Week 4--notes Flashcards
lifetime prevalence of back pain
70-85%
annual prevalence of back pain
15-45%
when is sciatic pain most common in the lifespan
between ages 40-45
usually from herniated disc
*herniation pain decreases with age because the disc dessicates
which gender has higher risk of back pain form herniation
men
which gender has higher overall risk of back pain from all causes
women
at what age do back pain complaints generally start to decrease
age 50
what are the types of back pain
- structural–i.e disc disease
- inflammatory–i.e ankylosing spondylitis
- infectious–i.e discitis
- neoplastic–i.e mets
- visceral–i.e aortic aneurysm
- idiopathic–i.e non specific
what patient factors can be associated with back pain
- age
- gender
- previous history of back injury
- relative strength
- smoking
- psychosocial factors–time off in past, understanding of cause, what patient expects will help
- “inheritance”
- occupational influences
what occupational influences can contribute to back pain
whole body vibration
forward bending and twisting
manual handling of materials
poor psychosocial conditions
frequent heavy lifting
what are some modifiable risk factors with regard to back pain
lack of fitness
poor health
obesity
smoking
drug dependence
what are some factors that have little to no association with back pain
height and weight
aerobic activity
absolute strength
define mechanical back pain
inflammation, irritation or injury to disc, facet joints, ligaments or muscles in the back
pain NEVER occurs below the knee
what is the most common cause of mechanical back pain
AGE related degeneration of discs, facet processes
muscle or ligament related injuries
define compressive back pain
occurs when nerve root leaving the spine is irritated or pinched
commonly due to herniated disc
what are waddells non-organic signs
- superficial tenderness
- non-anatomic tenderness
- axial loading
- simulated rotation
- distracted straight leg raise
- regional sensory changes
- regional weakness
- overreaction
* when these occur, look also for other causes of pain
describe a method of triaging low back pain
- simple back pain
- back pain with neuro involvement
- back pain with suspected serious spinal pathology (red flags)
what is simple back pain
lumbar or lumbosacral pain with no neuro involvement
“mechanical” pain, varying over time and with physical activity
patient’s general health is good
*xray/CT/MRI results are not associated with symptoms described by patient or perceived disability (many findings are common with asymptomatic patients and there is a poor association with pain)
how should you exclude serious spinal pathology in simple back pain
xray is sufficient
what is back pain with neurological involvement
patients must have one or more symptoms and signs indicating possible neuro involvement
i. e
- pain radiating below the knee which is as intense or more intense than the back pain
- pain often radiating to foot or toes
- numbness or paresthesias in the painful area
- positive for radicular irritation with straight leg raise
- motor/sensory or reflex signs supporting nerve root involvement
how should you manage back pain with neuro involvement
neuro signs and sx in the absence of red flags often resolve themselves without recourse to surgery
patients progress statistically twice as slowly as patients with simple back pain
referral for specialist consult should NOT be required until clinician has seen functional deficit persistent or deteriorating after 4 WEEKS
x ray sufficient to exclude spinal path
what are red flags for back pain (suggestive of serious spinal pathology)
- violent trauma (fall from height, auto accident)
- constant, progressive, non mechanical pain
- thoracic or abdo pain
- pain at night that is not eased by prone position
- hx or suspected cancer, HIV or other pathologies that can cause back pain
- chronic corticosteroid consumption
- unexplained fever, weight loss, chills
- significant and persistent limitation of lumbar flexion
- loss of feeling in the perineum (saddle anesthesia)
- recent onset urinary incontinence
if someone is off work 0-4 weeks, how likely are they to RTW
80-100% will RTW
if someone is off work more than 12 weeks how likely are they to RTW
less than 60%
how should you treat acute low back pain
i.e within 0-4 weeks
after 48 hours from acute injury, suggest NSAIDs
muscle relaxants
advise to remain active
how should you treat subacute low back pain
4-12 weeks
advise to remain active and do exercises
consider multidisciplinary rehab program
low evidence for massage, NSAIDs, other analgesics
how should you treat persistent low back pain
over 12 weeks
multidisciplinary program
behavioural therapy
exercises
what % of back pain will not have a precise diagnosis
85%
define radiculopathy
objective neurological deficit
define nociceptive pain
nociceptors sense and respond to tissue damage
pain usually localized, constant, throbbing, dull
i.e burns, bruises, sprains, fracture
define neuropathic pain
result of dysfunction or injury to PNS or CNS
nerves can be inflamed or compressed
pain usually burning, electric, tingling, sharp
i.e carpal tunnel syndrome, phantom limb, post shingles, RSD
LMN signs
weakness
decreased tone
decreased reflexes
decrease sensation
UMN signs
babinski
increased reflexes
usually increased tone
red flags on back pain physical exam
very decreased ROM
midline tenderness
new or progressive deformity
neuro deficit
lower extremity spasticity
abnormal gait
loss of balance
saddle anesthesia
how do you manage cauda equina syndrome
medical and surgical emergency
what signs would suggest inflammatory causes of back pain
morning stiffness lasting more than 1 hour
age of onset younger than 30 or over 60
worse earliest in am and with activity
*advil better than tylenol for the pain
symptoms suggestive of benign low back pain
dull and achy
diffuse aching with associated muscle tenderness
exacerbated with movement (“mechanical”)
relieved with rest in recumbent position
no radiation of paresthesias
no dermatomal pattern
able to find a position of comfort
DTRs normal
what are red flag low back pain conditions
tumours
infection
fracture
cauda equina
examples of inflammatory back pain
ankylosing spondylitis
PMR
what is the most common disease of the SPINAL CORD after middle life
cervical degenerative myelopathy
signs of cervical degenerative myelopathy
UMN signs
spasticity
loss of balance
signs of cervical or lumbar radiculopathy
objective signs of neuro deficit (sensory loss, motor loss or impaired reflexes) in segmental distribution (LMN findings)
caused my compression or compromise of spinal nerve or its root
how does acute radiculopathy present
abrupt onset
severe shooting, “electric” pain with radicular distribution
accompanied by motor or sensory deficits
most often due to herniated disc (“soft disc”)
how does chronic radiculopathy present
gradual
sensory symptoms predominate
wasting and decreased tone, might have weakness
usually due to osteophytic compression (“hard” disc)
which are more common, pharmacodynamic or pharmacokinetic drug interactions
pharmacodynamic are 75%
i.e additive CNS depression, serotonin syndrome etc
what are the 2 main pharmacokinetic systems that contribute to drug interactions
CYP P450 system
transport protein system
what is the CYP p450 system
super family of heme-containing mono-oxygenases
responsible for detoxing foreign compounds mostly in the liver
large variability between people–enviro and genetic
what drug should not be combined with the drug below, and why:
NSAIDs
ACEi–> causes inhibition of vasodilating renal prostaglandins, leading to renal impairment
what drug should not be combined with the drug below, and why:
clopidogrel
omeprazole –> inhibition of CYP metabolism to active metabolite leading to decreased clopidogrel effectiveness
major severity
what drug should not be combined with the drug below, and why:
warfarin
NSAIDs–> increased bleeding risk, delayed onset
what drug should not be combined with the drug below, and why:
ACEi
spironolactone–>
enhanced hyperkalemic effects
what drug should not be combined with the drug below, and why:
SSRIs
warfarin–> leads to enhanced anticoagulation/antiplatelet action leading to altered anticoagulation
what should you think of when syncope presents as:
slow onset, slow offset
hyperventilation or hypoglycemia
what should you think of when syncope presents as:
abrupt onset, slow offset
seizure disorder
what should you think of when syncope presents as:
abrupt onset, abrupt offset
usually cardiac
arrhythmic–> brady or tachy
obstructive–> aortic stenosis, HCM, myxoma
vascular–> vasovagal, orthostatic hypotension
prominent risk factors for long QT syndrome
congenital
elderly, female
heart failure
myocardial ischemia
hypokalemia
more than one QT prolonging drug
other risk factors for long QT syndrome
brady less than 50
electrolyte disturbances
altered nurtition
hypothyroid
hyperglycemia
hypertension
one QT prolonging drug
list 3 commonly used QT prolonging drugs
methadone –> risk as normal doses
fluoxetine–> risk at normal doses
trazodone
name the 4 dopamine pathways
- mesocortical pathway
- nigrostriatal pathway
- mesolimbic pathway
- tuberoinfundibular pathway
what does the mesocortical pathway do?
associated with cognition and motivation
associated with negative symptoms of schizophrenia/psychosis
what are the negative symptoms of psychosis/schizophrenia associated with the mesocortical dopamine pathway
5 As
alogia
anhedonia
affective flattening
avolition
asociality
what does the tuberoinfundibular dopamine pathway do
controls prolactin secretion
what does the nigrostriatal dopamine pathway do
controls motor functions
what does the mesolimbic dopamine pathway do
associated with memory and emotional behaviours
associated with positive symptoms of psychosis/schizophrenia
what are the positive symptoms of psychosis/schizophrenia associated with the mesolimbic pathway
delusions
hallucinations
disorganized speech/thinking
disorganized or catatonic behavior
which dopamine pathway is associated with:
mediation of antipsychotic efficacy, and the treatment of psychosis
mesolimbic