LMN, Lower Motor Neuron

Clinic

• LMN nerve fibers traveling from the lower motor neuron(s) in the Anterior horn of the spinal cord, or in the motor nuclei of the cranial nerves, to the relevant muscle(s).
• UMN (Upper motor neuron lesion) often presents with spastic paralysis – paralysis accompanied by severe hypertonia.

Entities

• Muscle paresis or paralysis / Strength decreased
• Fibrillations
• Fasciculations
• Hypotonia or Atonia
• Hypo reflexia
• Ascent extensor plantar reflex

Causes

Dynamic	Static
Guillain–Barré syndrome C. botulism ALS Progressive muscular atrophy Monomelic amyotrophy	Trauma to peripheral nerves Cauda equina syndrome

Differential diagnosis

• Myasthenia gravis

• Hypotonia / Flaccidity
• Ipsilateral (same side) weakness of individual muscles.
• Atrophy
• Weak or absent deep tendon plantar reflexes and abdominal reflexes
• Fasciculations (Twitching)

Miasms

Viruses that selectively attack ventral horn cells such as

• WNE
• PLV