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.