ALS/CRPS - neuro Flashcards
ALS UMN or LMN?
-ALS at its onset is usually one or the other: all UMN or all LMN degeneration.
-But eventually, all ALS becomes a mix of UMN and LMN pathology/symptoms. In fact, if you are considering a MN disorder that only has UMN OR LMN symptomatology, then it can’t be ALS.
-Mixed UMN and LMN pathology
#1 is ALS
-think ALS in any pt who presents with weakness WITHOUT sensory changes, and their exam shows UMN AND LMN symptoms
-progressive
Motor Neuron Disease pathological findings
- Motor Neuron Disease pathological findings
- neuron shrinkage – cell nuclei shrink
- accumulation of pigmented lipid
- accumulation of neurofilaments and other proteins (spheroids)
- eventual neuron death -> denervation = losing the nerve supply to periphery \
- loss of axonal attachment to peripheral muscle -> atrophy = “amyotrophic”
- thinning CSTs -> fibrillary gliosis (firm) come together and lose axons but proliferation occurs and causes it to thicken= “lateral sclerosis”
ALS Etiologies
- possibly associated with military service, exposure to pesticides and insecticides, tobacco use
- gene mutations, especially in free radical suppression genes
ALS Signs and Sxs
more LMN disease
- onset-symptom usually is asymmetric ascending (toes to ankle to calf and on up) weakness (“stretching in bed before getting up leads to muscle cramps”)
- atrophy and fasiculations - muscle weakness
- if bulbar involvement, onset-symptom usually is dysphagia, difficulty chewing and abnl face+tongue movt’s
more UMN disease
- spasticity
- hyperreflexia
- “muscle stiffness»_space; muscle weakness”
- Dysarthria – difficulty speaking
- excessive weeping and laughing (loss of UMNs to emotional centers)
ALS Dx
- progressive weakness
- simultaneous UMN and LMN symptoms
- “definite” = 3 of 4 sites involved (bulbar, cervical, thoracic, lumbosacral)
- “probable” = 2 of 4
- “possible” = 1 of 4
ALS Tx
-there is nothing to arrest the underlying pathology, but, you can prolong survival with riluzole 100mg qday. MOA = reduces neuronal excitotoxicity. Common SEs = nausea, dizziness, wt loss and increased LFTs.
-rule out treatable etiologies
PT referral:
-orthotics (especially foot drop brace -> aids in gait, decreases falls)
-maximize ADLs with adaptive equipment
-ROM and strengthening exercises
Respiratory testing -> Respiratory Therapy and -Pulmonologist referrals
- breathing exercises
- ventilatory-assist options
Complex regional pain syndrome (CRPS)
- a disabling neuropathic pain disorder that affects the physical and psychologic aspects of a patient’s life
- controversial, in that there are no universal guidelines, nor any specific tests which rule in or rule out its presence
- often missed by primary care providers
- no cure
- one of the many pain syndromes that are associated with vasomotor (capillary function) and sudomotor (sweat function) changes
- can be sympathetically-mediated pain (improves with a sympathetic nerve block) or non-sympathetically-mediated pain (doesn’t improve post SNB)
etiology CRPS
- tissue damage, either with documented nerve damage (CRPS II) or no specific nerve injury (CRPS I). This points toward the need for electrodiagnostics.
- can be just due to sprain/strain
- commonly occurs after surgery, especially toe or foot or ankle surgeries
- also after injections, especially for plantar fasciitis or Morton’s neuroma
- unclear mechanisms, but felt to be due to PNS hypersensitivity and CNS sensitization
CRPS signs and symptoms
- pain out of proportion to the extent of tissue damage, or lasting longer than the typical post-surgical healing time
- usually a constant burning crampiness
- hypesthesia (“does a pinch feel like terrible burning?”)
- allodynia (“do nonpainful things give you pain?”)
- hyperpathia (sensation even when stimulus stops- vibrio testing)
- vasomotor changes: skin color, temp, edema and hair or nail changes (one side hot and swollen and red, the other side looks normal; nail changes on one side but not the other; swollen distal extremties in a person who doesn’t normally have peripheral edema)
- sudomotor changes: one side doesn’t sweat like the other (“does one sock get wet and the other doesn’t?”)
- usually unilateral (asymmetric)
- usually distal
- pain may be diffuse or dermatomal
- used to be split into 3 stages, but now more thought of as acute (hot, red, swollen skin) vs. chronic (cold, dusky, shiny skin)
CRPS dx
- Budapest criteria
- pain out of proportion to injury extent + at least 1 of 4 (sensory, vasomotor, sudomotor, motor symptoms) + provider must find at least 2 of 4 (above)
- sensitivity = 98% (almost no FalseNegatives)
- specificity = 36% (64% FalsePositives)
CRPS Tx
- PT (as early and as aggressive as you can)
- active ROM ASAP, desensitization techniques… -neuropathic pain meds: anticonvulsants > tricyclic antidepressants, neurontin or lyrica ASAP, then cymbalta if no help, consider desipramine, NSAIDs
- consider tramadol short term (maybe for PT only), vasodilators (prazosin or clonidine patch), muscle relaxers (especially tizanidine), DMSO cream or EMLA cream or lidoderm/lidogel
- early referral to pain specialist, physiatrist or neurologist, especially for sympathetic nerve blocks
CRPS work-up
- no labs necessary
- XR not terribly helpful
- will show osteopenia, but late in dz
- Triple Phase Bone Scan (TPBS)
- Positive 3rd phase periarticular uptake
- Positive 1st and 2nd phase asymmetric uptake
