A Personalized Approach to Pain Relief
Dr. Cassius strives to give each patient the individualized care they need, taking a holistic perspective and utilizing the most advanced and state of the art diagnostic and treatment techniques. He is one of the world leaders in the development and use of Segmental Neuromyotherapy for the diagnosis and treatment of all types of painful conditions. He successfully treats professional athletes as well as medically complicated patients with chronic debilitating pain.
Experience Life Without Pain
Dr. Cassius understands that living with chronic pain can be incredibly challenging, impacting both physical and emotional well-being. That’s why we specialize in advanced techniques that minimize discomfort, reduce recovery time, and promote faster return to daily activities.

Our Practice
Specialties
Physical Medicine & Rehabilitation
Physical medicine & rehabilitation specialists, or physiatrists, are doctors who specialize in helping patients rehabilitate from injuries or complications of disease. This could include a weekend warrior coming back from a broken leg, or an aging grandmother dealing with arthritis. Dr. Cassius may employ a range of treatment & rehabilitation techniques, including physical therapy, occupational therapy and nerve stimulation treatments, among others.
Pain Management
Pain management doctors specialize in caring for patients who are dealing with chronic pain, whether resulting from injury, disease, or otherwise. Dr. Cassius creates customized pain management plans for patients that may include therapy, medication management, or minimally invasive procedures. When creating a customized pain management plan, Dr. Cassius will evaluate the patient and their medical history, in addition to performing tests to arrive at a precise diagnosis.
Conditions Treated
These conditions include:
- Shoulder pain
- Neck pain
- Migraines
- TMJ
- Hip pain
- Foot pain
- Plantar fasciitis
- Sciatica
- Herniated disc
- Motor vehicle accidents
- Pelvic pain and dysfunction
- Abdominal pain
- Fibromyalgia
- Osteoarthritis
- Scoliosis
- Degenerative disc disease
- Degenerative spinal conditions
- Muscle sprain/strain
- Myelopathy
- Shingles
- Post herpetic neuropathy
- Neuropathic pain
- Spinal stenosis
- Spondylolisthesis
- Spasticity
- Second opinions regarding surgery
Procedures
Dr. Cassius performs cutting-edge, minimally invasive procedures designed to effectively alleviate pain and improve quality of life. These include:
- complete neuromusculoskeletal evaluations
- injections for nerve and muscle block
- trigger point injections
- Botox injections for relief of pain and spasticity
- electromyographic studies
- second opinions for possibly avoiding surgery
Collaborations
Dr. Cassius works closely with other health care professionals including:
- physical therapists
- chiropractors
- massage therapists
- acupuncturists
- podiatrists
- primary care physicians
Our Treatment Process
History
Exam
Personalized Plan
Reviews
Read what patients are saying about Dr. David Cassius.
Julie V., Redmond, WA
I had a brain tumor that wasn't cancerous but gave me horrible headaches. I had 5 brain surgeries but they didn't help. Dr. Cassius was the first doctor to really find out what was causing my pain and give me a plan to treat it. He has a different approach to pain. He looks at the body as a whole and helps you move toward a pain-free life. He truly cares about his patients and makes sure he is there to help them as much as possible. I am now completely off narcotics and finally realizing I might be able to go back to work. Because of Dr. Cassius I have great reduced the number of prescriptions I take.
Amelia L., Austin, TX
I saw Dr. Cassius for generalized pain and a frozen shoulder. Although I did not consult him for depression, I was depressed at the time. He really listened and ASKED me questions, ordered lots of blood work and figured out I had extreemely low levels of vitamin D and a thyroid deficiency. This tuaght me that I MUST have sunshine to be healthy in my body and my head. I am thankful to Dr. Cassius for alerting me to the wide range of possible causes for pain and depression and did not send me straight to anti-depressants. I am following his counsel.
Florence G., Issaquah, WA
Dr. Cassius is a truly great doctor who really takes the time to get to know his patients and is very thoughtful about treatment. Even after we moved away, my husband makes the effort to fly to Seattle to see rather than find someone local. If you are told that you need surgery or to stick to pain meds for the rest of your life, see him for a second opinion. He will be honest with you and let you know if there are alternative treatments.
Matthew T., Seattle, WA
GREAT GUY!! Very compassionate and knows what he is talking about. I was at a terrible place in my life and David got me on the road to recovery, but changed my life forever.
Joe L., Seattle, WA
Dr. Cassius is an amazing doctor, care provider and person. Besides providing me complete long-term relief from chronic pain, Dr. Cassius is the proverbial last of a dying breed of caregiver that goes way beyond the corporate model of healthcare. He takes a lot of time to understand who you are, what is going on in your life and how that relates to your current health.
Anne D., San Francisco, CA
I can't say enough positive about this physician. A few years ago, after seeing every kind of specialist for pain, I ended up in his office. I had resigned myself to living in great pain and thought I would be on opioids for life. He has been able to help off those and has made a positive impact on my life.