Tuesday, December 24, 2013

Statin myopathy pearls

1. Occurs in fifteen percent of those receiving statins

3.  Risk factors for include: 
      higher dose statin
      statin myopathy in a first degree relative
      older age
      small build
      concurrent systemic disease (renal, hepatic, or diabetes)
      multiple medications including fibrates, nitrates and cyt P450 metabolized drugs
genetic polymorphisms may exist

4.  Time course of onset usually one month but may be delayed years

5.  Presentation:  weak, high CK, irritability on EMG

6.  Co Q depletion may play a role, but studies have not shown CoQ is helpful

7.  Immune mediated myopathies can follow withdrawal of statin.

8.  fibrates, nitrates and ezetimibe also can cause myopathy

Head drop in neurologic disease: differential and pearls

Clinical: typically occurs in women over age 65
neck extensor weakness is usually subacute and associated with proximal arm weakness

EMG abnormal (myopathic or denervating) in cervical or thoracic paraspinal muscles but normal in limb muscles

Immunomodulators don't affect prognosis

ALS  (usually not isolated finding)
MG   ( three percent have headdrop as initial presentation)

carnitine deficiency
myotonic dystrophy
congenital myopathy
Parkinson's disease

Briemberg-Use of MRI-- in MG signal from paraspinals is normal, in isolated myopathy of neck muscles there is edema seen.The MG would be seronegative myasthenia gravis.