Motor neurone disease (MND)

Motor neurone disease is a group of conditions in which the motor nerve cells gradually die — the cells that carry instructions from the brain to the muscles. The muscle itself is healthy to begin with, but the instructions reach it less and less well, so it weakens and wastes. The commonest form has a name of its own, amyotrophic lateral sclerosis or ALS, and in everyday speech people often say "ALS" when they mean the whole group. The disease is rare and usually begins after the age of fifty, although it can start earlier. There is as yet no cure, but there is a great deal that genuinely changes how a person feels and how long they live, and the earlier it is put in place, the clearer the difference.

How it usually begins

The onset is almost always quiet and one-sided: one arm, one leg or the speech is affected, rather than everything at once. People notice they can no longer get a key into a lock, that they drop a mug, cannot do up a button or hold on to a shopping bag. Or they start catching a toe on the doorstep and turning the ankle: the foot stops lifting, and that gait is known as foot drop.

If the muscles of the face, tongue and throat go first, the picture is different: speech becomes slurred, as though the mouth were full, the voice turns nasal, water goes down the wrong way and saliva collects in the mouth. Family usually hear the change in speech before the person does.

Almost everyone gets twitching under the skin — small ripples running through a muscle — and cramps at night. Twitching on its own happens in a great many perfectly healthy people, especially with tiredness, coffee and too little sleep, and is not a reason for alarm. The worrying combination is different: twitching together with increasing weakness and visible wasting of the very same muscle.

There are also things this disease does not usually do, and they are worth knowing. Sensation, sight, hearing, bladder and bowel function and eye movements are all preserved. If someone has numbness and pins and needles, the cause is most likely something else.

How it changes over time

Weakness spreads from where it started into neighbouring areas. Muscles waste, joints lose their range, and stiffness and increased tone appear — the sort that makes a leg jerk and bend only with difficulty.

Swallowing and speech follow their own line. At first dry food and thin liquids are hard to get down; then meals take longer and longer, weight falls and food goes the wrong way. Saliva is no longer swallowed and spills out, while in some people it goes the other way and becomes thick and stringy.

Breathing is the third line. The breathing muscles weaken imperceptibly, and the first signs of it show up at night: lying on a low pillow is uncomfortable, sleep is broken and full of vivid dreams, mornings start with a headache, the day is spent fighting sleepiness and concentration slips. This is not nerves and not age — it is a sign that the lungs are not being ventilated overnight, and it needs a conversation with a doctor of its own.

In roughly half of people thinking and behaviour change to some degree: flexibility goes, and irritability, indifference and bluntness appear. In a small proportion this amounts to frontotemporal dementia. Something else is common too — sudden laughing or crying that does not match the mood; it is a consequence of the disease rather than of despair, and it responds to treatment.

The pace differs from person to person. Some forms run over years and decades, others move faster, and no one can tell from a first appointment which it will be.

The four forms and what separates them

The distinction matters mainly at the beginning; over time the forms come to resemble one another.

• Amyotrophic lateral sclerosis — the commonest. Weakness begins in an arm or a leg, and wasting is combined with increased tone.
• Progressive bulbar palsy — begins with speech and swallowing, affecting the muscles of the tongue, throat and face. It is more often seen in older women.
• Progressive muscular atrophy — weakness and wasting only, without stiffness; it usually runs more slowly.
• Primary lateral sclerosis — a rare form dominated by stiffness and spasticity in the legs, without obvious wasting. It is the slowest of all and affects life expectancy far less.

Why it happens and whether it runs in families

Motor neurones die because misfolded proteins build up inside the cell; what sets that process going is not fully understood. Several conditions are thought to come together — features of a person's genes and something from outside that has not yet been pinned down.

In about one person in ten, someone in the family has already had MND or frontotemporal dementia. Several genes responsible for these cases have been identified, the commonest being one called C9orf72. Even with a known mutation, though, not everyone who carries it develops the disease, so the question of testing relatives is one to take to a clinical geneticist rather than settle alone — and only if the person genuinely wants the answer.

Among the things people often ask about: the disease is not infectious, is not passed on by caring for someone with it, and is not caused by stress, personality or an operation in the past.

How the diagnosis is made and what has to be ruled out

The diagnosis is made by a neurologist, and it rests first of all on examination: the aim is to find, in one and the same area, signs of damage at two levels at once — the cell in the spinal cord and the pathway coming down from the brain. There is no single test that settles the matter.

The main confirming investigation is needle electromyography together with nerve conduction studies. It shows what no scan can: the traces of motor neurone loss within the muscles, including muscles that are not yet weak. An MRI of the brain and neck is done not to "see MND" — the disease is invisible on a scan — but to exclude a disc pressing on the spinal cord, a tumour or multiple sclerosis. Blood tests are taken as well: thyroid hormones, vitamin B12, creatine kinase, markers of inflammation and sometimes particular antibodies.

The point of all this checking is not to miss conditions that look similar but can be treated. They do occur: compression of the spinal cord in the neck, multifocal motor neuropathy, myasthenia gravis, inflammatory muscle disease. That is why a diagnosis is rarely made at a single appointment, and why a repeat examination a few months later is part of the process rather than time wasted.

What treatment can do

There is no agent that stops the disease, but there is treatment that slows it and makes life appreciably easier.

The one medicine shown to prolong life in ALS is riluzole. Its effect is modest, measured in months, and it is started as early as possible. For the rare form linked to a mutation in the SOD1 gene, a treatment aimed at the gene itself has become available; it is used only once the genetic result confirms it.

The second thing that genuinely lengthens life and improves it is non-invasive ventilation: a machine with a mask, most often used overnight. It is introduced not "at the end" but as soon as there are signs of underbreathing at night, which is why breathing tests are repeated at regular intervals.

The third is nutrition. When a meal takes more than half an hour, food goes the wrong way and weight is falling, a gastrostomy is discussed: a fine tube into the stomach. That conversation is also had early, while the procedure is still easy to tolerate.

The rest is aimed at individual symptoms: medicines that lower muscle tone for stiffness and cramp; medicines that reduce saliva, or thin it and a cough assist device when it is thick; antidepressants for uncontrollable laughing and crying; pain relief. A physiotherapist keeps the joints moving, an occupational therapist fits supports, a wheelchair and adaptations at home, and a speech and language therapist supplies techniques and devices for communication, including recording your own voice in advance. Follow-up is usually arranged as regular meetings with the team every two to three months.

Breathing, swallowing and when help is needed urgently

Call an ambulance (in Spain, Italy, Portugal, Poland and Ukraine the single European number is 112) if:

• breathing suddenly becomes difficult, there is not enough air at rest, or the lips or fingers turn blue;
• the person has choked and cannot cough it clear;
• confusion appears, or drowsiness from which they are hard to rouse;
• a temperature and breathlessness follow an episode of choking — that is how pneumonia from food entering the airway begins.

A doctor is needed the same day, without putting it off, if headaches have appeared on waking, daytime sleepiness has set in, lying flat has become uncomfortable, or the person can no longer manage meals or is losing weight quickly.

One point deserves separate mention: ordinary doses of sleeping tablets and strong sedatives suit people with MND badly, because they suppress breathing that is already weak. Any new medicine, including anything bought over the counter, is worth clearing with the doctor who is looking after the condition.

Online consultation

Muscle power, reflexes and tone cannot be tested through a screen, so the first diagnosis is always made in person. Before and after that, though, a remote appointment earns its place.

Before a diagnosis it helps to work out what is going on and where to go: to set out what stopped working and when, to separate harmless twitching from real weakness, and to decide whether a neurologist is needed urgently and which tests are worth having before that appointment.

Once the diagnosis is made, the questions multiply while the energy for travelling shrinks. A video call is a convenient way to go through what to do about cramp and stiffness, how to manage saliva, how to vary meals when swallowing is hard, how to tell whether it is time to discuss breathing support, and which medicines are safe. A separate and equally important part is support for the people doing the caring, whose questions often go unasked everywhere else. For sudden breathlessness, choking or clouding of consciousness the call to make is to an ambulance, not to a doctor.

This material is for information only and does not replace medical advice.