Neuroanatomy provides the most useful basic science in developing a list of causes for hoarseness. Hoarseness may occur from involvement of the larynx, myoneural junction of the vocal cord muscles, vagus nerve, or the brainstem. When these structures are cross-indexed with the many etiologies suggested by the mnemonic VINDICATE, a chart like Table 39 can be prepared.
The larynx may be involved with acute infections such as diphtheria and influenza and with chronic infections such as TB and syphilis. It may also be involved with allergy, neoplasms, and chronic trauma from overuse of the voice. Smoking and alcohol are common causes of hoarseness. Hypothyroidism may present with hoarseness.
The myoneural junctions prompt the recall of myasthenia gravis, whereas the peripheral portion of the vagus nerve prompts the recall of the greatest number of disorders; thyroid tumors and surgery to the thyroid, mediastinal tumors, and aortic aneurysms are only a few. Lead and diphtheria may cause a neuritis to this nerve. The intracranial portions of the vagus nerve may be involved by basilar artery aneurysms, basilar meningitis, platybasia, and foramen magnum tumors.
In the brainstem, the nucleus ambiguus is involved in poliomyelitis, ependymomas, Wallenberg syndrome, syringomyelia, and amyotrophic lateral sclerosis. Multiple sclerosis and gliomas may involve the roots of the ambiguus nucleus as they pass through the brainstem white matter.
Approach to the Diagnosis
A careful examination of the larynx with a laryngoscope or the fiberoptic bronchoscope is essential. The indirect laryngeal mirror is difficult to use and probably should be discarded by those unfamiliar with its use. If no local disease is found, evidence of vagal nerve palsy will be noted by the cord paralysis. A chest x-ray, thyroid function tests, blood lead level, and Tensilon test may be necessary to diagnose recurrent laryngeal involvement. Intracranial lesions will demonstrate other neurologic signs. A skull roentgenogram, CT scan, and spinal tap will probably give valuable clues to their cause. X-ray films of the cervical spine, an RA test, and arteriogram may be necessary.
Other Useful Tests
1. CBC (anemia, infection)
2. Sedimentation rate (inflammation)
3. Tuberculin test (TB)
4. VDRL test (syphilis of the vocal cords)
5. Nose and throat culture (pharyngitis)
6. Sputum culture (pneumonia)
7. AFB culture (TB)
8. Acetylcholine receptor antibody titer (myasthenia gravis)
9. C1 esterase inhibitor level (angioneurotic edema)
10. Allergy skin test
11. Otolaryngology consult
12. CT scan of the mediastinum (mediastinal tumor)
13. Aortogram (aortic aneurysm)
14. Radioiodine (RAI) uptake and scan (thyroid tumor)
|
|
|
Hoarseness |
Case Presentation #48
A 48-year-old white woman complained of hoarseness which was intermittent at first but had become steady in the past 4 months. She has a history of heavy smoking and moderate alcohol consumption.
Question #1. Utilizing your knowledge of anatomy and neuroanatomy, what would be your list of possibilities?
Physical examination reveals thickening of the hair, skin, and nails but is otherwise unremarkable. Fiberoptic laryngoscopy was negative for mass or ulceration of the vocal cords.
Question #2. What is your diagnosis now?
