PNS Flashcards
T/F: Unmyelinated fibres are more numerous in peripheral nerves than myelinated ones.
True
It is the most susceptible element of the nerve fiber.
Myelin sheath
Focal degeneration of the myelin sheath with sparing of the axon
segmental demyelination
A reaction of both the axon and myelin distant to the site of disruption of an axon
Wallerian degeneration
It is a highly characteristic histopathologic change in the nerve cell body characterised as swelling of the cell cytoplasm and marginalisation and dissolution of the Nissl substance
chromatolysis
A condition with an axonal process in which there may be mainly proximal weakness.
Porphyria
T/F: The maximum degree of denervation atrophy after an acute injury to the axons occurs in 90-120 days and reduces muscle volume by 75-80%.
True
T/F: In the toxic and metabolic neuropathies, sensory loss usually exceeds weakness.
True
T/F: Polyradiculopathy differs from polyneuropathy in that the neurologic signs are asymmetrical with an erratic distribution.
True
Autoantibody seen in almost all patients with ophthalmoplegia in GBS
anti-GQ1b
Autoantibody with the highest tigers being associated with GBS cases that follow Campylobacter infection
Anti-GM1
In GBS, vital capacity below this level necessitates mechanical ventilation
10 ml/kg
The only serious reaction encountered in IVIg infusion
Anaphylaxis in those who congenitally lacked IgA
T/F: 5-10% of GBS patients encounter recurrence of the acute polyneuropathy.
True
Curative of acute ureic polyneuropathy
kidney transplantation
Initial and often the most prominent symptom of acute intermittent porphyria
moderate to severe colicky abdominal pain
The use of intravenous glucose and intravenous hematin is deemed as the most effective therapy
Porphyric Polyneuropathy
Agents that can produce a polyneuropathy that may be fatal in a matter of days
Triorthocresyl phosphate (TOCP), thallium, arsenic and other organophosphates
T/F: Almost all cases of paraneoplastic sensory neuropathy demonstrate anti-Hu antibodies.
True
It has the characteristic presentation of a motor mononeuropathy in the distribution of the radial nerves
Lead neuropathy
T/F: Chemotherapeutic agents particularly cisplatin, carboplatin and bortezomib are known to evoke a dose dependent predominantly sensory polyneuropathy
True
T/F: Isolated involvement of practically all the major peripheral nerves has been described in diabetes and the most frequently affected is the femoral nerve.
True
T/F: More than half of all cases of mononeuropathy multiplex can be traced to a systemic vasculitis involving the vasa nervorum.
True
T/F: A characteristic feature of Churg-Strauss disease is the excess of circulating and tissue eosinophils and a tendency of the vasculitis to involve the lungs and skin.
True