hi,
thank you for providing the brief history of you.
As mentioned that you had a
brain injury in the past and now the pain is in the base of the thumb a thorough neuromuscular assessment is advised.
Also, since the pain is in the base of the thumb, after a Neuromuscular assessment it will be possible to comment if it was due to the brain injury or a pathology of the tendon.
Also, for this, you can take a
physical therapy which will help improve in the functional ability of your hand to function. The therapsit will provide you Therapeutic
ultrasound therapy and TENS therapy for reducing the inflammation and pain.
As hand is a complex structure it needs a precise understanding of the injury and also the precise
rehabilitation plan to get the maximum functional Mobility of the hand.
you may have pain which can be related to neuropathic or may be just a
tendonitis. For both of it, physcial therapy can help you to regain the strength and mobility.
Regards
Jay Indravadan Patel