Last updated: Friday, 21, January, 2011
Review clinical features especially associated disease; drug therapy; presence of myotonia, myasthenia or cardiomyopathy; history of brown urine (myoglobinuria).
See also Myoglobinuria
CK is usually elevated but the degree of elevation does not necessarily correlate with the severity of muscle weakness.
FBC, blood film; CRP
Extractable nuclear antibodies, Jo-1 antibodies. Muscle biopsy (consult pathologist prior to procedure).
See under Adrenocortical insufficiency
Muscle wasting secondary to severe, systemic illness
Muscle biopsy, including chemical pathology studies, may be helpful (consult pathologist prior to procedure as special collection techniques are required for open biopsies).
Prenatal diagnosis (including molecular genetics) is available for some disorders.
Measure potassium during episode of paralysis.
See Mitochondrial disorders