Foot pain and loss of feeling and weakness in toes.

[Don-Johnson]

  I am experiencing burning and soreness in the ball of my left foot along with cramping and weakness in the toes.  I have lost some feeling in my big toe.  At times it becomes difficult to walk because of the pain and discomfort.
  I have had an EMG test, blood work, and a physical exams and all show no problem.  My physician suspected tarsal tunnel syndrome and sent me to a podiatrist.  The podiatrist found no problem, but suggested that I buy some arch support inserts for my shoes.  I have been wearing the inserts for approximately two weeks and have experienced very little or no relief.
  The symtoms started shortly after I had experience pain in my heal as a result of an iritation of the plantar facia.  Could this have created the problem?
  Do you have any suggestions as to the cause of my problem and what I might do to relief the pain and discomfort.
===========================================================================
Dear Don:
Foot pain, specially if it is worse with standing or wieght-bearing is far more frequently from a local foot problem (such as plantar fascitis, arthritis, gout, stress fracture, ligamentous strain, etc) than from a neurological problem. Neurological problems that can cause foor pain include L5 or S1 root problems in the back, polyneuropathies, libial neuropathy in the leg rather than in the foot, tarsal tunnel syndrome (tibial neuropathy distal to the ankle), plantar neuropathies, and intergidital neuropathies. Vascular causes of foot pain are also in the differential diagnosis.
The big toe numbness, however, does raise the likelihood of your having nerve involvement. A true tarsal tunnel syndrome that can be convincingly demonstrated by an appropriately designed EMG examination is quite uncommon. Isolated medial plantar nerve neuropathy can be difficult to diagnose by EMG due to some limitations of the technique. Several of these neuroapthies do not have an obvious cause. Poorly fitting footwear can be implicated in some cases. Plantar fascitis is not cited as a cause. Rare causes such as nerve sheath tumors may need to be excluded in your case with MRI examimation in the foot or leg, if clinically indicated.
Another neurological opinion from an expert neuromuscalar specialist from a major academic neurology department is probably indicated. After a search for diagnosis is completed, local injections of steroids/local anesthetic may be used in some cases with benefit, an addition to change of footwear.