The symptoms may include muscle weakness and atrophy due to degeneration of upper and lower motor neurons. because of atrophy and weakness patient lose the ability to initiate and control the voluntary movements.
The earlier symptoms of ALS also include twitching, cramping or stiffness of the affected muscles. These may be slurred speech. The symptoms depend on which motor neuron in body is affected or damaged first. Patient with leg affected may experience difficulty in walking or running or notice some kind of stumbling or tripping. Dropped foot is also common. Arm onset patients experience difficulty in manual tasks such as button their shirts, turning a key in a lock. The symptoms remain confied to one limb for longer period of time for the whole length of illness known as monomelic amyotrophy. These patients also find difficulty in speaking or swallowing. These patients speak slurred, quieter or show nasal characters . Other symptoms include difficulty in swallowing or loss of mobility. Sometime respiratory problems may be common, because intercostal muscles get affected and patient finds difficulty in breathing.
In some cases, difficulty in moving or swallowing takes place. Patient is not able to speak or form words. sometime drooling or gagging is also present. Upper motor neuron symptoms are also present like tightness and stiffness in muscle, reflexes become exaggerated i.e. hyperreflexia, including overactive gag reflex. Lower motor neuron symptoms include muscle weakness and atrophy. Pseudobulbar effects are also common also known as emotional liability in which patient looses control over emotions.
In the later stage aspiration pneumonia is common and requires feeding tube. Diaphragm and intercostal muscles get weak therefore forced vital capacity and inspiratory pressure is reduced. There is head drop due to weakness of neck muscles.
Physical examination through doctor and know about medical history helps to determine ALS. Physical examination shows-
2) Tremors, Spasm, Twitching .
3) Abnormal reflexes
4) Difficulty in walking
5) Increased reflexes at joints
6) Difficulty in controlling emotions( emotional liability)
7) Loss of gag reflex
8) Twitching of tongue.
Other tests include–
a) Blood test– That helps to rule out other conditions.
b) Breathing test– That is mainly used to check the involvement of lung muscles.
c) Cervical spine CT or MRI– Helps to rule out any disease or injury at neck that mimics ALS.
d) Electromyography– Wire electrode is inserted to see the function of nerves or measure nerve conduction velocity.
e) Genetic testing to know family history of ALS.
f) Head CT/MRI– In order to rule out other conditions like spinal cord tumors, herniated disc, syringomyelia etc.
g) Lumbar puncture can be done.