Diseases of Muscles and Neuromuscular Junction

Genetic- X-linked Recessive; 1/3 are spontaneous mutations

inheritance pattern of Duchennes Muscular Dystrophy

Duchennes Muscular Dystrophy

a rare, inherited genetic disorder that causes progressive muscle weakness and wasting due to LACK OF DYSTROPHIN ; primarily found in males

2-5 years old, Gowers and Meryon’s sign, difficulty walking, Pseudohypertrophy

Usually age of diagnosis for Duchennes Muscular Dystrophy, and symptoms

Meryon’s Sign

shoulder girdle weakness proximal, sign of Duchennes

proximal to distal

Duchennes effects the body _____ to _______

Gower’s sign

hip girdle weakness proximal, sign of duchennes

bladder/bowel, smooth muscle

structures not effected by Duchnenne’s

plantar flexion and inversion

Equinovarus

hip extension

hip flexion contracture leads to loss of

knee extension

knee flexion contracture leads to loss of

corticosteriods long term, increased body weight

one of the best older treatments for Duchennes MD, and whats a major side effect

creatine kinase enzyme

found in blood in elevated levels with muscular dystrophy

gene therapy/replacement (age 4-6) 2 hour infusion

best new treatment for Duchennes MD

Beckers Muscular Dystrophy

less severe inherited genetic disorder that causes progressive muscle weakness and wasting due to DECREASE OF DYSTROPHIN ; primarily found in males

milder, some dystrophin, less cardiac involvement, no mental disability, later diagnosis, older age of onset and longer survival

How is Beckers different from Duchennes (MD)

polymyositis

autoimmune muscular disorder where inflammatory cells invade muscle tissue with NO skin involvement,

paraneopastic syndrome

response to cancerous tissue, body fights it but also hurts healthy tissue

dermatomyocytis

autoimmune muscular disorder where inflammatory cells invade muscle tissue WITH skin involvement

ovarian and other cancers

polymyositis and dermatomyositis increases risk of _________

heliotrope rash

common dermatomyositis rash around eyes

2 times; 30-60

women are ____ as likely to be diagnosed with polymyositis/dermatomyositis than men; age

paraneoplastic; cancer

polymyositis and dermatomyositis may be due to _________ syndrome, and we should screen for ________

long term (6 month) corticosteroids, graded exercise

treatment of polymyositis and dermatomyositis

Myasthenia Gravis

most common neuromuscular junction disorder

Myasthenia Gravis

autoimmune disorder characterized by weakness in most commonly used muscles

weakness of most used muscles (face, diaphragm, trunk and neck), fatigue

common symptoms of Myasthenia Gravis

Thymus tumor

10% of Myasthenia Gravis cases are due to ______________

ptosis, dysphagia, chewing difficulty, proximal extremity weakness, diplopia

common signs of Mysetenia Gravis

Weakness of diaphragm that could be fatal

Myasthenia Crisis

short acting anti-cholinesterase, Simpson Plus Test, EMG

Testing for Myasthenia Gravis

Thyrectomy, energy conversion, medications

treatments for Myasthenia Gravis