Botulinum Toxin for Cramps in Diabetic Neuropathy

Botulinum Toxin for Muscle Cramps in Diabetic Patients With Diabetic Neuropathy

Objective: previous studies suggest that botulinum toxin A (BoNT/A) can reduce muscle hyperactivity.

Research Design and Methods: a single-center, double-blind and placebo-controlled study investigating the efficacy and safety of BoNT/A intramuscular injection for treating calf or foot cramps refractory to common pharmacological drugs in patients with diabetic peripheral neuropathy. Fifty patients were subdivided in two matched groups (cases and controls) and BoNT/A (100 or 30 units) was injected for each side into the gastrocnemious or the small flexor foot muscles, respectively, according to the predominance of leg or foot cramps. Responders were evaluated again with a second BoNT/A administration.

The changes of pain intensity (primary outcome) and the changes in cramp frequency, the and the Cramp Severity Scale (CSS) were evaluated over the course of 20 weeks after BoNT/A administration.

Study Overview

• Status: Completed
• Conditions: Diabetes Mellitus; Muscle Cramps Aggravated
• Intervention / Treatment: Drug: Botulinum toxin type A; Other: Normal saline

Detailed Description

This was a single-center, randomized, double-blind, placebo-controlled prospective study.

A consecutive series of 303 out-patients with type 2 diabetes was screened for muscle cramps.Patients were asked to report in a questionnaire the frequency, localization, intensity and time of the day of cramps. Out of these 303 diabetic patients with cramps, fifty patients satisfied the inclusion/exclusion criteria and entered the study.

Cramp Evaluation

a) Clinical evaluation All patients completed a baseline diary in the week before treatment. Every day the number of muscle cramp episodes was reported three times a day and the intensity of pain was rated on a scale 0 to 10, with 0 indicating no pain and 10 indicating "the worst pain imaginable" (Brief Pain Inventory-Modified Short Form, BPI-MSF, point 1). Daily data in this pre-treatment week were averaged and considered "basal" values. A similar daily diary, reporting the number of pain episodes, their intensity, time of the day and duration (less or more than 1 min) was kept throughout the study for the three days before each control visit.

The severity of cramps interference on daily life was graded according to the functional scale Cramp Severity Score (CSS): 0= no cramps; 1= occasional day or night cramps not interfering with daily activities or with nocturnal sleep; 2= frequent muscle cramps triggered by muscle exercise not significantly interfering with daily activity or with nocturnal sleep; 3= continuous or subcontinuous muscle cramps limiting daily activities or nocturnal sleep; 4= continuous cramps severely interfering with daily activities and nocturnal sleep (4).

Randomisation: patients were randomly assigned to either the treatment or control groups according to a computer-generated list. Randomization was stratified in order to match age, gender, duration of diabetes and the frequency and severity of cramp episodes in the two groups.

At time 0 each patient received four i.m. injections, two injections for each side, containing either BoNT/A (100 units diluted in 1 ml saline) or saline. The total dose, for each side, was 100 units for the gastrocnemius muscle or 30 units for the small flexor foot muscles. The calf or the foot muscles were chosen according to the patient predominant leg or foot cramps. Patients in the control group received the same volumes of normal saline in the same muscles. The injections were prepared by a research nurse and both the treating physician and the patients were left blind.

Ten visits were scheduled after initial evaluation: at weeks 1 and 2 after BoNT/A injection and, thereafter, every other week until week 16 and then at week 20. Ratings of the three days before each control visit were averaged to obtain values for each post-injection evaluation. The number of cramp episodes and cramp severity score (both self-reported in the daily diary) were obtained at 1, 4, 8, 12, 16 and 20 weeks after BoNT/A or placebo administration.

Positive response to treatment: a 30% or greater reduction of the primary outcome score.

• Study Type: Interventional
• Enrollment (Actual): 50
• Phase: Phase 2

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 45 years to 75 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• accepting to participate to the study;
• age ≥ 45 and ≤ 75 years ;
• diabetes duration > 5 years and diabetic distal symmetric neuropathy present;
• stable glycemic control with last HbA1c value <9.0% (or 75 mmol/mol);
• cramps present at rest in either calf or foot muscles or both for at least 6 months;
• occurrence of cramps at least 3 times a week in the previous three months;
• previous unsuccessful or poorly tolerated pharmacological treatment with at least two of the following drugs: carbamazepine, quinine, phenytoin, magnesium supplements, and benzodiazepines.

Exclusion Criteria:

• the presence of other neurological diseases and of nephropathy, macro-angiopathy, cirrhosis, and lumbar disc diseases or the inability to give informed consent because of cognitive impairment.
• Patients previously treated with BoNT/A for any reason were also excluded

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: SINGLE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
ACTIVE_COMPARATOR: botulinum toxin type A; Botulinum toxin type A (100 or 30 units) was injected for each side into the gastrocnemious or the small flexor foot muscles, respectively, according to the predominance of leg or foot cramps.	Drug: Botulinum toxin type A; botulinum toxin type A injections Botulinum toxin type A (100 or 30 units) was injected for each side into the gastrocnemious or the small flexor foot muscles, respectively, according to the predominance of leg or foot cramps.
PLACEBO_COMPARATOR: Normal saline; The same dosage as the active group, but with normal saline alone were injected into the gastrocnemious or the small flexor foot muscles, respectively, according to the predominance of leg or foot cramps.	Other: Normal saline; Normal saline injections The same dosage as the active group, but with normal saline alone were injected into the gastrocnemious or the small flexor foot muscles, respectively, according to the predominance of leg or foot cramps.; Other Names: Placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
pain intensity on a 0-10 severity scale	the intensity of pain was rated on a scale 0 to 10, with 0 indicating no pain and 10 indicating "the worst pain imaginable"	20 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
cramp frequency	the changes in cramp frequency, the Cramp Severity Scale (CSS) were evaluated over the course of 20 weeks after BoNT/A administration	20 weeks
the Cramp Severity Scale (CSS)	the changes in the Cramp Severity Scale (CSS) were evaluated over the course of 20 weeks after BoNT/A administration	20 weeks
the Cramp Threshold Frequency (CTF)	the changes in the Cramp Threshold Frequency were evaluated over the course of 20 weeks after BoNT/A administration	20 weeks

Collaborators and Investigators

• Sponsor: Presidio Ospedaliero Garibaldi-Centro

Publications and helpful links

General Publications

• Bertolasi L, Priori A, Tomelleri G, Bongiovanni LG, Fincati E, Simonati A, De Grandis D, Rizzuto N. Botulinum toxin treatment of muscle cramps: a clinical and neurophysiological study. Ann Neurol. 1997 Feb;41(2):181-6. doi: 10.1002/ana.410410209.

Study record dates

Study Major Dates

• Study Start (ACTUAL): September 27, 2014
• Primary Completion (ACTUAL): May 3, 2017
• Study Completion (ACTUAL): May 3, 2017

Study Registration Dates

• First Submitted: June 9, 2017
• First Submitted That Met QC Criteria: August 2, 2017
• First Posted (ACTUAL): August 3, 2017

Study Record Updates

• Last Update Posted (ACTUAL): August 3, 2017
• Last Update Submitted That Met QC Criteria: August 2, 2017
• Last Verified: August 1, 2017

More Information

Terms related to this study

• Keywords: botulinum toxin; diabetic neuropathy; muscle cramps
• Additional Relevant MeSH Terms: Nervous System Diseases; Neurologic Manifestations; Endocrine System Diseases; Diabetes Complications; Diabetes Mellitus; Musculoskeletal Diseases; Muscular Diseases; Neuromuscular Diseases; Peripheral Nervous System Diseases; Neuromuscular Manifestations; Diabetic Neuropathies; Spasm; Muscle Cramp; Physiological Effects of Drugs; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Peripheral Nervous System Agents; Cholinergic Agents; Membrane Transport Modulators; Acetylcholine Release Inhibitors; Neuromuscular Agents; Botulinum Toxins; Botulinum Toxins, Type A; abobotulinumtoxinA
• Other Study ID Numbers: btx for cramps

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• product manufactured in and exported from the U.S.: No