The sentence families use is almost always the same. He is grand in the morning. By teatime his eye is closed over, his voice has gone soft, and he cannot finish his dinner without resting halfway. Then he sleeps, and the next morning he is grand again.
That daily arc is not tiredness, and it is not ageing. It is the single most distinctive sign of myasthenia gravis, an autoimmune condition in which antibodies jam the junction between nerve and muscle. Muscles work, then fade with use, then recover with rest. And in Ireland, as across western Europe, it has quietly become a condition of people in their seventies rather than the young women it was once described in.
TL;DR
- Myasthenia gravis causes fatigable weakness: better after rest, worse after use, worse in the evening. Droopy eyelid, double vision, slurred or nasal speech and difficulty chewing are the usual openers.
- Across western Europe most people with myasthenia are now over 65, and incidence in that age group has roughly doubled in 35 years while rates under 50 have not moved.
- Ireland has two population figures for it, both roughly 15 per 100,000, published in 2016 and 2017. Nothing has been published since.
- Nearly one in five people whose myasthenia starts after 65 presents with a life-threatening event, and crisis risk is highest in the first six months after diagnosis.
- Common medicines can unmask or worsen it. The Irish product information for ciprofloxacin and for timolol glaucoma drops both name myasthenia gravis in plain terms.
- At 24 September 2026, 27,887 adults were waiting a first neurology outpatient appointment in Ireland, 4,544 of them longer than 18 months.
- The outlook for later-onset myasthenia is genuinely good. Most people respond well to standard treatment, and active treatment is recommended at any age.
Fatigability is the whole diagnosis
Plenty of things make an older person weak. What makes myasthenia different is the shape of the weakness over a day, and the specific muscles it picks.
It starts above the neck far more often than below it. In a large series of people with later-onset disease, 79% had a drooping eyelid as their first symptom and 19% had double vision. Bulbar symptoms, meaning the muscles of speech and swallowing, came early in 28%. Between a third and a half of people over 65 still have eye symptoms only at the point of diagnosis.
The tell is repetition. A lid that sits normally first thing and closes over after twenty minutes of reading. Double vision that appears while watching television and clears after a nap. A voice that starts clear on the phone and turns nasal or breathy by the end of the call. Chewing that gets harder as the meal goes on, so the second half of the dinner is abandoned. Some people develop weakness of the neck extensors and find their head dropping forward by evening, which is often blamed on the neck rather than on the junction.
Limb weakness, when it comes, is usually in the shoulders and hips rather than the hands and feet. The stairs are fine once and impossible the fourth time. Hanging washing on a line is the classic complaint, because it asks the shoulders to hold a position repeatedly. None of this is subtle once you know to ask. The trouble is that almost nobody asks.
After 65, it is largely a condition of men
The textbook picture of myasthenia, a woman in her twenties or thirties, is a description of one subgroup that has simply stopped being the biggest one.
A nationwide Danish study covering 35 years found that half of all new cases had symptoms beginning after 65. Comparing the late 1980s with the period 2016 to 2021, the incidence rate in the over-65 group more than doubled, with a rate ratio of 2.2. In the 50 to 65 group it rose by a factor of 1.9. In people under 50, it did not rise at all. German insurance claims data for 2019 put the annual incidence among men aged 70 to 79 at 19.8 per 100,000, against 0.5 per 100,000 for men in their thirties.
Something has changed, and it is not purely better detection, because better detection would have lifted the younger figures too. The leading explanation is immunosenescence, the age-related drift in immune regulation that makes autoimmune disease more common after 70. The practical consequence is simple: a GP seeing a drooping eyelid in a man of 76 is looking at the group in which this condition is now most common, not least common.
What it gets called instead
Everything myasthenia does after 70 has a more boring explanation available, and the more boring explanation usually wins first.
A drooping lid gets attributed to a stretched eyelid tendon or to the loose lid skin that is genuinely common with age, both of which are real and both of which sit happily alongside an undiagnosed myasthenia. Cataract, glaucoma and macular degeneration muddle both the eye symptoms and the testing. Swallowing trouble gets put down to reflux or to degenerative changes in the upper spine. Generalised weakness gets put down to deconditioning, to a bad winter, to grief.
The most consequential confusion is stroke. Myasthenia with double vision and bulbar symptoms can come on fast, and brainstem stroke is frequently the working diagnosis when an older person is admitted acutely before myasthenia is identified. There is a silver lining in that: suspected stroke gets you seen urgently, which is why diagnostic delay in this age group is actually shorter than in younger patients. One Australian series put the median delay at 102 days, which is far from good but far better than the years some younger people wait.
If you have read our pieces on sudden facial weakness or on degenerative cervical myelopathy, the pattern will be familiar. A treatable neurological condition presents in a way that resembles ordinary ageing, and the resemblance costs months.
Ireland counted it, twice, over a decade ago
Ireland has produced two population estimates of myasthenia gravis, and they agree with each other closely.
A team at St Vincent’s University Hospital, publishing in the Irish Medical Journal in 2016, pulled case lists from consultant neurologists and ophthalmologists, a neuroimmunology laboratory, general practitioners and the Myasthenia Gravis Association. They screened 1,715 records, included 706 cases and arrived at a prevalence of 15.38 per 100,000, with a slight female excess across all ages and visible variation between counties. A separate study of adult neuromuscular disease across the Republic, published in Neurology in 2017 with a prevalence point of December 2013, put myasthenia gravis at 15.12 per 100,000.
Two independent methods, essentially the same number. That is reassuring about the figure and unsettling about everything else, because registry countries that capture cases by mandatory reporting find considerably more: Nordic data show prevalence rising to roughly 80 per 100,000 in men over 70, and German claims data exceeded 200 per 100,000 in the oldest men. Those are different populations, methods and years, so they are not a like-for-like rebuke of the Irish number, but the Irish authors said it themselves, that some of their figures may understate the true prevalence. And that is where it rests. Motor neurone disease in Ireland has a register. Myasthenia gravis does not, and the most recent published Irish count is now a decade old.
Getting seen, and what the queue looks like
Confirming myasthenia is not difficult once somebody suspects it. Antibodies to the acetylcholine receptor are detectable in up to 90% of people with generalised disease, and a positive result in someone with fatigable weakness settles the question. For the 10% to 20% who test negative, repetitive nerve stimulation has a sensitivity of up to 80%, and single fibre EMG can confirm it, though it needs careful interpretation in older people whose nerves may be abnormal for other reasons. A negative antibody test on a standard assay should prompt a more sensitive cell-based assay and, if suspicion persists, a repeat in three to six months.
The ice pack test, in which a cold pack is held over a drooping lid to see whether it lifts, is cheap, quick and recommended at any age; the older edrophonium test is now avoided in later life because of the cardiac risk. Around 5% of people with onset after 65 have a thymoma, so a scan of the chest is standard, but thymectomy is not recommended after 65 unless one is found.
All of that depends on getting to a neurologist. National Treatment Purchase Fund data for the archive date of 24 September 2026 record 27,887 adults waiting a first neurology outpatient appointment, the ninth largest adult outpatient list in the country. Of those, 6,545 had been waiting between six and twelve months, 3,491 between twelve and eighteen months, and 4,544 longer than eighteen months. Close to one in six has been waiting more than a year and a half.
That matters more here than for most referrals, because later onset and older age are both independent risk factors for myasthenic crisis, and the risk is highest in the first six months after diagnosis. The period during which active treatment matters most is the period many people spend on a list.
If the symptoms are fluctuating weakness of the eyes, speech or swallowing, say so in those words to your GP, and ask whether the referral can be marked urgent. Shortness of breath or a change in swallowing is not a waiting list matter at all.
Not on the list, and not on the map
Ireland’s Long-Term Illness Scheme gives free medicines, with no means test and no prescription charge, to people with any of sixteen named conditions. We covered it in detail in an earlier piece on the scheme and its frozen list. Checked again on the HSE’s own page, last reviewed in December 2025, the list is unchanged, and it still includes muscular dystrophy, multiple sclerosis, parkinsonism, epilepsy, spina bifida and hydrocephalus.
Muscular dystrophy is a disease of muscle. Myasthenia gravis is a disease of the junction that tells muscle to contract. One is on the list and one is not, though a person with myasthenia takes pyridostigmine and often an immunosuppressant for life either way. Without a medical card they pay up to €80 a month under the Drugs Payment Scheme, which is €960 a year. The State’s own 2022 spending review observed that confining eligibility to sixteen conditions, when the World Health Organization defines over a hundred as long-term or chronic, “could be seen as arbitrary”, and noted that France reviews its equivalent list more regularly than Ireland does.
The absence repeats elsewhere. The Neurological Alliance of Ireland lists 33 member organisations, among them Muscular Dystrophy Ireland, MS Ireland, Epilepsy Ireland, Spina Bifida Hydrocephalus Ireland and Polio Survivors Ireland. There is no myasthenia organisation among them. The conditions with an Irish voice are broadly the conditions on the list, and myasthenia has neither.
The medicines that can make it worse
This is the section worth writing down and bringing to appointments. A long list of ordinary medicines can worsen myasthenic weakness, and two of the commonest are prescribed to older adults constantly. The Irish summary of product characteristics for ciprofloxacin, under its warnings section, states that it “should be used with caution in patients with myasthenia gravis”, and lists “exacerbation of symptoms of myasthenia gravis” among its adverse reactions. The patient leaflet in an Irish box of Ciproxin 500mg puts it even more plainly: tell your doctor “if you have myasthenia gravis (a type of muscle weakness) because symptoms can be exacerbated”. Ciprofloxacin is a workhorse for urinary tract infections in later life.
The second is less expected. Timolol eye drops for glaucoma are a beta-blocker, and enough of the drug is absorbed systemically to matter. The Irish product information for Timoptol lists “increases in signs and symptoms of myasthenia gravis” under nervous system disorders, and the patient leaflet carries the same wording. People do not think of eye drops as medication, and they frequently do not mention them when asked what they take.
Other classes flagged in the international literature include aminoglycoside and macrolide antibiotics, magnesium given intravenously or in high oral doses, some beta-blockers taken by mouth, penicillamine, hydroxychloroquine and the immune checkpoint inhibitors used in cancer treatment. Infections themselves commonly trigger exacerbations, which is one reason influenza, pneumococcal, COVID-19 and shingles vaccination is actively recommended for people with myasthenia.
Nothing here means refusing a needed antibiotic. It means the prescriber needs to know the diagnosis, and that a new or worsening weakness after starting something new is a reason to ring, not to wait and see. The same medicines-list discipline we described in our piece on anticholinergic burden applies here, eye drops and all.
When it is an emergency
Myasthenic crisis is weakness severe enough to compromise breathing or swallowing, and it needs intensive care, not an outpatient appointment.
In a Spanish registry of 424 people whose myasthenia began after 65, close to 20% presented with a life-threatening event at onset, a far higher proportion than in younger patients. The risk is concentrated in the first six months after diagnosis, and infection is a frequent trigger.
Go to an emergency department, or call 112 or 999, if there is breathlessness at rest or when lying flat, a weak or ineffective cough, difficulty clearing secretions, choking or coughing on food and drink, or a rapid worsening of speech and swallowing over hours. Tell the ambulance crew and the triage nurse the words “myasthenia gravis” if the diagnosis is known, because it changes what is safe to give.
Outcomes from crisis, including weaning from ventilation, are broadly similar across age groups. Older people are more prone to deconditioning afterwards, so rehabilitation matters, but a crisis is not a verdict.
The part that should reassure you
Later-onset myasthenia, for all the delay getting to it, generally behaves well.
People whose disease starts after 65 tend to need fewer immunosuppressive drugs and lower doses to control it, relapse less often than those with early-onset disease, and are less likely to prove treatment-resistant. In a Canadian series, 71% improved on immunosuppressive therapy, 24% reached pharmacological remission, and 79% managed on fewer than three immunosuppressants. Eye-only myasthenia beginning after 65 has a more benign long-term course than eye-only disease in younger people, and only about a third of those with onset after 70 go on to develop generalised disease.
Treatment starts with pyridostigmine, which you can adjust day to day with your team’s guidance. Its side effects deserve attention in later life, since bradycardia, dizziness, urinary urgency or retention, cramps and diarrhoea all land harder when there are other conditions in the mix. Prednisolone combined with azathioprine, mycophenolate or tacrolimus is standard first-line immunosuppression, with rituximab an alternative. Existing diabetes is a relative contraindication for steroids, which is worth raising early given how common that combination is. The newer complement inhibitors and FcRn blockers appear to work as well at 75 as at 35, though trials have under-recruited the oldest patients, so the evidence there is thinner than it should be.
The explicit recommendation in the current review literature is that treatment aims in later life should be as ambitious as in younger patients: full remission on medication, or minimal symptoms. Age is not a reason to settle, and current guidance recommends 150 minutes a week of moderate activity once the condition is stable, which surprises people who have been told to rest.
Where to start
If this sounds like someone in your house, keep a note for a week before the GP appointment, because “tired” will not get you where “my eyelid closes over every evening and is fine by morning” will. For the cost side, check eligibility for a medical card first, since it covers everything rather than one condition, and register for the Drugs Payment Scheme in the meantime to cap monthly costs at €80. Citizens Information is the clearest guide to both. Rare Diseases Ireland describes itself as a home for all rare diseases, including those with no organisation of their own, which describes this one exactly. The UK charity myaware publishes good plain-English information that is open to anyone, though it is based in Britain.
At Críonna Health we keep returning to conditions that are treatable, reasonably well understood, and still routinely filed under getting older. Myasthenia gravis is near the top of that list. It responds to treatment, it is confirmed by a blood test, and the thing most likely to delay it is that nobody thought to ask what the weakness does between breakfast and bedtime.
This article is for general information and is not medical advice. If you are concerned about weakness, drooping eyelids, double vision or changes in speech or swallowing, speak to your GP. If breathing or swallowing is affected, go to an emergency department or call 112 or 999.
📷 Photo by Ashwini Chaudhary(Monty) on Unsplash
