39 Radiculopathy, Neuropathy Flashcards
Roots that do not contain sensory nerve fibers ?
C1, Co1
Cervical herniations MC affect:
C7»_space; C6
Cervical spondylosis MC affects:
C5, C6
Cervical spondylosis:
Epidemiology?
60+ y/o, M>F (slight)
Lumbosacral radiculopathies MC affect:
L5, S1
Signs/symptoms associated with radiculopathies?
- sharp, electric, radiating pain; worsened by movements that stretch the nerve root
- Weakness/Atrophy: motor nerve fibers w/in myotome lost (1 root affected = one myotome lost)
- Paresthesias (sensory nerve fibers for dermatome are lost)
- Muscle Stretch Reflexes: ↓ ~ classic LMN disease finding
Cervical Maneuvers associated with cervical radiculopathy?
neck extension (best), neck rotation, Spurling’s Maneuver
Epidemiology of disc herniations?
Epidemiology of spondylosis?
50 yo
MC cause of cervical spondylosis?
myeloradiculopathy (Spinal Canal Stenosis)
**can present ~ALS from compression of CST
MC causes of lumbosacral spondylosis?
- neurogenic claudication (ambulation –> lower extremity pain/weakness)
- Cauda Equina Syndrome
What bone conditions/injuries contribute to radiculopathy? How?
- Trauma (younger patients ): causes spinal column instability = ↑risk of radiculopathy
- Bone Disease:
- osteoporosis/malacia
- Paget’s Disease
- AVN from pro-longed steroids (SLE) - Neoplastic
- constitutional symptoms (weight loss)
- Cauda Equina Syndrome
Imaging for dx of radiculopathy?
MRI
greater contrast sensitivity + Gadolinium Contrast allows det scar tissue vs. disk protrusion
Function of EDX?
confirms clinical diagnosis from History and Physical
EDX assesses:
- sensory/motor nerves
- muscle fibers
- demyelination + axon loss
- location of d/o
- severity/prognosis
- diagnosis
Conservative trx for radiculopathy?
- *most improve w/in 6 weeks
- AVOID Bed Rest: be as routine as possible
- PT
- Rx: pain, steroids, nerve blockers
Features of polyneuropathy?
symmetric/distal weakness in glove/stocking pattern
Features of Mononeuritis?
weakness + sensory loss in nerve’s distribution pattern (myotome/dermatome)
Features of Mononeuritis complex?
multiple myotomes/dermatomes involved
Findings of plexopathies (LMN Disease)?
- ↓reflex
- ↓conduction velocity
- denervation/↓# motor units on EMG
Muscle biopsy in plexopathies (LMN Disease)?
atrophic fibers + fiber type grouping
Lesion of Median nerve?
Carpal Tunnel = numbness in Lateral 3.5 Digits + Atrophy of Thenar Compartment
(weakness in wrist flexion)
Lesion of Ulnar nerve?
medial elbow entrapment =
- Numbness in 5th and 1/2 of 4th Digits
- Atrophy of Hypothenar/Interosseous
Lesion of radial nerve?
axillary entrapment = wrist drop
Lesion of peroneal nerve?
compr at fibular head or knee = foot drop
Demyelinating Neuropathy:
Nerves Affected?
large myelinated axons =
- fibers joining muscles
- fibers for reflexes
- position/vibratory sense
Demyelinating Neuropathy:
Path?
patchy segmental demyelination with preservation of axon
Demyelinating Neuropathy:
Symptoms?
weakness (proximal + distal), ↓reflexes, ↓epicritic + intact protopathic
Demyelinating Neuropathy:
Diseases?
Guillain Barre, Diphtheria, Diabetes
Axonal Neuropathy:
Etiology?
Uremia + Toxins
Axonal Neuropathy:
Symptoms?
- distal areflexia
- stocking-glove sensory deficit
- trophic changes
Axonal Neuropathy:
Pathology?
myelin ovoids characteristic of axonal degradation
Axonal Neuropathy:
Nerve conduction?
normal w/↓amplitude of APs
Wallerian Neuropathy:
Etiiology?
trauma + Vasculitis
Wallerian Neuropathy:
Path?
Toluidine blue stain demonstrates pale fascicle area without myelinated fibers
Charcot Marie Tooth Disease:
Etiology?
hereditary (AD) disease, periph demyelinating:
- Type 1A: del of myelin protein PMP Ch. 17
- Type 1B: def of protein 0 Ch. 1
**PMP 22: peripheral myelin protein is involved in compaction of myelin on peripheral nerves
Charcot Marie Tooth Disease:
Symptoms?
Signs Below Knee:
- distal muscle weakness
- atrophy of leg below knee
- orthopedic foot problems (hammer toe/↑arch feet)
DM Neuropathy:
Pathogenesis of diffuse sensory motor neuropathy?
↑Sorbitol + ↓Myoinositol In Nerves
DM Neuropathy:
Types of neuropathies?
- Mononeuropathy
- Mononeuritis Complex
- Dif Polyneuropathy (sensory, motor, ANS, mixed)
- Truncal (truncal sensory deficit)
- Diabetic Amyotrophy (LS Plexus ischemia)
DM Neuropathy:
Presentation of diffuse sensory motor neuropathy?
burning of feet –> numbness, weakness
DM Neuropathy:
Prognosis of diffuse sensory motor neuropathy?
improves w/ good control of DM
What causes the excess sorbitol in DN?
excess glu converted to sorbitol via aldose reductase
*Sorbitol Dehydrogenase: enzyme required to convert sorbitol —> fructose; lacking in Schwann Cells, Retina, Lens, Kidneys
What are the consequences of excess sorbitol in DN?
Osmotic damage –> ↑osmotically active particle in Schawnn Cells, which causes: Vasculopathy and Entrapment Neuropathies
DM Neuropathy:
Pathogenesis of mononeuritis, mononeuritis multiplex, and diabetic ophthalmoplegia?
caused by infarct to nerves or plexus
Guillain Barre Syndrome:
etiology?
AI, 2-weeks post-infection with Campy, EBV, CMV, Mycoplasma
Guillain Barre Syndrome:
Clinical findings?
- Paralysis
- Radiculoneuropathy: acute + inflammatory
- Mild paresthesia (no sensory defect)
- Areflexia
Guillain Barre Syndrome:
Description of paralysis?
- ascending –> respiratory/facial DZ
- progressive prox demyelination (occurs over 2-3 weeks post-infection)
- symmetrical
Guillain Barre Syndrome:
Trx?
- Symptoms: respiratory assistance
2. ɣ Globulin Infusion: get rid of antibodies
Chronic Inflammatory Neuropathy:
Etiology?
AI inflammatory neuropathy affecting the myelin sheath
Chronic Inflammatory Neuropathy:
Clinical findings?
- Paralysis (sym w/distal + prox features)
- Severe loss of epicritic system (intact pain/temperature)
- Conduction Block
- Areflexia
*no cranial nerve deficits or central demyelination
Chronic Inflammatory Neuropathy:
Path?
segmental demyelination with signs of de/re-myelination
Chronic Inflammatory Neuropathy:
Trx?
Steroids, Immunosuppressant, ɣGlobulin
Chronic Inflammatory Neuropathy:
Labs/Imaging/Biopsy?
- EMG shows ↓denervation
- incr CSF protein
- biopsy = segmental demyelination
