LMN- Muscle Flashcards
What is the difference between anterior horn cell and muscle involvement in terms of weakness and wasting?
Anterior horn cell involvement shows wasting»_space; weakness, while muscle involvement shows weakness > wasting.
What is the distribution of weakness in LMN-Muscle involvement?
Lower limb > Upper Limb.
What are the preserved reflexes in LMN-Muscle involvement?
Reflexes are preserved.
What are the features of muscle involvement in terms of proportionate weakness and wasting, reflexes, and involuntary movements?
Muscle involvement shows weakness > wasting, late hyporeflexia, and absence of fasciculations.
What are the positive and negative symptoms of a muscle disorder classification?
Positive symptoms include myalgia, cramps, contractures, myotonia, and myoglobinuria.
Negative symptoms: Weakness, exercise, fatigue
What are the types of channelopathies related to muscle disorders?
Calcium channelopathies: include Hypokalemic Periodic Paralysis, Episodic Ataxia Type 2, and SCA type 6.
Na channelopathies: Myotonia,Hyperlalemic periodic paralysis
Potassium channelopathies: Anderson Tawil syndrome.
What is the relationship between exercise intolerance and muscle disorders?
Exercise intolerance is a non-specific symptom of muscle disorders characterized by abnormal fatiguability after trivial exercise without contractures or myoglobinuria.
What is myoglobinuria?
Myoglobinuria is a symptom of muscle disorders characterized by the presence of myoglobin in the urine, indicating muscle breakdown.
What is the difference between constant myalgia and episodic myalgia?
Constant myalgia is associated with inflammatory muscle disorders, while episodic myalgia is associated with metabolic myopathies such as McArdle’s disease.
What is the most likely cause of abnormal fatiguability after trivial exercise without contractures or weakness or cramps?
Inflammatory muscle disorders can result in abnormal fatiguability after trivial exercise without contractures or weakness or cramps.
What is the most common cause of muscle pain and stiffness in the hip, shoulder, and pelvic girdle, with morning stiffness and an ESR >50mm/Hr?
Polymyalgia rheumatica occurs in giant cell arteritis and is the most common cause of muscle pain and stiffness in the hip, shoulder, and pelvic girdle, with morning stiffness and an ESR >50mm/Hr.
What is the mechanism of action of steroids in treating polymyalgia rheumatica?
Steroids are 100% responsive in treating polymyalgia rheumatica by reducing inflammation.
What is the cause of muscle cramps in most cases?
Muscle cramps are benign and can be caused by metabolic factors such as dehydration, renal failure, hyponatremia, and myxedema.
Is it common for myopathy to cause vague aches and muscle discomfort in the presence of a normal neuromuscular examination and laboratory studies?
No, it is extremely uncommon for myopathy to cause vague aches and muscle discomfort in the presence of a normal neuromuscular examination and laboratory studies.
What are some metabolic causes of muscle cramps?
Dehydration, Renal Failure, Hyponatremia, Myxedema, Anterior horn cell diseases (MND), etc.
What is the difference between muscle cramps and muscle contractures?
Contractures last longer, are electrically silent with Needle EMG, and are specific to certain muscular dystrophies such as Emery-Dreifuss Muscular Dystrophy (EMD).
What is myotonia?
Myotonia is the phenomenon of impaired relaxation of muscle after forceful voluntary contraction.
Myotonia improves with exercise
What are some conditions that show myotonia?
Hyperkalemic Periodic paralysis, Myotonic dystrophy, Myotonia congenita.
What is Paramyotonia Congenita?
Paramyotonia Congenita is a condition where symptoms worsen with activity and exposure to cold worsens both myotonia and Paramyotonia.
What are some types of congenital myopathies?
Central Core myopathy, Centronuclear Myopathy, Nemaline Myopathy, Congenital Myotonic Dystrophy.
What is the most common type of adult onset muscle dystrophy?
Limb girdle muscle dystrophy.
What is Emery Dreifuss muscle dystrophy known for?
Prominent contractures.
What is Duchenne Muscular Dystrophy?
It is an X-Linked dystrophy with progressive muscle degeneration caused by defective protein - Dystrophin.
At what age does Duchenne Muscular Dystrophy usually onset?
3-5 years.
What are the common presentations of Duchenne Muscular Dystrophy?
Frequent falls, lumbar lordosis, protuberant abdomen, and waddling gait.
At what age does toe walking with heel cord contracture usually occur in Duchenne Muscular Dystrophy?
6 years.
At what age are individuals with Duchenne Muscular Dystrophy usually wheelchair-bound?
12 years
What is the most common cause of death in individuals with Duchenne Muscular Dystrophy?
Recurrent pulmonary infection.
Recurrent pulmonary infection.
What is Gowers Sign?
It is limb-girdle weakness.
It is limb-girdle weakness.
What are the complications of Duchenne Muscular Dystrophy?
Dilated cardiomyopathy and conduction abnormalities, mental retardation, pseudohypertrophy of calf muscles, and scoliosis which impairs lung function.
What is the management for Duchenne Muscular Dystrophy?
Steroids (limited use).
What is Becker’s Muscular Dystrophy?
It is an X-Linked recessive disorder with a later onset (5-60 years) and individuals can survive above 40 years.
The most common cause of death is cardiomyopathy, and contractures are less common. Steroids are more effective in Becker’s Muscular Dystrophy.
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What is the most common cause of death in patients with muscular dystrophy?.
Cardiomyopathy
What is the difference between DM1 and DM2?
DM1 presents with distal muscle weakness, while DM2 presents with proximal muscle weakness.
What is the genetic inheritance pattern of myotonic dystrophy?
Autosomal dominant.
What is the hallmark facial feature seen in myotonic dystrophy?
Hatchet facies.
Which neck muscle is most commonly involved in myotonic dystrophy?
Sternocleidomastoid muscle.
What is the additional finding seen in patients with myotonic dystrophy besides muscle weakness?
Cardiac conduction abnormalities.
What is the mechanism of inheritance in myotonic dystrophy?
Trinucleotide repeat disorder.
What is the age range for patients with myotonic dystrophy?
5-60 years (non-specific).
What is the effect of steroids in Becker’s dystrophy compared to Duchenne muscular dystrophy?
Steroids are more effective in Becker’s dystrophy.
What is the most common type of muscle weakness seen in DM1?
Distal muscle weakness.
What are the three types of Distal Myopathy?
Welander Myopathy, Nonaka Myopathy, Miyoshi Myopathy.
What are some drugs that can cause Drug Induced Myopathies?
Statins/Fibrates, D-Penicillamine, Zidovudine, Amiodarone, Hydroxychloroquine, Steroids, Alcohol/Amphetamine, Colchicine.
What are the four types of Inflammatory Muscle Disorders?
Polymyositis, Dermatomyositis, Inclusion body Myositis, Immune Mediated Necrotizing Myopathy.
What is the difference between Polymyositis and Dermatomyositis?
Polymyositis and Dermatomyositis are both sub-acute, bilaterally symmetrical, and affect proximal muscles.
What are the peculiarities of Inclusion Body Myositis?
Inclusion Body Myositis is characterized by asymmetrical distal to proximal involvement, quadriceps involvement, and is more common in elderly patients presenting with frequent falls.
What are the peculiarities of repetitive movements in dermatomyositis?
Pharyngeal and neck flexor muscles are involved, while extra-ocular and facial muscles are always spared.
What is the pathognomonic feature of Gottron’s papule in dermatomyositis?
Violaceous, flat-topped papule on the extensor aspect of MCP and PIP joints.
What is the Shawl sign in dermatomyositis?
It is a sign of dermatomyositis characterized by a rash on the posterior neck.
What is the V sign in dermatomyositis?
It is a sign of dermatomyositis characterized by a rash on the anterior neck.
What is the heliotrope rash in dermatomyositis?
It is a violaceous periorbital erythema/edema.
What is the Gottron’s rash/sign in dermatomyositis?
It is a rash on the extensor surfaces of the hands and fingers.
What is the Holster sign in dermatomyositis?
It is edema on the lateral aspect of the thigh.
What is the cause of interstitial lung disease (NSIP) in dermatomyositis?
Anti-synthetase antibody/Anti-Jo antibody.
What is the cause of dermatomyositis?
Anti Synthetase Antibody /Anti Jo Antibody
What are the possible effects of dermatomyositis?
Interstitial Lung disease (NSIP), arthritis (similar to SLE), Raynaud’s Phenomenon, and Mechanic Hand.
What is Mechanic Hand, and in which diseases is it seen?
Mechanic Hand is crusting and erosion of the lateral aspect of the index and middle finger, and it is seen in both Polymyositis and Dermatomyositis.
diagnostic method for dermatomyositis?
Muscle Biopsy.
What is the treatment for dermatomyositis/polymyositis without interstitial lung disease?
Steroid + Methotrexate.
Steroid + Methotrexate.
What are the nail changes and telangiectasia of fingers in dermatomyositis?
They are dermatological manifestations of dermatomyositis.
What is the treatment for dermatomyositis/polymyositis with interstitial lung disease?
Steroid + Cyclophosphamide/MMF
