Some examples are Back and / or neck pain: Osteoarthritis - or rheumatoid arthritis-associated herniated disk or spinal cord compression Fever and / or rash: Infectious neuropathy, infectious radiculopathy, brain infection, or rheumatic disorders Headache: Brain tumor, stroke, or encephalopathy Joint pain: Rheumatic disorders Undernutrition: Vitamin B12 deficiency Excessive intake of high-mercury seafood: Toxic polyneuropathy Past medical history should identify known conditions that can cause numbness, particularly the following: Diabetes or chronic kidney disease: Polyneuropathy Infections such as HIV, syphilis, or Lyme disease: Infectious peripheral neuropathy or brain infection Coronary artery disease, atrial fibrillation, atherosclerosis, or smoking: Stroke Cancer (particularly lung cancer): Paraneoplastic anti-Hu subacute sensory or motor neuropathy Osteoarthritis or RA: Radiculopathy Family history should include information about any familial neurologic disorders.