S3_L4: Neuropathies Flashcards
Determine which kind of degeneration is described
- the nerve degenerate from the point of axonal damage outward
- “dying back” phenomenon
- Focal degeneration of the myelin sheath, axon is spared
A. Segmental demyelination
B. Wallerian degeneration
C. Axonal degeneration
- B
- C
- A
TRUE OR FALSE: Recovery is much slower with wallerian or axonal degeneration because the axon must first regenerate and then reinnervate the muscle, sensory organ, or blood vessel before function returns.
True
Source: Adams & Victor
TRUE OR FALSE: In segmental demyelination, recovery of function may be rapid because the intact but denuded axon needs only to become remyelinated.
True
Sensory neuronopathy is AKA?
Ganglionopathy
Degeneration that is progressive distal to proximal, resulting from metabolic, toxic, or degenerative disorders. It occurs as symmetrical neuropathies.
Axonal degeneration
What is the most susceptible element of the nerve fiber?
Myelin sheath
Determine which peripheral nerve is involved
- Compression of nerve on hard surface
- Entrapment of nerve under inguinal ligament
- Most common chronic entrapment peripheral neuropathy
- Compression over fibular head by cast, in debilitated patient sitting with legs crossed, or in inebriate sleeping on side on hard surface
- Compression of nerve in axilla or upper arm in patient sleeping with arm over chair back, edge of bed, etc, or by crutches
A. Lateral femoral cutaneous nerve
B. Peroneal nerve
C. Ulnar nerve
D. Radial nerve
E. Median nerve
- C
- A
- E
- B
- D
Determine which peripheral nerve is involved
- Thenar atrophy, tingling and pain in thumb, index, and middle fingers
- Foot drop
- Wrist drop
- Interosseous wasting between thumb and index finger
- Numbness and dysesthesias in lateral thigh
A. Lateral femoral cutaneous nerve
B. Peroneal nerve
C. Ulnar nerve
D. Radial nerve
E. Median nerve
- E
- B
- D
- C
- A
Most common of mononeuropathies that affect the cranial nerves
Facial mononeuropathy / Bell’s Palsy
Which cranial nerve is involved in Bell’s palsy?
Cranial nerve VII (facial nerve)
It is the most common polyneuropathy, commonly seen in more than 50 years of age.
Diabetic neuropathy
A polyneuropathy with infection with painful erythematous vesicular eruptions confined to dermatomal regions of the body.
Herpes zoster
It is an early pattern of sensory loss in leprosy, affecting cooler skin areas and it does not follow other segmental or nerve distribution.
Hansen’s disease
A polyneuropathy with infection that affects the ear, face, and nose. It has centrally healed areas and tend to be hyperstatic. In late stages, claw hand may be present. However, warm areas are not affected.
Leprosy
An ancillary procedure used to determine whether the cause of the polyneuropathy is metabolic, nutritional, or toxic.
Biochemical tests
It is the most commonly used ancillary procedure to determine if a nerve injury is present. It localizes the site of the injury along the course of the motor unit.
Electromyography-Nerve Conduction Velocity (EMG-NCV) tests
Determine the corresponding chronicity of the ff
- Muscle atrophy
- Inflammatory, immunologic, toxic, or vascular etiology
- Toxic, nutritional, and systemic diseases of nerve
- Hereditary or a metabolic disease
A. chronic, evolve slowly over many years
B. several months, long standing etiology
C. acute onset with rapid evolution
D. subacute, over several weeks and months
- B
- C
- D
- A
Determine the corresponding clinical pattern of the ff neuropathies
- Weakness and sensory loss in the territory of a single peripheral nerve
- Disorders of the network of nerves; Only one limb is affected
- Weakness is symmetrical and progress bilaterally
- Mononeuropathy multiplex
- Neurologic signs are asymmetrical & it affects multiple spinal nerve roots
A. Polyneuropathy
B. Polyradiculopathy
C. Mononeuropathy
D. Plexopathy
E. Multiple mononeuropathies
- C
- D
- A
- E
- B
Determine whether it is a motor or sensory neuronopathy
- disorder of the anterior horn cells
- ganglionopathy
- loss in both proximal and distal distributions
- widespread weakness, fasciculations, and atrophy
A. Motor neuronopathy
B. Sensory neuronopathy
- A
- B
- B
- A
Determine which type of CMT is described
- Loss of pupillary reflex
- Begins in the second decade of life
- Hypertrophic
- Glove-and-stocking hypesthesia
- Tendon reflexes preserved except ankle jerk
A. CMT type 1
B. CMT type 2
C. CMT type 3
- C
- B
- A
- C
- B
Determine which type of CMT is described
- Most common CMT form
- Dejerine-Sottas disease
- Slowing of motor conduction with segmental demyelination and onion bulb formation
- Autosomal recessive trait
- Peripheral nerves are not enlarged
A. CMT type 1
B. CMT type 2
C. CMT type 3
- A
- C
- A
- C
- B
Determine which type of CMT is described
- Distal impairment of vibration and position sense
- Most common pattern of inheritance is autosomal dominant
- Mild axonal degeneration
- All reflexes lost
- Severe infantile, Beginning in childhood or infancy
A. CMT type 1
B. CMT type 2
C. CMT type 3
- A
- A
- B
- A
- C
Determine which type of CMT is described
- Pain and paresthesias in the feet are early symptoms
- hypomyelination neuropathy of infancy
- charcot’s joint on both ankle d/t lack of pain sensations
- Life expectancy is normal
- In the severe congenital form, death may occur
A. CMT type 1
B. CMT type 2
C. CMT type 3
- C
- C
- A
- A
- C
It is the most common form of inherited peripheral neuropathy
Charcot-Marie-Tooth Disease
Enumerate the 4 Hallmarks of CMT
- Genetic transmission
- Complete symmetry
- Slow progression
- Loss of myelin out of proportion to axons
Charcot-Marie-Tooth Disease is AKA?
Provide the 2 other names
Hereditary Motor-Sensory Neuropathy (HMSN)
Peroneal muscular atrophy
Which fiber type has no myelin?
C fibers
Determine the corresponding function of the ff fibers
- Unmyelinated pain and temperature fibers
- intrafusal muscle fibers
- touch, pressure, vibration, stretch
- extrafusal skeletal muscles
- Preganglionic autonomic fibers
- Some nerve endings serving pain, pressure, temperature, and touch
A. Alpha
B. Beta
C. Gamma
D. Delta
E. B fibers
F. C fibers
- F
- C
- B
- A
- E
- D
What are the three symptoms that are not prominent features in most neuropathies?
Fasciculations, Cramps, Spasms
Determine which event in Wallerian degeneration occurs with the ff timeframes
- Myelin gets denatured chemically
- Macrophages from the endoneurium invade the degenerating myelin sheath
- Neurofilaments break up
- Myelin sheath breaks down into lipid droplets around the axon
A. In less than 24 hrs
B. Within 10 days
C. Within a month
D. Within 3 mos
- C
- D
- A
- B
The primary process of myelin breakdown involves the (1)___, while the secondary process involves the (2)___.
- Schwann cell
- Axonal disease
It is a polyneuropathy d/t a specific degeneration of a whole nerve cell
Neuronopathy
What is the recovery rate of peripheral nerves?
3 mm/day
What pattern of sensory loss is seen with metabolic causes of neuropathy?
Stocking-glove pattern
What is the best diagnostic test samples for arsenic poisoning?
Hair and nail samples
Arrange the events of degeneration in order
1. Regeneration of the axon & the excess sprouts degenerate
2. Chromatolysis is associated in time with sprouting
3. Target cell is reinnervated & chromatolysis is no longer present
4. Motor axon has been severed, and the motor neuron is undergoing chromatolysis
4213
In neuropathies that affect the largest diameter, heavily myelinated fibers, what is affected early and out of proportion to weakness?
Tendon reflexes
It is pain due to stimulus not usually causing pain, such as tactile stimuli.
Allodynia
It is the term for the sensory threshold is actually raised and it is the sensory experience or response that is exaggerated
Hyperpathia
It is the term for increased sensitivity to stimulation
Hyperesthesia
In the DM clinical syndrome called acute ophthalmoplegia, which cranial nerves are affected?
Cranial nerves 3 and 6 (Oculomotor and abducens)
The preventive treatment for diabetic neuropathy is
Maintain blood glucose close to the normal range
TRUE OR FALSE: Porphyria is an axonal process in which there may be mainly proximal weakness, making it an exception to the distal axonal pattern
True
Source: Adams & Victor
TRUE OR FALSE: In neuropathies, sensation is affected symmetrically in the distal limbs, and more in the legs than in the arms
True
It is a previously very common infectious disease of the spinal cord and CNS d/t syphilis, purely affecting the posterior roots. Ataxia without weakness is a characteristic of this disease
Tabes dorsalis
Source: Adams & Victor
Sensory ataxia could be a manifestation of large fiber peripheral neuropathies and conditions that cause dysfunction of what structure in the spinal cord?
Dorsal column
A cellular or humoral attack on various components of myelin is a classic example of?
Guillain-Barre Syndrome
Determine the classification of the ff disorders of peripheral nerves
- Benign monoclonal gammopathy
- Charcot-Marie-Tooth (CMT)
- Infiltrative polyneuropathy
- Paraneoplastic neuropathies
- Multiple myeloma
A. Genetically determined
B. Polyneuropathy with paraproteinemia or dysproteinemia
C. Polyneuropathy with malignant disease
- B
- A
- C
- C
- B
Determine the classification of the ff disorders of peripheral nerves
- Uraemic neuropathy
- Heavy metal poisoning
- Nutritional neuropathy
- HIV
- Diphtheria
A. Metabolic polyneuropathy
B. Toxic polyneuropathy
C. Polyneuropathy with infection
- A
- B
- A
- C
- B
Determine the classification of the ff disorders of peripheral nerves
- Chronic relapsing demyelinating polyneuropathy
- Acute demyelinating or axonal polyneuropathy
- Porphyria
- Metachromatic leukodystrophy
- Refsum’s disease
A. Guillain-Barre syndrome and related disorders
B. Hereditary neuropathies with known biochemical abnormalities
- A
- A
- B
- B
- B
TRUE OR FALSE: Diphtheria is when a bacterial toxin acts directly on the membranes of the Schwann cells near the dorsal root ganglia and adjacent parts of motor and sensory nerves.
True
Source: Adams & Victor
TRUE OR FALSE: In toxic and metabolic neuropathies, sensory loss exceeds weakness
True
Which deep sensation is often affected more than the others when sensory loss is present?
Vibratory sense
TRUE OR FALSE: The distally predominant pattern in impairment of motor function is not generally found in the acute and chronic demyelinating inflammatory neuropathies.
True
A patient presents with loss of sensory functions but has preserved reflexes.
What may be implicated?
Affectation of central projections of the sensory ganglion cells
It manifests with particularly intense, severe form of burning pain in a limb, usually from a traumatic partial nerve lesion of the ulnar, median, posterior tibial, peroneal, or occasionally some other nerve.
Causalgia
It is a pattern of diverse, asymmetric nerve involvement. The onset is non-simultaneous and the lower limb is more commonly affected.
Mononeuropathy multiplex
Diminution or loss of tendon reflexes is a sign of?
Peripheral nerve disease
In diffuse axonal damage, which muscles are affected more severely and earlier than the others?
Lower extremity muscles
TRUE OR FALSE: Diffuse or localized arterial diseases may injure nerves by occluding their nutrient arteries (vasanorvorum).
True
What comprises the leptomeninges?
Arachnoid and pia mater
