Your symptoms are suggestive of pinched nerves in the neck. This usually causes one sided symptoms and do not point to anything serious like stroke or neuropathy; especially with the MRI of head being normal. Tingling can be referred to the head from muscles, nerves, bones, joints and vascular structures in the neck. Pinched nerves in the neck are giving you neck pain, tingling down in left arm and numbness. This can be due to;
1) Herniated/degenerated disc in neck
2) Cervical spondylosis; bone spurs in the neck vertebrae pressing on the nerves.
Following investigations would be required;
1) X-ray of the neck spine
2) MRI of the neck
3) Nerve conduction velocity (NCV) study
4) Electromyography (EMG)
Following measures would be helpful;
1) Neck care in the activities of daily living.
a) No working on computer for more than half an hour in a single stretch. Same for TV.
b) Monitors and televisions exactly in front (180 degrees).
c) Contour pillow: Should fill the hollow when lying on back or straight. Available over the counter.
2) Cervical Collar or Brace
3) Cervical traction
4) Anti-inflammatory analgesics like Ibuprofen
5) Some physicians do give oral steroids in severe radiculopathy cases, in which pain / numbness / tingling is quite significant.
6) Physical therapy: gradually increasing exercises from passive stretching to active against resistance regime.
7) Electrotherapy in the form of TENS, interferential and laser and ultrasound.
8) Hot fomentation
9) Local analgesic patch / ointment / spray.
10) Acupuncture / Acupressure
You can consult following specialists;
c) Specialist in Physical medicine and rehabilitation
Please feel free for your follow up questions.
I would be happy to assist you further, if you need any more information.