Amyotrophy
Definition and Clinical Features
Amyotrophy is a term used to describe the thinning or atrophy (wasting) of muscle tissue, which is accompanied by weakness. The term implies a neurogenic cause for the muscle wasting, as opposed to a primary muscle disease (myopathy). When amyotrophy results from damage to lower motor neurons, it may also be accompanied by fasciculations (visible muscle twitches).
Amyotrophy is the wasting of muscle due to denervation. It is commonly seen in the small muscles of the hand in conditions like Amyotrophic Lateral Sclerosis (ALS).
Neuroanatomical Basis and Causes
Although the term implies a neurogenic origin, its use is nonspecific with respect to the exact location of the neurological lesion. Amyotrophy can result from damage at various levels of the peripheral nervous system:
- Lower Motor Neurons (Anterior Horn Cells):
- Amyotrophic Lateral Sclerosis (ALS)
- Benign Focal Amyotrophy (Monomelic Amyotrophy)
- Disinhibition-dementia-parkinsonism-amyotrophy complex (DDPAC)
- Nerve Roots (Radiculopathy):
- Diabetic Amyotrophy (a polyradiculopathy, often affecting L2-L4 nerve roots)
- Plexus (Plexopathy):
- Neuralgic Amyotrophy (Parsonage-Turner Syndrome)
Cross References
Atrophy; Fasciculation; Neuropathy; Plexopathy; Radiculopathy; Wasting
