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Related Experiment Video

Updated: Jun 19, 2026

A Protocol for Comprehensive Assessment of Bulbar Dysfunction in Amyotrophic Lateral Sclerosis (ALS)

A Protocol for Comprehensive Assessment of Bulbar Dysfunction in Amyotrophic Lateral Sclerosis (ALS)

Published on: February 21, 2011

Brainstem pathology in spasmodic dysphonia.

Kristina Simonyan¹, Christy L Ludlow, Alexander O Vortmeyer

¹Laryngeal and Speech Section, Medical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20814-1416, USA. simonyak@ninds.nih.gov

The Laryngoscope

|October 2, 2009

Summary

Neuropathological examination of brainstem tissue in spasmodic dysphonia (SD) patients revealed inflammation and mild neuronal degeneration. These findings offer new insights into the underlying causes of this voice disorder.

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A Protocol for Comprehensive Assessment of Bulbar Dysfunction in Amyotrophic Lateral Sclerosis (ALS)

A Protocol for Comprehensive Assessment of Bulbar Dysfunction in Amyotrophic Lateral Sclerosis (ALS)

Published on: February 21, 2011

Area of Science:

Neurology
Pathology
Speech Science

Background:

Spasmodic dysphonia (SD) is a primary focal dystonia affecting laryngeal muscles during speech.
Its pathophysiology remains largely unknown, necessitating further investigation into potential neurological underpinnings.

Purpose of the Study:

To investigate the neuropathological features in postmortem brainstem tissue of individuals with spasmodic dysphonia.
To compare these findings with control brainstem tissue to identify potential disease-specific alterations.

Main Methods:

Postmortem brainstem tissue samples from two spasmodic dysphonia patients and four controls were analyzed.
Histopathological examination focused on identifying inflammation, neuronal degeneration, protein accumulations, demyelination, and axonal integrity.

Main Results:

Inflammatory clusters were observed in the reticular formation, surrounding key nuclei (solitary tract, spinal trigeminal, ambigual), inferior olive, and pyramids in SD patients.
Mild neuronal degeneration and depigmentation were noted in the substantia nigra and locus coeruleus.
No abnormal protein accumulations, demyelination, or axonal degeneration were detected in the examined SD tissues.

Conclusions:

The presence of inflammation and mild neuronal changes in specific brainstem regions suggests a potential neuropathological basis for spasmodic dysphonia.
These findings contribute to understanding the pathophysiology of SD and may guide future research into its mechanisms and potential treatments.