NMJ and Muscle - Ringle Flashcards
What is the only proven tx for ALS (to increase longevity)?
Riluzole
Neuropathy = \_\_\_\_ weakness Myopathy = \_\_\_\_\_ weakness
Neuropathy - distal
Myopathy - central
Amyotrophic Lateral Sclerosis (ALS)
Progressive disease affecting both the CNS and the PNS. Likely many genes can cause the phenotype. Demyleination is seen in the corticospinal tract. Initial presentation can involve weakness in the face (bulbar), hands, or legs. May present with fasciculations.
Tx with riluzole, Tx to improve QOL, palliative care + advance directives.
What is the pseudobulbar affect?
Inappropriate laughing/crying sometimes seen in ALS patients. Can treat with antidepressants.
How might you treat limb weakness and difficulty speaking, swallowing, and breathing.
Could treat increased salivation with cholinergic antagonist (eg scopolamine)
Swallowing - chin tuck, cough, multiple swallows.
NIPPV (positive pressure ventilation)
How would insufficient respiration present in a patient with a neuromuscular disorder?
Retention of CO2 causes headaches and confusion. Patients don’t say “I’m short of breath” they simply wake with these symptoms
Charcot Marie Tooth
Severe distal atrophy of muscle due to sensory and motor loss. Many variants. Not a fatal disease. Tx is OT, PT, orthopedic intervention.
Duplication of CMT1a (chr17) = CMT
Deletion of CMT1a = HNPP
CMT1a codes for PMP22 (Peripheral Myelinating Protein)
Diabetic neuropathies
Most often starts in the feet. Hand involvement commonly starts when sensory loss reaches the knees. Can see lumbosacral plexopathies which affect hip stability, and foot drop. Can also see autonomic dysfunction (diarrhea, postural hypotension, increased sweating). Mononeuropathies also seen (carpal tunnel, ulnar lesions). Pathophysiology is though to be due to ischemia of the small vessels that supply peripheral nerves.
Recommendations include foot care (nightlight, foot checks) and pain management.
Myasthenia Gravis
Myasthenia Gravis is an autoimmune disorder due to Ab against the Ach receptor in the NMJ. Treatment involves immune supression and surgical thymectomy, as well as cholinesterase inhibitors (pyridostigmine).
Clinically, aspiration of food is a common problem, and ptosis, difficulty speaking/chewing, and respiratory weakness are concerns.
Duchenne Muscular Dystrophy (becker)
An X-linked muscular disorder involving the dystrophin protein. Severe worsening proximal muscle weakness results in a waddling gait and difficulty rising from the ground (gower maneuver). Muscle atrophy and connective tissue deposition results in calf pseudohypertrophy. Boys often walk on their toes, a result of muscular imbalance and subsequent tendon shortening. Most are confined to a wheelchair by age 9-12, which can lead to severe kyphoscoliosis. Most boys succumb to respiratory failure in their 20s.
The gene mutation can be screened prenatally (amnio) and mothers can be screened prior to conception (blood).
