Carcinomatous Neuromyopathy

 05 November 2004

Brain & Henson, 1958: dysfunction at any level in nervous system in cancer patients

Shy & Silverstein, 1965: proximal muscle weakness & neuropathy

Imply neither neuropathy nor myopathy, but both  which occur in cancer patients, although changes more related to weight loss than the presence of cancer.

Symmetrical peripheral neuropathy

100% late disease

Begins with 15% weight loss

Peripheral neuropathy alone was not found in the absence of weight loss

Often axonal

Sensorimotor

Myopathy

100% late disease

Type II fibre atrophy, minimal other changes

Strength is out of proportion to wasting

Usually proximal

Myoedema:      local mounding of the muscle immediately following brisk tap with tendon

hammer. Swelling has to be crosswise or diagonal to fibre orientation for at least 1 sec before gradually disappearing. Electrically silent.

CK often normal

Mononeuropathies

13% patients

commonest peroneal nerve palsy

Eaton Lambert syndrome

3% in late disease for small cell lung cancer

subacute sensory neuropathy (small cell lung cancer)

cerebellar degeneration (small cell lung cancer, gynecological malignancies)

motor neurone disease (small cell lung cancer)

encephalomyelitis (small cell lung cancer)

retinopathy

opsoclonus (neuroblastoma, breast)

autonomic neuropathy

myositis/dermatomyositis