Neuromuscular Flashcards
Which pulmonary parameter is predictive of mortality in a child with Duchenne muscular dystrophy?
(a) Maximal expiratory pressure
(b) Peak flow rate
(c) Cough peak flow
(d) Forced vital capacity
Answer:(d)
Commentary: One simple method of assessing the interplay between pump function and load is the measurement of the forced vital capacity (FVC) and fractional lung volumes. In boys with Duchenne muscular dystrophy (DMD), the relationship between the absolute value of FVC and age can be divided into 3 epochs: one of gradual increase coincident with their ambulatory period, followed by a plateau phase at 10 to 12 years when they become confined to wheelchairs, and then a gradual but persistent decline thereafter. However, when the FVC is described as a percent of the predicted value, it is lower than normal and diverges from the normal curve over time. The decline in FVC to a value of less than 1 liter may also predict mortality in patients who do not receive assisted ventilation.
Reference: Panitch H. The pathophysiology of respiratory impairment in pediatric neuromuscular disease. Pediatrics 2009;123(suppl):S215-S218.
Your patient is having difficulty writing or performing tasks in certain positions. He has an asymmetric tremor that is present only with movement. You suspect which type of tremor?
(a) Essential
(b) Primary orthostatic
(c) Cerebellar
(d) Dystonic
Answer: (d)
Commentary: Suspect a dystonic tremor if it is very asymmetrical and shows postural dependence. There may be associated dystonia elsewhere in the body. The tremor may have task specificity, such as writing or postural dependence. A cerebellar tremor will often have other cerebellar signs present and often improves if the patient performs movement with eyes closed. Essential tremor is symmetrical and best seen with an outstretch hand. Primary orthostatic tremor presents as unsteadiness or tremor in the legs that increases with prolonged standing, and the symptoms are relieved by sitting or walking.
Reference: Harris MK, Shneyder N, Borazanci A, Korniychuk E, Kelley RE, Minagar A. Med Clin
North Am. 2009;93(2):371-388.
A significant improvement in quality of life for advanced ALS patients is attributed to
(a) having advanced directives.
(b) invasive ventilation to prolong life.
(c) earlier hospice transition.
(d) placement in long-term care.
Answer:(c)
Commentary: Improved quality-of-life for advanced ALS patients is attributed to optimizing inhome
care and early hospice transition. Hospice can ease the burden of care by the family members. Hospice organizations have guidelines for early entry into hospice during advanced stages. Most patients who undergo invasive mechanical ventilation do so emergently and often against their wishes. Invasive ventilation is not preferred in over 92% of ALS patients surveyed. Often, there is a lack of advanced directives to guide the treating team. Lack of physician communication with the patient about advanced directives is the major barrier to patients developing their advanced directives.
Reference: Joyce N, Carter G. In: Braddom RL. Physical medicine and rehabilitation. 4th ed. Philadelphia: Elsevier-Saunders; 2011. p1056-7.
Which pulmonary function parameters would you expect to increase in a child with advanced neuromuscular disease?
(a) Total lung capacity
(b) Vital capacity
(c) Residual volume
(d) Expiratory reserve volume
Answer:(c)
Commentary: Patients with neuromuscular diseases (NMDs) demonstrate a restrictive pattern when fractional lung volumes are measured. There is a reduction in total lung capacity, vital capacity, and the expiratory reserve volume. In contrast, residual volume (the volume of air that remains in the lungs after a maximal, complete expiratory maneuver) can actually be elevated when the respiratory muscles are too weak to deform the chest wall inward to deflate the lungs fully. These patterns will be exaggerated in children with NMDs who also develop scoliosis.
Forced expiratory flows are typically reduced in proportion to lung volume so that the ratio of the
forced expiratory volume in the first second (FEV1) to FVC is normal or high.
Reference: Panitch H. The pathophysiology of respiratory impairment in pediatric neuromuscular disease. Pediatrics. 2009;123(suppl):S215-S218.
Which deep heat method recommends the use of protective eyewear to prevent the formation of
cataracts?
(a) Ultrasound
(b) Short wave diathermy
(c) Fluidotherapy
(d) Microwave diathermy
Answer:(d)
Commentary: Microwave diathermy is another form of electromagnetic energy that uses conversion as its primary form of heat production. Temperature distribution in a particular tissue is affected largely by its water content. In general, tissues with high water content absorb greater amounts of energy and are selectively heated. General heat precautions should be observed with microwave procedures. Metal implants, pacemakers, sites of skeletal immaturity, reproductive organs and brain, and fluid-filled cavities (eye, bullae, effusions, etc.) should be avoided. Microwaves can cause cataracts and protective eye wear should be worn by both patient and
therapist to reduce risk.
Reference: Basford J. Therapeutic physical agents. In: DeLisa JA, Gans BM, Walsh NE, editors.
Physical medicine and rehabilitation: principles and practice. 4th ed. Philadelphia: Lippincott-
Raven; 2005. p 260.
Which disorder does NOT have pes cavus as a feature?
(a) Poliomyelitis
(b) Cerebral palsy
(c) Friedreich ataxia
(d) Peroneal spastic foot
Answer: (d) Commentary: The etiology of pes cavus includes malunion of calcaneal or talar fractures, burns, sequelae resulting from compartment syndrome, residual clubfoot, and neuromuscular disease. The remaining cases are idiopathic and nonprogressive. Neuromuscular diseases, such as muscular dystrophy, Charcot-Marie-Tooth (CMT) disease, spinal dysraphism, polyneuritis, intraspinal tumors, poliomyelitis, syringomyelia, Friedreich ataxia, cerebral palsy and spinal cord tumors can cause muscle imbalances that lead to elevated arches. Multiple theories have been proposed for the pathogenesis of pes cavus. Duchenne described intrinsic muscle imbalances causing an elevated arch. Whereas, peroneal spastic foot is characterized by pain in the foot, limited subtalar motion, pes planus deformity, and shortening with spasm of the peroneal muscles often initiated by minor trauma or unusual activity.
Reference:Turner, NS. Pes Cavus. E medicine 2010. Available at: http://
Which muscle group displays the earliest pattern of weakness in Duchenne muscular dystrophy?
(a) Ankle dorsiflexors
(b) Neck flexors
(c) Shoulder flexors
(d) Knee extensors
Answer: (b) Commentary: In Duchenne muscular dystrophy, weakness is first seen in the neck flexors during preschool years. Pelvic girdle weakness precedes shoulder girdle weakness by several years. Ankle dorsiflexors are weaker than plantarflexors; ankle everters are weaker than inverters; knee extensors are weaker than flexors; hip extensors are weaker than flexors.
Reference:McDonald CM. Neuromuscular diseases. In: Alexander MA, Matthews DJ, editors. Pediatric rehabilitation: principles and practice. 4th ed. New York: Demos; 2010. p 289.
Which symptom most frequently impacts quality of life in patients with incurable cancers?
(a) Fatigue
(b) Anorexia
(c) Weakness
(d) Depression
Answer: (a) Commentary: Cancer patients experience a much broader range of symptoms that impact their quality of life and their ability to address existential issues at the end of life than those listed here. A systematic review of symptom prevalence studies in patients with incurable cancer identified fatigue (74%), pain (71%), lack of energy (69%), weakness (60%) and anorexia (53%) being the most prevalent that impact quality of life. The prevalence of nausea is 40% in the last 6 weeks of life. Fatigue is often the primary condition adversely affecting quality of life.
Reference: (a) Brooksbank M. Palliative care: Where have we come from and where are we going? Pain 2009;144 (3):233-5.(b) Cheville AL. Palliative care. In: DeLisa JA, Gans BM, Walsh NE, editors. Physical medicine and rehabilitation: principles and practice. 4th ed. Philadelphia: Lippincott-Raven; 2005. p 536-7.
Which symptom is the most predictive of cardiac disease in Duchenne muscular dystrophy?
(a) Palpitations
(b) Syncope
(c) Dyspnea
(d) Cachexia
Answer: (c) Commentary: The most frequent predictive symptom is dyspnea. Absence of exertion dyspnea from lack of physical activity allows myocardial impairments to remain clinically silent and difficult to detect. A high index of suspicion is required. Electrocdardiogram abnormalities in both Duchenne and Becker muscular dystrophy patients are attributed to progressive fibrosis of the cardiac conduction system and impairment in the cardiac autonomous nervous system. Palpitations and syncope will be related to the conduction abnormalities and occurs late in the disease process. Cachexia is a late finding that occurs when feeding becomes difficult as a result of heart failure and dyspnea.
Reference:(a)Manzur AY, Kinali M, Muntoni F. Update on the management of Duchenne muscular dystrophy. Arch Dis Child 2008;93:986-90.(b) Kilmer DD. Myopathy. In: DeLisa JA, Gans BM, Walsh NE, editors. Physical medicine and rehabilitation: principles and practice. 4th ed. Philadelphia: Lippincott-Raven; 2005. p 916-21.(c) McDonald CM. Neuromuscular diseases. In: Alexander MA, Matthews DJ, editors. Pediatric rehabilitation: principles and practice. 4th ed. New York: Demos; 2010. p 277-333.
What is your next course of action in a 7-year-old boy newly diagnosed with Duchenne muscular dystrophy?
(a) Evaluate for a wheelchair
(b) Recommend spinal orthosis to correct scoliosis
(c) Order an echocardiogram
(d) Order physical therapy for contracture reduction
Answer: (c) Commentary: Duchenne muscular dystrophy is an X-linked recessive disorder caused by the absence of dystrophin. Prognosis is poor because of cardiac involvement leading to severe heart failure. Baseline echocardiograms and electrocardiograms should be obtained after establishment of the diagnosis. Contractures are common in DMD, but typically are seen after 13 years of age. Scoliosis incidence is between 33% to 100% and presents between ages 12 and 15 years corresponding to the adolescent growth spurt. Orthotics and a wheelchair will be necessary in the course of the disease, but not at age 7.
Reference: (a) Finsterner J, Stollberger C: The heart in human dystrophinopathies. Cardiology 2003;99(1):1-19.(b) McDonald CM, Han JJ, Abresch RT, Carter G. Myopathic disorders. In: Braddom RL, editor. Physical medicine and rehabilitation. 3rd ed. Philadelphia: Elsevier-Saunders; 2007. p 1110. (c) McDonald CM. Neuromuscular diseases. In: Alexander MA, Matthews DJ, editors. Pediatric rehabilitation: principles and practice. 4th ed. New York: Demos; 2010. p 277-333.
When using ultrasound, the production in a sound field of gas bubblesthat grow and collapse producing high temperatures and tissue damage is called
(a) standing waves.
(b) oscillatory movement.
(c) acoustic streaming.
(d) unstable cavitation.
Answer: (d) Commentary: Unstable cavitation refers to bubbles that continue to grow in size and then collapse. The high temperatures and pressures generated by this can produce platelet aggregation, localize tissue damage and cause cell death. The physiologic effects of ultrasound can be divided into thermal and nonthermal effects. Nonthermal effects include cavitation, media motion (acoustic streaming, microstreaming) and standing waves.
Reference:Weber DC, Hoppee KM. Physical agent modalities. In: Braddom R L, editor. Physical medicine and rehabilitation. 3rd ed. Philadelphia: Saunders-Elsevier; 2007. p 466.
