The Symptom Checklist-90 Revised questionnaire: no psychological profiles in complex regional pain syndrome-dystonia

Depression, Anxiety, Psychological Symptoms and Health-Related Quality of Life in People Living with HIV

OBJECTIVE

To investigate the levels of depression, anxiety, psychological symptoms and health-related quality of life (HRQOL) in people infected with human immunodeficiency virus (HIV) and to assess the risk factors.

METHODS

A total of 121 people living with HIV (PLWHIV) were included, and 61 health individuals were selected as healthy controls. Their sociodemographic information was collected. The Self-Rating Depression Scale, Self-Rating Anxiety Scale, Symptom Checklist 90 and Short-Form Health Survey-36 were used.

RESULTS

The depression score was higher in PLWHIV (47.83 ± 10.58 vs 36.52 ± 9.69 P<0.001). Similar results were observed in anxiety score (41.06 ± 11.24 vs 32.31 ± 7.99, P<0.001). Multivariable analysis revealed that younger age (OR=0.929, P=0.004) and smoking (OR=4.297, P=0.001) were identified as independent factors of depression while young age (OR=0.890, P=0.008) and alcohol consumption (OR=4.801, P=0.002) were independent factors of anxiety. Results of SCL-90 questionnaire showed that hostility, paranoia ideation were significantly more pronounced when PLWHIV had depression. Results of HRQOL showed that physical functioning (82.88 ± 14.73 vs 93.41 ± 9.22, P<0.001) and mental health (57.46 ± 17.64 vs 65.68 ± 17.44, P=0.012) were lower in PLWHIV with depression. For PLWHIV with anxiety, vitality (56.96 ± 14.61 vs 67.58 ± 17.57, P=0.004), social functioning (64.52 ± 23.97 vs 74.64 ± 21.47, P=0.036) and mental health (52.57 ± 14.21 vs 65.03 ± 17.98, P=0.001) were lower. High depression level was showed the independent risk factor associated with poor HRQOL (OR=0.370, P=0.001).

CONCLUSION

Depression and anxiety were very common in PLWHIV. Physicians should not only focus on the antiviral treatment of these patients but also monitor their mental status, especially that of younger patients. For PLWHIV with depression and anxiety, psychological intervention should be provided, and social role rebuilding may be good for depression and anxiety alleviation.

Psychological therapy for inpatients receiving acute mental health care: A systematic review and meta-analysis of controlled trials

OBJECTIVES

The effectiveness of psychological therapies for those receiving acute adult mental health inpatient care remains unclear, partly because of the difficulty in conducting randomized controlled trials (RCTs) in this setting. The aim of this meta-analysis was to synthesize evidence from all controlled trials of psychological therapy carried out with this group, to estimate its effects on a number of important outcomes and examine whether the presence of randomization and rater blinding moderated these estimates.

METHOD

A systematic review and meta-analysis of all controlled trials of psychological therapy delivered in acute inpatient settings was conducted, with a focus on psychotic symptoms, readmissions or emotional distress (anxiety and depression). Studies were identified through ASSIA, EMBASE, CINAHL, Cochrane, MEDLINE, and PsycINFO using a combination of the key terms 'inpatient', 'psychological therapy', and 'acute'. No restriction was placed on diagnosis. The moderating effect of the use of assessor-blind RCT methodology was examined via subgroup and sensitivity analyses.

RESULTS

Overall, psychological therapy was associated with small-to-moderate improvements in psychotic symptoms at end of therapy but the effect was smaller and not significant at follow-up. Psychological therapy was also associated with reduced readmissions, depression, and anxiety. The use of single-blind randomized controlled trial methodology was associated with significantly reduced benefits on psychotic symptoms and was also associated with reduced benefits on readmission and depression; however, these reductions were not statistically significant.

CONCLUSIONS

The provision of psychological therapy to acute psychiatric inpatients is associated with improvements; however, the use of single-blind RCT methodology was associated with reduced therapy-attributable improvements. Whether this is a consequence of increased internal validity or reduced external validity is unclear. Trials with both high internal and external validity are now required to establish what type, format, and intensity of brief psychological therapy is required to achieve sustained benefits.

PRACTITIONER POINTS

Clinical implications: This review provides the first meta-analytical synthesis of brief psychological therapy delivered in acute psychiatric inpatient settings. This review suggests that brief psychological therapy may be associated with reduced emotional distress and readmissions.

LIMITATIONS

The evidence in this review is of limited quality. The type, format, and intensity of brief psychological therapy required to achieve sustained benefits are yet to be established.

Increased prevalence of posttraumatic stress disorder in CRPS

BACKGROUND

Although specific psychological disorders in complex regional pain syndrome (CRPS) have not been identified, studies suggest that CRPS patients may have increased rates of traumatic life events. Because these events do not always lead to apparent psychological symptoms, we systematically screened CRPS patients for posttraumatic stress disorder (PTSD) to determine if PTSD could be a risk factor for CRPS.

METHODS

Consecutive CRPS patients referred to two university hospital centres (University of Erlangen, UMC Mainz) between December 2011 and April 2013 were prospectively examined using a diagnostic PTSD instrument (Post-traumatic Stress Diagnostic Scale (PDS). We also tested maladaptive coping strategies (brief-COPE inventory) and the PDS severity score as predictors for CRPS. Patients with non-CRPS extremity pain and healthy individuals were used as control groups.

RESULTS

We collected data from 152 patients with CRPS, 55 control patients and 55 age- and sex-matched healthy individuals. Fifty-eight CRPS patients (38%), six non-CRPS pain patients (10%) and two healthy individuals (4%) met diagnostic criteria for PTSD. Initial PTSD symptom onset was prior to CRPS in 50 CRPS patients (86%) and during the course of CRPS in eight patients. Results of a logistic regression revealed that the PTSD severity score was associated with CRPS (p < 0.0001). Maladaptive coping strategies (p < 0.0001) were related to PTSD.

CONCLUSIONS

posttraumatic stress disorder (PTSD) is more frequent in patients with CRPS than it is in the general population.

SIGNIFICANCE

Research has not yet provided support for specific psychological predictors for CRPS.

Complex regional pain syndrome: From diagnosis to rehabilitation

Complex regional pain syndrome (CRPS) is a debilitating pathology characterised by intense chronic pain associated with vasomotor, sensory and motor dysfunction of the affected limb. Although the pathophysiology of CRPS is not fully understood, it is recognised that inflammatory processes and autonomic dysfunction are involved. These processes are associated with peripheral and central sensitisation as well as changes in brain structure and function, and are reflected in the clinical presentation of CRPS. CRPS management requires an interdisciplinary team and requires the therapeutic approach to be individualised. With regard to pharmacological treatment, bisphosphonates, corticosteroids, ketamine and anticonvulsants have been demonstrated to be effective for CRPS management. Psychotherapy, including cognitive-behavioural therapy, has produced promising results but more studies are needed to confirm its efficacy. Among rehabilitation interventions, there is evidence of the efficacy of physiotherapy and occupational therapy in diminishing CRPS symptoms and achieving a higher level of functioning. In this regard, the rehabilitation modality that seems the most promising according to the actual literature is graded motor imagery, which can help to reverse the maladaptive neuroplasticity occurring in CRPS.

A review of psychosocial factors in complex regional pain syndrome

Complex regional pain syndrome (CRPS) is a disabling pain condition poorly understood by medical professionals. Because CRPS is particularly enigmatic, and has significant impact on patient function, researchers have examined psychological processes present among patients with this diagnosis. This systematic review examines psychosocial factors associated with CRPS, both predictors and sequelae. Our conclusions are that CRPS is associated with negative outcomes, both psychological (e.g., increased depression and anxiety) and psychosocial (e.g., reduced quality of life, impaired occupational function) in nature. However, research does not reveal support for specific personality or psychopathology predictors of the condition.

Fixed dystonia of the left hand in a violinist: a rare functional disorder

BACKGROUND

Fixed dystonia leads to an immobile abnormal posturing of the affected limb. There is an ongoing debate whether this condition is psychogenic in origin.

CASE REPORT

We present a 21-year-old violinist with fixed dystonia after an acute overuse injury with a transient cyanosis but no signs for psychological trauma. After Incobotulinumtoxin injection, symptoms subsided within 8 hours.

DISCUSSION

Our case corroborates the notion that fixed dystonias after minor injuries are functional disorders. It underlines the necessity of a biopsychosocial approach to functional disorders, considering the possibility of an overlay between organic and non-organic disorders.

Peripheral trauma induced dystonia or post-traumatic syndrome?

The relationship between peripheral trauma and dystonia has been debated for more than a century but the issue still remains controversial. There are passionate supporters and detractors of the association and both the groups have their own arguments. This review aims to critically evaluate those arguments and presents current understanding of this association. In the process, the relevant case series and scientific papers exploring this subject have been discussed. Upon careful review of available literature coupled with their own experience, the authors believe that peripheral trauma can predispose to abnormal posturing of a body part after variable intervals. To call this posturing a "post-traumatic dystonia" might be premature and the term "post-traumatic syndrome" can be used instead. More work is needed to unravel the pathophysiology of this post-traumatic syndrome.

Movement disorders in complex regional pain syndrome

About 25% of the patients with complex regional pain syndrome (CRPS) suffer movement disorders, including loss of voluntary control, bradykinesia, dystonia, myoclonus, and tremor. These movement disorders are generally difficult to manage and add considerably to the disease burden. Over the last years, interesting findings have emerged that show how tissue or nerve injury may induce spinal plasticity (central sensitization), which alters sensory transmission and sensorimotor processing in the spinal cord and is associated with disinhibition. These changes, in turn, set the stage for the development of movement disorders seen in CRPS. There are no randomized control studies on the treatment of movement disorders in CRPS but findings from fundamental and clinical research suggest that strategies that enhance the central inhibitory state may benefit these patients.

Complex regional pain syndrome: an actual survey

Complex regional pain syndrome - in the past called sympathetic reflex dystrophy - is, in its pathophysiology, still not fully understood. However, research in the last few years has led to a better understanding of the illness and the beginning of a pathophysiologically- orientated therapy. The core hypothesis is based on neuropeptide release, neurogenic inflammation and its sympathetic dependence. Therapy should be based on current pathophysiological concepts regarding CRPS and neuropathic pain and could thereby lead to a good outcome of the illness.

Complex regional pain syndromes: new pathophysiological concepts and therapies

Complex regional pain syndrome (CRPS), formerly known as Sudeck's dystrophy and causalgia, is a disabling and distressing pain syndrome. We here provide a review based on the current literature concerning the epidemiology, etiology, pathophysiology, diagnosis, and therapy of CRPS. CRPS may develop following fractures, limb trauma or lesions of the peripheral or CNS. The clinical picture comprises a characteristic clinical triad of symptoms including autonomic (disturbances of skin temperature, color, presence of sweating abnormalities), sensory (pain and hyperalgesia), and motor (paresis, tremor, dystonia) disturbances. Diagnosis is mainly based on clinical signs. Several pathophysiological concepts have been proposed to explain the complex symptoms of CRPS: (i) facilitated neurogenic inflammation; (ii) pathological sympatho-afferent coupling; and (iii) neuroplastic changes within the CNS. Furthermore, there is accumulating evidence that genetic factors may predispose for CRPS. Therapy is based on a multidisciplinary approach. Non-pharmacological approaches include physiotherapy and occupational therapy. Pharmacotherapy is based on individual symptoms and includes steroids, free radical scavengers, treatment of neuropathic pain, and finally agents interfering with bone metabolism (calcitonin, biphosphonates). Invasive therapeutic concepts include implantation of spinal cord stimulators. This review covers new aspects of pathophysiology and therapy of CRPS.

Regulation of peripheral blood flow in complex regional pain syndrome: clinical implication for symptomatic relief and pain management

BACKGROUND

During the chronic stage of Complex Regional Pain Syndrome (CRPS), impaired microcirculation is related to increased vasoconstriction, tissue hypoxia, and metabolic tissue acidosis in the affected limb. Several mechanisms may be responsible for the ischemia and pain in chronic cold CPRS.

DISCUSSION

The diminished blood flow may be caused by either sympathetic dysfunction, hypersensitivity to circulating catecholamines, or endothelial dysfunction. The pain may be of neuropathic, inflammatory, nociceptive, or functional nature, or of mixed origin.

SUMMARY

The origin of the pain should be the basis of the symptomatic therapy. Since the difference in temperature between both hands fluctuates over time in cold CRPS, when in doubt, the clinician should prioritize the patient's report of a persistent cold extremity over clinical tests that show no difference. Future research should focus on developing easily applied methods for clinical use to differentiate between central and peripheral blood flow regulation disorders in individual patients.

Clinical expression profiles of complex regional pain syndrome, fibromyalgia and a-specific repetitive strain injury: More common denominators than pain?

PURPOSE

To systematically evaluate and compare the clinical manifestations, disease course, risk factors and demographic characteristics of Complex Regional Pain Syndrome type 1 (CRPS), fibromyalgia (FM) and a-specific Repetitive Strain Injury (RSI).

METHOD

A literature search was performed using terms related to the aforementioned topics and diseases. Only original clinical studies that included at least 20 subjects were eligible.

RESULTS

Fifty-nine studies on CRPS, 73 on FM and 7 on a-specific RSI were identified. The diseases show similarities in age distribution, male-female ratio, pain characteristics and sensory signs and symptoms. Motor, autonomic and trophic changes are frequently reported in CRPS, but only occasionally in FM and RSI. Systemic symptoms are found in patients with CRPS and FM, and in a subgroup of patients with RSI. In all three disorders, symptoms usually start locally, but may spread to other body regions later, which, in the case of FM, is a prerequisite for diagnosis. Disease onset is always, usually, or occasionally of traumatic origin in RSI, CRPS and FM, respectively. Anxiety and depression are more frequent in patients compared to controls, but probably not very different from patients with other pain conditions or chronic diseases.

CONCLUSIONS

Apart from some obvious differences between CRPS, FM and RSI, the similarities are conspicuous. The common features of CRPS, FM and a-specific RSI may suggest that a common pathway is involved, but until patients with these type of symptoms are assessed with a uniform assessment procedure, a thorough comparison cannot be made. A systematic evaluation of patients with a suspected diagnosis of CRPS, FM or RSI, may lead to a better appreciation of the differences and similarities in these diseases and help to unravel the underlying mechanisms.

Is there an association between psychological factors and the Complex Regional Pain Syndrome type 1 (CRPS1) in adults? A systematic review

Complex Regional Pain Syndrome type 1 (CRPS1) is a complication after trauma or surgery. Its pathophysiology is still a matter of debate, and psychological factors have been suggested to play a role, although their influence is unclear. The aim of this study was to investigate the evidence for the influence of psychological factors on the onset and maintenance of CRPS1 in adults. In a systematic review, articles were selected using Cochrane, Pubmed/Medline, Psychinfo, and Cinahl since 1980. Only original articles and empirical studies were included. Based on these selection criteria, 31 articles were identified. Studies were evaluated and weighted using a quality assessment instrument. The few prospective studies do not report a relationship between CRPS1 and depression, anxiety, neuroticism, or anger. The results of the retrospective/cross-sectional studies yield contradictory results regarding psychological problems in patients with CRPS1. A majority show no association, and studies with a higher methodological quality lean to a conclusion of no relationship between psychological factors and CRPS1. The majority of included studies (N=24; 77%) had only a poor to moderate methodological quality. Although many patients with CRPS1 are stigmatized as being psychologically different, this literature review identified no relationship between CRPS1 and several psychological factors. Only life events seemed to be associated with CRPS1: patients who experienced more life events appeared to have a greater chance of developing CRPS1. More studies with greater methodological quality and more participants should be performed on the association between psychological factors and the development and course of CRPS1.

Psychological features of patients with complex regional pain syndrome type I related dystonia

The objective of this study was to evaluate psychological features in severely affected patients with complex regional pain syndrome type I- (CRPS-I) related dystonia. Personality traits, psychopathology, dissociative experiences, the number of traumatic experiences, and quality of life were studied in 46 patients. Findings were compared with two historical psychiatric control groups [54 patients with conversion disorder (CD) and 50 patients with affective disorders (AD)] and normative population data. The CRPS-I patients showed elevated scores on the measures for somatoform dissociation, traumatic experiences, general psychopathology, and lower scores on quality of life compared with general population data, but had significantly lower total scores on the measures for personality traits, recent life events, and general psychopathology compared with the CD and AD patients. Rates of early traumatic experiences were comparable with the CD and AD patients, and the level of somatoform dissociation was comparable to the CD patients, but was elevated in comparison to the AD patients. Early traumatic experiences were reported in 87% of the CRPS-I patients and were found to be moderately related to somatoform dissociative experiences, indicating that early traumatic experiences might be a predisposing, although not a necessary factor for the development of CRPS-I-related dystonia. Although the psychological profile of the patients with CRPS-I-related dystonia shows some elevations, there does not seem to be a unique disturbed psychological profile on a group level.

Medical history and the onset of complex regional pain syndrome (CRPS)

Knowledge concerning the medical history prior to the onset of complex regional pain syndrome (CRPS) might provide insight into its risk factors and potential underlying disease mechanisms. To evaluate prior to CRPS medical conditions, a case-control study was conducted in the Integrated Primary Care Information (IPCI) project, a general practice (GP) database in the Netherlands. CRPS patients were identified from the records and validated through examination by the investigator (IASP criteria) or through specialist confirmation. Cases were matched to controls on age, gender and injury type. All diagnoses prior to the index date were assessed by manual review of the medical records. Some pre-specified medical conditions were studied for their association with CRPS, whereas all other diagnoses, grouped by pathogenesis, were tested in a hypothesis-generating approach. Of the identified 259 CRPS patients, 186 cases (697 controls) were included, based on validation by the investigator during a visit (102 of 134 visited patients) or on specialist confirmation (84 of 125 unvisited patients). A medical history of migraine (OR: 2.43, 95% CI: 1.18-5.02) and osteoporosis (OR: 2.44, 95% CI: 1.17-5.14) was associated with CRPS. In a recent history (1-year before CRPS), cases had more menstrual cycle-related problems (OR: 2.60, 95% CI: 1.16-5.83) and neuropathies (OR: 5.7; 95% CI: 1.8-18.7). In a sensitivity analysis, including only visited cases, asthma (OR: 3.0; 95% CI: 1.3-6.9) and CRPS were related. Psychological factors were not associated with CRPS onset. Because of the hypothesis-generating character of this study, the findings should be confirmed by other studies.

Clinical and neurophysiological characterization of myoclonus in complex regional pain syndrome

The origin of myoclonus in patients with complex regional pain syndrome (CRPS) is unknown. Eight patients with CRPS related myoclonus were clinically evaluated and studied with intermuscular and corticomuscular coherence analysis. Jerks were present at rest, aggravated during action and were frequently associated with tremulousness or dystonia. Electromyography demonstrated a burst duration ranging from 25 to 240 ms with burst frequencies varying from <1 jerk/s during rest to 20 Hz during action. Coherence studies showed increased intermuscular coherence in 4 patients in the 6 to 12 Hz band, as reported in patients with enhanced physiological tremor. In 2 patients side-to-side coherence was observed, pointing to a central oscillatory drive. Significant coherence entrainment was detected in 5 patients. We conclude that the characteristics of myoclonus in CRPS are different from other forms of myoclonus.

Patients with Ehlers Danlos syndrome and CRPS: a possible association?

Rare patients are left with chronic pain, vasodysregulation, and other symptoms that define complex regional pain syndrome (CRPS), after limb traumas. The predisposing factors are unknown. Genetic factors undoubtedly contribute, but have not yet been identified. We report four CRPS patients also diagnosed with the classical or hypermobility forms of Ehlers Danlos syndrome (EDS), inherited disorders of connective tissue. These patients had been diagnosed using standard diagnostic criteria for CRPS and for EDS. All had sustained joint injury; in three this had been surgically treated. The association of these two diagnoses leads us to hypothesize that EDS might contribute to the development of CRPS in one or more of the following ways: via stretch injury to nerves traversing hypermobile joints, increased fragility of nerve connective tissue, or nerve trauma from more frequent surgery. We review the clinical presentation of the different Ehlers Danlos syndromes and provide clinical criteria that can be used to screen CRPS patients for EDS for clinical or research purposes.

The Challenge to Manage Reflex Sympathetic Dystrophy/Complex Regional Pain Syndrome

The challenge to understand reflex sympathetic dystrophy/complex regional pain syndrome may require a better understanding of the complex relationship between the central and peripheral nervous systems. There is no comprehensive hypothesis that clearly explains the etiology and no uniformly successful treatment method. This brief summary of the challenge reviews some of what is known, hypothesizes a possible etiologic mechanism, and proposes 10 common-sense principles for management that recognizes the handicap of limited knowledge.

Patients initially diagnosed as 'warm' or 'cold' CRPS 1 show differences in central sensory processing some eight years after diagnosis: a quantitative sensory testing study

We used quantitative sensory testing (QST) to gain further insight into mechanisms underlying pain in CRPS 1. Specific goals were: (1) to identify altered patterns of sensory processing some 8 years after diagnosis, (2) to document differences in sensory processing between 'warm' and 'cold' diagnostic subgroups, (3) to determine relationships between changed sensory processing and disease progression regarding pain. The study was performed on a cohort of patients (n=47) clinically diagnosed with CRPS 1 of one upper extremity approximately 8 years previously. Pain was quantified by VAS and MacGill Pain Questionnaire (MPQ), and all subjects underwent electrical and mechanical QST. Cold patients (n=13) had poorer MPQ scores than warm ones (n=34), and more pain on electrical stimulation. Their evoked pain increased with disease progression and correlated with clinical pain measures. For both diagnostic subgroups, thresholds to pressure pain were lower on the affected extremity and with disease progression. Eight years after original diagnosis, cold CRPS 1 patients have poorer clinical pain outcomes and show persistent signs of central sensitisation correlating with disease progression. The latter is not the case for warm CRPS 1 patients. Both diagnostic subgroups show greater pressure hyperalgesia on the affected limb and with disease progression. QST may prove useful in the subdiagnosis of CRPS 1 and in quantifying its progression, with both applications warranting further investigation for clinical and research use.

Complex regional pain syndrome

Complex regional pain syndrome (CRPS) may develop after limb trauma and is characterized by pain, sensory-motor and autonomic symptoms. Most important for the understanding of the pathophysiology of CRPS are recent results of neurophysiological research. Major mechanism for CRPS symptoms, which might be present subsequently or in parallel during the course of CRPS, are trauma-related cytokine release, exaggerated neurogenic inflammation, sympathetically maintained pain and cortical reorganisation in response to chronic pain (neuroplasticity). The recognition of these mechanisms in individual CRPS patients is the prerequisite for a mechanism-oriented treatment.

Patient-based outcomes of cervical dystonia: A review of rating scales

Decisions on treatment choice for patients are based on trials and outcome studies that are wholly dependent upon the scientific quality of the rating scales used. This study reviewed rating scales used in cervical dystonia outcome research to determine the extent that they satisfy recommended criteria for rigorous measurement.

The Pain Distress Inventory: development and initial psychometric properties

A new 26-item self-report measure, the Pain Distress Inventory (PDI), was designed to assess affective distress symptoms related to physical pain. Phases 1 to 3 were designed to construct the PDI using contemporary test development strategies. Studies 1 and 2 were conducted to define and confirm the four-factor oblique structure of the PDI: PDI-Depression, PDI-Anger, PDI-Pain Sensitivity, and PDI-Somatic Anxiety. The internal consistency reliability estimates were high for both the PDI total and scale scores. Study 3 examined relationships of the PDI with demographic variables and pain- and psychological-related responses. Scores on the PDI were useful in predicting scores on a pain-interference index and a pain-symptom index. Study 4 was designed to replicate previous findings of reliability and validity. The PDI total and scale scores were useful in differentiating between the responses of the clinic and nonclinic study participants. Limitations and potential uses of the PDI are discussed.

Complex regional pain syndrome--diagnostic, mechanisms, CNS involvement and therapy

Complex regional pain syndromes (CRPS, formerly reflex sympathetic dystrophy and causalgia) are neuropathic pain conditions of one extremity developing inadequately after a trauma. The initiating trauma affects primarily the extremity, but can also be a central lesion (e.g., spinal cord injury, stroke). CRPS is clinically characterized by sensory, autonomic and motor disturbances. Pathophysiologically there is evidence for functional changes within the central nervous system and for involvement of peripheral inflammatory processes. The sympathetic nervous system plays a key role in maintaining pain and autonomic dysfunction in the affected extremity. After a primary central lesion, secondary peripheral changes in the paretic extremity are suggested to be important in initiating a CRPS. Though there is no diagnostic gold standard, careful clinical evaluation and additional test procedures should lead to an adequate diagnosis. An early diagnosis and an interdisciplinary approach are important for optimal and successful treatment.

Leg muscle reflexes mediated by cutaneous A-beta fibres are normal during gait in reflex sympathetic dystrophy

OBJECTIVES

Reflex sympathetic dystrophy (RSD) is, from the onset, characterized by various neurological deficits such as an alteration of sensation and a decrease in muscle strength. We investigated if afferent A-beta fibre-mediated reflexes are changed in lower extremities affected by acute RSD.

METHODS

The involvement of these fibres was determined by analyzing reflex responses from the tibialis anterior (TA) and biceps femoris (BF) muscles after electrical stimulation of the sural nerve. The reflexes were studied during walking on a treadmill to investigate whether the abnormalities in gait of the patients were related either to abnormal amplitudes or deficient phase-dependent modulation of reflexes. In 5 patients with acute RSD of the leg and 5 healthy volunteers these reflex responses were determined during the early and late swing phase of the step cycle.

RESULTS

No significant difference was found between the RSD and the volunteers. During early swing the mean amplitude of the facilitatory P2 responses in BF and TA increased as a function of stimulus intensity (1.5, 2 and 2.5 times the perception threshold) in both groups. At end swing the same stimuli induced suppressive responses in TA. This phase-dependent reflex reversal from facilitation in early swing to suppression in late swing occurred equally in both groups.

CONCLUSIONS

In the acute phase of RSD of the lower extremity there is no evidence for abnormal A-beta fibre-mediated reflexes or for defective regulation of such reflexes. This finding has implications for both the theory on RSD pathophysiology and RSD models, which are based on abnormal functioning of A-beta fibres.