What are the symptoms of amyotrophic lateral sclerosis?
ALS may begin as weakness, awkwardness, or atrophy in one or more limbs. It may start as a difficulty swallowing or speaking. The symptoms may be very subtle at first, and may be overlooked. Common symptoms include the following:
- Difficulty standing, walking, or running
- Clumsiness - Frequent tripping or falls
- Difficulty with fine hand motions such as buttoning, writing, turning a key in a lock
- Atrophy of hand muscles
- Atrophy of tongue
- Difficulty chewing food
- Difficulty swallowing (dysphagia)
- Difficulty speaking
- Oversensitive gag reflex
- Difficulty forming words (dysarthria)
- Weakness and atrophy in specific muscles
- Tight, stiff muscles (spasticity)
- Muscle cramps
- Muscle twitching visible under skin (fasciculations)
There may be evidence for frontal lobe dysfunction in patients with ALS. Usually, this dysfunction is subclinical (not readily apparent or causing symptoms) and it is detectable only when looked for specifically with focused tests. However, in a minority of patients, clinically significant cognitive impairment becomes evident, with a continuum of abnormalities extending all the way to frank frontotemporal dementia. In addition to difficulties in planning and sequencing (the most common manifestations of "executive dysfunction" due to frontal lobe disease) some patients may express an otherwise inexplicable nonchalance or lack of insight into their situation and its impact on themselves and their loved ones and others; fortunately rarely, they may become less friendly than their usual selves. These aspects of ALS, when present, may pose major challenges to caregivers and healthcare personnel alike, and they may be associated with shorter survival.
Depression and anxiety may occur in patients with ALS. Though difficult to prove, these are likely part of the disease process itself, rather than mere reactions of the patients to their condition. Depression and anxiety are treatable.
Finally, some patients with ALS frequently exhibit a so-called pseudobulbar affect, manifesting as involuntary, uncontrolled outbursts of crying or laughter, which is distinct from their underlying mood.
As the disease progresses, the person with ALS loses the ability to carry out everyday activities such as dressing, eating, and working. Eventually getting out of bed becomes impossible without assistance. The person becomes restricted to a wheelchair or bed (the development of bedsores can be a problem.) As the respiratory muscles weaken, breathing becomes more and more difficult. The risk of pneumonia increases.
Hereditary (familial SOD1) and nonhereditary (sporadic) cases of ALS may have similar symptoms and course, but in some forms of ALS these manifestations may be quite distinct (for instance, there are cases of familial ALS with juvenile onset).