can you do to help speed up your recovery of back pain? (5)
- stay active and continue with daily activities
- take anti-inflammatory medications e.g. ibuprofen
- use an ice pack to reduce pain and swelling
- use a heat pack to relieve joint stiffness or muscle spasms
- exercises and stretches
What should you NOT do when you have back pain?
Do not stay in bed for long periods of time
When should you see a GP about your back pain? (4)
- back pain does not improve after treating it at home for a few weeks
- the pain is stopping you doing your day-to-day activities
- pain is severe or getting worse over time
- you are worried about the pain or struggling to cope
When should you call 111/urgent GP appointment about your back pain? (6)
- high temperature
- unintentional weight loss
- lump/swelling in back or back has changed shape
- pain does not improve after resting/worse at night
- pain worse on sneezing/coughing/pooping
- pain coming from top of back (between shoulders) rather than lower back
When should you call 999/go to A&E about your back pain? (6)
- pain, tinging, weakness or numbness in both legs
- numbness/tingling around genitals/buttocks
- difficulty peeing
- loss of bladder/bowel control (peeing/pooping yourself)
- chest pain
- it started after a serious accident e.g. car accident
What are some treatments for back pain? (6)
- painkillers / medicines to relax muscles in back
- physiotherapy and group exercise sessions
- manual therapy - trained therapist massages and moves muscles, bones and joints in back
- CBT to help cope with the pain
- procedure to seal off some of the nerves in the back so they stop sending pain signals (only for long-term lower back pain)
- surgery e.g. if caused by a medical condition like a slipped disc and other treatments have not helped
What is somatotopic arrangement?
Different areas in body correspond to different areas of somatosensory cortex
What is contralateral arrangement?
LHS of SSC represents RHS of body, RHS of SSC represents LHS of body
What is affective neuroscience?
The study of the neural mechanisms of emotions - some brain regions can initiate a physiological and motivational output
What can stimulation of cingulate cortex by the right type of signal cause?
Aversion
What can stimulation of insula by the right type of signal cause?
Vasoconstriction, sweating, increase in pulse rate
What can stimulation of amygdala by the right type of signal cause?
Fear
What can stimulation of reticular formation (in brainstem) by the right type of signal cause?
Arousal
Describe what happens when the wrist is touched.
- touch detected by touch and pressure receptors e.g. Michael’s discs, Meissner’s corpuscles, Pacinian corpuscles, Ruffini’s, end-organs and low threshold nerve endings
- these receptors need to excite the wrist region of contralateral somatosensory cortex
- 1st neuron synapses within medulla oblongata and decussates
- 2nd neuron synapses in thalamus to 3rd neuron, connected to SSC
What pathway is activated by touch?
Dorsal column medial lemniscus system
- 1st neuron through dorsal column of SC
- 2nd neuron through medial lemniscus of brainstem
What does the dorsal column medial lemniscus system deal with?
Fine touch, 2-point discrimination, conscious proprioception, vibration sensations
Where are nociceptors embedded?
In the cell membrane of high-threshold neurons
What kind of stimulus do nociceptors need to initiate an action potential?
Require higher stimulus
What is transduction?
Process in which stimulus converted to action potential
What kinds of stimulus are there? (3)
- mechanical
- thermal
- chemical
Why do we feel pain at the site of inflammation?
Chemoreceptors initiate AP in response to cytokines that are generally released at site of inflammation = feel pain
What is the tract that pain takes?
Spinothalamic tract
What are some different pathways in the spinothalamic tract?
- sharp pain (fast) = A-delta fibres (neospinothalamic tract)
- dull pain (slow) = C-fibres (paleospinothalamic tract)
- differences in speed due to differences in myelination
Describe what happens after a pinprick.
Pinprick –> neospinothalamic tract –> enters SC at dorsal horn and synapses –> decussates to other side in SC –> ascends along SC straight to thalamus where it synapses with 3rd neuron –> AP to corresponding SSC
What is the part of the spinothalamic tract for sharp pain also connected to?
S2 region for visual integration, and the insula causing vasoconstriction, sweating and increased pulse rate
Describe what happens during dull pain of inflammation.
Paleospinothalamic tract –> enters SC at dorsal horn and synapses –> decussates at SC –> reaches reticular formation (arousal) –> thalamus and synapses with 3rd neuron –> SSC + cingulate cortex (aversion) + amygdala (fear)
Why is there immediate musculoskeletal action when sensing pain?
Reflex arc circuit at spinal cord that directly connects to the appropriate muscles
What sides of the spinal cord do the dorsal column and spinothalamic pathways ascend through?
- dorsal column = ipsilateral - decussate in medulla
- spinothalamic = contralateral - decussate in spinal cord
- DISC - dorsal ipsilateral spinothalamic contralateral
What is the journey of an action potential due to a pin prick in the right hip?
Mechanoreceptor –> dorsal horn –> thalamus –> left somatosensory cortex
What is the difference between A-delta and C-fibres?
- AD fibres are myelinated –> external pain, sharp, good localisation
- C-fibres are non-myelinated –> internal pain, dull, poor localisation, goes through reticular formation (arousal)
What are some potential causes of Paul’s back pain - middle back, leg numbness, cannot pee? (7)
- vertebra
- spinal cord (likely as symptoms are nervous)
- nerve roots (likely as symptoms are nervous)
- lumbar muscles
- aorta (less likely - AAA very severe and more acute)
- kidneys (less likely)
- pancreas (less likely - no abdominal pain that radiated to back)
What is the science of referred pain?
- nerves from different places (internal and external sensory nerves) come together in the spinal cord
- external (good localisation) and internal (poor localisation) signals end up in the same part of the dorsal horn before being relayed up to the brain
- brain may confuse the zone where the signal comes from - thinks it is an external problem instead of internal
What is mechanical back pain?
- mostly in lower back, sometimes radiates to buttocks and thighs
- source of pain may be in spinal joints, discs, vertebrae or soft tissues
- accounts for 97% of cases
What is radiculopathy?
- range of symptoms produced by pinching/compression of a single exposed nerve root in the spinal column
- pinched nerve can occur at different areas along the spine - cervical, thoracic or lumbar
- common cause is narrowing of space where nerve roots exit spine, which can be due to stenosis, bone spurs, disc herniation (nucleus pulposus herniates laterally and compresses) etc
In radiculopathy, is the pain usually on one or both sides?
Unilateral pain - one side
What is cauda equina syndrome (CES)?
- dysfunction of multiple lumbar and sacral nerve roots of the cauda equina
- medical emergency - patient suffers compression to spinal nerve roots inside the dura, beyond termination of the SC
What are the causes of cauda equina syndrome?
Most commonly due to a (centrally) prolapsed intervertebral disc, although rarely due to infection or tumour
What are the most common sites of nerve compression in cauda equina syndrome?
L4/L5 and L5/S1 (nerves above preserved, nerves below function affected)
Describe the development of the spinal cord.
- filum terminale (FT) is a fibrous band that extends from the conus medullaris to the periosteum of the coccyx
- fixate, stabilise and buffer the distal SC from normal and abnormal cephalic and caudal traction
- conus medullaris/conus terminalis is the tapered, lower end of SC - near L1 and L2
Where does the spinal cord end in embryological development?
Vertebral column continues to grow but SC stops at L1 = exposed nerve roots travel down to exit at the right vertebral level in the cauda equina
Why does compression of the nerves in cauda equina syndrome cause difficulty initiating micturition?
- S2-S4 nerves pass in level of L4 in cauda equina
- compression of S2-S4 nerve roots by L4/L5 disc = loss of innervation by S2-S4 nerves
- parasympathetic control comes from craniosacral region and this control would be lost if nerves in sacral region are compressed
- parasympathetic control promotes detrusor contraction and internal sphincter relaxation (allows urination) - without this control there is difficulty initiating micturition
What is the role of the pelvic nerve (S2-S4) in micturition?
- parasympathetic innervation
- detrusor contraction + internal sphincter relaxation
- urination
- (dysfunctional in CES)
What is the role of the hypogastric nerve (L1-L3) in micturition?
- sympathetic innervation
- detrusor relaxation + internal sphincter contraction
- allows bladder to fill
- (functional in CES = bladder fills, but urine cannot leave = retention)
What is the role of the pudendal nerve (S2-S4) in micturition and CES?
- controls external sphincter = voluntary control
- internal sphincter eventually opens due to Pa overload
- pudendal nerve affected –> no voluntary control –> urinary incontinence (after urinary retention)
What are the red flags of cauda equina syndrome? (7)
- bilateral sciatica
- severe or progressive bilateral neurological deficit of the legs e.g. major motor weakness with knee extension, ankle eversion, or foot dorsiflexion
- difficulty initiating micturition or impaired sensation of urinary flow, if untreated this may lead to irreversible urinary retention with overflow urinary incontinence
- loss of sensation of rectal fullness, if untreated may lead to irreversible faecal incontinence
- perianal, perineal or genital sensory loss (saddle anaesthesia or paraesthesia)
- laxity of the anal sphincter (consider PR examination of anal tone but this does not need to be performed in primary care)
- erectile dysfunction
What investigation should be done immediately for CES?
MRI spine
What consequences can failure to quickly refer or treat a patient presenting with signs of CES have?
- serious consequences including paralysis, incontinence and impaired mobility
- lower back pain is a very common complaint and at its earliest stages CES is very difficult to diagnose
What is a critical point regarding referral of CES?
The critical point is that a referral needs to be made in time to allow surgical treatment before the syndrome is complete - essential to give patient a chance of salvaging useful function
Why are claims for clinical negligence in relation to CES common?
Due to the significant impact it can have on a patient’s life
For a clinical negligence claim to be successful, what does the claimant have to show?
- the care provided by the doctor fell below a reasonable standard - there has been a ‘breach of duty’
- show that the breach has caused loss or damage - termed ‘causation’
- both claimants and defendants will instruct independent experts to investigate these two aspects of a claim
Why can CES claims be made for a large amount of money?
- degree of damage that resulted from the breach of duty will often only be a fraction of the claim, with the care costs and consequential losses forming the bulk of the overall value of the case
- e.g. delay in referral = patient suffered complete loss of bladder and bowel function –> award of £130,000 for that injury alone
- on top of this, the patient is entitled to claim compensation for any care, aids and equipment required, and their ‘loss of earnings’ if they are no longer able to continue working
- if the patient was a high earner and still had many years of employment ahead of them, this can equate to a very large payment in compensation as the aim is to put the patient back in the position they would have been ‘but for’ the negligence
What is the claim like if the patient has made good recovery with very limited sequelae?
- claim may only be worth a small amount to reflect a period of pain or suffering
- if the independent expert evidence indicates that the same level of injury would have occurred in any event, there may be no compensation awarded or the compensation will be very small
- this may be the case if the delay was only a matter of hours, or if the injury was already established at the time the patient saw the doctor
What are the MDU tips regarding CES?
- conduct a full examination to establish the likely cause of the back pain and make a record that this has been done
- consider whether there are any red flags
- if red flags are present, the patient needs to be seen in hospital emergency (call the orthopaedic or neurosurgical specialist for immediate advice, or if this is not available, arrange for the patient to be admitted to hospital via the emergency department)
- if no red flags are present, make a record in the notes to demonstrate you have actively considered the condition
- if, after the assessment, the patient is being managed as having simple mechanical back pain, make sure you give appropriate safety netting advice. This should include advising the patient of the red flag symptoms and the importance of seeking urgent medical attention if these appear. Again, try to make a record in the notes of the specific safety netting advice that has been given
What is the procedure for surgical management of CES called?
Micro diskectomy for cauda equina syndrome
