Diagnostic Conundrums - Neurology

A 56 year old male presented on 27 Dec 2006 with c/o vague pains all over the body. He gave h/o fever with chills about a week before onset of these symptoms. Clinically there was no significant abnormality and an initial diagnosis of Viral Fever (? Chikungunya) was made. He was treated with Tab paracetamol (acetaminophen) 500 mg tid with Tab B Complex daily.

He came back to us on 16 Jan 2007 with (i) Pain and swelling in the small and medium sized joints, with early morning stiffness (ii) Parasthesiae in the lower limbs (iii) Mild breathlessness.
Clinically: Vitals were within normal limits. There was marked swelling of the Interphalangeal and ankle joints.
Investigations: Hb 12.5 gm%, ESR 10 mm, Total Count: 5000/cumm, P 70, L 27, E 02, M 01, Random Blood Sugar 90 mg%, VDRL - Non Reactor, RA Factor - non reactor
The diagnosis now looked like Sero Negative Polyarthritis.
He was started on Tab Diclofenac 50 mg bid, Tab Folic Acid 5 mg od.

0n 22 Jan 2007 he was reviewed and his condition had worsened - (i) increased pain all over (ii) Unable to walk or lift hands above the head (iii) increasing tremulousness.
Clinically - All joints were swollen and movements of all limbs were sluggish. This prompted me to do a CNS exam:
Power UL - Grade IV, Lower limbs Gd III - IV, Deep Tendon Jerks Bilaterally diminished, absent ankle jerks. Plantars were flexors.
Sensory - Fine touch was absent till mid chest. There was patchy loss of pain and vibration sense over the legs and upper arms.
This got my suspicion up and I thought of an Acute Cervical Cord Lesion.
NIMHANS being the closest and most affordable we sent him there. By the time he reached NIMHANS, about 150 km over bad roads, he had developed acute retention of Urine and needed to be catheterised.
MRI showed:
1. Extruded disc material and superior migration/ Extradural lesion at C5 C6 levels causing focal compression and thinning of cord.
2. Cervical Spondylosis with myelomalacial changes.

Just putting up this as a reminder that what is apparent may not be the actual facet of the illness. We need to keep our eyes and ears open for the most unexpected. After this I did a search using both PubMed and Google Scholar, but really found no such progression described.
Any comments from the Neurologists/Physicians/Neurosurgeons??