oꢀabꢁꢂulꢃꢀuꢄꢂꢁxꢃꢀA uꢅꢆ ꢃꢀ mG
7
3
cystocele. Her primary urinary bother was that of nocturia
for the treatment of dystonia. The case study concludes that
every two hours with severe nighttime urgency and a very
poor quality of life. She had previously been diagnosed with
MG and followed by a neurologist. She was taking mesti-
non, an acetylcholinesterase inhibitor, for control of her
MG symptoms, which precluded the use of anticholinergic
medications. Her MG symptoms were mild, manifesting only
as bilateral ptosis.
individuals with underlying neuromuscular conditions can
develop more generalized weakness after Botox treatment
and that caution should be used when administering Botox
to these individuals, even in small doses.
We have presented two cases of comorbid OAB and MG
that have successfully been treated with intra-detrusor Botox.
Both patients were treated after careful consultation with
their neurologist. We have also limited the dosage to 100
units in order to minimize the heightened theoretical risk
of systemic side effects in the setting of MG. This report
highlights the lack of evidence to support the practice of
withholding Botox from all patients with MG.
®
She was started on mirabegron (Myrbetric ) 50 mg daily
and a pessary was fitted for her cystocele. Mutichannel
urodynamics confirmed terminal detrusor overactivity at
reduced bladder volumes. Her symptoms were not well-
controlled on Myrbetriq and she subsequently requested
Botox therapy. After consulting her neurologist, permission
was given to proceed with Botox treatment at a dose of 100
units. In April 2015, she received her first treatment. She
reported no worsening of her neurological status at her one-
month followup. Her nocturia improved to once every four
hours and led to a significant improvement in her quality of
life. We plan to continue with Botox injections for ongoing
symptom control.
Competing interests: Dr. Baverstock has served as an Advisory Board member for Allergan, Astellas,
and Pfizer; a member of the Speakers’ Bureau for Allergan, AMS, Astellas, and Pfizer; received
payment/grants/honoraria from Allergan, AMS, Astellas, and Pfizer; and has participated in clinical
trials for Allergan, Astellas, and Pfizer. The remaining authors declare no competing financial or
personal interests.
This paper has been peer-reviewed.
Discussion
The medical literature is sparse when reporting the use of
Botox in patients with MG. Most of the available experi-
ence is reported in the use of Botox for cosmetic indica-
tions and in those with dystonia. One case study describes
References
1
.
Allergan, Inc. Clostridium botulinum type A neurotoxin complex (900kD) Sterile vacuum-dried concentrate
powder for solution for injection 50, 100 and 200 Allergan units per vial Neuromuscular Paralytic Agent.
Botox Product Monogram 2014; Retrieved from http://www.allergan.ca/assets/pdf/ca_botox_pm.pdf.
Accessed November 30, 2015.
4
a 49-year-old woman with both MG and cervical dystonia.
The individual was treated for her dystonia using Botox,
with no observed flare in her MG symptoms. Her MG did
not progress following the Botox treatment. Another study
reports treatment of dystonia with Botox in an individual
2
.
Bird SJ. Clinical Manifestations of Myasthenia Gravis. UpToDate 2015; Version 12: Topic 5170.
3. Office of Communications and Public Liaison. Myasthenia Gravis Fact Sheet. National Institute of
Neurological Disorders and Stroke 2015; c2015 [updated 2015 July 27]; NIH Publication No. 10-768.
Retrieved from http://www.ninds.nih.gov/disorders/myasthenia_gravis/detail_myasthenia_gravis.
htm. Accessed December 11, 2015.
4
5
6
5
with comorbid MG. The treatment was successful and,
.
.
.
Goncalves MR, Barbosa E, Zambon AA, et al. Treatment of cervical dystonia with botulinum toxin in
a patient with myasthenia gravis. Arq Neuropsiquiatr 1999;57:683-5. http://dx.doi.org/10.1590/
S0004-282X1999000400024
Fasano A, Bentivoglio A, IalongoT, et al. Treatment with botulinum toxin in a patient with myasthe -
nia gravis and cervical dystonia. Neurology 2005;64:2155-6. http://dx.doi.org/10.1212/01.
WNL.0000165997.77985.32
using EMG guidance and small dosage, the individual was
safely treated without any side effects or generalized weak-
ness. This was partially achieved through use of a more
concentrated solution than usual to prevent spreading of
the Botox to other muscle areas.
Dressler D. Subclinical myasthenia gravis causing increased sensitivity to botulinum toxin therapy. J Neural
Transm 2010;117:1293-4. http://dx.doi.org/10.1007/s00702-010-0481-9
Other research suggests that pre-existing conditions, such
as MG, may increase the potency of Botox-type drugs, caus-
7. Iwase T, Iwase C. Systemic effect of local and small-dose botulinum toxin injection to unmask subclinical
myasthenia gravis. Graefes Arch Clin Exp Ophthalmol 2006;244:415-6. http://dx.doi.org/10.1007/
s00417-005-0130-4
6
ing adverse effects, such as muscle weakness. However,
it is also suggested that this can be corrected for by dose
adjustment. A similar suggestion is made in a case study that
reports MG symptoms worsening post-Botox administration
Correspondence: Dr. Andrea Civitarese, Alberta Cancer Centre, Calgary, AB, Canada; andrea@vesia.ca
CUAJ • May-June 2016 • Volume 10, Issues 5-6
E185