00:00 / 00:00




Nervous system




0 / 8 complete

USMLE® Step 1 questions

0 / 3 complete

High Yield Notes

13 pages



of complete


USMLE® Step 1 style questions USMLE

of complete

A 17-year-old female presents to her primary care physician with worsening occipital headaches, gait disturbance, and diminished pain sensation. She recently burned herself while cooking after keeping her hand on a pan “that did not feel hot when touched.” The patient has also been experiencing worsening occipital headaches that wake her up from sleep as well as feelings of discoordination while walking. Vitals are within normal limits. Neurologic exam is notable for gait ataxia, down beating nystagmus, as well as bilateral loss of pain and temperature sensation in the upper extremities. Which of the following anatomic structures is directly disrupted by this patient's disease process? 

External References

First Aid








Syringomyelia p. 506

Horner syndrome p. 559

spinal cord lesions p. 548


In syringomyelia, syrinx means cyst or cavity, and myelia means a condition of the spinal cord. So, syringomyelia is a cystic enlargement of the spinal cord, and it typically starts medially and enlarges outwards, eventually damaging the spinothalamic tract, which is a part of the spinal cord that sends sensory signals about pain, pressure, temperature, and touch to the brain.

Now, the spinal cord itself is composed of both grey and white matter. Grey matter is found within medial portion of the spinal cord and is shaped like a butterfly. This is where the cell bodies of different neurons can be found. In the center of the grey matter there’s a small cavity the central canal which is filled with cerebrospinal fluid. Cerebrospinal fluid helps provide nutrients and mechanical support to the brain and spinal cord. Surrounding the grey matter is white matter, which consists of the axons of various neurons. The spinal cord has different neural tracts that carrying sensory information to and from the brain. The corticospinal tract is a descending pathway which carries motor information from the brain to various muscles. The dorsal column, located in the posterior portion of the spinal cord, is responsible for sensing pressure, vibration, fine touch, and proprioception, or the awareness of one’s body position in space. Then there’s the spinothalamic tract, which is divided into two distinct tracts - the lateral spinothalamic tract which is responsible for sensing pain, pressure, and temperature, as well as the anterior spinothalamic tract which senses crude touch. The spinothalamic tract carries all of this sensory information from the spine up to the thalamus of the brain where the information is processed. This happens through three neurons that synapse with one another. First, a primary neuron carries sensory information, such as pain, from the skin to the dorsal horn of the spinal cord, where it synapses with a secondary neuron. The secondary neuron ascends 1-2 vertebral levels and decussates or crosses to the opposite side of the spinal cord via an area of white matter called the anterior white commissure. The secondary neuron then ascends up the length of the spinal cord via the anterior or lateral spinothalamic tracts, eventually synapsing at the ventral posterior nuclei of the thalamus. Finally, from there, a third neuron arises from nuclei in the thalamus and carries the signal to the primary sensory cortex or the postcentral gyrus of the brain where the sensory signal is interpreted.


Syringomyelia refers to a condition in which a fluid-filled cavity, or syrinx, develops within the spinal cord, and it is most commonly caused by an Arnold-Chiari II malformation. The expanding cavity interferes with the spinothalamic tract which is responsible for pain, pressure, temperature, and crude touch, and results in the loss of these sensations in a cape-like distribution along the arms and back.

Syringomyelia may cause pain, paralysis, weakness, Horner syndrome, and stiffness in the back, shoulders, and extremities. In some cases, it can cause scoliosis or an abnormal curvature of the spine. Treatment depends on the severity of the condition and may include medications, physical therapy, and surgery.


  1. "Robbins Basic Pathology" Elsevier (2017)
  2. "Harrison's Principles of Internal Medicine" McGraw Hill Education/ Medical (2018)
  3. "Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)
  4. "CURRENT Medical Diagnosis and Treatment 2020" McGraw-Hill Education / Medical (2019)
  5. "Post-traumatic syringomyelia (cystic myelopathy): a prospective study of 449 patients with spinal cord injury." Journal of Neurology, Neurosurgery & Psychiatry (1996)
  6. "Scoliosis associated with syringomyelia: analysis of MRI and curve progression" European Spine Journal (2007)

Copyright © 2023 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Cookies are used by this site.

USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.