kine 3p92 midterm 2

When does the majority of bone mass density decrease following SCI?

4 months after injury and typically reaches a level approx. 2/3 that of pre-injured (able-bodied values) within 16-24 months

What are the mechanisms behind bone loss after SCI?

1. Loss of weight bearing on bones

2. Reduction in the blood flow to bone (interosseous circulation)

3. Drug therapies associated with SCI

define heterotypic ossification after SCI?

The spontaneous formation of bone in muscle or connective tissue. Most commonly in the hips, knees and elbows

What is type 2 diabetes mellitus?

the pancreas doesn't produce enough insulin OR the body has an impaired response to insulin (insulin resistance)

What is type 1 diabetes?

where the pancreas produces little to no insulin - insulin dependent

why is there an increased risk of diabetes in SCI patients?

1. Loss of muscle mass and ability to contract

2. Increased insulin resistance

describe glucose intolerance

An inability to properly store / metabolize glucose

Describe insulin resistance

· An inability to respond to, and use, insulin. i.e. Any given amount of insulin secreted from the pancreas results in a lesser transport of glucose into muscle and liver, and fat into adipose tissue. · Due to decreased muscle mass (No decrease in GLUT 4 levels)

What are some benefits to exercise training for those with SCI in regards to glucose intolerance?

· Increased muscle mass · Decreased insulin resistance (Increased insulin sensitivity) · Increased GLUT 4 content in muscle

Why do SCI patients have decreased fatigue resistance in muscles?

SCI is generally characterized by fibre type shift towards a type IIx fibre predominance and Reduction in the Na+, K+ - ATPase enzyme Yes (~50%)

descrie spasticity

· Involuntary, random, increase in muscle tone (agonists and antagonists) common in individuals with UMN SCI. · Velocity-dependent, position dependent

what is clonus

Repetitive contraction of a muscle due to an uninhabited stretch reflex

what are contractures?

Reduced range of motion in a joint due to chronic shortening of a muscle

What is the purpose of the Ashworth test of spasticity?

· Move the joints of the lower limb (hip, knee, ankle) and record the amount of resistance (spasticity) based on a 6 point scale · Need a metronome

describe a male erection

Vasodilation of the arteries supplying the penis and relaxation of the smooth muscle of the corpus cavernosum and corpus spongiosum. Blood fills the vascular spaces of the corpus cavernosum and the corpus spongiosum. Engorgement of the corpus cavernosum and corpus spongiosum compresses the veins of the penis and the blood gets trapped.

Describe how the nervous system is involved in male erection

The initial vasodilation of the arteries and the relaxation of the smooth muscle is under neural control from both the parasympathetic and sympathetic nervous systems.

What happens during female arousal?

Vaginal lubrication caused by secretions from the greater vestibular glands. Vascular engorgement (erection) of the clitoris which also contains erectile tissue (corpus cavernosum, but NO corpus spongiosum)

describe how the nervous system is involved in female arousal

This is the female analogue to the male erection. i.e. also under neural control from both the sympathetic and parasympathetic nervous systems.

What is male emission?

peristaltic contractions in the vas deferens transports sperm from the testis to the end of the vas deferens. Secretions from the seminal vesicles and prostate are added to sperm to form semen. Further contractions of the vas deferens transports semen to the posterior urethra

What is is female emission?

peristaltic contractions of the fallopian tubes and Further contractions of the uterus Emission is under control of the sympathetic nervous system

Describe male ejaculation

the propulsion of semen from the posterior urethra. Involves contractions of the muscles of the pelvic floor and Closure of the bladder neck

define retrograde ejaculation

occurs when semen enters the bladder instead of emerging through the penis during orgasm. Although you still reach sexual climax, you might ejaculate very little or no semen. This is sometimes called a dry orgasm. Retrograde ejaculation isn't harmful, but it can cause male infertility.

Describe female ejaculation

Female ejaculation also occurs as a result of the pelvic floor muscle contraction. Ejaculation is under the control of somatic motor neurons

What are the two types of neural control of erection/lubrication?

1. reflexogenic (higher quality)

2. psychogenic (lower quality)

Describe a reflexogenic neural output of erection/lubrication

· Response to touch · Sensory afferents -Sacral E.C. -> PNS

Describe a psychogenic neural output of erection/lubrication

· Psychological arousal · Brain -uses Thoracolumbar E.C. SNS and -Sacral E.C. PNS

Describe what happens to erection/lubrication after SCI

· None during spinal shock · Recovery takes days - years (1 or 2) · Incomplete injuries =erection/lubrication very likely

What happens during a complete SCI above T11 for erection/lubrication?

· No psychogenic erections/lubrication · Reflexogenic erections/lubrication in tact (occur commonly during body-care) · Erection/lubrication maintenance an issue

What happens during a complete SCI between L2-S2 for erection/lubrication?

· Preservation of reflexogenic and psychogenic erection/lubrication · Erection/lubrication maintenance is an issue

What happens during a complete SCI between T11-L2 or S2-S4 for erection/lubrication?

· varying degrees of preservation of either reflexogenic or psychogenic erection/lubrication · erection/lubrication maintenance is an issue. total damage to an erection centre will eliminate the corresponding type of erection/lubrication, as will damage to the LMN's

Describe Ejaculation after SCI

The preservation of true ejaculation after SCI is rare

1. Complete SCI above sacral E.C.: Ejaculation is rare since the main pathway for emission is impaired

2. Complete SCI at sacral E.C.: Ejaculation is rare since the somatic ejaculation reflex is impaired. Incomplete injuries may result in preservation of ejaculation

describe orgasm after SCI

Orgasm is fairly common after SCI: · mainly a cerebral event, not necessarily due to genital stimulation · may be achieved by stimulation above the level of SCI · even in complete SCI some deep sensation is perceived

describe male fertility after SCI

· due to impaired ejaculation · due to lower quality sperm (low motility and malformation) o infection, antibiotic use, elevated scrotal temperature due to prolonged sitting, stress, non-drainage due to impaired ejaculation

describe female fertility after SCI

· no permanent threat to fertility, menstrual cycle may stop at time of injury, but usually resumes after 5-12 months · most women with SCI who become pregnant deliver their babies vaginally

What are some erection maintenance measures?

o Pump and Tourniquet o Penile implants (semi rigid or hydraulic) o Injection of medication into penis (vasodilators)

What are some ejaculation assistance measures?

o Vibroejaculation (Ferticare) o Medically induced ejaculation (midodrine) o Electroejaculation o Testicular puncture

What are some issues during pregnancy and labour for females with SCI?

o High risk of pressure sores during pregnancy o Chronic maternal hypotension may affect baby's birth weight o May be completely dilated and about to give birth without knowing o 2/3 of all women with SCI above T6 experience A.D. during childbirth (epidural helps)

Define ischemic heart disease

An inadequate oxygen supply to meet the needs of the heart, primarily due to occlusion of the coronary arteries.

Which group of SCI invidiudals are most at risk for ischemic heart disease?

Complete Tetraplegia

What are causes of ischemic heart disease

-clotting -smooth muscle spasm -atherosclerosis (BIGGEST contributor)

what are sticker platelets?

a) Platelet aggregation (sticking to each other) is facilitated by platelet derived growth factor (PDGF) b) Platelet Aggregation is inhibited by prostacyclin (PGI2)

What is PDGF?

platelet derived growth factor

What is silent ischemia?

Ischemia that occurs in the absence of any subjective symptoms. Individuals with complete tetraplegia may not feel the chest pain (angina) normally associated with ischemic heart disease

What are some reasons for why individuals with SCI more susceptible to ischemic heart disease?

o HDL levels o "Stickier" platelets o Obesity o Inactivity o Silent ischemia

Describe Non-ischemic heart disease

· Cardiac dysfunction that is not primarily due to an occlusion of the coronary arteries

Which SCI populations are most at risk for non-ischemic heart disease?

Complete paraplegia, Incomplete tetraplegia and complete tetraplegia

What are some non-ischemic heart diseases?

congestive heart failure and rhythm disorder

What is congestive heart failure?

when the heart muscle is overworked due to stress, high blood pressure, arteriosclerosis, and fluids begin to collect in the body tissues, esp. the lungs

Why may individuals with tetraplegia be at an increased risk of death due to congestive heart failure?

· Atrophy of the peripheral blood vessels · Stiffening of the peripheral blood vessels · Increased total peripheral resistance

Why may individuals with tetraplegia be at an increased risk of death due to rhythm disorders?

· Disturbance to the autonomic outflow to the heart

describe cerebrovascular disease

o Damage to or occlusion of the blood vessels that supply the brain ® Stroke ® Brain damage or death.

Which SCI populations are most at risk for cerebrovascular disease?

Complete Tetraplegia

why are individuals with SCI at an increased risk of cerebrovascular disease?

· Susceptibility to autonomic dysreflexia

What is autonomic dysreflexia?

a life-threatening emergency in spinal cord injury patients that causes a hypertensive emergency; it occurs AFTER spinal shock has resolved; the symptoms are severe headache, diaphoresis, nausea, nasal congestion, and bradycardia

What is pulmonary circulation?

circulation between heart and lungs

which individuals with SCI at an increased risk of death due to diseases of the pulmonary circulation?

All populations, Incomplete paraplegia, Complete paraplegia, Incomplete tetraplegia and complete tetraplegia

What are some different types of cardiovascular dysfunction associated with SCI

1. Orthostatic intolerance

2. Autonomic dysreflexia

Describe Orthostatic intolerance

Orthostatic hypotension, postural hypotension · Inability to withstand an upright posture (sitting-up, standing-up) without experiencing syncope (fainting) due to extreme drop in blood pressure. · Most common in individuals with T6 injuries or higher

Why are SCI individuals susceptible to orthostatic intolerance?

· Loss of sympathetic drive to the abdomen (splanchnic vascular bed) and large vessels of the legs · Loss of sympathetic drive to the heart · Loss of muscle pump

What are some prevention methods for orthostatic intolerance?

· Abdominal binder · Stockings · Fluid and salt intake · Medications to increase BP

Describe autonomic dysreflexia

autonomic hyperreflexia · An abnormal reflex response, whereby a noxious (bad) stimulus below the level of the SCI causes an intense vasoconstriction, also below the level of the SCI · The intense vasoconstriction may cause dangerously large increases in blood pressure (especially in individuals injured at T6 or higher) which may result in a stroke or seizures.

What are some symptoms of autonomic dysreflexia?

1. Large increase in BP

2. Pounding headache

3. Flushed face and neck, but, pale below the SCI

4. Sweating above the SCI

5. Nausea

6. Possibly a reduction in heart rate (bradycardia)

What are some causes of autonomic dysreflexia

1. Bladder issues (distension, infection)

2. Bowel issues (constipation or impaction)

3. Skin issues (pressure sores, burns, general injuries to skin)

4. Sex (for the female and the male)

5. Bone fracture

6. Other "painful" stimuli below the SCI...

What are some treatment measures for autonomic dysreflexia

1. Don't lie down!

2. Remove the noxious stimulus o Check catheter line (kinks; gently, slightly irrigate) o Check bowel o Remove or loosen tight clothing o Etc...

3. Medication (nifedipine...if not contraindicated)

4. Call 911

describe the effect of autonomic dysreflexia in relation to exercise

· Athletes with SCI will often induce A.D. ("boost") in order to enhance exercise performance

Aside from death due to urosepsis, bladder dysfunction after SCI may result in:

· Urinary incontinence · Inability to urinate o Urinary Tract Infection o Autonomic dysreflexia o Renal failure · Penile Erosion

What is the detrusor muscle?

Smooth muscle found in the wall of the bladder that remains relaxed to allow the bladder to fill and store urine, and contracts during urination to release urine.

What innervates the detrusor muscle

· Receives parasympathetic (S2-S4) and sympathetic (T11-L1) innervation. · External sphincter and pelvic floor (periurethral) muscles: Receive somatic innervation (S2-S4)

Define micturition

act of passing urine

Describe the micturition reflex

The micturition reflex (urination) involves the contraction of the detrusor muscle and relaxation of the external urethral sphincter. When the bladder is sufficiently distended with urine, stretch receptors in the wall of the bladder signal the micturition reflex center in the spinal cord to send a motor impulse along the parasympathetic nerves to the detrusor muscle.

what is continence

the ability to control movements of the bowels and bladder

How does continence work?

A) Reflex control of pelvic floor muscles: (Allows for continence without constant conscious thought) Contraction of pelvic floor muscles (Compresses urethra) Bladder fills B) Voluntary control of external sphincter and pelvic floor muscles: Sensation from full bladder (stretch receptors)

describe voluntary peeing

-Sensation from full bladder (stretch receptors) -Sacral Cord (S2-S4) Sensory info ascends to cortex -Motor info descends to S2-S4 -Increases parasympathetic outflow to detrusor AND -Relaxation of external sphincter and pelvic floor muscles AND -Drop of pelvic floor muscles, Contraction of abs

What are some Complications in bladder function following SCI

Bladder function following (complete) SCI depends largely on the integrity of the micturation reflex. · Reflexive bladder · Areflexive bladder · Detrusor sphincter dyssynergia

What is areflexic bladder?

Occurs when the sacral micturation reflex is disrupted i.e. damage to S2-S4 or cauda equina injury Peeing is hindered:

1. No parasympathetic outflow to detrusor muscle in response to stretch

2. Functional sphincter is still intact as bladder fills

what is a reflexive bladder?

Occurs in those with intact S2-S4 segments (micturation reflex), but disrupted descending input to S2-S4. · Voluntary peeing ability is lost. · Bladder will empty reflexively (not completely) once there is a sufficient stretch on the bladder wall. (UTI, sepsis, stones, AD)

describe the detrusor sphincter dyssynergia

A condition in which the external sphincter contracts simultaneously with or immediately following the contraction of the detrusor muscle.

What are some Complications following detrusor sphincter dyssynergia

Stagnant urine in bladder: · UTI, sepsis, stones Increased pressure in bladder: · AD -Vesicoureteral reflux -Hydronephrosis: -Pyelonephritis:

define Vesicoureteral reflux

Backflow of urine into the ureters

define Hydronephrosis:

Kidneys distended with urine; may lead to kidney damage and failure (with severe pain).

define Pyelonephritis:

Inflammation of the kidneys, usually due to bacterial infection; may lead to kidney damage and failure.

What is an indwelling catheter?

A catheter that is left inside the bladder to provide continuous urinary drainage - also called a foley catheter. · Less work for nursing staff · Increased risk of urethral damage, UTI

Describe intermittent catheterization

Best intervention to reduce the risk of infection in a pt who is unable to void -Pt straight cathed about every 3 hrs -Pt may be taught to do at home: Wash and reuse the same cath repeatedly when in own environment -In hospital, sterile technique used every single time

What are some risks to catheterization?

· No hand function, no caregiver, urethral abnormality · High risk of UTI, urethral erosion, seminal vesiculitis, prostatitis, urethral diverticula, gangrene or ischemic necrosis of the penis Increased risk of bladder cancer

describe neurostimulation in relation to bladder disfunction

· Electrodes are placed on the ventral roots of the S2-S4 segments · Stimulates detrusor contractions (and external sphincter contractions, but detrusor lasts longer)

describe Dorsal root rhizotomy in relation to bladder disfunction

· Cut the dorsal roots of the S2-S4 segments · Therefore, no afferent feedback from the bladder to the spinal cord · Therefore, increase bladder storage capacity, eliminate incontinence due to micturation reflex, eliminate AD...BUT...also eliminate sexual reflexes and sensation

describe the management of detrusor sphincter dyssynergia

Avoid Credé manuever or hitting the bladder as it will only increase bladder pressure Instead: · Catheterization · External sphincterotomy · Stent in external sphincter

what does bowel dysfunction entail after SCI

1. Neurogenic bowel · The bowels fill during the day(s) and then reflexively empty · Possible bowel accidents · Bowel routines help to prevent accidents

2. Difficulty (fully) emptying the bowels · Constipation and impaction are common · Laxatives (Senekot) and diet help

define allodynia

Pain evoked by a normally non-painful stimulus to normal skin

define hyperalgesia

Increased sensitivity to noxious stimulation

define central pain

Pain associated with a lesion of the CNS

define radicular pain

· : Pain associated with damage to the peripheral nervous system (dorsal root)

define paresthesia

Abnormal skin sensation (burning, tingling

What is musculoskeletal pain

· Pain that arises from damage or overuse to structures such as bones, ligaments, muscles etc. OR damage to spinal structures (acute pain prior to spinal stabilization) · May occur anywhere in those with incomplete injuries, but only at or above the lesion level in those with complete injuries. May be described as dull, aching, worse with activity, eased by rest.

What is visceral pain

· Pain that arises from pathology of the (abdominal) organs possibly due to secondary health complications associated with SCI (bladder or bowel distension or disease). Must consider level and severity of injury... · May be described as dull, poorly localized, cramping etc.

describe Neuropathic pain

· Pain that occurs following damage to the central or peripheral nervous system I. Neuropathic at level of pain: o Pain that is perceived within two segments above or below the lesion level o May be described as burning, stabbing, electric, shooting, presence of allodynia

What is neuropathic pain at the radicular level?

Pain due to damage of the peripheral nervous system (dorsal root)

What is neuropathic pain at the central level?

Pain due to damage (changes) of the central nervous system

Describe neuropathic below level of pain

· Pain that is perceived at least 3 segments below the level of the injury · May be described as burning, tingling, aching, shooting, stabbing · More likely to be diffuse compared to neuropathic at level pain.

what are Possible mechanisms behind neuropathic at level radicular pain

· Damage to the dorsal root may cause preferential damage to the Ad fibres, resulting in an imbalance favouring excitation of the substantia gelatinosa Descending tracts (corticospinal and reticulospinal) may also synapse on the substantia gelatinosa and cause an inhibitory effect (via endorphin, serotonin, NE release ® GABA release)