Hi, Sensory nerves are the small nerves responsible for sensation throughout the body.
Motor nerves are the larger nerves responsible for all voluntary skeletal and somatic movement such as moving the leg or arm
Polyneuropathy is the simultaneous malfunction of many peripheral nerves throughout the body, Polyneuropathy usually affects both sides of the body equally.
distal primarily - mainly affecting the extremities like hands or feet.
Demyelinating meaning there is damage to the protective covering (myelin sheath) that surrounds some of the nerves.
The axon runs right in the centre of the nerve then covered by the myelin sheath, the nerve signals transmit through the axon itself.

One of the most common reasons for polyneuropathy can be due to diabetes, but may be due to lots of other possibilities, like excessive use of alcohol. Nutritional deficiencies (such as vitamin B deficiency), Anemia due to vitamin B12 deficiency (pernicious anemia) may also cause chronic polyneuropathy. Other causes include an underactive thyroid gland (hypothyroidism), liver failure, and kidney failure. Rare causes include certain cancers, such as lung cancer, and taking excessive amounts of vitamin B6 (pyridoxine).

Your neuro will send you off for tests to hopefully find the reason this is happening.
good luck anyway,
Aussie :)