HI, thanks for using healthcare magic
If the arterial
ultrasound was fine a few months ago then it is not likely that the abnormal sensation that you are experiencing is related to circulation.
Changes would not develop in this short period of time.
It is not likely due to the
vitamin b12 supplements either since low vitamin b12 is a cause of altered sensation.
There are other causes of this problem which is called neuropathy. Some of these include : (a)
liver or
kidney disease
(b)diabetes
(c)trauma to the nerves in the area eg if there is arthrtis or other changes in the spine
(d)side effect of medication
(e)infection such as shingles
(f)
hormonal conditions- some cases of
thyroid disease
(g)exposure to toxins
(h)idiopathic- in some cases, the cause is not known
(i)low levels of folate
If it continues or worsens and you wish to determine the cause, then you may need to consider seeing your doctor for assessment.
This assessment would include physical examination and may also require blood tests and imaging.
Imaging would be include the lower spine to look for any changes that may be affecting the nerves.
Bloods would include screening for infection, checking vitamin levels (folate, vitamin b12), diabetes screening, liver and kidney disease.
There are medications that can help and treatment can also be directed at the particular cause if found.
I hope this helps