Neuromuscular, Neurocutaneous, and spinal cord diseases Flashcards Preview

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Flashcards in Neuromuscular, Neurocutaneous, and spinal cord diseases Deck (46)
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What is pathophysiology of myasthenia gravis

Autoantibodies against nicotinic acetylcholine receptors at NMJ junction, fatigue through day, better with rest


What is the most common and most common initial symptoms, and what can it be limited to in elderly ppl for myasthenia gravis

Extraocular eye muscles, with ptosis, diplopia, and blurred vision


What goes weak and what is preserved in myasthenia gravis

Skeletal muscles weak, sensation and reflexes preserved


How are limb muscles affected in myasthenia gravis

Proximal and Asymmetric


Other symptoms of myasthenia gravis besides eye symptoms

Dysarthria, dysphagia, and generalized weakness


What is myasthenia crisis and what percent of patients does it occur in?

An exacerbation of myasthenia gravis with respiratory muscles affected, requiring intubation15%


Four diagnostic modalities of myasthenia gravis

1.) Acetylcholine antibody test - specific, 20% beat it
2.) EMG - shows decremental conduction of motor nerves
3.) Edrophonium test - acetylcholine esterase inhibitor, improves symptoms but not used
4.) CT to see if thymoma is present - 75% have abnormal histology, 15% have actual thymoma


Treatment for myasthenia gravis (Five things)

1.) AChE inhibitor - symptoms only - pyridostigmine
2.) Thymectomy - symptoms and remission, do even when there is no thymoma
3.) Immunosuppressive drugs - corticosteroids second line, azathioprine and cyclosporine third line
4.) Plasmapharesis - removes antibodies, last resort
5.) IV immunoglobulins - myasthenia crisis


What is the forced vital capacity indication for intubation for patients with myasthenia gravis

Less than 15ml/kg, unless crisis, in which case do not wait


Where are lambert-eaton's autoantibodies directed towards

Presynaptic calcium channels


Difference between symptoms of myasthenia gravis and lambert eaton

Lambert Eaton - improves with stimulation, hyporeflexia

Myasthenia Gravis - diminishes with stimulation, reflexes preserved


What cancer is lambert-eaton associated with

Small cell lung cancer


Gene mutation and result of duchenne's mulscular dystrophy

X-linked recessive - no dystrophin, no inflammation


Progression of muscular weakness in duchenne's muscular dystrophy

Starts proximal and symmetric in children (pelvis girdle), progresses distally


Two distinguishing features of duchenne's muscular dystrophy

1.) Gower's maneuver - Patients use hands to get up
2.) Enlarged calf muscles - first true hypertrophy, then pseudohypertrophy as fat replaces muscle


Final complications of duchenne's muscular dystrophy

Wheelchair bound, respiratory failure, and death in third decade


What diagnostic lab is distinguished in duchenne's, and what can you use to test for duchenne's

Serum creatinine phosphokinase

Definitive: DNA testing


What is the treatment used for duchenne's muscular dystrophy

Prednisone - 5 years and older with declining motor skills

Surgery - fixes scoliosis, once wheelchair bound


Similaries and differences for becker's muscular dystrophy vs. duchenne's muscular dystrophy

X-linked recessive too, less common, later onset and less severe because some dystrophin present


What two other hereditary diseases can cause muscle weakness

Mitochondrial disorders: Ragged red muscle fibers

Glycogen storage diseases: Mcardle's - muscle cramping after exercise because no glycogen phosphorylase


What three things can exacerbate myasthenia gravis

1.) Beta blockers
2.) Antibiotics - aminoglycosides and tetracyclines
3.) Antiarrhythmics - quinidine, procainamide, and lidocaine


What are the genetics of neurofibromatosis type 1

Autosomal dominant


What are the clinical features of neurofibromatosis type 1

1.) Cafe au lait spots - pigmented spots
2.) Neurofibromas - benign tumors of nerve sheath - treat by surgery
3.) CNS tumors - gliomas, meningiomas
4.) Axillary or inguinal freckling
5.) Lisch nodules - iris hamartomas (dendritic melanocytes in iris)
6.) Bony lesions


What are the complications of neurofibromatosis type 1

1.) Scoliosis
2.) Pheochromocytoma
3.) optic nerve glioma
4.) Renal artery stenosis
5.) Bone erosion


What are the clinical features of neurofibromatosis type 2

1.) Bilateral acoustic neuromas - classic
2.) Multiple meningiomas
3.) Cafe au lait spots
4.) Neurofibromas
5.) Cataracts


What are the clinical features of tuberous sclerosis

1.) Cognitive impairment
2.) Epilepsy
3.) Skin lesions (angiofibromas - papules with fibrous tissue, adenoma sebaceum)


What are the complications of tuberous sclerosis

1.) Retinal hamartoma - can lead to retinal detachment
2.) Renal angiomyolipoma - could hemorrhage
3.) Rhabdomyoma


What is Sturge-Weber syndrome classic visible features

Facial vascular nevi (port wine stain), epilepsy, mental retardation


What should you treat in sturge weber syndrome



What is the see pathologic feature of sturge-weber syndrome

Capillary angiomatoses of pia mater - knots of capillaries