Bennet Flashcards
1
Q
Segmental demyelination
A
- selective loss of individual myelin internodes with preservation of the axon
- after demyelination, the reminaing schwann cells can proliferate and remyelinate the axon
- reconsituted myelin sheaths are both thinner with a shorter internodal length
2
Q
wallerian degeneration
A
- occurs after transection of the axon
- proximmally the axon will degenerate back to the node of ranvier, with possible chromatolysis of the cell body
- distally the axon and its myelin sheath disintegrate and are digested y the schwann cell
3
Q
Main categories of systemic neuopathy
A
- DIABETIC
- alcoholic
- nutritional
- guillain-barre
4
Q
axonal degeneration
A
- occurs when dysfunction of the neuron renders it unable to maintain its axon
- degeneration begins at the peripheral terminal of the axon, and proceeds towards the cell body, there is often chromatolysis of the cell body
- dysfunction can be halted regeneration and recovery of nerve function can occur
5
Q
symptomatology
A
- motor paralysis –> persistent impairment of motor function over weeks or months signifies segmental demyelination, axonal interruption or destruction of motor neurons
- tendon reflexes –> loss of reflexes is invariable sign of periperhal nerve disease
-
Fasciculations and cramps
- neuromyotonia = stat in which the affected muscles ripple and quiver and occassionally cramp
- Paresthesia and dysesthesisa = tingling, electric, novacaine like sensation (can be burning pain)
- Sensory ATAXIA and TREMOR
- Autonomic disorders = anhydrosis and orthostatic hypertension
6
Q
sensory loss in systemic neuropthy**
A
- tends to affect the distal segments of the limbs, preferably in legs
- PATTERN 1
- loss of touch pressure, vibratory, two-point discrimation, and joint position sense as the disease worsens the disease progresses proximally and includes loss of paina nd temp sensation
- PATTERN 2
- primary loss of pain and temp with a less impairment of pressure, vibratory, and position sense
- PATTERN 1
7
Q
Charcot marie tooth
A
- characterized by demyelinating and remyelination (motor and sensory deficits)
- stork leg appearance
- thenar and hypothenar wasting
- pes cavus, hammertoes
8
Q
Roussy-Ievy
A
- a varient of freidrich’s ataxia and CMT
- Static tremor
- mild distal weakness
- sensory loss
- Pes cavus and claw foot
9
Q
Guillian-barre syndrome
A
- Acute ascending motor paralysis
- possible triggered by unknown viral antigen
- Weakness is most common symptom, but leg pain, tingling and numbness are initial complaints
- reflexes are absent
- respiratory failure will ensue
- Autonomic
- instability of heart rate and blood pressure
- tx is plasmapharesis and immunoglobulin
10
Q
Neuropathies with disproteinemia
A
- there is an assoc. between polyneuropathy and multip myeloma and macroglobulinemia
- sensorimotor
- may be severe and does not reverse with suppression of myelome
- CONSISTENT WITH AXONAL DEGENERATION
11
Q
Alcohol neuropathy
A
- nutritional deficiency often occurs simultaneously with alcohol toxicity
- the neuropathy is usually sensorimotor caused by AXONAL DEGENERATION (pain and paresthesias)
- optic atrophy and myopathy can also be seen in chronic alcoholics
12
Q
Distal symmetric polyneuropathy
A
- MOST COMMONLY recognized form of diabetic neuropathy
- sensory deficits and symptoms, which generally predominate over motor involvement
- LOSS OF LARGE SENSORY AND MOTOR FIBERS = LOSS touch, proprioception, muscle function
- NEUROPATHIC PARESTHESIAS or DYSESTHESIAS
- LOSS OF SMALL FIBERS = LOSS ofpain and temp
- LOSS OF LARGE SENSORY AND MOTOR FIBERS = LOSS touch, proprioception, muscle function
- Appears first in the most distal portions of the extremities and progresses proximally (STOCKING-GLOVE DISTRIBUTION)
13
Q
Late complications of distal symmetric polyneuropathy
A
- foot ulcerations
- embedded foreign bodies
- unrecognized trauma
- neuroarthropathy
- chronic venous stasis ulcers
- vascular ulcers
14
Q
REVIEW SLIDES FOR THIS LECTURE… SUPER BORING
A
