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
Hypokalemic periodic paralysis is associated with mutations in genes encoding for what ion channels?
Ca (10% Na)
Helpful in the prevention of HPP
Low sodium diet, avoidance of large meals and of exposure to cold, acetazolamide
Defined as sustained contraction or failure of muscular relaxation.
Myotonia
Autoantibody associated with the pharyngeal-cervical-brachial syndrome
GT1a
T/F: in contrast to the acute polyneuropathies, subacute polyneuropathy has prominent sensory features and are of axonal type.
True
In paraneoplastic neuropathy, improvement occurs if the tumor can be treated effectively except for this type?
Sensory neuronopathy
Nerve affected by Lead neuropathy
Radial nerve
It is the most common cause of polyneuropathy in general practice
Diabetes Mellitus
Nerve biopsy will show necrotizing arterities in medium-sized vessels with infiltrating eosinophils and occlusio of vessels.
Polyarteritis nodosa
Finding of circulating c-ANCA
Wegener granulomatosis
What type of arteritis occurs in Rheumatoid Arthritis?
Small-vessel fibrinoid type
Involvement of a single nerve with sarcoid most often implicates which nerve?
Facial nerve
Treatment of Lyme neuropathic syndrome
Ceftriaxone 2g OD for 1 month
Confirmatory test for celiac-sprue neuropathy
Antigliadin antibodies, anti-transglutaminase antibodies and histologic examination of a duodenal biopsy
T/F: monoclonal proteins underlie the largest group of otherwise unexplained neuropathies in adults.
True
Most often paraprotein class associated in polyneuropathy in adults.
IgM
Systemic condition occurring mainly in older persons and characterized by fatigue, weakness and a bleeding diathesis.
Macroglobulinemia
Most useful screening test for amyloid neuropathy
Serum and urine analysis searching for an abnormal paraprotein
T/F: In CIDP, the clinical course is monophasic in 1/3, stepwise and progressive in another third and relapsing in the remaining third.
True
Treatment for multifocal motor conduction block and motor neuropathy
IVIg infusion
The maximum degree of denervation atrophy after an acute injury to the axons occurs in how many days?
90-120 days
Main disability in CMT disease
Walking difficulty
The only distinguishing clinical feature between CMT type 1 and 2?
Enlargement of the nerves in type 1
The most prevalent form of CMT disease
CMT1A
A condition which is due to deletion of PMP22 in chromosome 17
Hereditary liability to pressure palsies (HNPP) (duplication in CMT disease)
T/F: in both CMT1A and HNPP, the PMP22 gene is functionally normal.
True
Diagnosis is based on a combination of retinitis pigmentosa, ataxia and chronic polyneuropathy coupled with an increase in phytanic acid.
Refsum disease (HMSN IV)
Manifested by the presence of enlarged yellow-orange (cholesterol-laden) tonsils
Tangier’s disease
Disease characterized by the congenital absence of the degradative enzyme sulfatase
Metachromatic Leukodystrophy
Often the most prominent manifestation of amyloidosis
Peripheral neuropathy
Vasculitic neuropathy characterized by its abrupt onset of pain or numbness at a focal site along a nerve followed in hours or days by motor or sensory loss in the distribution of that nerve and then by involvement in a saltatory fashion of other peripheral nerves
Polyarteritis nodosa
T/F: most patients with brachial plexus neuropathies develop without apparent cause
True
Genetic basis of heredofamilial brachial plexopathy
Mutation of SEPN1
Most common disorder affecting the median nerve and the most frequent nerve entrapment syndrome
Carpal tunnel syndrome
Manifested by the characteristic clawhand deformity
Complete ulnar paralysis
Most common cause of femoral neuropathy
Diabetes
The most frequently compressed nerve
Median nerve
T/F: The lingual nerve is a branch of the trigeminal mandibular nerve
True
T/F: Bell’s palsy is probably more common in diabetic and hypertensive patients.
True
In Bell’s palsy, what precedes recovery of motor function?
Recovery of taste
Bilateral facial palsy that is acute in onset and is associated with parotid gland swelling from sarcoidosis
Uveoparotid fever or Heerfordt syndrome
The sequential painless affection of contiguous or noncontiguous nerves over several days or weeks is particularly characteristic of what condition?
Meningeal carcinomatosis or lymphomatosis
Most frequent and most elusive symptom of myopathy.
Weakness
Another form of fibrous contracture that is found in newborns involving multiple muscle groups.
Arthrogryposis
T/F: As a general rule, muscle diseases are identified by a predominantly proximal weakness that is symmetric.
True
Popeye effect
Fascioscapulohumeral dystrophy
Most common cause of isolated quadriceps femoris weakness
IBM or a restricted form of Becker muscular dystrophy
The distinguishing feature of the disease is the early appearance of contractures in the flexors of the elbow, extensors of the neck and posterior calf of the muscles.
Emery-Dreifuss muscular dystrophy
The distinguishing feature of the disease is the early appearance of contractures in the flexors of the elbow, extensors of the neck and posterior calf of the muscles.
Emery-Dreifuss muscular dystrophy
T/F: The later the onset of Erb dystrophy, the more likely the course will be benign.
True
Most common adult muscular dystrophy
Myotonic dystrophy Type 1
Associated with an exaggerated forward curvature of the neck (“swan neck”)
DM1
Most common distal muscular dystrophy associated with dysferlin mutation
Miyoshi dystrophy
Characterized by a docal dissolution of myofibrils followed by an accumulation of degradative products
Myofibrillar myopathy
Optimal dose of prednisone which appears to slightly retard the tempo of progression of Duchenne dystrophy
0.75mg/kg given daily
T/F: With the exception of phosphoglycerate kinase deficiency, all the glycogenoses are inherited as autosomal recessive traits.
True
The primary abnormality is a deficiency in myophosphorylase
McArdle disease
How many percent of patients with myasthenia have hyperthyroidism?
5% (MG is 20-30x higher in hyperthyroidism)
In myoglobinuria, this is said to protect the kidneys by preventing myoglobin casts
Alkalinization of the urine by ingestion or infusion of sodium bicarbonate
The muscle biopsy shows elements of both myopathic and neuropathic disease with the special feature in muscle of rimmed vacuoles on the Gomori trichrome stain that are more central in the muscle fibers than those seen with inclusion body myositis.
Colchicine myoneuropathy
This enzyme is thought to function primarily during aerobic exercise and facilitate the regeneration of ATP from ADP through the action of adenylate kinase.
Myoadenylate
Disease characterized by severe cramping of muscle, universal alopecia, amenorrhea, intestinal malabsorption, epiphyseal destruction and retarded growth
Satoyoshi syndrome
Uncommon disease characterized by myotonia, muscular hypertrophy, nonprogressive course and dominant inheritance.
Myotonia congenita (Thomsen Disease)
Tonic spasm of muscle after forceful voluntary contraction
Myotonia
Infantile form of acid maltase deficiency
Pompe disease
The pathological hallmark for mitochondrial myopathy
Ragged red fibers
T/F: During the rigor phase in malignant hyperthermia, the oxygen consumption in muscle increases three-fold and serum lactate 15-20 fold.
True
Distinct form of periodic paralysis characterized by the triad of weakness, ventricular dysrhythmias with long QT syndrome and dysmorphic features.
Andersen disease
The phenomenon of pseudomyotonia is observed in what condition?
Hypothyroidism
Condition of persistent and intense spasms, particularly of the proximal lower limbs and lumbar paraspinal muscles.
Stiff man syndrome
Most characteristic finding in stiff man syndrome
Axial spasm
Myopathic condition with predominantly distal weakness and facial atrophy
Myotonic dystrophy
Most common type of Carnitine Palmitoyltransferase Deficiency
Type 1
Most common dystrophic change in a nonmuscular tissue in myotonic dystrophy
Lenticular opacities
What antibody is found in myasthenia gravis patients with negative AchR antibodies
MuSK antibody
Treatment of choice for multifocal motor neuropathy
IVIg infusion
Mechanism of action of nitric oxide damage to the spinal cord
Cobalamin inactivation
Sural nerve biopsy shows multiple focal thickening of myelin sheaths called tomaculum
Hereditary neuropathy with liability to Pressure palsies (HNPP)
Most common neurologic manifestation of multiple myeloma
Compressive radiculopathy
May present with distal arm and proximal leg weakness
Inclusion body myositis
Most prevalent neuromuscular disease in adults
Classic myotonic dystrophy type 1
T/F: Dermatomyositis affects children and adults while polymyositis affects adults and rarely children.
True
Causes disruption of muscle microtubule-dependent cytoskeletal network which leads to deficient transport and intracellular accumulation of lysosomes and autophagic vacuoles
Colchicine myopathy
Mostly affected in mitochondrial disorders
Transfer RNA
T/F: Nearly all cases of PEO are because of mitochondrial disorders.
True
Most typical feature of MERFF
Myoclonus
A 33 year old man presents with progressive weakness and impaired muscle relaxation, cataract, “hatchet face” and male pattern baldness with facial weakness. The genetic abnormality is most likely
Expanded unstable CTG repeat on chromosome 19q
This is also known as Rippling muscle disease because of severe elevation of Creatine kinase
Caveolinopathy
Bunina bodies is pathognomonic of what disease?
ALS
Cause of the waddle in Duchenne muscular dystrophy
Bilateral weakness of the gluteus medius
T/F: In dermatomyositis patients who respond to steroids, the serum CK decreases before the weakness subsides while with relapse, the serum CK rises before the weakness returns.
True
The clinical manifestations of neuropathic disorders are distal weakness and atrophy. However, what neuropathic condition present with proximal weakness instead?
Spinal muscular atrophy
T/F: Paresthesia and sensory loss in CTS often involves all fingers but should not involve the thenar eminence.
True
T/F: In cases of chronic muscle diseases, avoid biopsies of severely affected muscles but in cases of relatively acute muscle disease, select severely affected muscles.
True
Most common cause of femoral neuropathy
Diabetes
T/F: In entrapment neuropathies, function is gradually impaired, motor more than sensory
False (sensory more than motor)
T/F: In contrast to acute polyneuropathies, however, most that are subacute have prominent sensory features and are of axonal type.
True
T/F: Combined paralysis of the levator and orbicularis oculi muscles indicate a myopathic disease.
True
T/F: Carbohydrate is metabolized during aerobic and anaerobic phases of metabolism; fatty acids are metabolized only aerobically.
True
