ABSTRACT
BACKGROUND: Children and adolescents with intellectual disability are at risk of developing psychiatric symptoms and disorders; yet, the estimates reported in the literature have been inconsistent, presenting a potential barrier for service planning and delivery. Sources of variability could arise from differences in measurement instruments as well as subgroup membership by severity of intellectual disability, gender and age. This systematic review aimed to address these gaps. METHOD: MEDLINE and PsycINFO databases were searched from inception to 2018 and selected studies were reviewed. Studies were included if they reported point prevalence estimates of mental health symptomology or diagnoses in a general population of 6- to 21-year-old individuals with intellectual disability. The Joanna Briggs Institute Prevalence Critical Appraisal Checklist was applied to eligible papers to appraise their scientific strength. Pooled prevalence for mental health symptomology was determined using a random-effects meta-analysis. RESULTS: A total of 19 studies were included, including 6151 children and adolescents. The pooled prevalence estimate captured by the Developmental Behaviour Checklist was 38% (95% confidence interval = [31, 46]), contrasting with 49% (95% confidence interval = [46, 51]) captured by the Child Behaviour Checklist; both rates were higher than a non-intellectual disability population. Severity of intellectual disability did not significantly influence the Developmental Behaviour Checklist risks. Insufficient data were available to conduct statistical analyses on the effects of age, gender and socioeconomic status. Of diagnosed psychiatric disorders, attention deficit/hyperactivity disorder (30%), conduct disorder (3-21%) and anxiety disorders (7-34%) were the most prevalent conditions. CONCLUSION: This review consists of the largest sample hitherto evaluated. In the intellectual disability population, mental health comorbidities could be better detected by a symptom phenotype than a psychiatric diagnostic phenotype. Crucially, future research needs to address the effect of measurement validity in the intellectual disability population. Estimated prevalence rates were high compared to the general population, indicating the importance of systematic screening, case detection and appropriate management.
Subject(s)
Intellectual Disability , Adolescent , Adult , Anxiety Disorders , Child , Comorbidity , Humans , Intellectual Disability/epidemiology , Mental Health , Prevalence , Young AdultABSTRACT
The global SARS-CoV-2/COVID-19 pandemic has required a reduction in nonemergency treatment for a variety of disorders. This report summarizes conclusions of an international multidisciplinary consensus group assembled to address evaluation and treatment of patients with thoracic outlet syndrome (TOS), a group of conditions characterized by extrinsic compression of the neurovascular structures serving the upper extremity. The following recommendations were developed in relation to the three defined types of TOS (neurogenic, venous, and arterial) and three phases of pandemic response (preparatory, urgent with limited resources, and emergency with complete diversion of resources). ⢠In-person evaluation and treatment for neurogenic TOS (interventional or surgical) are generally postponed during all pandemic phases, with telephone/telemedicine visits and at-home physical therapy exercises recommended when feasible. ⢠Venous TOS presenting with acute upper extremity deep venous thrombosis (Paget-Schroetter syndrome) is managed primarily with anticoagulation, with percutaneous interventions for venous TOS (thrombolysis) considered in early phases (I and II) and surgical treatment delayed until pandemic conditions resolve. Catheter-based interventions may also be considered for selected patients with central subclavian vein obstruction and threatened hemodialysis access in all pandemic phases, with definitive surgical treatment postponed. ⢠Evaluation and surgical treatment for arterial TOS should be reserved for limb-threatening situations, such as acute upper extremity ischemia or acute digital embolization, in all phases of pandemic response. In late pandemic phases, surgery should be restricted to thrombolysis or brachial artery thromboembolectomy, with more definitive treatment delayed until pandemic conditions resolve.
Subject(s)
Betacoronavirus/pathogenicity , Coronavirus Infections/prevention & control , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Practice Guidelines as Topic , Thoracic Outlet Syndrome/diagnosis , Triage/standards , COVID-19 , Consensus , Coronavirus Infections/epidemiology , Coronavirus Infections/transmission , Coronavirus Infections/virology , Decompression, Surgical/standards , Elective Surgical Procedures/methods , Elective Surgical Procedures/standards , Emergency Treatment/methods , Emergency Treatment/standards , Humans , Infection Control/standards , Interdisciplinary Communication , Limb Salvage/methods , Limb Salvage/standards , Patient Selection , Pneumonia, Viral/epidemiology , Pneumonia, Viral/transmission , Pneumonia, Viral/virology , SARS-CoV-2 , Telemedicine/standards , Thoracic Outlet Syndrome/etiology , Thoracic Outlet Syndrome/therapy , Thrombolytic Therapy/methods , Thrombolytic Therapy/standards , Time-to-Treatment/standardsABSTRACT
A patient with neurogenic thoracic outlet syndrome was initially treated with scalenectomy, first rib resection, and wrapping of the brachial plexus (BP) with amnion membrane (AM) to prevent postoperative adhesions. Twelve months later, at reoperation for recurrent symptoms, the AM was observed to be intact. The BP had no scar tissue around it. Recurrence was due to scarring around the nerve roots superior to the portion of the plexus that had been wrapped with AM. It was concluded that the AM had successfully protected the portion of the BP that had been wrapped. Longer term studies are in progress.
ABSTRACT
The flow of terrestrial carbon to rivers and inland waters is a major term in the global carbon cycle. The organic fraction of this flux may be buried, remineralized or ultimately stored in the deep ocean. The latter can only occur if terrestrial organic carbon can pass through the coastal and estuarine filter, a process of unknown efficiency. Here, data are presented on the spatial distribution of terrestrial fluorescent and chromophoric dissolved organic matter (FDOM and CDOM, respectively) throughout the North Sea, which receives organic matter from multiple distinct sources. We use FDOM and CDOM as proxies for terrestrial dissolved organic matter (tDOM) to test the hypothesis that tDOM is quantitatively transferred through the North Sea to the open North Atlantic Ocean. Excitation emission matrix fluorescence and parallel factor analysis (EEM-PARAFAC) revealed a single terrestrial humic-like class of compounds whose distribution was restricted to the coastal margins and, via an inverse salinity relationship, to major riverine inputs. Two distinct sources of fluorescent humic-like material were observed associated with the combined outflows of the Rhine, Weser and Elbe rivers in the south-eastern North Sea and the Baltic Sea outflow to the eastern central North Sea. The flux of tDOM from the North Sea to the Atlantic Ocean appears insignificant, although tDOM export may occur through Norwegian coastal waters unsampled in our study. Our analysis suggests that the bulk of tDOM exported from the Northwest European and Scandinavian landmasses is buried or remineralized internally, with potential losses to the atmosphere. This interpretation implies that the residence time in estuarine and coastal systems exerts an important control over the fate of tDOM and needs to be considered when evaluating the role of terrestrial carbon losses in the global carbon cycle.
ABSTRACT
The diagnosis of brachial plexus compression-either neurogenic thoracic outlet syndrome (NTOS) or neurogenic pectoralis minor syndrome (NPMS)-is based on old fashioned history and physical examination. Tests, such as scalene muscle and pectoralis minor muscle blocks are employed to confirm a diagnosis suspected on clinical findings. Electrodiagnostic studies can confirm a diagnosis of nerve compression, but cannot establish it. This is not a diagnosis of exclusion; the differential and associated diagnoses of upper extremity pain are always considered. Also discussed is conservative and surgical treatment options.
ABSTRACT
The supraclavicular approach to scalenectomy and first rib resection has been modified since the original description in 1985. The incision is 1 to 2 cm above the clavicle, 1 cm lateral to the midline, and 5 to 7 cm long. Subplatysmal skin flaps are created. The sternocleidomastoid muscle is mobilized on its lateral edge and retracted but not divided. The scalene fat pad is split vertically, the omohyoid muscle excised, and the C5 nerve root dissected free. The accessory phrenic nerve is identified, if present, arising medially from C5, and preserved. The rest of the plexus is dissected free, muscular and connective tissue removed from all nerve roots and trunks, and the subclavian artery identified. The phrenic nerve is identified on the medial edge of the anterior scalene muscle (ASM). The ASM is divided on the first rib. The ASM is elevated, freed, and divided as high as possible and free of C5. The middle scalene muscle is dissected. C5 and C6 branches of the long thoracic nerve are identified and protected as the portion of middle scalene muscle adjacent to the nerves of the plexus is excised. The decision on whether the first rib is to be removed is determined by whether the lower trunk of the plexus is touching the first rib. If the rib is removed, its posterior end is freed, divided, and 1 cm excised. The rest of the rib is freed from the intercostal muscles with a periosteal elevator or harmonic scalpel, the pleura is separated from the inner surface of the rib, and the anterior end divided with an infraclavicular rib cutter. The operation has been made safer by identifying and dissecting the C5 nerve root before looking for the phrenic nerve.
Subject(s)
Brachial Plexus/physiopathology , Clavicle/innervation , Decompression, Surgical/methods , Osteotomy/methods , Ribs/surgery , Thoracic Outlet Syndrome/surgery , Anatomic Landmarks , Decompression, Surgical/adverse effects , Dissection , Humans , Patient Positioning , Radiography , Recurrence , Reoperation , Ribs/diagnostic imaging , Surgical Flaps , Thoracic Outlet Syndrome/diagnosis , Thoracic Outlet Syndrome/physiopathology , Treatment OutcomeABSTRACT
The biological carbon pump, which transports particulate organic carbon (POC) from the surface to the deep ocean, plays an important role in regulating atmospheric carbon dioxide (CO2) concentrations. We know very little about geographical variability in the remineralization depth of this sinking material and less about what controls such variability. Here we present previously unpublished profiles of mesopelagic POC flux derived from neutrally buoyant sediment traps deployed in the North Atlantic, from which we calculate the remineralization length scale for each site. Combining these results with corresponding data from the North Pacific, we show that the observed variability in attenuation of vertical POC flux can largely be explained by temperature, with shallower remineralization occurring in warmer waters. This is seemingly inconsistent with conclusions drawn from earlier analyses of deep-sea sediment trap and export flux data, which suggest lowest transfer efficiency at high latitudes. However, the two patterns can be reconciled by considering relatively intense remineralization of a labile fraction of material in warm waters, followed by efficient downward transfer of the remaining refractory fraction, while in cold environments, a larger labile fraction undergoes slower remineralization that continues over a longer length scale. Based on the observed relationship, future increases in ocean temperature will likely lead to shallower remineralization of POC and hence reduced storage of CO2 by the ocean.
ABSTRACT
OBJECTIVE: This study aims to estimate the risk of hot flashes relative to natural menopause and to evaluate the associations of hormone levels, behavioral variables, and demographic variables with the risk of hot flashes after menopause. METHODS: We performed annual assessment of 255 women who were premenopausal at baseline and reached natural menopause within 16 years of follow-up. RESULTS: The prevalence of moderate/severe hot flashes increased in each premenopausal year, reaching a peak of 46% in the first 2 years after the final menstrual period (FMP). Hot flashes decreased slowly after menopause and did not return to premenopausal levels until 9 years after the FMP. The mean (SD) duration of moderate/severe hot flashes after the FMP was 4.6 (2.9) years (for any hot flashes, 4.9 [3.1] y). One third of women at 10 years or more after menopause continued to experience moderate/severe hot flashes. African-American women (obese and nonobese) and obese white women had significantly greater risks of hot flashes compared with nonobese white women (interaction, P = 0.01). In multivariable analysis, increasing follicle-stimulating hormone levels before the FMP (P < 0.001), decreasing estradiol (odds ratio, 0.87; 95% CI, 0.78-0.96; P = 0.008), and increasing anxiety (odds ratio, 1.05; 95% CI, 1.03-1.06; P < 0.001) were significant risk factors for hot flashes, whereas higher education levels were protective (odds ratio, 0.66; 95% CI, 0.47-0.91; P = 0.011). CONCLUSIONS: Moderate/severe hot flashes continue, on average, for nearly 5 years after menopause; more than one third of women observed for 10 years or more after menopause have moderate/severe hot flashes. Continuation of hot flashes for more than 5 years after menopause underscores the importance of determining individual risks/benefits when selecting hormone or nonhormone therapy for menopausal symptoms.
Subject(s)
Hot Flashes/epidemiology , Menopause , Adult , Aging , Attitude to Health , Cohort Studies , Female , Hot Flashes/etiology , Hot Flashes/pathology , Humans , Longitudinal Studies , Pennsylvania/epidemiology , Prevalence , Risk Factors , Severity of Illness IndexABSTRACT
Correlations between particulate organic carbon (POC) and mineral fluxes in the deep ocean have inspired the inclusion of "ballast effect" parameterizations in carbon cycle models. A recent study demonstrated regional variability in the effect of ballast minerals on the flux of POC in the deep ocean. We have undertaken a similar analysis of shallow export data from the Arctic, Atlantic, and Southern Oceans. Mineral ballasting is of greatest importance in the high-latitude North Atlantic, where 60% of the POC flux is associated with ballast minerals. This fraction drops to around 40% in the Southern Ocean. The remainder of the export flux is not associated with minerals, and this unballasted fraction thus often dominates the export flux. The proportion of mineral-associated POC flux often scales with regional variation in export efficiency (the proportion of primary production that is exported). However, local discrepancies suggest that regional differences in ecology also impact the magnitude of surface export. We propose that POC export will not respond equally across all high-latitude regions to possible future changes in ballast availability.
ABSTRACT
Compression of the neurovascular bundle to the upper extremity can occur above or below the clavicle; thoracic outlet syndrome (TOS) is above the clavicle and pectoralis minor syndrome is below. More than 90% of cases involve the brachial plexus, 5% involve venous obstruction, and 1% are associate with arterial obstruction. The clinical presentation, including symptoms, physical examination, pathology, etiology, and treatment differences among neurogenic, venous, and arterial TOS syndromes. This review details the diagnostic testing required to differentiate among the associated conditions and recommends appropriate medical or surgical treatment for each compression syndrome. The long-term outcomes of patients with TOS and pectoralis minor syndrome also vary and depend on duration of symptoms before initiation of physical therapy and surgical intervention. Overall, it can be expected that >80% of patients with these compression syndromes can experience functional improvement of their upper extremity; higher for arterial and venous TOS than for neurogenic compression.
Subject(s)
Pectoralis Muscles/innervation , Thoracic Outlet Syndrome/diagnosis , Thoracic Outlet Syndrome/therapy , Upper Extremity/innervation , Animals , Diagnosis, Differential , Humans , Pectoralis Muscles/abnormalities , Predictive Value of Tests , Recovery of Function , Risk Factors , Thoracic Outlet Syndrome/classification , Thoracic Outlet Syndrome/physiopathology , Treatment OutcomeABSTRACT
Brachial plexus compression (BPC) occurs above the clavicle as neurogenic thoracic outlet syndrome (NTOS) and below as neurogenic pectoralis minor syndrome (NPMS). It was recently noted that 75% of the adults seen for NTOS also had NPMS and in some this was the only diagnosis. This is also true in children but has not yet been reported. Because surgical treatment of NPMS is a minimum risk operation for pectoralis minor tenotomy (PMT), recognition of NPMS and distinguishing it from NTOS becomes important. In this study, 40 operations, 20 PMT and 20 NTOS procedures, were performed. Success rate for PMT was 85% and for thoracic outlet decompression was 70%. It was concluded that in children, as in adults, BPC is more often due to combined NTOS and NPMS. Surgical PMT should be considered first as the treatment of choice for children with NPMS. Thoracic outlet decompression is available if PMT is unsuccessful.
Subject(s)
Decompression, Surgical , Muscular Diseases/surgery , Osteotomy , Pectoralis Muscles/surgery , Ribs/surgery , Tenotomy , Thoracic Outlet Syndrome/surgery , Adolescent , Age Factors , Child , Decompression, Surgical/adverse effects , Female , Humans , Male , Muscular Diseases/congenital , Muscular Diseases/diagnosis , Osteotomy/adverse effects , Patient Selection , Pectoralis Muscles/abnormalities , Pectoralis Muscles/diagnostic imaging , Radiography , Retrospective Studies , Ribs/diagnostic imaging , Tenotomy/adverse effects , Thoracic Outlet Syndrome/diagnosis , Treatment Outcome , Young AdultABSTRACT
BACKGROUND: Although first described over 60 years ago, neurogenic pectoralis minor syndrome (NPMS) has only recently been noted to be present in over half the patients with a clinical diagnosis of neurogenic thoracic outlet syndrome (NTOS). Similarly, NPMS has also been observed in the majority of patients with recurrent NTOS. This study explores the role of pectoralis minor tenotomy (PMT) in patients with recurrent NTOS. METHODS: A total of 86 patients with symptoms of recurrent NTOS, who had failed to improve on conservative management, were evaluated by history and physical examination for both NPMS and NTOS. Diagnostic tests included pectoralis minor muscle (PMM) blocks, scalene muscle blocks, and medial antebrachial cutaneous nerve (MAC) measurements. Surgery was either PMT alone or PMT plus brachial plexus decompression (BPD). Follow-up was 1 to 3 years. RESULTS: All patients had multiple symptoms of pain, weakness, and paresthesia. Patients who qualified for PMT alone had slightly fewer symptoms than those who required PMT plus BPD. There was essentially no difference in physical findings between the 2 groups. It was the response to PMM blocks and scalene muscle blocks that determined which of the 2 operations was performed. Pectoralis minor tenotomy alone gave 69% good results in 65 operations, with 8% fair and 23% failures. Pectoralis minor tenotomy plus BPD in 39 operations gave 58% good improvement, 20% fair and 22% failures. CONCLUSION: All patients with recurrent NTOS should be evaluated clinically for NPMS. If patients complain of pain or tenderness in the anterior chest wall and axilla, a diagnostic PMM block should be performed. A good response to the block suggests that consideration be given to performing PMT alone as it a simple, low-risk outpatient procedure. If unsuccessful, BPD can be performed at a later date. If there is a poor response to the PMM block, BPD is indicated along with PMT, provided there were some symptoms of NPMS.
Subject(s)
Brachial Plexus/surgery , Decompression, Surgical , Nerve Compression Syndromes/surgery , Pectoralis Muscles/surgery , Tenotomy , Thoracic Outlet Syndrome/surgery , Adolescent , Adult , Aged , Electrodiagnosis , Female , Humans , Male , Middle Aged , Nerve Block , Nerve Compression Syndromes/diagnosis , Pectoralis Muscles/innervation , Physical Examination , Recurrence , Thoracic Outlet Syndrome/diagnosis , Treatment Outcome , Young AdultABSTRACT
BACKGROUND: Since 2005 when we became aware of pectoralis minor syndrome (PMS), more than 75% of patients diagnosed with neurogenic thoracic outlet syndrome (NTOS) also have neurogenic PMS (NPMS), and about 30% have only NPMS, without NTOS. METHODS: Diagnosis was made based on history, physical examination, pectoralis minor (PM), and scalene muscle blocks with lidocaine. Pectoralis minor tenotomy was performed as an outpatient procedure under local anesthesia with heavy sedation through a 5-7 cm transaxillary incision. RESULTS: The clinical picture included pain or tenderness in the anterior chest wall and axilla, together with physical findings of tenderness over the pectoralis minor tendon. Other symptoms were extremity pain, weakness, and paresthesia, similar to symptoms of NTOS. In 76 patients, 100 operations were performed: 48 for NPMS combined with NTOS and 52 for NPMS-alone. Features distinguishing the PM-alone group were fewer and milder occipital headaches, less neck pain, and fewer positive physical findings. Preoperatively, 85% of the of the PM-alone group were still employed compared to only 57% of the combined group (p=0.01). Success rates with 1-3-year follow-up for the PM-alone group were 90% good-excellent, 2% fair, and 8% failed; for the combined group success rates were 35% good-excellent, 19% fair, and 46% failed. All but one of the failures was immediate, only one was late. The only complication was 3 wound infections. Most patients returned to work within a few days. In the combined PMS/TOS group, most of the failed patients subsequently had thoracic outlet operations. CONCLUSION: PMS commonly accompanies NTOS and frequently exists alone. Its recognition is important as many patients with suspected NTOS can be treated successfully with a simple, essentially risk-free PM tenotomy. Should this fail, thoracic outlet decompression can always be performed at a later date.
Subject(s)
Decompression, Surgical/methods , Nerve Compression Syndromes/surgery , Orthopedic Procedures , Pectoralis Muscles/surgery , Thoracic Outlet Syndrome/surgery , Adolescent , Adult , Aged , Colorado , Decompression, Surgical/adverse effects , Diagnosis, Differential , Disability Evaluation , Electromyography , Employment , Female , Headache/etiology , Humans , Male , Middle Aged , Nerve Block , Nerve Compression Syndromes/complications , Nerve Compression Syndromes/diagnosis , Nerve Compression Syndromes/physiopathology , Orthopedic Procedures/adverse effects , Pain/etiology , Paresthesia/etiology , Pectoralis Muscles/innervation , Physical Examination , Recurrence , Thoracic Outlet Syndrome/complications , Thoracic Outlet Syndrome/diagnosis , Thoracic Outlet Syndrome/physiopathology , Time Factors , Treatment Outcome , Young AdultABSTRACT
The addition of iron to high-nutrient, low-chlorophyll regions induces phytoplankton blooms that take up carbon. Carbon export from the surface layer and, in particular, the ability of the ocean and sediments to sequester carbon for many years remains, however, poorly quantified. Here we report data from the CROZEX experiment in the Southern Ocean, which was conducted to test the hypothesis that the observed north-south gradient in phytoplankton concentrations in the vicinity of the Crozet Islands is induced by natural iron fertilization that results in enhanced organic carbon flux to the deep ocean. We report annual particulate carbon fluxes out of the surface layer, at three kilometres below the ocean surface and to the ocean floor. We find that carbon fluxes from a highly productive, naturally iron-fertilized region of the sub-Antarctic Southern Ocean are two to three times larger than the carbon fluxes from an adjacent high-nutrient, low-chlorophyll area not fertilized by iron. Our findings support the hypothesis that increased iron supply to the glacial sub-Antarctic may have directly enhanced carbon export to the deep ocean. The CROZEX sequestration efficiency (the amount of carbon sequestered below the depth of winter mixing for a given iron supply) of 8,600 mol mol(-1) was 18 times greater than that of a phytoplankton bloom induced artificially by adding iron, but 77 times smaller than that of another bloom initiated, like CROZEX, by a natural supply of iron. Large losses of purposefully added iron can explain the lower efficiency of the induced bloom(6). The discrepancy between the blooms naturally supplied with iron may result in part from an underestimate of horizontal iron supply.
Subject(s)
Carbon/metabolism , Iron/metabolism , Seawater/chemistry , Antarctic Regions , Chlorophyll/analysis , Chlorophyll/metabolism , Chlorophyll A , Eutrophication , Geography , Geologic Sediments/chemistry , Oceans and Seas , Phytoplankton/metabolism , Seasons , Time FactorsABSTRACT
BACKGROUND: : Arterial and venous thoracic outlet syndrome (TOS) were recognized in the late 1800s and neurogenic TOS in the early 1900s. Diagnosis and treatment of the 2 vascular forms of TOS are generally accepted in all medical circles. On the other hand, neurogenic TOS is more difficult to diagnose because there is no standard objective test to confirm clinical impressions. REVIEW SUMMARY: : The clinical features of arterial, venous, and neurogenic TOS are described. Because neurogenic TOS is by far the most common type, the pathology, pathophysiology, diagnostic tests, differential and associate diagnoses, and treatment are detailed and discussed. The controversial area of objective and subjective diagnostic criteria is addressed. CONCLUSION: : Arterial and venous TOS are usually not difficult to recognize and the diagnosis can be confirmed by angiography. The diagnosis of neurogenic TOS is more challenging because its symptoms of nerve compression are not unique. The clinical diagnosis relies on documenting several positive findings on physical examination. To date there is still no reliable objective test to confirm the diagnosis, but measurements of the medial antebrachial cutaneous nerve appear promising.
Subject(s)
Thoracic Outlet Syndrome/classification , Thoracic Outlet Syndrome/pathology , Thoracic Outlet Syndrome/surgery , History, 20th Century , History, 21st Century , Humans , Thoracic Outlet Syndrome/historyABSTRACT
A reliable objective test is still needed to confirm the diagnosis of neurogenic thoracic outlet syndrome (NTOS). Over the past 20 years, it has been suggested that responses to medial antebrachial cutaneous nerve (MAC) and C8 nerve root stimulation could be used for this purpose. Herein, we explore this thesis. A clinical diagnosis of NTOS was established in 41 patients, all of whom underwent surgical decompression. Preoperatively, all patients were studied with MAC sensory neural action potential (SNAP) determinations and C8 nerve root stimulation. Controls were 19 asymptomatic, healthy volunteers. MAC sensory latency on 79 control sides was 1.5-2.4 msec, while latency in 41 symptomatic patients ranged 2.2-2.8 msec. Latency of 2.5 or greater was noted in 30 patients (specificity 99%, sensitivity 73%), confirming a diagnosis of NTOS, while the remaining 11 (27%) fell into the borderline zone of 2.2-2.4 msec. The latency difference between right and left sides in controls was 0-0.2 msec in 17 (89%), while in NTOS patients 31 had a difference of 0.3 msec or more (sensitivity 89%, specificity 63%). Amplitudes of 10 muV or more occurred in 77 of 79 control sides, whereas the amplitude was under 10 muV in 28 patients (specificity 97%, sensitivity 68%). Amplitude ratios between right and left sides in controls were 1.7 or less. Ratios of 2.0 or more were measured in 25 patients (specificity 100%, sensitivity 61%). Using the four diagnostic criteria (latency over 2.4 msec, latency difference between sides of 0.3 or more, amplitude under 10 muV, and amplitude ratios of 2.0 or more), 40 of the 41 patients had at least one of the four diagnostic criteria, 23 patients (56%) had three or four positive criteria, and 12 (29%) had two. C8 nerve root stimulation responses were below normal (56 M/sec) in 54%. MAC measurement is a fairly reliable technique for confirming the diagnosis of NTOS. Latency determination appeared to be a slightly more consistent measurement in this study, but amplitude and C8 nerve root stimulation were also helpful. A combination of these techniques seems to be the most reliable approach.
Subject(s)
Forearm/innervation , Musculocutaneous Nerve/physiology , Neural Conduction , Thoracic Outlet Syndrome/diagnosis , Action Potentials , Adolescent , Adult , Electric Stimulation , Electromyography , Female , Humans , Male , Middle Aged , Sensitivity and Specificity , Spinal Nerve Roots/physiology , Thoracic Outlet Syndrome/surgeryABSTRACT
Thoracic outlet syndrome (TOS) is a nonspecific label. When employing it, one should define the type of TOS as arterial TOS, venous TOS, or neurogenic TOS. Each type has different symptoms and physical findings by which the three types can easily be identified. Neurogenic TOS (NTOS) is by far the most common, comprising well over 90% of all TOS patients. Arterial TOS is the least common accounting for no more than 1%. Many patients are erroneously diagnosed as "vascular" TOS, a nonspecific misnomer, whereas they really have NTOS. The Adson Test of noting a radial pulse deficit in provocative positions has been shown to be of no clinical value and should not be relied upon to make the diagnosis of any of the three types. The test is normal in most patients with NTOS and at the same time can be positive in many control volunteers. Arterial TOS is caused by emboli arising from subclavian artery stenosis or aneurysms. Symptoms are those of arterial ischemia and x-rays almost always disclose a cervical rib or anomalous first rib. Venous TOS presents with arm swelling, cyanosis, and pain due to subclavian vein obstruction, with or without thrombosis. Neurogenic TOS is due to brachial plexus compression usually from scarred scalene muscles secondary to neck trauma, whiplash injuries being the most common. Symptoms include extremity paresthesia, pain, and weakness as well as neck pain and occipital headache. Physical exam is most important and includes several provocative maneuvers including neck rotation and head tilting, which elicit symptoms in the contralateral extremity; the upper limb tension test, which is comparable to straight leg raising; and abducting the arms to 90 degrees in external rotation, which usually brings on symptoms within 60 seconds.
Subject(s)
Thoracic Outlet Syndrome/diagnosis , Angiography , Diagnosis, Differential , Electromyography , Exercise Test , Humans , Peripheral Vascular Diseases/complications , Peripheral Vascular Diseases/diagnosis , Thoracic Outlet Syndrome/etiologyABSTRACT
PURPOSE: Although the usual site of nonthrombotic venous obstruction of the upper extremity is the subclavian vein, other sites may be the cause of such obstruction. This study describes the diagnosis and treatment of six patients with partial axillary vein obstruction by the pectoralis minor muscle, a condition that can mimic subclavian vein obstruction. METHODS: A chart review of patients undergoing pectoralis minor tenotomies (PMT) between 2004 and 2006 revealed six patients (3 men and 3 women), aged 17 to 39, who underwent seven PMT procedures for symptoms of arm swelling, cyanosis, and pain or tightness. Diagnosis was suggested by history and physical examination and was confirmed by dynamic venography. Patients with paresthesia suggesting associated neurogenic pectoralis minor compression were given a pectoralis minor muscle block. As an outpatient, PMT was initially performed with an infraclavicular approach but later through the transaxillary route. Follow-up was by phone interview in five patients and a physical examination in one. RESULTS: Venography demonstrated axillary vein compression under the pectoralis minor, which was more significant than the minor degree of subclavian vein compression seen on the same venogram. Follow-up was 1.5 years to 10 years in three patients and 3 months in the other three. All six patients experienced good-to-excellent relief of all symptoms. There were no surgical complications. CONCLUSION: Axillary venous obstruction by the pectoralis minor must be distinguished from subclavian vein obstruction, which presents with similar symptoms. PMT is a simple, risk-free, outpatient procedure that has produced uniformly good results.