ALS is also known as amyotrophic lateral sclerosis. It is a degenerative disease of the nerve cell of brain and the spinal cord. It is a rapid irreversible progressive disease of the motor neuron of the cranial nerves and corticospinal tracts.
In this disease the motor neuron cell dies or degenerates, and the ability of the brain and the spinal cord to control the various muscles is lost.
As ALS disease is incurable, its detection during the early stage is important to start aggressive treatment.
The symptoms and progression of ALS disease can depend where it affects first, in spinal cord or in brain stem.
Early signs of the disease are usually missed and overlooked; the patient feels weakness in single limb, for e. g in hand after writing or brushing teeth or after shaving. The objects fall from the hand. This is followed soon by the other hand. Weakness gradually spreads proximally and is followed in a few weeks or months by similar weakness in the legs.
Soon after this the bulbar muscles are affected and tongue is first to get affected. Speech and swallowing becomes difficult. The palate drops and a pool of saliva may be observed in the pharynx as voluntary and reflux swallowing is impaired. As a result aspiration pneumonia occurs.
Loss of muscle power makes the patient disabled and paralyzed, it occurs as spinal cord nerves get affected. In the late stage paralysis of respiratory muscles occurs and the patient dies.
Two conditions most likely to be mistaken for ALS disease are atherosclerotic pseudo-bulbar palsy and myasthenia gravis.
Most cases of ALS disease die in two to five years, rarely the patient survives beyond five years after diagnosing the disease.