Dear patients son, your mother has been diagnosed with ALS,which we call in medical terminology as amyotrophic lateral sclerosis,which is a degenarative disease of the cells in brain and spinal cord (collectively brain and spinal cord is called central nervous system) which cotrol the voluntary activity of the muscles of our body . The reason for this nerve cell degenration is mostly unknown though exposure to some factors like repetative head injury in some sports or professions, to some chemicals, electrical shocks, electromegnatic fields or head injury have been attributed but it has not been proven with consistency.Some abnormal proteins called Prions have also been implicated in its causation but without consistency.This degenaration of neurons (nerve cells) is a progressive process and till date no drug or any other intervention has been shown to stop it though some drugs like riluzole slow it down modestly. The net result of this nerve cell degeneration is weakness, wasting, twitching and stiffness of the muscles which were supplied by these degenerated nerve cells. The rapidity with which the disease progresses is variable , in some patients it may worsen fast and in some others it may progress slowly like in case of famous physicst Stephen Hawking, however average life span after the on set of symptoms is about 3 to 3.5 years. Fast decline is generally seen in patients above 40 years of age. Other diseases with similar symptoms and other features like that of ALS may include some of the remedable conditions like Mysthenia Gravis, Dics Herniations, Cervical Spondylosis, myopathies like spinal muscular atrophy , Multiple Sclerosis, Syrongomyelia, Peripheral Neuropathy,HIV, Lyme Disease and Syphilis and others and theses need to be differentiated from ALS with appropriate testing like EMG(electromyography), NCV(Nerve conduction velosity), MRI Brain and Spinal Cord, Muscle biopsies, and appropriate blood testing like HIV, VDRL testing. In case of your mother ,if she had already under gone these diagnostic tests and other conditions have been ruled out and it has been shown with almost certainty that she suffers from ALS , then taking in to consideration that she has weakenesss already in three limbs i.e both lower limbs and right upper limb, Sshaped body, she seems to be moderately advanced case though in most advanced cases patients become bed bound,are unable to perform activities of daily living like using the toilets and tooth brushing.having difficulty in speaking(dysphonia), difficulty in swallowing(dysphagia), difficulty in breathing(dyspnoea). Swallowing difficulty can lead to the choaking and aspiration of food in to the lungs leading to aspiration pneomonia. When ever she develops these symptoms , may not necessarily in the next 6 months but sooner or later it may happen and in that situition she needs proper nursing care involving care of mouth, care of eyes,care of urination and defacation ,care of skin , frequent posture changing to prevent bed sore formation, feeding with the help of a tube passed through nose in to stomach, assisted breathing support with the help of a machine called BiPAP machine and finally patients may require the formation of a small hole in the wind pipe infront of the neck called tracheostomy to give them breathing through that hole because that prevents the oral secretions and food from passing into the lungs