Peripheral Nerve Disorders Flashcards
List clinical signs of PNS syndromes
- Motor Dysfunction
- Sensory Dysfunction
- ANS Dysfunction
- Neuropathic pain and/or muscle pain (myalgia) common
- Hyper-excitability of remaining nerve fibers
PNS symptom: Motor Dysfunction
- Weakness/paresis of denervated muscle
- hyporeflexia
- hypotonia
- atrophy
- fatigue
PNS symptoms: Sensory Dysfunction
- Paresthesias
- Proprioception losses may yield sensory ataxia
- insensitivity may yield limb trauma
PNS symptoms: ANS dysfunction
- Vasodilation and loss of vasomotor tone
- dryness
- warm skin
- edema
- OH
what does hyper-excitability of remaining nerve fibers look like in PNS syndromes?
- Sensory dysesthesia → hyperalgesia, pins and needles, numbness, tingling, burning
- Motor → fasciculations
Describe tropic changes due to denervaion in PNS syndromes
- muscle atrophy
- skin becomes shiny
- nails become brittle
- subcutaneous tissues thicken
- ulceration of cutaneous and subcutaneous tissues
- poor wound healing
- infections
- neurogenic joint damage
what is a mononeuropathy
- weakness, numbness, pain, paresthesias, confined to the distribution of the involved nerve
- most common causes:
- entrapment
- trauma
- prolonged limb immobility (e.g. surgery)
- Example → carpal tunnel syndrome
Classification of nerve damage in mononeuropathy
- Neuropraxia
- local myelin damage, axon remains intact
- Axontmesis
- continuity of axon is lost
- may or may not include damage to epinerium, perineurium, and/or endoneurium
- loss of continuity leads to Wallerian degeneration
- Neurotmesis
- complete transection of nerve
- surgery necessary
how are PNS injuries different from CNS injuries?
- PNS can regenerate under certain circumstances
- Axonal sprouting
- regenerative
- collateral
- Axonal sprouting
what is a multiple mononeuropathy?
- involves two or more nerves in different parts of the body
- Vasculitis = dangerous cause of multiple mononeuropathy
- if suspected, an urgent referral should be made for an electrodiagnostic eval
- Individual nerves are affected, producing a random, asymmetrical presentation of signs
what is a polyneuropathy?
-
symmetrical involvement: sensory, motor, autonomic
- Sensory → Motor → Autonomic
- Distal → Proximal
- Feet → legs → fingertips → hands
- Affects longest peripheral nerves in extremeties
- small nerve fibers → large nerve fibers
Motor symptoms for Polyneuropathies
- Weakness
- Cramping
- Fasciculations
- Muscle Loss
- Bone degeneration
- Loss of ankle reflexes
- trophic changes
Sensory Symptoms for Polyneuropathies
- Earlier in disease
- loss of temp
- pain (hypo or hyper)
- As disease progresses
- loss of vibration
- loss of light touch discrimination
- loss of proprioception/kinesthesia
Autonomic Symptoms for Polyneuropathies
Diverse manifestations
- impaired breathing
- dysarthria
- temp dysregulation
- in particular - decrease sweating
- GI dysfunction
- Loss of bowel/bladder control
- Erectile dysfunction
- Loss of BP control
- orthostasis very common
common causes of polyneuropathies
- Diabetes Mellitus
- 60-70% of pts with DM have mild-severe forms of PN
- Other
- Autoimmune disorders
- chronic kidney disease
- HIV and liver infections
- low level of vitamin B12
- Poor circulation in LEs
- Underactive thyroid gland
- Trauma
- Tumor
- Alcoholism
Risk factors for diabetic polyneuropathy
- Obesity
- Sedentary lifestyle
- HTN
- Decreased glycemic control
- Alcoholism
- Smoker
Diabetic Polyneuropathy prognosis
- CAN BE PREVENTED with appropriate disease management and compliance
- Progression of symptoms progresses slowly over years
- depends largely on how well the pt’s DM is managed
- Treating DM may halt progression and improve symptoms of the neuropathy, but recovery is exceptionally slow
Interventions for Diabetic Polyneuropathy
- Aerobic Conditioning
- Balance training
- Resistance training
- Patient education
parameters for aerobic conditioning in Diabetic Polyneuropathy
- 150 min/week
- 50-70% HRmax
- mRPE 5-7(RPE 14-16)
Balance training in Diabetic Polyneuropathy
- Cannot improve sensory loss
- strengthen other balance systems to compensate
Aspects of pt education for diabetic polyneuropathy
- skin care and inspection
- shoe consideration
- nutritional consult
- fall risk management
- importance of aerobic exercise
- strategies to reduce sedentary lifestyle
- compliance to program
what is CMT?
Charcot Marie Tooth Disease
- most common inhereted neuro disorder
- affecting 1 in every 2,500
- Males > Females
- progressive muscle weakness
- typically becomes noticeable in adolescence or early adulthood, but the onset of disease can occur at any age
- eventually effects both motor and sensory nerves