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
Cryoglobulinemia is associated with this infection?
Hepatitis C
Triad of cranial nerve palsies, radiculitis and aseptic meningitis
Lyme disease
T/F: In contrast to acute GBS, many cases of CIDP respond favourably to the administration of prednisone
True
T/F: Multifocal motor neuropathy predominate in men.
True
Intermediate host for leprosy
Armadillos
T/F: A polyneuropathy that advances slowly over 10 years or more is almost invariably genetic in origin.
True
It is a multi system neurologic disease characterized by the widespread deposition in nervous tissue of corpora amylacea
Polyglucosan disease
Clinical manifestation of retinitis pigments, ataxia and chronic polyneuropathy coupled with an increase in blood phytanic acid.
Refsum disease
Drugs which may be helpful to alleviate the pain in Fabry Disease
Phenytoin, Carbamazepine, Gabapentin and Amitriptyline
well-known complications of acromegaly
nerve entrapment, polyneuropathy
Proven curative of familial amyloid polyneuropathy
Liver transplantation
If there is male-to-male transmission in Charcot-Marie-Tooth Disease, what gene should be investigated?
GJB1
It may be the only electrophysiologic abnormality early after a traumatic injury of the brachial plexus
absence of late responses (F wave)
The usual cause of a lesion of the entire brachial plexus
vehicular trauma
T/F: Erb-Duchenne palsy usually persist throughout life
True
Genetic basis for heredofamilial brachial plexopathy
SEPN1
Dose of radiation associated with radiation damage
> 6000 cGy
supplies the serratus anterior muscle which fixates the lateral scapula to the chest wall
long thoracic nerve of Bell
supplies the supraspinatus and infraspinatus muscles
suprascapular nerve
most frequent nerve entrapment syndrome
Carpal tunnel syndrome
consists of hyperflexion of the wrist for 30-60 seconds
Phalen Maneuver
elicited by lightly tapping the volar aspect of the wrist at the transverse carpal ligament (distal to the first wrist crease)
Tinel sign
manifest by a characteristic clawhand deformity, wasting of the small hand muscles
complete ulnar paralysis
T/F: The earliest symptom in metastatic lumbosacral plexopathy is usually pain whereas in radiation plexopathy it is weakness
true
this sensory nerve originates from the 2nd and 3rd lumbar roots and supplies the anterolateral aspect of the thigh from the level of the inguinal ligament
Lateral Cutaneous nerve
The most common cause of femoral neuropathy
Diabetes
Most common cause of sciatica
rupture of one of the lower lumbar intervertebral discs
T/F: Diplopia is common in MG but it does not correspond to the innervatory pattern of a nerve, instead it is the result of asymmetricak weakness of several muscles in both eyes.
True
T/F: Familial occurrence of Myasthenia Gravis is known but is rare.
True
T/F: The period of danger of death in MG is greatest in the 1st year and from 4-7 years after the onset.
True
T/F: A later age at onset of MG is associated with higher incidence of fatal respiratory crisis.
True
T/F: The number and size of the presynaptic vesicles and their quanta of acetylcholine are normal in Myasthenia graves.
True
T/F: A proportion of young women with MG have moderately elevated tigers of ANA without the clinical manifestations of SLE.
True
Given several minutes in advance to counteract the unpleasant muscarinic effect of neostigmine
Atropine 0.8mg
Starting dose of Azathioprine in MG
50 mg BID
An agent used in Lambert-eaton syndrome that blocks potassium channels in the distal motor terminal enhancing the release of Ach vesicles.
3,4-diaminopyridine (3,4-DAP)
Prenatal myasthenic disease which consist of arthrogryposis, pterygia and respiratory distress.
Escobar Syndrome
The serum enzyme other than CK that is derived predominantly from skeletal muscle.
Aldolase
Most susceptible element of the nerve fiber
Myelin sheath
Most common cause of acute or subacute generalized paralysis in practice.
Guillain-Barre syndrome
Most frequent identifiable antecedent infection in GBS
Campylobacter jejuni
T/F: Pain and aching discomfort usually precede weakness in GBS.
True