Chapter 27: Diseases of Peripheral Nerves Flashcards
Why is the peripheral nerve dysfunction caused by neuronopathies equally likely to affect proximal and distal parts of the body?
Damage at the level of neuronal cell body
Which structures are injured in the CMT2 variant of CMT disease and when does it present?
Axonal injury; typically severe w/ early childhood onset

Which type of neuropathy is seen with lepromatous leprosy (Hansen Disease) and which sensory fibers will be lost?
- Symmetric polyneuropathy affected cool distal extremities and face
- Involves pain fibers, loss of sensation = injury; since pt’s are rendered unaware of injurious stimuli –> large traumatic ulcers

If VZV is reactivated it travels along sensory nerves and leads to what?
Painful, vesicular skin eruption (shingles) in a sensory dermatomal distribution

Morphologically what is the most prominent lesion seen in Guillain-Barre Syndrome?
Segmental demyelination affecting peripheral nerves

Upon sural nerve biopsy in patient with Chronic inflammatory Demyelinating Poly(radiculo)neuropathy what is a characteristic finding?
Onion-bulbs: excessive proliferation –> multiple layers of Schwann cells wrap around an axon like the layers of an onion

Demyelinating forms of Charcot-Marie-Tooth (CMT) disease are associated with what morphological features?
- Demyelination and remyelination including Schwann cell hyperplasia —> Onion-bulb formation
- Hyperplasia may be so severe that involved nerve is palpably enlarged
Which type of neuropathy is the most common paraneoplastic form and which malignancy is it most commonly associated with?
Sensorimotor neuronopathy in setting of Small cell lung cancer = most common

Which nerve is affected in Morton neuroma and what histologic finding is seen?
- Interdigital nerve at intermetatarsal sites –> foot pain; “walking on a marble”
- Histologically = perineural fibrosis

What are the primary targets of damage in demyelinating neuropathies?
Schwann cells w/ their myelin sheaths
Clinical presentation of Guillain-Barre Syndrome is dominated by what signs/sx’s; what characteristic CSF finding will there be?
- Ascending paralysis and areflexia
- DTR’s lost early in the process
- ↑ CSF protein levels w/ little or no CSF pleocytosis (inflammatory cells remain confined to the roots

How is Chronic inflammatory Demyelinating Poly(radiculo)neuropathy treated?
Glucocorticoids + IVIg + plasmapheresis

Which dermatomes are commonly affected by VZV reactivation; what kind of damage is seen?
- Thoracic or trigeminal nerve dermatomes
- Neuronal destruction and loss of affected ganglia
- Axonal degeneration of periphral nerves after death of sensory neurons

What is a a distinctive presentation of neuropathy associated with monoclonal gammopathies?
POEMS: Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal gammopathy, and Skin changes

In lepromatous leprosy (Hansen Disease) Schwann cells are invaded by Mycobacterium leprae and what pattern of peripheral nerve damage will be seen?
Segmental demyelination and remyelination + loss of both myelinated and unmyelinated axons

Familial amyloid polyneuropathies are mainly due to germline mutations in which gene?
Transthyretin gene
Focal destruction of which neuronal structures may be seen with reactivation of VZV?
Large motor neurons in anterior horn or cranial nerve nuclei

“Saturday night palsy” is due to compression of which nerve?
Radial nerve in the upper arm

Prevalence of peripheral neuropathy associated with diabetes is dependent on what?
Duration of the disease

2/3’s of Guillain-Barre Syndrome cases are preceded by what; which etiologies have been implicated?
- Acute, influenza-like illness
- Campylobacter, CMV, EBV, and Mycoplasma penumoniae, or prior vaccination

Other than peripheral neuropathy, what is another manifestation of diabetic nervous system dysfunction that is often seen?
Autonomic dysfunction: postural hypotension, incomplete bladder emptying (↑ infections) and sexual dysfunction

Mononeuritis multiplex describes a disease process that damages several nerves in a haphazard fashion and is commonly due to what?
Vasculitis i.e., polyarteritis nodosum

Which painful nodule composed of non-neoplastic haphazard whorled proliferation of axonal processes and assoc. Schwann cells results from failure of axons to find their distal target during regeneration ?
Traumatic neuroma aka “pseudotumor”

Characteristic “stocking and glove” distribution of sensory deficits is seen with what anatomic pattern of peripheral neuropathies?
Polyneuropathies













