The Oculosympathetic Pathway

The oculosympathetic pathway.

The oculosympathetic pathway is important for localizing lesions that may occur along its path. The common pathway consists of the first-order (central) neuron originating from the hypothalamus, descending down the brainstem and cervical spinal cord to the ciliospinal center of Budge-Waller at the level of C8-T2. The second-order (preganglionic) neuron then exits the spinal cord, travels around the apex of the lung, and travels up to the superior cervical ganglion, which is at the level of the jaw/carotid bifurcation. The third-order (postganglionic) neuron then branches to innervate the facial sweat glands, iris dilator muscle, and Müller and inferior tarsal muscles.

Image credit: Illustration by Christine Gralapp. American Academy of Ophthalmology. Used with permission for educational purposes.

Pharmacologic Testing for Horner Syndrome (video): Lecture from Dr. Andrew Lee, M.D.

Video credit: Lee AG. Pharmacologic Testing for Horner Syndrome. Video. YouTube. Available online. Accessed 02-27-2019.

Dilation Lag (video)

Two examples of dilation lag (Horner's syndrome). In the first example, the right pupil dilates much faster than the left pupil when the light is turned out. In the second example, the left pupil dilates much faster than the right pupil when the light is turned out.

Video credit: Digre KB, Jacobson D, Balhorn R. Dilation Lag. Video. [Neuro-Ophthalmology Virtual Education Library: NOVEL Web Site]. 2005. Available online. Accessed 02-27-2019.

Horner Syndrome

Right Horner syndrome.

Note the anisocoria (right pupil smaller than left pupil) and right upper lid ptosis. There is not a prominent right lower lid ptosis present.

Image credit: American Academy of Ophthalmology. Used with permission for educational purposes.

Horner Syndrome

Right Horner syndrome.

Note the anisocoria (right pupil smaller than left pupil), and right upper eyelid ptosis. Right lower eyelid ptosis is not as pronounced in this case.

Image credit: American Academy of Ophthalmology. Used with permission for educational purposes.

Horner Syndrome

Right Horner syndrome.

Note the anisocoria (right pupil smaller than left pupil) and right upper and lower ptosis. In a child, the most common cause of congenital Horner syndrome is birth trauma to the brachial plexus, with acquired childhood Horner syndrome concerning for neuroblastoma. Apraclonidine should be avoided in small children due to the risk of CNS and respiratory depression.

Image credit: American Academy of Ophthalmology. Used with permission for educational purposes.

Horner Syndrome

Left Horner syndrome.

Note the anisocoria (right pupil larger than left pupil) suggesting miosis of the left pupil. There is left upper lid ptosis and a very slight left lower lid ptosis, consistent with paralysis of the Müller and inferior tarsal muscles, respectively. There is also some mild increased conjunctival injection in the left eye, which can occur due to the disruption of sympathetic innervation to the periocular blood vessels.

Image credit: American Academy of Ophthalmology. Used with permission for educational purposes.