PMR 5 - neuromuscular disorders Flashcards
Which of the following motor neuron diseases typically causes both upper and lower motor neuron signs?
a. Spinal muscle atrophy lI
b. Primary lateral sclerosis (PLS)
c. Amyotrophic lateral sclerosis (ALS)
d. Poliomyelitis
C) Weakness may be due to upper or lower motor neuron loss. Upper motor neuron (UMN) signs include weakness, spasticity, hyperreflexia, and upgoing plantar response.
Lower motor neuron (LMN) signs include weakness, atrophy, flaccidity, hyporeflexia, and fasciculations. ALS patients with UMN pathology will often have a loss of dexterity or feeling of stiffness in their limbs. Spasticity may further exacerbate weakness and loss of function. This is due to the involvement of the vestibulospinal and reticulospinal tracts. LMN symptoms in the ALS population include ( muscle weakness, with some muscle fasciculations, atrophy, and muscle cramping.
Cramping of abdominal or other trunk muscles should prompt a clinician to strongly consider ALS as a possible diagnosis.
Primary lateral sclerosis (PLS is classified as an UMN lesion. Spinal muscle atrophy II (SMA II) and poliomyelitis are classified as LMN lesions.
A 60-year-old man without any significant past medical history presents to vour outpatient office with asymmetric atrophy, weakness, and fasciculations.
He also complains of some difficulty swallowing his meals and complains of a strained and strangled quality in his speech. He describes normal bowel and bladder function. Which of the following is most likely his diagnosis?
a. Amyotrophic lateral sclerosis (ALS)
b. Spinal muscle atrophy III
c. Primary lateral sclerosis (PLS)
d. Poliomvelitis
A) ALS most commonly affects people in the age group of 40 to 60 years, and the mean age of onset is around 60 years. Onset is > usually insidious and painless. Asymmetric weakness is the most common presentation.
Dysphagia (oral, pharyngeal), dysarthria, drooling, and aspiration can occur and are signs and symptoms representing bulbar muscular weakness. Also, strained, strangled quality of speech, reduced rate, and low pitch indicate a spastic dysarthria. Bowel and bladder function is typically spared in ALS.
Which of the following is considered a poor prognostic factor in patients with amyotrophic lateral sclerosis (ALS)?
a. Predominance of upper motor neuron (UMN) findings at diagnosis
b. Long period from symptom onset to diagnosis
c. Younger age of onset
d. Pulmonary dysfunction early in the clinical course
D) Poor prognostic factors include predominance of lower motor neuron (LMN)
findings at diagnosis, short period from symptom onset to diagnosis, and older age at time of onset. Bulbar and pulmonary dysfunction early in the disease course is also a poor prognostic factor. Women typically present with bulbar symptoms, as compared with men. It is important to note that electrodiagnostic indicators of poor prognostic indicators include profuse spontaneous fibrillations, positive sharp waves, and low-amplitude compound muscle action potential.
What is the prognosis for patients with amyotrophic lateral sclerosis?
a. 50% die within 3 years
b. 100% die within 3 years
c. 50% live up to 7 years
d. 50% live up to 10 vears
A) The overall median 50% survival rate is
2.5 years after diagnosis. Survival rate is largely dependent on a patient’s decision to use mechanical ventilation and/or a feeding tube, but the 5-year survival rate is between 4% and 30%. Around 10% will live for 10 years.
Which of the following pharmacologic agents has been approved for patients with amyotrophic lateral sclerosis (ALS)
to slow the progression and improve survival?
a. Levodopa
b. Riluzole
c. Baclofen
d. Rebif
B) This is an antiglutamate agent that may be effective in slowing the disease, prolonging ventilator time, and may improve survival in patients with bulbar onset disease.
However, side effects can include asthenia, and the medication is expensive.
Nonpharmacological management of ALS includes rehabilitation, preventing contractures, submaximal exercise, tracheostomy, and respiratory therapy. Rebif is a beta interferon that is used to modify the course in multiple sclerosis patients. Baclofen is a derivative of gamma-aminobutyric acid (GABA) and is primarily used to treat spasticity. Levodopa is a medicine used to control symptoms of Parkinson’s disease.
Levodopa does not slow the disease process, but it improves muscle movement and delays severe disability.
Which of the following motor neuron diseases typically causes lower motor neuron signs and has the earliest disease onset?
a. Kugelberg-Welander disease
b. Primary lateral sclerosis (PLS)
c. Amyotrophic lateral sclerosis (ALS)
d. Werdnig-Hoffmann disease
D) Upper motor neuron signs include weakness, spasticity, hyperreflexia, and upgoing plantar response. Lower motor neuron signs include atrophy, flaccidity, hyporeflexia, and fasciculations. Werdnig-Hoffmann disease is also known as spinal muscular atrophy type I, or acute infantile-onset SMA. This severe disorder often results in death by the age of 2, and disease onset is 3 to 6 months. Recent studies have shown that there is a reported increase in longevity, most likely a result of better overall medical management. However, SMA type I carries the worst prognosis of all the forms of SMA, as patients may never be able to reach the childhood milestone of sitting independently.
The disease course is rapid and fatal secondary to respiratory failure. SMAll and III have later onset, and progression is generally slower. Kugelberg-Welander disease is also called SMA type III. All forms of spinal muscle atrophy are classified as lower motor diseases. PLS is an upper motor neuron disease, and ALS is classified as both upper and lower lesion motor disease.
A 16-year-old male presents to your office with concerns that recently he uses his hands and arms to “walk” up his own body from a squatting position.
He states that he was otherwise independent with standing and walking and has been doing well as a student and plans on attending college. Which lower motor neuron disease does he most likely have?
a. Spinal muscular atrophy (SMA) type I
b. SMA type lI
c. SMA type III
3d. Amyotrophic lateral sclerosis (ALS)
C) SMA type III (spinal muscular atrophy) is also known as Kugelberg-Welander disease.
The disease onset is later than that of type I and II, occurring between 2 and 15 years of age. Patients typically live a normal life expectancy. The progression is slower than the other two variants. Patients usually achieve independent standing/walking. This patient presents with Gower’s sign, which can be seen in SMA type III patients because proximal weakness is greater than distal weakness. These patients typically have normal intelligence. Complications in SMA III are less frequent, but may include hand tremor, tongue fasciculations (late onset), and areflexia. All forms of spinal muscle atrophy are classified as lower motor diseases, and ALS is classified as both upper and lower lesion motor disease.
A patient with spinal muscular atrophy
(SMA) type iI (chronic Werdnig-Hoffmann) can usually achieve which of the childhood milestone below?
a. Assisted sitting
b. Independent sitting
c. Independent standing
d. Independent ambulation
B) SMA type Il is also known as chronic Werdnig-Hoffmann. The disease onset is between 2 and 12 months, and death (often by respiratory failure) occurs by 10 years of age.
These patients can usually achieve.
milestones including independent sitting.
They may be able to stand or walk with an assistive device. Answer choice D is therefore incorrect and refers to someone with SMA type III. SMA type I patients never attain the ability to sit independently, and this severe disorder usually results in death by the age of 2.
Which of the following motor neuron diseases has the best prognosis?
a. Kugelberg-Welander disease
b. Chronic Werdnig-Hoffmann
c. Werdnig-Hoffmann disease
d. Both B and C, as their clinical course is similar
A) Spinal muscular atrophy (SMA) type lis also known as Werdnig-Hoffmann disease.
Death usually occurs by 2 to 3 years of age.
The progression is rapid and fatal. Patients with SMA type II, known as chronic Werdnig-Hoffmann, usually die by about 10 years of age. Again, the progression is fatal. Patients with SMA type IlI, known as Kugelberg-Welander disease, have a normal life expectancy with a slow progression.
Which of the following pharmacologic agents is a first-line treatment for spasticity in patients with amyotrophic lateral sclerosis (ALS)?
a. Tizanidine
b. Dantrolene
c. Benzodiazepine
d. Baclofen
D) Baclofen is a GABA analogue used to facilitate motor neuron inhibition at spinal levels and is the first-line treatment. Dosing can be started at 5 to 10 mg two to three times per day. It can be titrated up to 20 mg four times per day. Potential side effects include weakness, fatigue, and sedation. Patients must be informed that abrupt discontinuation of baclofen may cause withdrawal seizures. Tizanidine is an alpha-2 agonist.
Benzodiazepine can be helpful, but can cause respiratory depression and somnolence.
Dantrolene blocks calcium release in the sarcoplasmic reticulum and is ineffective at reducing muscle tone, but can cause generalized muscle weakness.
Which of the following is the most common presenting form of motor neuron disease in adults?
a. Amyotrophic lateral sclerosis (ALS)
b. Poliomyelitis
c. Spinal muscular atrophy (SMA)
d. Primary lateral sclerosis (PLS)
A) ALS is also called Lou Gehrig’s disease, as it was named after the New York Yankees’ first baseman who passed away from this disorder. This is unfortunately still the most widely known motor neuron disease and is the most common presenting form. The incidence of ALS is approximately 1.6 to 2.4 cases per 100,000 population.
Which of the following is not included in the Halstead and Rossi (1987) criteria in defining postpolio syndrome?
a. History of previous diagnosis of polio
b. Stability for approximately 5 years
c. Recovery of function
d. No other medical problem to explain new symptoms of weakness/atrophy
B) The answer choice would be correct if it was stability for approximately 15 years.
Postpolio syndrome is a diagnosis based on exclusion. It has been well defined by the Halstead and Rossi criteria (1987): 1.
Confirmed history of poliomyelitis 2. Partial to fairly complete neurologic and functional recovery 3. A period of neurologic and functional stability of at least 15 years in duration 4. Onset of two or more of the following health problems since achieving a period of stability: unaccustomed fatigue, muscle and/or joint pain, new weakness in muscles previously affected and/or unaffected, functional loss, cold intolerance, new atrophy 5. No other medical diagnosis to explain these health issues.
Which virus has been implicated in the development of poliomyelitis?
a. Herpes virus
b. Papillovirus
c. Picornavirus
d. Poxvirus
C) Acute poliomyelitis is a disease that causes degeneration of the anterior horn cell, and is caused by the polio virus. The polio virus is a small RNA virus belonging to the enterovirus group of the picornavirus family.
Picornavirus orally enters the body and spreads via lymphoid system leading to orphaned muscle fibers and potential central nervous system involvement. All other answer choices are DNA viruses.
Of the following, which is a disorder of neuromuscular transmission due to an autoimmune response against acetylcholine receptors on the postsynaptic membrane?
a. Myasthenia gravis.
b. Lambert-Eaton myasthenic syndrome (LEMS)
c. Botulism
d. Amvotrophic lateral sclerosis (ALS)
A) Neuromuscular junction disorders can be classified into two categories: presynaptic or postsynaptic. LEMS and botulism are presynaptic disorders, and myasthenia gravis is a postsynaptic disorder. Myasthenia gravis is a disorder resulting in a decreased quantal response because of an autoimmune response against acetylcholine receptors on the postsynaptic membrane. LEMS is a disorder of neuromuscular transmission due to an autoimmune response against the active sites on the presynaptic membrane. Botulism is a disorder of neuromuscular transmission caused by Clostridium botulinum toxins blocking exocytosis of acetylcholine from the nerve terminal. ALS is a motor neuron disease that presents with both upper and lower motor neuron lesions that is caused by degeneration of the anterior horn cell
What is the etiology of Lambert-Eaton myasthenic syndrome (LEMS)?
a. Disorder of neuromuscular transmission caused by
Clostridium botulinum toxins blocking exocytosis of acetvicholine from the nerve terminal
b.Disorder of neuromuscular transmission caused by C. botulinum toxins blocking endocytosis of acetylcholine from the nerve terminal
c. Disorder resulting in a decreased quantal response because of an autoimmune response against acetylcholine receptors on the postsynaptic membrane
d. Disorder of neuromuscular transmission due to an autoimmune response against the active sites on the presynaptic membrane
D) This decreases calcium entry into the cell, causing a decreased release of acetylcholine into the synaptic cleft. There is a strong association with malignancy, such as small cell (oat cell) carcinoma of the lung.
Answer choice A describes botulism, and answer choice C describes myasthenia gravis.
A 45-year-old man presents to your office with complaints of fatigue and weakness that are exacerbated with rest and often improved with exercise. He denies vision disturbances bilaterally.
On physical exam, there is notable weakness in bilateral quadriceps. Which neuromuscular junction disorder may he have, and which location is affected?
a. Myasthenia gravis (MG);
postsynaptic
b. Lambert-Eaton myasthenic syndrome (LEMS); presynaptic 3 c. Myasthenia gravis; presynaptic
d. LEMS; postsynaptic
B) LEMS is a disorder of neuromuscular transmission due to an autoimmune response against the active sites on the presynaptic membrane. Patients complain of proximal fatigue and weakness that affects mainly the lower limbs, such as the quadriceps.
Symptoms are exacerbated with rest and improved with exercise. Rarely are there neck, facial, or bulbar muscle involvements. It is important to note that there is sparing of ocular muscles. There is also often an association with malignancy, most commonly oat cell carcinoma of the lung. Onset occurs more in males than in females (2:1) and in those older than 40 years. Unlike MG, LEMS patients may experience an increase in strength after a series of muscle contractions.
A 49-year-old woman presents to your clinic with complaints of fluctuating double vision and droopy eyelids. The patient is sent for a test where edrophonium chloride is injected, and there is brief improvement in her symptoms. Which of the following does she most likely have?
a. Myasthenia gravis (MG)
b. Lambert-Eaton myasthenic syndrome (LEMS)
c. Botulism
d. Amyotrophic lateral sclerosis (ALS)
A) Myasthenia gravis patients may complain of proximal muscle fatigue and weakness exacerbated with exercise, heat, or time of day (evening). It is important to note that there can be facial or bulbar symptoms, including ptosis, diplopia, dysphagia, or dysarthria. This patient presents with ocular myasthenia gravis. Ocular involvement is an extremely common initial presentation in MG patients. Drooping of eyelids and intermittent diplopia result from levator palpebrae (extraocular muscles) involvement, which is seen in 90% of MG cases. The test here describes the edrophonium (Tensilon) test.
An intravenous solution of edrophonium chloride is injected into a patient. A total of 10 mg of the cholinergic drug is prepared, and a
2-mg dose is injected. If there is no reaction in
30 seconds, the remaining 8 mg is administered. A brief improvement in muscle activity is regarded as a positive result.
Edrophonium chloride is also used to distinguish between myasthenia gravis and a cholinergic crisis. Because edrophonium chloride can precipitate respiratory depression, the test should not be performed unless an anticholinergic antidote, such as atropine, and respiratory resuscitation equipment are available.
A 49-year-old female presents to your clinic with complaints of fluctuating double vision 18. and droopy eyelids.
The patient is sent for a test where edrophonium chloride is injected, and there is brief improvement in her symptoms. Which of the following treatments is most appropriate?
a. Trivalent ABE antitoxin
b. Guanidine
c. Treat the malignancy
d. Mestinon
D) Mestinon (pyridostigmine) reversibly binds to and inactivates acetylcholinesterase, which is a cholinesterase inhibitor. This patient has myasthenia gravis (MG). Mestinon 60 to 120 mg orally every 3 to 8 hours can be used to treat MG. Other treatment options for MG include thymectomy, corticosteroids, immunosuppressive agents, and plasmapheresis. Answer choice C is correct in Lambert-Eaton myasthenic syndrome (LEMS) patients with malignancy. Initial treatment should be aimed at the neoplasm because weakness frequentlv improves with effective cancer therapy. No further LEMS treatment may be necessary in some patients.
Answer choice A is used for patients with botulism.
Symptoms of botulism present how soon after spore ingestion?
a. 1 hour
b. 2 to 4 hours
c. 1 day
d. 1 month
C) Symptoms such as blurred vision and diplopia can occur, along with nausea and vomiting, between 12 and 36 hours after consuming raw meat, fish, canned vegetables, or honey, making answer choice C the best answer. Bulbar symptoms are noted first and include ptosis, dysphagia, or dysarthria.
Gastrointestinal symptoms include nausea and vomiting, and then there may be widespread paralysis or flaccidity. If severe, there may be respiratory dysfunction. Lab work may reveal botulinum toxin in the stool or blood serum. Recovery occurs from collateral sprouting of nerves.
A 4-year-old boy is brought into your office because his mother has noticed that he has difficulty getting up from a seated position on the floor while playing with his toys. On physical exam, there is increased gastrocnemius calf circumference bilaterally. You think the child may have dystrophic myopathy.
The maneuver the child performs to assist him in standing is caused by:
a. Proximal leg weakness
b. Distal leg weakness
c. Proximal arm weakness
d. Distal arm weakness
A) The maneuver noted here is Gower’s sign, which is the inability to rise from a seated position on the floor. The patient has to use his hands and knees for assistance in a fourpoint stance. He will bridge the knees into extension and leans the upper extremity forward. This will substitute hip extension weakness (proximal leg weakness) and lean the upper extremities forward. The patient then moves the upper extremities up the thigh, and a full hip extension is achieved in an upright stance. The Gower’s sign indicates proximal muscle weakness. Also, this patient has pseudohypertrophy, which is seen in patients with either Duchenne or Becker’s muscular dystrophy. The enlargement in the calf is not due to increased muscle. It is a result of increased fat and connective tissue.
Which myopathy is characterized by a steadily progressive, X-linked muscular dystrophy that is characterized by absent dystrophin or less than 3% that is normal?
a. Becker’s muscular dystrophy (BMD)
b. Duchenne muscular dystrophy (DMD)
c. Limb-girdle muscular dystrophy (LGMD)
d. Facioscapulohumeral dystrophy (FSHD)
B) DMD is an X-linked disorder with an abnormality in the Xp21 gene locus. There is dystrophin deficiency that disrupts the membrane cytoskeleton and leads to membrane instability. Chronically, this will lead to fibrotic replacement of muscle and failure of regeneration, with muscle fiber death. Absent dystrophin or less than 3% of normal is diagnostic of DMD. Becker’s is also an X-linked disorder, but quantitative dystrophin analysis shows either 20% to 80% dystrophin levels. Answer choice C and D are not X-linked disorders.
Becker’s muscular dystrophy is characterized by:
a. Autosomal dominant condition
b. Autosomal recessive condition
c. X-linked, absent dystrophin
d. X-linked, reduced dystrophin
D) Becker’s muscular dystrophy has an X-linked inheritance, but has a slower clinical progression than Duchenne. They both have the same gene location (Xp21), but patients with Becker’s muscular dystrophy have 20% to 80 %, or even normal quantities, of dystrophin.
Which of the following myopathies is not associated with cardiac abnormalities?
a. Becker’s muscular dystrophy (BMD)
b. Duchenne muscular dystrophy (DMD)
c. Facioscapulohumeral dystrophy (FSHD)
d. Limb-girdle muscular dystrophy (LGMD)
C) The presence of cardiac abnormalities in FSHD is rare. It is important to note that cardiomyopathy is seen prominently in Becker’s and Duchenne muscular dystrophy.
These patients have abnormalities in the dystrophin protein that is also present in myocardium and Purkinie fibers. ECG abnormalities can be seen, such as Q waves in lateral leads, elevated ST segments, poor R wave progression, and resting tachycardia.
Cardiomyopathy is seen in nearly all patients older than 18 years in Duchenne.
Cardiomyopathy may also be seen in Limb-girdle muscular dystrophy.
Cognition may be impaired in which of the following myopathies?
a. Becker’s muscular dystrophy (BMD)
b. Duchenne muscular dystrophy (DMD)
c. Facioscapulohumeral dystrophy (FSHD)
d. Limb-girdle muscular dystrophy (LGMD)
B) The dystrophin isomer is present in the brain. Since there is an absence of this dystrophin protein in DMD, there have been lower intelligence quotients seen in affected children. Mean IQ scores have been 1 to 1.5 standard deviations below the normal population. An increase in autism and obsessive-compulsive disorder is also seen in DMD patients.
- A patient with Duchenne muscular dystrophy (DMD) is at risk to have which of the following as his or her disease progresses?
a. Sudden cardiac death
b. Contractures
c. Scoliosis
d. All of the above
D) Patients with DMD often have contractures by 13 years of age. The lower limb contractures have been strongly associated with wheelchair reliance.
Contractures may mostly affect ankle plantar flexors, knee flexors, hip flexors, iliotibial
L band, elbow flexors, and wrist flexors.
Scoliosis is prevalent in 33% to 100% in DMD patients and is strongly related to age. Fifty percentage will acquire scoliosis by the age of 12 to 15 years. There is no causal relationship between wheelchair use and scoliosis.
Cardiac abnormalities happen in DMD patients because of absence of dystrophin, which is also present in myocardium and Purkinje fibers. ECG abnormalities can be seen, such as Q waves in lateral leads, elevated ST segments, poor R wave progression, and resting tachycardia. Cardiomyopathy is seen in nearly all DMD patients older than 18 years.
An 18-year-old boy with an X-linked genetic disease has a mild functional disability, proximal muscles weakness, prominent calves, lordosis, and a waddling gait. He is not wheelchair bound. Which of the following conditions is he most likely to have?
a. Becker’s muscular dystrophy (BMD)
b. Duchenne muscular dystrophy (DMD)
c. Facioscapulohumeral dystrophy
(FSHD)
d. Limb-girdle muscular dystrophy (LGMD)
A) BMD is an X-linked muscular dystrophy with similar clinical pattern and gene locus to Duchenne, but with mild and slower progression. The patient in this question is 18 years old and is still able to ambulate.
Patients with Duchenne are usually wheelchair bound by the age of 10, if not treated with corticosteroids. Ambulation past 14 years of age should raise suspicion for a milder muscular dystrophy such as Becker’s or LGMD. LGMD is an autosomal recessive condition.
A 19-year-old female presents to your outpatient office with complaints of not being able to 27. smile or close her eyes.
She is not able to whistle and has some hearing difficulties. On physical exam, scapula winging is present. Which of the following is she most likely to have?
a. Becker’s muscular dystrophy (BMD)
b. Duchenne muscular dystrophy (DMD)
c. Facioscapulohumeral dystrophy (FSHD)
d. Limb-girdle muscular dystrophy (LGMD)
C) FSHD is a slowly progressive muscular dystrophic myopathy and involves the facial and shoulder girdle muscles. It is an autosomal dominant condition. Presentation is usually before the age of 20 and usually presents with weakness of the facial (orbicularis oculi and orbicularis oris) or shoulder girdle muscles (scapular and humeral distribution). Prominent scapula winging and biceps/triceps weakness may be present. There is relative sparing of the deltoid. Patients can be described as having an expressionless face and have difficulty with pursing lips, smiling, drinking through a straw, or whistling. There is also asymmetry of muscle involvement, which is unlike most other muscular dystrophies. Patients with FSHD also have sensorineural hearing deficits, and therefore all should have screening audiometry.
A teenager presents with an elbow flexion contracture and mild weakness that has affected 28. his ability to walk.
On physical exam, you also notice a neck extension contracture. Which of the following is the most likely to have?
a. Becker’s muscular dystrophy (BMD)
b. Emery-Dreifuss muscular dystrophy (EMD)
c. Facioscapulohumeral dystrophy (FSHD)
d. Limb-girdle muscular dystrophy
(LGMD)
B) This is an X-linked and slowl progressive myopathy caused by an abnormality of the protein emerin with a gene locus identified at Xq28. Patients usually present in the teenage years, and early el bow flexion contractures are the hallmark of the disease. Ankle equinus, rigid spine, and neck extension contractures can also be seen and are often more limiting than the weakness.
This disease is also associated with cardiac arrhythmias and almost always present by the age of 40. 24-hour Holter monitoring is required, as arrhythmias may not be obvious clinically or on routine ECG. EMD is managed by promotion of ambulation, prevention of deformities or their progression, monitoring cardiac status, and assessment of respiratory function.
All of the following are clinical features of facioscapulohumeral dystrophy except:
a. Inability to extend the wrist
b. Inability to whistle a
c. Deltoid muscle weakness
d. Protruding shoulder blades
C) Although the term facioscapulohumeral dystrophy (FSHD) would imply that all the muscles of the shoulder and upper arm are atrophic, the deltoid is surprisingly well preserved in many cases. This can be overlooked since scapular fixation prevents the deltoid from exerting its maximal effect. It is best to have the patient lying down with the examiner’s hand pressing down on the thorax backward to prevent the scapula from moving. When examined in this manner, the deltoid is normal in strength or only slightly weak. The inability to extend the wrist is a characteristic posture adopted by these patients. Answer choice B and D are cardinal clinical signs. Other clinical presentations may include lordosis and pelvic girdle weakness, deafness, and fundal changes.
Some patients may benefit from surgery that fixes the scapula to facilitate abduction of the arms.
In central core disease, all of the following may be present except:
a. Floppy infant
b. Congenital hip dislocation
c. Mitochondria present on muscle biopsy
d. Association with malignant hyperthermia
C) Central core disease is an autosomal dominant congenital myopathy. Onset is shortly after birth, and the infant is noted to be floppy and attains milestones slowly.
Congenital hip dislocation is often noted, and as the child ages, he or she cannot run and jump like their peers. Weakness is more pronounced in the proximal muscles, and patients can show a Gower’s sign. It is important to note that there is an association with malignant hyperthermia when receiving general anesthesia. This is because central core disease’s gene locus is at 19q13.1, which is the same gene locus as the malignant hyperthermia gene. On light microscopy, the muscle cells have cores that lack mitochondria.
A judicious workup for carcinoma is recommended in adult patients with newly diagnosed:
a. Inclusion body myositis
b. Polymyositis
c. Steroid myopathy
d. Dermatomyositis
D) Dermatomyositis is an inflammatory myopathy that appears to have an association with occult carcinoma in adults. The true incidence may be as high as 10% to 20%. Because of this, it is important to search for carcinoma in adult patients, especially males 40 years of age and older. There is a higher correlation with dermatomyositis and carcinoma, than with poly myositis. Steroid myopathy is a toxic myopathy and is caused by long-standing administration of exogenous steroids.
The age of onset for idiopathic inflammatory myopathies is:
a. Bimodal
b. Early
c. Late
d. Not specific and can occur at any time
A) The three primary types of inflammatory myopathy are polymyositis, dermatomyositis, and inclusion body myositis (IBM). All are thought to involve immune-mediated processes, possibly triggered by environmental factors in genetically susceptible individuals. The age of onset for idiopathic inflammatory myopathies is bimodal. Peaks occur between 10 and 15 years of age in children and between 45 and 60 years of age in adults.
A patient presents to vour office with malaise, fever, weight loss, and proximal muscle weakness and tenderness. On physical examination, he is noted to have a heliotrope rash with periorbital edema. Which of the following does he most likely have?
a. Primary idiopathic polymyositis
b. Primary idiopathic dermatomyositis
c. Rheumatoid arthritis
d. Childhood dermatomyositis or polymyositis
B) Patients with primary idiopathic dermatomyositis typically present with proximal muscle weakness and a characteristic rash on the face (heliotrope rash). A rash may also be noted on the extensor surfaces of the knees, elbows, ankles, and the dorsum of the hands.
Which of the following inflammatory myopathies is not treated primarily with corticosteroids or other
immunosuppressive medications?
a. Childhood dermatomyositis
b. Adult dermatomyositis
c. Polymyositis
d. Inclusion body myositis (IBM)
D) IBM clinically presents with asymmetric, slowly progressive, painless weakness in proximal and distal muscles. It is associated with a polyneuropathy. It is not responsive to pharmacologic intervention, such as steroids and immunosuppressive agents. Treatment choices primarily involve appropriate rehabilitation interventions, which include provision of assistive devices.
Childhood dermatomyositis is treated with only corticosteroids and is effective in inducing a remission and preventing a recurrence. Also, treatment can be stopped over time. Adult dermatomyositis and polymyositis are treated with corticosteroids and supplemented by immunosuppressive medications. This is usually not discontinued.
Which of the following is an ergot derivative and stimulates D2 receptors in the treatment of Parkinson’s disease?
a. Pergolide
b. Bromocriptine
c. Ropinirole
d. Pramipexole
B) Medications used to treat Parkinson’s disease work by increasing dopamine action and/or decreasing the cholinergic effect. Bromocriptine is an ergot derivative that stimulates dopamine D2 receptors. Nonergot derivatives include ropinirole (Requip) and pramipexole (Mirapex).
Which of the following is not a sign/symptom of Parkinson’s disease?
a. Impaired vibration or position sense
b.Resting tremor
c. Slowing of movements
d. Tremor superimposed on muscular rigidity
A) Of the signs/symptoms of Parkinson’s disease, the ones that are most common are resting tremor, bradykinesia/hypokinesia, and
“cogwheel” rigidity. The resting tremor (sometimes referred to as pill rolling tremor) is 3 to 5 Hz and is the most common symptom, affecting about 65% of patients.
The tremor is suppressed by activity or sleep and worsened by fatigue or stress.
Bradykinesia is slowing of movements.
“Cogwheel rigidity” is tremor superimposed on muscular rigidity. Other symptoms include a shuffling gait, masked facies, and postural instability. Patients can have depression, dementia, and/or orthostatic hypotension.
The movement disorder that results from a decrease in dopamine input in the striatum and an increase in cholinergic input is:
a. Multiple sclerosis
b. Friedreich’s ataxia
c. Parkinson’s disease (PD)
d. Huntington’s disease
C) PD involves a pathologic degenerative process of the brainstem nuclei. This is especially true of dopaminergic cells of the substantia nigra. In addition, there is an excess of cholinergic neurons in the caudate nuclei. This causes an imbalance between cholinergic and dopaminergic input in the striatum and is responsible for the symptoms seen in PD.
A patient with advanced Parkinson’s disease comes to your clinic hoping to decrease his symptoms. He has tried antiparkinsonian drugs, but still has resting tremor, rigidity, and bradykinesia that interfere with his quality of life. What can you recommend that may help reduce his symptoms?
a. Subthalamic deep brain stimulation
b. Thalamotomy
c. Pallidotomy
d. There is nothing more you can offer
A) Subthalamic deep brain stimulation has been effective in reducing symptoms and has been shown to reduce the need for antiparkinsonian medications by at least half.
This is the most common surgical procedure used in Parkinson patients, although destructive surgery is another option.
U Thalamotomy is surgical destruction of cells in the thalamus and can alleviate tremor on the contralateral side. Pallidotomy is the permanent ablation of part of the globus pallidus. This can be used in alleviating dyskinesias, stiffness, and the inability to perform or restart certain tasks.
Parkinson’s disease can be effectively medically treated with all of the following except:
a. L-Dopa
b. Dopamine receptor agonist
c. Dopamine receptor antagonist
d. Anticholinergic agents
C) An example of a dopamine receptor antagonist is haloperidol. This medication is used in movement disorders such as Huntington’s disease, but has extrapyramidal and anticholinergic side effects. These side effects can mimic parkinsonian-like symptoms, making answer choice C incorrect.
All other answer choices can be effectively used in the treatment of Parkinson’s disease.
Other treatment options can also include amantadine and selective monoamine oxidase
B (MAO-B) inhibitors.
A common side effect of anti-Parkinson drugs (e.g., Sinemet, Requip) is:
a. Facial flushing
b. Erectile dysfunction
c. Tachycardia
d. Postural hypotension
D) Postural hypotension is a common problem in many anti-Parkinson drugs.
Postural hypotension can be treated with salt tablets or mineralocorticoids (such as fl udrocortisone or midodrine). Other side effects of these medications include confusion and hallucinations. L-dopa may cause nausea, abdominal cramping, and diarrhea.
Of the following, which does not cause drug-induced Parkinsonism?
a. Metoclopramide
b. Interferon beta-1a
c. Amiodarone
d. Haloperidol
B) Interferon beta-1a is used to treat the relapsing/remitting form of multiple sclerosis.
Answer choices A, C, and D all may cause drug-induced Parkinsonism.
A 32-year-old man presents to your office with hyperkinetic, involuntary, jerky movements. His sister states that she fears he also has dementia and that he is acting like her deceased father, uncle, and grandfather. They all passed away after having similar symptoms.
This patient most likely has:
a. Parkinson’s disease
b. Multiple sclerosis
c. Huntington’s disease
d. Friedreich’s ataxia
C) Huntington’s disease is a hereditary disease (autosomal dominant) that has been linked to a trinucleotide CAG repeat HD gene.
GABA has been found in decreased levels in the basal ganglia, as well as there is a decrease in substance P and enkephalins.
The onset is usually from the ages 30 to 50, although 10% have been found to have juvenile onset, which occurs before the age of
20. Unfortunately, many die from aspiration pneumonia about 15 to 20 years after the onset of symptoms. The classic symptoms are chorea or choreoathetosis, which are hyperkinetic, involuntary, jerky movements.
The other classic symptoms are dementia and personality disorder. A family history is usually noted.
Which of the following is false regarding multiple sclerosis (MS) and pregnancy?
a. Relapses decrease during pregnancy
b. Higher relapse rate in the first 3 months postpartum
c. Women should not worry about pregnancy worsening their disease process
d. Increased incidence of MS by over 50% among their offspring
D) The incidence of MS in the offspring of patients with MS is only slightly increased (3% for girls and 1% for boys). The net effect of pregnancy on the course of MS is neutral.
This is due to the fact that there is a decrease in relapse during pregnancy, but higher than normal relapse during the first 3 months postpartum. Therefore, women should not fear that pregnancy can worsen their MS.
Which of the following is true of multiple sclerosis (MS) and pregnancy?
a. Interferon beta is a safe treatment option during pregnancy
b. Glatiramer acetate is a safe treatment option during pregnancy
c. Breastfeeding increases relapse rate in the first 6 months postpartum
d. Restarting disease-modifying agents during breastfeeding is recommended
B) Interferon beta is FDA category C for pregnancy and is therefore stopped before a woman decides to try to have a child.
Interferon beta has been shown to increase the rate of miscarriage. The risk for relapse is lower overall during pregnancy, so the drug is discontinued before conceiving. Glatiramer acetate is FDA category B and may be a better option for those who want to continue medications during pregnancy. Breastfeeding is known to decrease relapse rate in the first few months postpartum, and it is recommended to restart medications when breastfeeding is stopped.
The etiology of which disease is thought to be an autoimmune response causing demyelination, axonal damage, and brain atrophy?
a. Parkinson’s disease
b. Huntington’s disease
c. Multiple sclerosis (MS)
d. Guillain-Barré syndrome
C) MS is considered an autoimmune disease. The disease affects the central nervous system most likely by causing demyelination, leading to plaque formation.
The plaque causes oligodendrocyte destruction, astrocyte proliferation, and glial scarring, making the propagation of action potential down a nerve impossible. Remission may occur during this disease process as remyelination occurs.
Which of the following is false regarding multiple sclerosis?
a. Affects males more frequently
than females
b. Affects Caucasians more frequently than African Americans
C. Increased incidence in higher socioeconomic class
d. There is no change in long-term relapses in pregnancy
A) Multiple sclerosis actually affects females more than males (2:1 female to male ratio). Answer choices B, C, and D are all true.
The net effect of pregnancy on the course of
MS is neutral. This is due to the fact that there is a decrease in relapse during pregnancy, but higher than normal relapse during the first 3 months postpartum. Therefore, women should not fear that pregnancy can worsen their MS.
Of the several patterns of multiple sclerosis, which is most common?
a. Secondary progressive
b. Progressive-relapsing
C. Relapsing-remitting
d. Primary progressive
C) There are six different subtypes of multiple sclerosis (MS). Eighty-five percentage of MS cases are the relapsing-remitting form of MS. This form is characterized by an acute exacerbation followed by a remission period. During the remission, patients can return to their baseline function or may have some form of disability after an exacerbation. The six subtypes of MS are as follows:
1. Relapsing-remitting
2. Secondary progressive
3. Benign
4. Progressive-relapsing
5. Primary progressive
6. Malignant
The following are all considered good prognostic factors in multiple sclerosis
(MS) except:
a. Age of onset greater than 35 vears
b. Optic neuritis at onset
c. Monosynaptic symptoms
d. Ataxia and tremor
D) Ataxia and tremor have a poorer prognosis for MS patients. All others choices are good prognostic factors. Optic neuritis is inflammation of the optic nerve. It may cause sudden, reduced vision in the affected eye and is considered a good prognostic factor when presenting at onset in MS patients.
C) Friedreich’s ataxia is a type of spinocerebellar degeneration disease. It has an autosomal recessive genetic
predisposition. All the features listed above are associated with cerebellar injury. GBS is generally preceded by a viral etiology and then develops a spontaneous ascending paralysis that usually resolves without any of the cerebellar symptoms. In SMA, there is generalized proximal muscle weakness and wasting of upper and lower extremities, with signs of upper and lower motor neurons (degeneration of spinal cord and anterior horn cells).
