Lateral horn

The lateral horn of the spinal cord is the small lateral projection of grey matter located between the dorsal horn and ventral horn and contain the neuronal cell bodies of the sympathetic nervous system.

Gross anatomy

On transverse section of the spinal cord, the spinal grey matter is described as being 'butterfly-shaped'. The two major projections of this grey matter form the dorsal and ventral horns. Between them, there is a much smaller lateral projection: the lateral horn.

It is found from T1 to L2 and contains cell bodies of the preganglionic sympathetic neurons.

Axons from neurons found within the lateral horn exit the spinal cord via the ventral spinal roots and white rami communicantes on their way to communicate with the sympathetic trunk.

Development

The lateral horns develop in the embryonic cord dorsolateral to the central canal. Following this, these cell bodies migrate laterally to form the horns themselves.

Pathology

• Horner syndrome
  • disruption of the lateral horns at the levels of T1-2 can lead to the classic triad of partial ptosis, anhydrosis and miosis from disruption of the sympathetic supply to the ipsilateral eye and surrounding structures.