Related Experiment Video
Updated: Jul 8, 2026

A Protocol for Comprehensive Assessment of Bulbar Dysfunction in Amyotrophic Lateral Sclerosis (ALS)
Published on: February 21, 2011
Current evidence for the organic etiology of spastic dysphonia
Abstract:
For over 100 years it has been universally assumed in the literature that spastic dysphonia is a functional or psychoneurotic voice disorder. In the last few years, new data have accumulated that support the concept that spastic dysphonia is caused by an organic, rather than a functional, abnormality. Histologic examination of segments of the recurrent laryngeal nerve removed from patients with spastic dysphonia has revealed myelin abnormalities in 30% of the nerves examined. Neurologic examination indicated brain stem or basal ganglia disturbances in some patients who had no apparent nerve disease.
Related Concept Videos
Myasthenia Gravis: Diagnostic Tests
The edrophonium test is a diagnostic tool for myasthenia gravis. It involves...
Larynx
Anatomy of the Larynx
The larynx consists of various components, including cartilage, muscles, and vocal cords. Its structure includes three large unpaired cartilages—the thyroid, cricoid, and epiglottis—and three smaller paired cartilages—the arytenoids, corniculates, and...
Biological Causes of Schizophrenia
Genetic Factors in Schizophrenia
The genetic basis of schizophrenia is strongly supported by family and twin studies.
Parkinson Disease ll: Pathophysiology
Myasthenia Gravis ll: Pathophysiology
Alterations in Muscle Tone ll

