denervation changes in muscles

Denervation changes in muscles or denervation myopathy can be observed in a number of settings and results from partial or complete loss of innervation.

There is a wide spectrum of clinical manifestations:

• temporary or permanent
• symptomatic or asymptomatic.

Pathology

Causes include :

• neuropathy
• autoimmune disorders
• viral infection
• prolonged nerve compression
• nerve infiltration by neoplasm
• penetrating injury
• Parsonage-Turner syndrome

Radiographic features

MRI

In the very early stage, muscle signal may be normal.

Acute denervation

• the earliest and most pathognomonic feature is increased T2 signal (best seen on a fat-saturated T2WI such as STIR) representing muscle edema
• normal muscle contrast enhancement
• muscle bulk is normal
• causative lesions may be apparent such as:
  • tumor compressing or displacing the neurovascular bundle
  • nerve discontinuity due to penetrating trauma

Subacute and chronic denervation

• features are less specific
• muscle atrophy and fatty infiltration with an increase in T1 signal
• heterogeneous edema-like signal

See also

• skeletal muscle edema - MRI

Siehe auch:

• T2 weighted image
• Diskusprolaps
• Muskelödem
• STIR - short tau inversion recovery
• diabetische Myonekrose
• quadrilateral space syndrome
• Atrophie nach Entlastung
• Muskelatrophie
• lipomatöse Atrophie

und weiter:

• quadrangular space syndrome
• Neuralgische Schulteramyotrophie
• Morbus Charcot-Marie-Tooth
• differential diagnosis of intramuscular high STIR signal on MRI
• Veränderungen nach Denervation Nervus peroneus communis
• fettige Atrophie Musculus teres minor