Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Alterations in Muscle Tone ll

Alterations in Muscle Tone ll

Alterations in muscle tone are common manifestations of neurological disorders and reflect dysfunction within different nervous system regions. Spasticity, paratonia, and dystonia represent distinct forms of hypertonia, each with unique mechanisms, clinical features, and diagnostic importance.CharacteristicsSpasticity happens from upper motor neuron lesions and is characterized by velocity-dependent resistance to passive movement. Clinical features include:Exaggerated deep tendon reflexesClonus...

Secondary Spinal Cord Injury llI: Pathophysiology

Secondary Spinal Cord Injury llI: Pathophysiology

Early Ischemia and Ionic ImbalanceWithin minutes of spinal cord injury, a secondary cascade begins, progressing over hours to weeks. Vascular damage reduces blood flow, causing ischemia and mitochondrial dysfunction. ATP depletion leads to ion pump failure, membrane depolarization, sodium influx, potassium efflux, and water accumulation, resulting in cellular swelling. Increased intracellular calcium further disrupts mitochondria and accelerates cellular injury.Excitotoxicity and Neuronal...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Redefining Spasticity: The Spasticity X Working Group Consensus Statement.

American journal of physical medicine & rehabilitation·2026

Same author

Effect of Capsaicin (8%) Topical System on Sensory Function in Patients With Diabetic Peripheral Neuropathy: Analysis of the PACE Study.

Muscle & nerve·2026

Same author

Botulinum toxin use in patients with neurological disorders: A U.S.-based claims database analysis.

PM & R : the journal of injury, function, and rehabilitation·2026

Same author

Sydenham Chorea With Elevated Interleukin-12 Levels Responsive to Plasmapheresis and Immunotherapy.

Cureus·2026

Same author

Effectiveness, safety, and quality of life outcomes of neurotoxin injections in the treatment of essential tremors: a systematic review.

Journal of neural transmission (Vienna, Austria : 1996)·2025

Same author

Diabetic Peripheral Neuropathy: Pathophysiology and New Insights into the Mechanism of Action of High-Concentration Topical Capsaicin.

Journal of experimental pharmacology·2025

Search research articles

Related Experiment Video

Updated: May 19, 2026

A Mouse Model of Direct Anastomosis via the Prespinal Route for Crossing Nerve Transfer Surgery

A Mouse Model of Direct Anastomosis via the Prespinal Route for Crossing Nerve Transfer Surgery

Published on: October 19, 2021

Contralateral weakness following botulinum toxin for poststroke spasticity.

Anila M Thomas¹, David M Simpson

¹Clinical Neurophysiology Laboratory, Department of Neurology, Mount Sinai Medical Center, One Gustave Levy Place, Box 1052, New York, New York 10029, USA.

|August 22, 2012

Summary

High doses of botulinum toxin A (BoNT) for poststroke spasticity can cause contralateral limb weakness due to toxin diffusion. This rare adverse effect, linked to specific injection techniques, is reversible.

More Related Videos

Standing Neurophysiological Assessment of Lower Extremity Muscles Post-Stroke

Standing Neurophysiological Assessment of Lower Extremity Muscles Post-Stroke

Published on: July 26, 2021

Motor Imagery Brain-Computer Interface in Rehabilitation of Upper Limb Motor Dysfunction After Stroke

Motor Imagery Brain-Computer Interface in Rehabilitation of Upper Limb Motor Dysfunction After Stroke

Published on: September 1, 2023

Related Experiment Videos

Last Updated: May 19, 2026

A Mouse Model of Direct Anastomosis via the Prespinal Route for Crossing Nerve Transfer Surgery

A Mouse Model of Direct Anastomosis via the Prespinal Route for Crossing Nerve Transfer Surgery

Published on: October 19, 2021

Standing Neurophysiological Assessment of Lower Extremity Muscles Post-Stroke

Standing Neurophysiological Assessment of Lower Extremity Muscles Post-Stroke

Published on: July 26, 2021

Motor Imagery Brain-Computer Interface in Rehabilitation of Upper Limb Motor Dysfunction After Stroke

Motor Imagery Brain-Computer Interface in Rehabilitation of Upper Limb Motor Dysfunction After Stroke

Published on: September 1, 2023

Area of Science:

Neurology
Pharmacology
Electrophysiology

Background:

Botulinum toxin A (BoNT) is used to treat poststroke spasticity.
Two patients developed unexpected contralateral limb weakness after BoNT treatment.

Observation:

Patients received high doses of BoNT with large dilution volumes.
Injections were administered into proximal upper extremity muscles.
Contralateral upper limb weakness was observed post-injection.

Findings:

Electrodiagnostic testing revealed neuromuscular junction blockade.
Repetitive nerve stimulation showed significant nerve conduction decrements.
Electromyography (EMG) indicated abnormal spontaneous activity and motor unit potentials.

Implications:

Contralateral weakness may result from BoNT diffusion across tissue planes.
High dose, high volume, and proximal injections are potential risk factors.
This adverse effect appears to be transient and improves over time.