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CLINICAL UPDATE
Key messages
Chronic craniofacial pain can be difficult to manage
Current treatments often have adverse effects
Non-destructive treatments offer analgesia and are simple to apply. radiofrequency treatment. Occipital neuralgia can respond to radiofrequency thermal lesions of the second cervical dorsal root
ganglion and third occipital nerve with quite prolonged periods of remission but, again, at the price of temporary post cervical area altered sensation and ‘burning’ dysaesthesias. Non-destructive electrical stimulation of cranial nerves or upper cervical nerve roots (neuromodulation) can provide very good analgesia with reduced downside risk as these electrodes are implanted subcutaneously through an introducing needle under ultrasound control.
The active electrode segments are placed adjacent to craniofacial sensory nerves including the supra and infraorbital nerves, the greater and lesser occipital nerves and even uncommon targets such as the auriculotemporal nerve and mandibular division nerves. An alternative placement in the cervical epidural space increases risk but can be effective for craniofacial pain states. Implanted systems can always be removed with little loss for the patient except perhaps financial expense, as these systems can be pricey. The introduction of sub-threshold stimulation waveforms in the past decade, especially 10 kHz high frequency stimulation and burst stimulation algorithms, have eliminated the often unpleasant paraesthesia sensations experienced in the face or occiput with earlier low (1-100 Hz) frequency systems. The newer waveforms have been shown to greatly improve the efficacy of stimulation compared with older ‘tonic’ waveform devices.
Sagital and Anteroposterior X-ray images of implanted supra and infraorbital electrodes for high frequency stimulation
Author competing interests – nil
FIVE MINUTE CLINICAL UPDATE Frozen Shoulder (Adhesive Capsulitis) Frozen shoulder is a common condition that causes a great deal of confusion, both from a diagnostic and treatment perspective. Primary or idiopathic frozen shoulder comes on spontaneously, although it often presents with a history of minor injury. There is a strong association with endocrine disorders, particularly diabetes. Women outnumber men. The typical patient is a middle-aged woman who was initially diagnosed with impingement and had some bursitis on her ultrasound. She has had lots of physiotherapy, two subacromial injections with no real response, and is now struggling with sleep and in severe pain. Pain levels are usually high. However, the diagnostic algorithm for frozen shoulder is simple. There are only
two criteria. Firstly, there is a global loss of active and passive range of motion, and x-rays are normal. What does this mean clinically? Understanding the difference between active and passive movement is key. In frozen shoulder, not only can the patient not move the joint fully in all directions (active), but neither can the examiner (passive). External rotation is the first movement usually involved. The only common differential diagnosis is arthritis, which will show up on an x-ray. All other conditions, such as impingement and rotator cuff tearing, will reduce active movement but the passive movement should be preserved. There are only three treatments for frozen shoulder with good clinical evidence to support them. The first, and the mainstay
By Dr David Colvin
of treatment, is glenohumeral cortisone injections. The injections have to be performed into the shoulder joint itself, not the bursa, and this is most commonly done with CT guidance. Within two weeks, there is often a substantial improvement in pain levels, but movement is slower to recover. It usually takes a course of 2-3 injections to see significant results. The other treatments are manipulation under anaesthetic or surgery to release the capsule. In my practice, surgery is almost exclusively reserved for diabetics who experience a more severe frozen shoulder. Frozen shoulder is a condition where symptoms evolve during the treatment phase. It almost always looks like impingement, initially. By the time the patient sees an orthopaedic surgeon, the condition has declared itself, and it’s easy to look like the clever specialist.
Western Orthopaedic Clinic is a multi-centre orthopaedic group, with rooms across Perth. We are committed to bringing the newest techniques and are involved in research in many areas.
Phone: +61 8 9489 8700 Email: woc@wocwa.com wocwa.com
MEDICAL FORUM | PAIN MANAGEMENT ISSUE
MARCH 2020 | 39
