Hoffman's syndrome

Last reviewed 01/2018

Clinical features central to a myopathy associated with hypothyroidism include:

  • muscular pains
  • stiffness
  • cramps, not necessarily associated with weakness
  • slowed muscle relaxation, most clearly seen following a tendon jerk

The delay in relaxation is not due to repetitive muscle excitation - as in myotonia - but is probably the result of a reduced rate of cross-bridge uncoupling.

There may be frank muscle weakness in some patients, and the muscles may be firm to palpation and enlarged.

Investigations reveal a raised creatine kinase and fibre atrophy seen on muscle biopsy.