About half of people with myasthenia gravis (MG) experience symptoms of urinary incontinence, while about one-third have signs of an overactive bladder, with an urgent need to urinate.

That’s according to a recent study in Israel, which also found that patients with late-onset MG had a higher prevalence of urinary symptoms and progressed more rapidly to urinary incontinence than those with early-onset disease.

“Our findings highlight the importance of inquiring about urinary symptoms in routine clinical evaluation of MG patients to enhance patient care and quality of life,” researchers wrote.

The study, “Urinary dysfunction in myasthenia Gravis: a cross-sectional case-control study,” was published in Neurological Sciences.

Recommended Reading

October 5, 2021 News by Vanda Pinto, PhD

Bladder Problems Common in MG, Particularly for Late-onset Patients

Urinary dysfunction in MG has been understudied

MG is driven by self-reactive antibodies that attack proteins involved in nerve-muscle communication. The disease commonly leads to muscle weakness in the head, neck, trunk, and limbs, although other muscles may also be affected.

Urinary dysfunction, particularly urinary incontinence and overactive bladder, has also been reported in MG patients, but it remains understudied.

To learn more, a team of researchers in Israel conducted a study involving 86 MG patients and 90 age- and sex-matched controls without MG. They used validated questionnaires widely employed to assess urinary symptoms.

More than half of the participants in both groups were men (56%), with a mean age of about 60 years.

The most common MG type was early-onset MG (EOMG, 47.7%), in which the disease manifests before age 50. It was followed by very late-onset MG (30.2%) and late-onset MG (LOMG, 22.1%) — two MG types that manifest after age 65 and 50, respectively.

Recommended Reading

January 20, 2026 News by Andrea Lobo

Thymus gland removal seen as effective option for late-onset MG

Late-onset MG patients had high prevalence of incontinence symptoms

The International Consultation on Incontinence Questionnaire – Urinary Incontinence Short Form (ICIQ-UI SF) questionnaire was used to assess the frequency and severity of urinary incontinence and its impact on daily life. The severity and frequency of overactive bladder symptoms were determined using the Overactive Bladder Symptom Score (OABSS) survey.

MG patients had a significantly higher prevalence of urinary incontinence symptoms, defined as an ICIQ-UI SF score of 6 or higher, than controls (52.3% vs. 12.2%). It was even higher in those with LOMG (63.2%). LOMG patients also started experiencing symptoms of urinary incontinence earlier than those with EOMG (within a median of 3.8 vs. 19.5 years).

Severe incontinence (32.6% vs. 2.2%) and stress incontinence (31.4% vs. 6.7%) were also more prevalent in MG patients than in controls.

MG patients also more frequently reported symptoms of overactive bladder than controls, including waking up to urinate three or more times during the night (27.9% vs. 11.1%) and having two or more episodes of urgency to urinate per day (38.4% vs. 2.2%).

[This study] “may offer insights into the neuromuscular mechanisms underlying urinary control, emphasizing the broader clinical implications of MG beyond its classically recognized muscles involvement..

While both men and women with MG had a higher burden of urinary symptoms than controls, a higher proportion of women with MG had incontinence (63.2% vs. 43.8%), stress incontinence (55.3% vs. 12.5%), and urinary urgency (60.5% vs. 41.7%) compared with men.

Further analysis also demonstrated that the scores of the MG Activities of Daily Living (MG-ADL) scale, a widely used measure of MG severity, were associated with ICIQ-UI SF and OABSS scores and were a risk factor for predicting urinary incontinence among MG patients.

Although patients with more severe disease (an MG-ADL score above 6) tended to develop urinary incontinence earlier than those with less severe disease, the difference was not significant.

According to researchers, this study “may offer insights into the neuromuscular mechanisms underlying urinary control, emphasizing the broader clinical implications of MG beyond its classically recognized muscles involvement. Future research could focus on evaluation of [urinary incontinence] in MG by urodynamic studies and the value of targeted interventions to mitigate its impact.”