Differential Diagnosis for 12th Cranial Nerve Palsy

The 12th cranial nerve, also known as the hypoglossal nerve, controls the movements of the tongue. Palsy of this nerve can lead to difficulties in speech, swallowing, and tongue movement. Here's a differential diagnosis organized into categories:

• Single Most Likely Diagnosis
  • Stroke or cerebral vasculature accident: This is often the most common cause of 12th cranial nerve palsy due to the nerve's location and its susceptibility to damage from vascular events in the brainstem or the nerve itself.
• Other Likely Diagnoses
  • Trauma: Head or neck injuries can cause damage to the hypoglossal nerve, leading to palsy.
  • Tumors: Both benign and malignant tumors in the brain, brainstem, or neck can compress the hypoglossal nerve, causing palsy.
  • Infections: Certain infections, such as meningitis or abscesses, can affect the nerve.
  • Multiple sclerosis: This autoimmune disease can cause demyelination of the nerve, leading to palsy.
• Do Not Miss Diagnoses
  • Brainstem stroke or infarct: While included in the broader category of stroke, brainstem strokes can have very subtle presentations and are critical to identify early due to their high morbidity and mortality.
  • Cranial nerve tumors (e.g., schwannomas): These can be benign but require early intervention to prevent further nerve damage.
  • Giant cell arteritis: Although more commonly associated with visual symptoms, this condition can cause cranial nerve palsies, including the 12th nerve, and requires prompt treatment to prevent complications.
• Rare Diagnoses
  • Amyotrophic lateral sclerosis (ALS): A progressive neurodegenerative disease that affects nerve cells in the brain and the spinal cord, leading to loss of muscle control.
  • Guillain-Barré Syndrome: An autoimmune disorder in which the body's immune system mistakenly attacks part of its peripheral nervous system, which can include the cranial nerves.
  • Neurosyphilis: A complication of untreated syphilis infection that can cause a variety of neurological problems, including cranial nerve palsies.
  • Sjögren's syndrome: An autoimmune disorder that can affect various parts of the body, including the nervous system, leading to cranial nerve palsies among other symptoms.

Each of these diagnoses has a different set of implications for treatment and prognosis, making a thorough diagnostic workup crucial for patients presenting with 12th cranial nerve palsy.