Types of post stroke pain syndromes
1. Some patients present with symptoms suggestive of complex regional pain syndrome CRPS. The area affected shows dysesthesia and allodynia and the area affected corresponds to the lesion causing the stroke, with frequent involvement of the face, hand and foot, sometimes spreading up to affect the upper parts of the upper and lower limb.
2. Central post stroke pain is a common pain syndrome after stroke, estimated to occur in over one-third of cases of post-stroke pain. Most commonly, it develops within 3 to 6 months of stroke although it may occur sooner. Symptom onset is often gradual, usually associated with improved subjective sensory loss and the appearance of dysaesthesia. The pain is quite severe and constant. CPSP is commoner in younger stroke victims who are reported to be twice as likely to develop this horrid pain. Most patients report a constant pain with superimposed lancinating pain as well as hyperalgesia and allodynia on examination. Patients who have sustained a thalamic stroke are more likely to develop CPSP. Dejerine-Roussy Syndrome occurs in around one third of cases of Central post stroke pain and is associated with thalamic strokes.
However central post stroke pain can also occur with strokes affecting the spinothalamic tracts, and brain stem as well as the cortex. Strokes affecting the right hemisphere are more commonly associated with pain.
3. Post stroke shoulder pain occurs in as much as 20% of patients by as early as two weeks following a stroke. Subluxation of the shoulder joint occurs due to loss of muscle strength and can result in significant disability thwarting patients from reaching their maximum functional potential. Adequate strength in the shoulder joints is important to allow patients to transfer from bed to chair, maintain balance and many aspects of daily living.
When the shoulder subluxates, the glenohumeral joint moves apart and there will be a palpable gap between the acromion and the humeral head. The subluxation can also impinge on the brachial plexus, in turn compounding pain.
4. Spasticity related pain post stroke is common, and associated with hypertonic muscles. One quarter of patients will develop hypertonic muscles soon after sustaining a stroke.
5. Headaches are commonly reported in the initial stages and these may be tension type or vascular type. Patients with previous history of headaches are more likely to report headaches in the acute phase and also six months post stroke.