2. Encephalopathy (mild somnolence progressing to stupor or coma in extreme cases)
3. Visual disturbances (usually detectable, and range from hemianopia, visual neglect, auras, visual hallucinations, and cortical blindness)
4. Seizures (sometimes can be presenting symptom, and are generalized tonic clonic)
Risk factors and conditions associated with PRES/RPLS
1. HTN (usually acute elevation of bp beyond upper limits of cerebral autoregulation--thought to be from vasogenic edema from breakthrough of autoregulation)
3. Immunosuppressive therapy (such as cyclosporine, tacrolimus, sirolimus, cisplatin)
Treatment/management of PRES/RPLS
1. HTN management
2. Seizure treatment usually with phenytoin, though other antiepileptics may be used. Phenytoin is usually tapered as symptoms and neuroimaging ginfindgs resolve, after 1-2 wks, but if there are recurrent, unprovoked seizures, can resume
3. Eclampsia: delivery
4. Reduction in dose of cytotoxic drug or removal of drug
5. There are other comorbid conditions that can contribute such as fluid overload, uremia, sepsis--treat
Treatment for myasthenia gravis
Mild disease: a longer acting anticholinesterase such as pyridostimgine or neostimgine
If CT scan reveals thymoma, thymectomy can improve symptoms
Patients who have antibodies to MuSK receptors tend to respond better to plasma exchange and immunosuppressive therapy.
Diagnosis of myasthenia gravis
Traditionally was made with Tensilon test with edrophonium; however this can precipitate cardiac arrhythmias, and has been replaced by anti-acetycholine receptor antibody test. If this is negative or equivocal, then antimuscle-specific tyrosine kinase (MuSK) antibody assay. Anticholinesterases are less effective in individuals who have MuSK receptor antibody positive disease.
Excerbating factors for myasthenia gravis
infections, electrolyte abnormalities, beta blockers calcium channel blockers, and several antibiotics, most notoriously the aminoglycoside class. These antibiotics are known to impair neuromuscular transmission, leading to weakness in a dose-dependent fashion. Other exacerbating factors include anti-arrhythmic agents, morphine, or barbiturates.