Hi, did you ever get a diagnosis or rid of your symptoms?
There are many conditions that causes peripheral neuropathy such as nutrient deficiencies, infections, exposure to toxic chemicals and various autoimmune diseases. Wikipedia has a long list of possible causes. Causes of a swollen submandibular salivary gland includes stone/s in the salivary duct, benign and malignant tumours, or Sjögren's disease (less common). Stones are most commonly found in the submandibular gland, where stones can obstruct Wharton's duct. It is frequently associated with chronic infection (Staphylococcus aureus, Streptococcus viridans) of the glands, dehydration (phenothiazines), Sjögren's syndrome and/or increased levels of calcium.
Extract from the neurologist's report: Visual acuity wat 6/6 bilaterally with normal fundus examination. Motor examination was unremarkable with well preserved and symmetrical reflexes bilaterally and downgoing plantars. Sensory examination was also unremarkable. Romberg's was negative. Multiple investigations including MRI Scan of the brain and C Spine, nerve conduction tests and visual evoked responses were normal. A multitude of blood tests have come back normal including the inflammatory markers. We have not discovered any structural basis for his multiple symptoms.
Might just add I have no history of depression or mental issues and I am not overly stressed personally or professionally.