confused with what the neurologist said and still fearful of ALS/MND

Thanks for the detailed response Christopher.  I understand that weakness and fasciculations together are usually due to ALS.  However when the neurologist does a neurological examination he can't find weakness even though i have the feeling of weakness on the left side of the body.  It almost feels like my left leg is full of led and my left arm is and that the left limbs feel tight and are not contracting/ functioning properly.  My neurologist believes nothing is wrong neurologically and he is a top consultant so that must mean i can't have ALS.

Can ALS be missed by a neurologist after seeing him 3 times?

Plus my age makes it almost impossible.

However to me I feel weak and have fasciculations and cramps.  I find it so difficult how the doctor can be sure i don't have ALS/MND.   And if it is not this whay else is there to explore considering that i have aleady had chest ct, brain mri, thoraci mri, lumber mri and a ridiculous amount of bloods

What are your beliefs on this?

Many thanks
James