What Is Motor Neurone Disease? An Australian Guide

What is motor neurone disease? An Australian guide

Two Australians are diagnosed with motor neurone disease every day. Two die from it every day. Those two sentences sit next to each other in almost every piece of literature on the condition, and the reason they are quoted so often is that together they describe something unusual: a disease where the number of people living with it barely moves, because the rate of arrival and the rate of departure are the same.

About 2,752 Australians were living with MND in 2025. That is roughly one person in every 10,030. It is not a common condition. But the lifetime risk of developing it is around 1 in 300 by the age of 85, which is considerably higher than most people would guess, and it is rising.

This guide covers what MND actually is at the level of the nerve cells involved, the different forms it takes and why the distinction matters, what the Australian numbers look like and what has changed in them recently, and the handful of things MND is most often confused with. It does not cover treatment, equipment, funding or care in any depth — those have guides of their own, linked throughout.

A word on terminology before we start. In Australia and the UK the condition is called motor neurone disease. In the United States it is usually called ALS, for amyotrophic lateral sclerosis, or sometimes Lou Gehrig’s disease. These are not quite synonyms: ALS is the most common form of MND, so “MND” is the family and “ALS” is the largest member of it. Australian clinicians use both, often in the same sentence, and the NDIS lists them together. If you are reading American material, assume ALS means roughly what MND means here.

What the motor neurones do, and what happens when they stop

Every voluntary movement you make runs down a two-stage relay.

The upper motor neurones start in the motor cortex, near the top of the brain, and run down through the brainstem and spinal cord. The lower motor neurones take over from there: their cell bodies sit in the brainstem and the spinal cord, and their long fibres run out to the muscles themselves. A signal to lift your foot begins as an upper motor neurone firing, hands off to a lower motor neurone, and ends with muscle fibres contracting.

MND is the progressive death of those cells. As they die, the signal stops arriving, and a muscle that receives no signal wastes away — which is what “amyotrophic” means. The pattern of weakness depends entirely on which neurones go first, and that is why two people with the same diagnosis can look completely different in the first year.

The distinction between the two types of neurone also produces two distinct kinds of weakness, and clinicians look for both because finding both is part of how the diagnosis gets made.

Lower motor neurone signs are the ones most people picture: muscles that shrink visibly, weakness, cramps, and fasciculations — the fine rippling twitches under the skin that patients often notice first and that can be unnerving to watch. Reflexes are reduced or absent. Muscle tone goes down.

Upper motor neurone signs look almost opposite: stiffness, spasticity, exaggerated reflexes, clumsiness in a limb that is not obviously wasted. Tone goes up rather than down.

A person with both patterns in the same limb, or in different parts of the body, is showing the signature of MND. That combination is unusual and it is the main reason an experienced neurologist can often tell within one examination what is probably happening, well before the tests confirm it.

Three things are generally spared, and they matter enormously for how the condition is lived with.

The sensory nerves. MND does not usually cause numbness or loss of sensation. People feel touch, temperature and pain normally. This is why pressure care matters so much — a person who cannot reposition themselves can feel every bit of the discomfort.

The bladder and bowel muscles themselves. Continence is usually preserved. Constipation is very common, but it is a consequence of immobility, reduced fluid and food intake, and medication, not of the nerves to the bowel failing.

The eye muscles, for the most part, and for a long time. This is the single most important fact in the whole of MND communication, because it is the reason eye-gaze technology works. When somebody can no longer speak, write, or move a hand, they can usually still direct their gaze — and a camera can read that and turn it into speech. More on this in communication and voice banking with MND.

The types, and why the distinction is worth knowing

MND is a group of conditions rather than one. The boundaries between them are blurry, people move between categories as the disease spreads, and the labels matter mainly because they carry different typical trajectories.

Amyotrophic lateral sclerosis (ALS) is the most common form, accounting for the clear majority of cases. Both upper and lower motor neurones are affected. It usually starts in one limb — a foot that drops, a hand that cannot grip — and spreads.

Progressive bulbar palsy starts in the bulbar region: the muscles of speech and swallowing, supplied by nerves from the brainstem. The first sign is slurred speech or difficulty swallowing rather than a weak limb. Bulbar onset is more common in women and in people with later onset, and it generally carries a shorter survival, partly because speech, swallowing and the cough mechanism are all compromised early. Progressive bulbar palsy appears on the NDIS lists under its own name.

Progressive muscular atrophy affects lower motor neurones predominantly. It tends to progress more slowly than ALS.

Primary lateral sclerosis affects upper motor neurones predominantly. It is rare, progresses slowly, and some people with it live for decades. It is also listed by name on the NDIS lists.

Kennedy’s disease, or spinal and bulbar muscular atrophy, is a genetic condition sometimes grouped with MND. It is X-linked, affects men, and progresses very slowly.

Two practical points come out of this list.

First, the speed varies more than most summaries admit. Average life expectancy after diagnosis is two to three years, and that number gets repeated so consistently that families treat it as a prediction. It is an average across a very wide spread. Around 5 to 10 per cent of people have a slowly progressive form and live more than ten years. Some live much longer than that. A person diagnosed with primary lateral sclerosis and a person diagnosed with bulbar-onset ALS have been given the same four-letter label and face very different situations.

Second, where it starts shapes what you need first. Limb onset means wheelchairs, hoists, home modifications and personal care come up early. Bulbar onset means speech pathology, communication technology, swallowing management and a gastrostomy conversation come up early. Both will eventually need all of it. But the order is not the same, and a support plan built for the wrong order wastes time nobody has.

The Australian numbers, and the thing that has changed in them

Here is where the picture has shifted recently, and where Australian research has produced something genuinely new.

A study led by Dr Carol Lee and Professor Dominic Rowe at Macquarie University’s MND Research Centre, published in the Medical Journal of Australia in 2026, went through Australian Bureau of Statistics cause-of-death data going back to the 1980s. The finding was stark: MND deaths have roughly trebled, from 238 in 1986 to 781 in 2023. The researchers expected the disease to kill around 800 Australians during 2026. MND now accounts for about one Australian death in every 234.

Some of that rise is what you would expect from an ageing, growing population and better diagnosis. The authors’ argument is that it is not all of it.

They found differences by place that are hard to explain away. Mortality over 2019 to 2023 was about 1.4 times higher in Tasmania and 1.2 times higher in South Australia than in New South Wales. Mortality was significantly higher in regional areas than in major cities. And only around 10 per cent of people with MND have a clear family history, so genetics cannot account for either the national increase or the geographic pattern — the rise is being driven by sporadic cases, the ones with no inherited cause.

The authors’ conclusion is that environmental risk factors are probably involved, that no single obvious factor explains it, and that Australia cannot investigate properly because it does not collect the data. Their recommendations were a compulsory state-wide MND registry and funding to look for environmental causes. The work itself was funded by NSW Health under a grant designated for MND research.

That last point is worth sitting with for a moment. Australia has an unusually high burden of this disease by international standards, regional Australia has a higher burden than metropolitan Australia, and we do not have a national registry that would let anybody find out why.

The rest of the demographic picture:

Those last two rows are the ones that go on to shape almost everything else, and each has a guide to itself. The genetics question is covered below. The age question — the fact that more than half of Australians diagnosed with MND are already past the age at which they can join the NDIS — is the single biggest structural problem in Australian MND care, and it is covered in MND over 65: the NDIS age bar and what Support at Home gives you instead.

MND is slightly more common in men than women. Around half of people are diagnosed under 60. It occurs in every country and every ethnic group studied.

Genetics: the 10 per cent, and the 90 per cent

Roughly one in ten people with MND has a clear family history. That form is called familial MND, and up to about 15 per cent of all cases are thought to involve a genetic mutation, including some where no family history is apparent.

The genes most often named are SOD1, C9orf72, TARDBP (which makes the TDP-43 protein) and FUS. C9orf72 is the most common single genetic cause and it is also the gene most associated with the overlap between MND and frontotemporal dementia, discussed below.

Where a faulty gene is identified in a person, each of their children, siblings and parents has a 50 per cent chance of carrying the same fault in the dominantly inherited forms. That is a 50 per cent chance of carrying it, not a 50 per cent chance of developing the disease — penetrance varies by gene and is not complete for all of them.

Genetic testing is a real decision with real consequences and it should not be approached casually. It affects insurance, it affects family members who may not want to know, and a positive result in a well person creates a situation with no treatment to offer. Genetic counselling before testing is not a formality. For most families, the single most useful thing to know is that nine out of ten cases are sporadic, with no identified inherited cause — so a diagnosis in a relative does not usually mean a meaningful risk to you.

The genetics has become more consequential in one specific respect. In late 2025, tofersen (brand name Qalsody) was listed on the Pharmaceutical Benefits Scheme from 1 October for people with SOD1-related ALS. Without the subsidy it costs up to around $28,600 per script; on the PBS, patients pay a maximum of $25, or $7.70 with a concession card. Around 70 Australians a year are expected to benefit. It is the first time a genetically targeted treatment for MND has been subsidised in Australia, and it means that for a small group, identifying the mutation now changes what can be offered.

For everybody else, riluzole remains the only disease-modifying medication generally available, and its effect is modest — it extends survival by somewhere between six and nineteen months when started early. Multidisciplinary clinic care has been estimated to add seven to twenty-four months, and non-invasive ventilation up to thirteen months. Those three interventions are the whole arsenal, and two of the three are about how care is organised rather than what drug is prescribed. Which is why the organisational failures in Australian MND care are not administrative inconveniences; they are clinical ones.

What MND is confused with

Several conditions produce overlapping early symptoms, and some of them are treatable. Ruling them out is the whole purpose of the diagnostic process, covered in getting an MND diagnosis. The ones that come up most often:

Cervical spondylotic myelopathy. Compression of the spinal cord in the neck from arthritic change can produce weakness, wasting in the hands, brisk reflexes in the legs and a stiff, clumsy gait — a combination of upper and lower motor neurone signs that can look very like MND. It is also surgically treatable. An MRI of the cervical spine is standard early.

Multifocal motor neuropathy. A rare immune-mediated condition that causes progressive, asymmetric weakness without sensory loss. It responds to intravenous immunoglobulin. Missing it means missing a treatable disease that mimics an untreatable one, which is why nerve conduction studies are done carefully.

Myasthenia gravis. Weakness that fluctuates and worsens with use, often starting with the eyelids, eye movements, speech or swallowing. Bulbar-onset MND and myasthenia can look similar at first. Myasthenia is treatable.

Inclusion body myositis. A muscle disease, not a nerve disease, which typically weakens the thigh and finger-flexor muscles and can cause swallowing difficulty.

Kennedy’s disease, for men with slowly progressive bulbar and limb weakness, because it carries a far better prognosis.

Cervical radiculopathy or a peripheral nerve entrapment, early on, when a single weak hand is the only sign.

There is also a different kind of confusion worth naming, because it costs people more than the clinical ones. MND is frequently mistaken, in the first several months, for nothing much. A slightly dragging foot gets treated as a back problem. A weak grip gets treated as a tennis elbow or a nerve entrapment. Slurred speech gets treated as stress, or alcohol, or a small stroke that did not show up. Physiotherapy is prescribed, exercises are given, three months pass, and then another referral. Thirteen months is the Australian average from first symptom to diagnosis, and most of that time is spent in exactly this kind of plausible, reasonable, wrong management.

Cognitive change: the part nobody mentions at diagnosis

MND has historically been described as a disease that leaves the mind untouched. That description is wrong, and it is still repeated.

More than half of people with MND experience some change in thinking or behaviour. About 35 per cent have mild changes. Up to 15 per cent develop changes significant enough to be diagnosed as frontotemporal dementia, giving a combined diagnosis of MND/FTD. The changes are frequently behavioural rather than memory-based: apathy, rigidity, impulsivity, irritability, loss of social filter. Sometimes they appear years before any motor symptom, which means the family has already been living with an unexplained personality change by the time the weakness arrives.

There is also emotional lability, or pseudobulbar affect — uncontrolled laughing or crying that does not match what the person actually feels. It is distressing, it is commonly mistaken for emotional collapse, and it is treatable.

This matters practically for one reason above all. Almost every piece of advice about MND tells families to plan ahead, make decisions early, appoint a decision-maker, and document what they want. All of that assumes capacity. If cognitive change is part of the picture — and in a substantial minority it is — then the window for those decisions is narrower than the physical progression suggests. Cognitive and behaviour change in MND covers it properly, and planning ahead with MND covers the documents.

What living with it involves, in outline

The rest of this library deals with each of these in detail. In outline, and in roughly the order they tend to arrive:

Breathing is the one that determines survival. The diaphragm is a muscle, and it weakens like the others. Non-invasive ventilation is the most effective life-extending treatment available in MND, and Australian access to it is patchy in ways that track with gender, postcode and age. See breathing and MND.

Swallowing and nutrition. Weight loss is a bad prognostic sign and a gastrostomy is best placed before things get difficult rather than after. See eating, swallowing and PEG feeding with MND.

Communication. About 80 per cent of people with MND develop changes to speech. Voice banking, done early, means a speech-generating device can later speak in something recognisably their own voice. See communication and voice banking.

Equipment and housing. This is where MND breaks ordinary disability processes, because the standard assessment-quote-approval-delivery cycle is slower than the disease. See equipment and home modifications with MND.

Funding. MND sits on NDIS List B, not List A, which surprises almost everybody. There is also a priority access pathway that very few people are told about. See MND and the NDIS.

Care at home, and eventually around the clock. See supported independent living and 24-hour support with MND.

The family. Unpaid carers of people with MND provided 5.37 million hours of care in Australia in 2025, averaging around 37.5 hours a week. See families and carers.