My doc told me muscle spasm/ tension caused arm numbness/pins and needle~ how long does it last?im on valium currently

Best to avoid benzos: Limited data available. arm numbness/pins and needle (paresthesia) can be from cervical spine spondylosis/DJD or shoulder joint pathology. Had you had any MRI cervical spine? Do you have any diagnosis of fibromyalgia , anxiety, depression issues also? Valium is a benzodiazepine, best to be avoided long term habit forming can develop dependency, tolerace. Ask PCP for pain clinic/rheumatology referr

With limited history: if cervical spasm from DJD with spinal stenosis treatment will help only control symptoms. Sometimes surgical intervention may be indicated if symptoms worsen

Depends upon nerve: Muscles can spasm around a nerve and cause pain and that pins a needles sensation. If it involves the whole arm then it may involve the brachial plexus. Try these exercises to help relieve the sensations. http://www.summitmedicalgroup.com/library/adult_health/sma_thoracic_outlet_syndrome_exercises/ If you get no relief see a physical therapist. Symptoms can last months if not relieved.