Piriformis syndrome is a collection of symptoms and signs of pain from piriformis muscle and is characterized by pain in buttock with variable involvement of sciatic nerve. This syndrome is often overlooked in clinical practice because its presentation has similarities with other spine pathologies. A major problem with the clinical diagnosis of piriformis syndrome is the lack of consistent objective findings and an absence of single test that is specific for piriformis syndrome. Therefore, a precise and reliable clinical method of diagnosing piriformis syndrome should be developed by clinicians.
BACKGROUND: Myofascial pain syndrome (MPS) is a regional musculoskeletal pain disorder that is caused by myofascial trigger points. The objective of this study was to determine the prevalence of MPS among chronic back pain patients, as well as to identify risk factors and the outcome of this disorder.
METHODS: This was a prospective observational study involving 126 patients who attended the Pain Management Unit for chronic back pain between 1st January 2009 and 31st December 2009. Data examined included demographic features of patients, duration of back pain, muscle(s) involved, primary diagnosis, treatment modality and response to treatment.
RESULTS: The prevalence of MPS among chronic back pain patients was 63.5% (n = 80). Secondary MPS was more common than primary MPS, making up 81.3% of the total MPS. There was an association between female gender and risk of developing MPS (χ(2) = 5.38, P = 0.02, O.R. = 2.4). Occupation, body mass index and duration of back pain were not significantly associated with MPS occurrence. Repeated measures analysis showed significant changes (P < 0.001) in Visual Analogue Score (VAS) and Modified Oswestry Disability Score (MODS) with standard management during three consecutive visits at six-month intervals.
CONCLUSIONS: MPS prevalence among chronic back pain patients was significantly high, with female gender being a significant risk factor. With proper diagnosis and expert management, MPS has a favourable outcome.
KEYWORDS: chronic back pain; myofascial pain syndrome; trigger point
Study site: Pain Management Unit, Hospital Universiti Sains Malaysia (HUSM), Kelantan, Malaysia
The original version of the Brief Pain Inventory (BPI) was translated into a Malay version by the standard procedure and was then evaluated for its psychometric properties. Of 119 eligible patients, a total of 113 (95%) agreed to participate in this study. Ages ranged from 18 to 76 years and interviews were conducted between August, 2004 and November, 2004. The pain intensity items demonstrated high loading with one factor, whereas the pain interference items were loaded on another factor. Two factors explained 62% of the variance. Compared to the Karnofsky Performance Scale, the pain intensity scales had a moderate negative (Pearson's) correlation (-0.520, P < 0.001) and the pain interference scales had a high negative correlation (-0.732, P < 0.001), showing good concurrent validity. The coefficient alpha of both subscales demonstrated good internal consistency of the items. The intraclass correlation coefficient for the test-retest stability was 0.61 for the pain intensity scale and 0.88 for the pain interference scale. The Malay version of the BPI is a reliable and valid instrument for cancer pain assessment and is comparable with the original version of the BPI in terms of structure and psychometric properties.
Complex regional pain syndrome secondary to brachial plexus injury is often severe, debilitating and difficult to manage. Percuteneous radiofrequency sympathectomy is a relatively new technique, which has shown promising results in various chronic pain disorders. We present four consecutive patients with complex regional pain syndrome secondary to brachial plexus injury for more than 6 months duration, who had undergone percutaneous T2 and T3 radiofrequency sympathectomy after a diagnostic block. All four patients experienced minimal pain relief with conservative treatment and stellate ganglion blockade. An acceptable 6 month pain relief was achieved in all 4 patients where pain score remained less than 50% than that of initial score and all oral analgesics were able to be tapered down. There were no complications attributed to this procedure were reported. From this case series, percutaneous T2 and T3 radiofrequency sympathectomy might play a significant role in multi-modal approach of CRPS management.