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Purpose Increasing evidence suggests that fibromyalgia most likely represents a neurological dysfunction. We previously hypothesized that at least some fibromyalgia cases may be caused by irritation of nerve root fibers and sensory neurons due to moderately increased cerebrospinal pressure. Because of the rostro-caudal hydrostatic pressure gradient, neurogenic abnormalities are expected to be most pronounced in sacral nerve roots. The purpose was to review electrodiagnostic tests of patients with fibromyalgia. Methods A retrospective review of electrodiagnostic test results, including the lumbar and sacral nerve root myotomes of patients diagnosed with fibromyalgia according to the 1990 criteria of the American College of Rheumatology was done. Results All 17 patients were female. Sural nerve responses could not be elicited in 12% and S1-Hoffmann reflex latencies were increased in 41%. In 12% of the patients, fibular motor nerve distal latency and conduction velocity were outside normal limits. Needle-EMG revealed neurogenic motor unit potentials in 0% of L2, 6% of L3, 29% of L4, 71% of L5, 47% of S1, 94% of S2, and 76% of S3-S4 myotomes. S3-S4 nerve-supplied anal reflexes were delayed in 94%. Conclusion This is the first time that electrodiagnostic data of both lumbar and sacral nerve root myotomes in fibromyalgia patients are presented. All patients showed neurogenic abnormalities that were more pronounced in the sacral than in the lumbar myotomes with a rather patchy distribution pattern. We propose that, in addition to skin punch biopsies to assess small fiber neuropathy, assessment of the anal reflex may be a useful part of the diagnostic pathway in patients with fibromyalgia.

Tarlov cysts (TCs) are dilations of nerve roots arising from pathologically increased hydrostatic pressure (HP) in the spinal canal. There is much controversy regarding whether these cysts are a rare source of pain or often produce symptoms. The aim of this review was to identify the reasons that symptomatic TCs (STCs) are easily overlooked. The literature was searched for data regarding pathogenesis and symptomatology. TCs may be overlooked for the following reasons: (1) STCs are considered clinically irrelevant findings; (2) it is assumed that it is clinically difficult to ascertain that TCs are the cause of pain; (3) MRI or electromyography studies only focus on the L1 to S1 nerves; (4) TCs are usually not reported by radiologists; (5) degenerative alterations of the lumbosacral spine are almost always identified as the cause of a patient’s pain; (6) it is not generally known that small TCs can be symptomatic; (7) examinations and treatments usually focus on the cysts as an underlying mechanism; however, essentially, increased HP is the main underlying mechanism for producing symptoms. Consequently, STCs may relapse after surgery; (8) bladder, bowel and sphincter dysfunction are not inquired about during history taking. (9) Unexplained pain is often attributed to depression, whereas depression is more likely the consequence of debilitating neuropathic pain. (10) The recognition of STCs is subject to gender bias, confirmation bias and cognitive dissonance and unconscious bias in publishing. There are several reasons STCs are underdiagnosed, mostly due to persistent misconceptions and biases. These slides can be retrieved under Electronic Supplementary Material.

Objective Pain in fibromyalgia (FM) and chronic fatigue syndrome (CFS) is assumed to originate from central sensitization. Perineural cysts or Tarlov cysts (TCs) are nerve root dilations resulting from pathologically increased cerebrospinal fluid pressure. These cysts initially affect sensory neurons and axons in dorsal root ganglia and produce sensory symptoms (pain and paresthesia). Symptomatic TC (STC) patients often complain about widespread pain and fatigue. Consequently, STC patients may initially be diagnosed with FM, CFS, or both. The objective of this study was to document the prevalence of TCs in patients diagnosed with FM or CFS. Design A retrospective study. Setting An outpatient clinic for musculoskeletal disorders. Subjects Patients diagnosed with FM according to the 1990 American College of Rheumatology criteria or with CFS according to the 1994 Centers for Disease Control criteria were selected. Methods Review of lumbar and sacral magnetic resonance imaging scans including TCs ≥5 mm in size. Results In total, 197 patients with FM, CFS, or both underwent magnetic resonance imaging. Ninety-one percent were women. The mean age was 48.1 (±11.9) years. TCs were observed in 39% of patients, with a mean size of 11.8 (±5.2) mm. In males, the prevalence was 12%, vs. 42% in females. Conclusions In patients diagnosed with FM or CFS, the prevalence of TCs was three times higher than that in the general population. This observation supports the hypothesis that STCs, FM, and CFS may share the same pathophysiological mechanism, i.e., moderately increased cerebrospinal fluid pressure, causing irritation of neurons and axons in dorsal root ganglia.

Background Tarlov cysts (TCs) are expanded nerve root sheaths that occur near the dorsal root ganglion and result from increased intraspinal hydrostatic pressure. TCs most frequently affect the lumbosacral plexus and therefore may cause specific symptoms such as perineal pain and neurogenic bladder, bowel, and sphincter problems. It has been estimated that 1% of the population has symptomatic Tarlov cysts (STCs). However, STCs appear to be underdiagnosed, with the pain reported by patients commonly attributed to degenerative alterations seen on MRI. The aim of the present study is to investigate the utility of a comprehensive questionnaire for use by physicians in establishing the diagnosis of STCs. Methods We compared questionnaire responses regarding patient history between 33 patients diagnosed with symptomatic TCs and 42 patients with chronic low back pain and sciatica due to disc problems or degenerative or inflammatory disorders. The diagnosis of STCs was confirmed using nerve conduction studies (NCS) and electromyography (EMG) of the sacral myotomes by an expert neurophysiologist. Results The questionnaire responses revealed specific differences in perineal symptoms (perineal pain, dyspareunia,coccygodynia), bowel symptoms (constipation, diarrhea), bladder symptoms (hesitation, retention, frequency), and anal sphincter problems (anal pain, mild fecal incontinence). Additionally, sitting, walking, and straining aggravated pain more frequently inSTC patients, and STC patients were more often forced to stop working and/or reduce their social activities. Conclusions Including the above-listed items in the patient history might facilitate differentiation of low back pain and sciatica due to STCs from that due to disc problems or degenerative or inflammatory disorders. ispartof: Acta Neurochirurgica vol:160 issue:4 pages:839-844 ispartof: location:Austria status: published

PURPOSE: To assess the independent association between ICU-acquired neuromuscular complications and 5-year mortality and morbidity. To explore the optimal threshold of the Medical Research Council (MRC) sum score, assessing weakness, for the prediction of 5-year outcomes. METHODS: Sub-analyses of a prospective, 5-year follow-up study including 883 EPaNIC patients (Early versus Late Parenteral Nutrition in Intensive Care) (Clinicaltrials.gov:NCT00512122), systematically screened in ICU for neuromuscular complications with MRC sum score ('MRC-cohort', N = 600), electrophysiology on day 8 ± 1 to quantify compound muscle action potential ('CMAP-cohort', N = 689), or both ('MRC&CMAP-cohort', N = 415). Associations between ICU-acquired neuromuscular complications and 5-year mortality, hand-grip strength (HGF, %predicted), 6-min-walk distance (6-MWD, %predicted) and physical function of the SF-36 quality-of-life questionnaire (PF-SF-36) at 5-years were assessed with Cox regression and linear regression, adjusted for confounders. The optimal threshold for MRC at ICU discharge to predict 5-year outcomes was determined by martingale residual plots (survival) and scatterplots (morbidity). RESULTS: Both lower MRC sum score at ICU discharge, indicating less strength [HR, per-point-increase: 0.946 (95% CI 0.928-0.968), p = 0.001], and abnormal CMAP, indicating nerve/muscle dysfunction [HR: 1.568 (95% CI 1.165-2.186), p = 0.004], independently associated with increased 5-year mortality. In the MRC&CMAP-cohort, MRC [HR: 0.956 (95% CI 0.934-0.980), p = 0.001] but not CMAP [HR: 1.478 (95% CI 0.875-2.838), p = 0.088] independently associated with 5-year mortality. Among 205 survivors, low MRC independently associated with low HGF [0.866 (95% CI 0.237-1.527), p = 0.004], low 6-MWD [105.1 (95% CI 12.1-212.9), p = 0.043] and low PF-SF-36 [- 0.119 (95% CI - 0.186 to - 0.057), p = 0.002], whereas abnormal CMAP did not correlate with these morbidity endpoints. Exploratory analyses suggested that MRC ≤ 55 best predicted poor long-term morbidity and mortality. Both MRC ≤ 55 and abnormal CMAP independently associated with 5-year mortality. CONCLUSIONS: ICU-acquired neuromuscular complications may impact 5-year morbidity and mortality. MRC sum score, even if slightly reduced, may affect long-term mortality, strength, functional capacity and physical function, whereas abnormal CMAP only related to long-term mortality. ispartof: INTENSIVE CARE MEDICINE vol:46 issue:6 pages:1184-1193 ispartof: location:United States status: published

Mieke Hulens,1 Ricky Rasschaert,2 Greet Vansant,3 Ingeborg Stalmans,4,5 Frans Bruyninckx,6 Wim Dankaerts1 1Department of Rehabilitation Sciences, Faculty of Kinesiology and Rehabilitation Sciences, Musculoskeletal Rehabilitation Research Unit, University of Leuven, Leuven, Belgium; 2Department of Neurosurgery, Sint-Jozefziekenhuis, Bornem, Belgium; 3Department of Social and Primary Health Care, Public Health Nutrition, University of Leuven, Leuven, Belgium; 4Department of Neurosciences, Ophthalmology Research Group, University of Leuven KU Leuven, Leuven, Belgium; 5Department of Ophthalmology, University Hospitals UZ Leuven, Leuven, Belgium; 6Clinical Electromyography Laboratory, Department of Academic Consultants, Faculty of Medicine, University Hospitals UZ Leuven, Leuven, Belgium Purpose: Idiopathic intracranial hypertension (IICH) is a condition characterized by raised intracranial pressure (ICP), and its diagnosis is established when the opening pressure measured during a lumbar puncture is elevated >20 cm H2O in nonobese patients or >25 cm H2O in obese patients. Papilledema is caused by forced filling of the optic nerve sheath with cerebrospinal fluid (CSF). Other common but underappreciated symptoms of IICH are neck pain, back pain, and radicular pain in the arms and legs resulting from associated increased spinal pressure and forced filling of the spinal nerves with CSF. Widespread pain and also several other characteristics of IICH share notable similarities with characteristics of fibromyalgia (FM) and chronic fatigue syndrome (CFS), two overlapping chronic pain conditions. The aim of this review was to compare literature data regarding the characteristics of IICH, FM, and CFS and to link the shared data to an apparent underlying physiopathology, that is, increased ICP.Methods: Data in the literature regarding these three conditions were compared and linked to the hypothesis of the shared underlying physiopathology of increased cerebrospinal pressure.Results: The shared characteristics of IICH, FM, and CFS that can be caused by increased ICP include headaches, fatigue, cognitive impairment, loss of gray matter, involvement of cranial nerves, and overload of the lymphatic olfactory pathway. Increased pressure in the spinal canal and in peripheral nerve root sheaths causes widespread pain, weakness in the arms and legs, walking difficulties (ataxia), and bladder, bowel, and sphincter symptoms. Additionally, IICH, FM, and CFS are frequently associated with sympathetic overactivity symptoms and obesity. These conditions share a strong female predominance and are frequently associated with Ehlers-Danlos syndrome.Conclusion: IICH, FM, and CFS share a large variety of symptoms that might all be explained by the same pathophysiology of increased cerebrospinal pressure. Keywords: chronic pain, fatigue, headache, Ehlers-Danlos, sympathetic activity, lymphatic olfactory pathway, small fiber neuropathy, Ménière’s disease, Tarlov cysts

Fibromyalgia (FM) exhibits characteristics of a neurological disorder, and similarities have been identified between FM and idiopathic intracranial hypertension (IICH). When intracranial pressure rises, the drainage of excess cerebrospinal fluid (CSF) through the subarachnoid space of the cranial and spinal nerves increases. Higher CSF pressure irritates nerve fibers inside nerve root sheaths and may consequently cause radicular pain, as was reported in patients with IICH. Moreover, the cut-off of 20-25 cm H20 used to define IICH may be too high, as has been suggested in patients with chronic fatigue syndrome. We hypothesize that the neurological symptoms of FM are caused by the dysregulation of cerebrospinal pressure (CSP) and that spinal fluid drainage can relieve this pain. Exploring the processes underlying increased CSP may provide an alternative explanation for the generation of unexplained widespread pain (WSP) and FM as opposed to central sensitization. Additionally, when performing a lumbar puncture for diagnostic reasons, it is useful to measure opening pressure in patients with chronic WSP. ispartof: MEDICAL HYPOTHESES vol:118 pages:55-58 ispartof: location:United States status: published

Fibromyalgia (FM) is a debilitating, widespread pain disorder that is assumed to originate from inappropriate pain processing in the central nervous system. Psychological and behavioral factors are both believed to underlie the pathogenesis and complicate the treatment. This hypothesis, however, has not yet been sufficiently supported by scientific evidence and accumulating evidence supports a peripheral neurological origin of the symptoms. We postulate that FM and several unexplained widespread pain syndromes are caused by chronic postural idiopathic cerebrospinal hypertension. Thus, the symptoms originate from the filling of nerve root sleeves under high pressure with subsequent polyradiculopathy from the compression of the nerve root fibers (axons) inside the sleeves. Associated symptoms, such as bladder and bowel dysfunction, result from compression of the sacral nerve root fibers, and facial pain and paresthesia result from compression of the cranial nerve root fibers. Idiopathic Intracranial Hypertension, Normal Pressure Hydrocephalus and the clinical entity of symptomatic Tarlov cysts share similar central and peripheral neurological symptoms and are likely other manifestations of the same condition. The hypothesis presented in this article links the characteristics of fibromyalgia and unexplained widespread pain to cerebrospinal pressure dysregulation with support from scientific evidence and provides a conclusive explanation for the multitude of symptoms associated with fibromyalgia. ispartof: Medical Hypotheses vol:110 pages:150-154 status: published

Tarlov cysts (TCs) consist of dilated nerve root sheaths filled with cerebrospinal fluid (CSF) and are most frequently found in the sacrum. It is estimated that 25% of detected TCs cause chronic pain and intestinal and urogenital symptoms due to compression of the sacral nerve root fibers inside the TC. Unfortunately, symptomatic TCs are frequently overlooked. It is assumed that TCs result from pathologically increased hydrostatic pressure (HP) in the dural sac that forces CSF into the nerve root sheaths. We hypothesize that in patients with TCs, increased spinal hydrostatic pressure is always associated with increased intracranial pressure. This hypothesis of increased cerebrospinal pressure might explain why patients with sacral TCs frequently report distant symptoms, such as headaches and pain in the neck and arms. In this paper, we describe a case report that provides evidence for this hypothesis. A 30-year-old man presented for the first time in our clinic complaining of lower back, leg, thoracic, neck, and arm pain; headaches; and bladder, bowel, and sphincter symptoms. He was born prematurely and suffered cerebral intraventricular bleeding followed by progressive hydrocephalus. Progression was stabilized with acetazolamide and lumbar punctures. At 19 years of age, his head circumference had further increased and he reported back pain and headaches. Fundoscopy showed no papilledema, and lumbar puncture for CSF evacuation improved the headaches and back pain. The former medical team chose not to insert a ventriculo-external shunt. Brain magnetic resonance imaging (MRI) showed significant dilation of all the ventricles. No CSF flow obstruction between the ventricles was observed. Surprisingly, MRI of the lumbar and sacral spine showed multiple large TCs. This case report indicates that hydrocephalus with a patent aqueduct may be associated with TCs because the increased intracranial pressure is transferred to the spinal canal. While increased intracranial pressure causes dilation of the ventricles, the associated increased spinal pressure may cause dilation of multiple spinal nerve root sheaths to form TCs. Furthermore, while the increased volume of the ventricles gradually compresses the neurons and axons of the brain against the bony skull, simultaneously, the increased pressure inside the nerve sheaths may also gradually compress the neurons and axons located inside the dorsal root ganglia and spinal nerves, resulting in neuropathic pain, sensory abnormalities, and neurogenic bladder and bowel symptoms. Hydrocephalus patients reporting neuropathic pain should be screened for the presence of TCs. ispartof: Medical Hypotheses vol:130 ispartof: location:United States status: Published online

Introduction. During periacetabular osteotomy (PAO), the sciatic, femoral, and obturator nerves are at risk. Most frequently nerve lesions can be attributed to a mechanical cause; however, in the absence of a clear mechanical cause surgeons are faced with a diagnostic problem and in many cases no diagnosis will be established. We report a case of inflammatory neuropathy of the lumbosacral plexus following a PAO.Case Presentation.A 31-year-old female developed weakness of ankle and knee flexion and extension 6 months after a PAO. Electrophysiological studies revealed damage to the obturator, femoral, and sciatic nerve consistent with an inflammatory lumbosacral plexopathy. MRI of the lumbosacral plexus was normal. The patient was treated with multimodal pain therapy and prolonged physiotherapy; nevertheless, symptoms worsened over time. At 2-year follow-up, there were no signs of recovery.Discussion.Inflammatory neuropathy of the lumbosacral plexus is a potential cause of pain and weakness after ipsilateral orthopaedic procedures. It should be distinguished from more frequently encountered mechanical causes of postsurgical neuropathy based on clinical suspicion, electrophysiological studies, MRI, and nerve biopsy. It is important that the orthopaedic community is aware of this complication since there is some evidence that early recognition and initiation of immunosuppressive therapy can lead to improved clinical outcome.

Tarlov, or perineural cysts (TC) are commonly overlooked as a cause of sacroischialgia and urogenital and bowel problems. TC can be seen on MRI, but are often considered asymptomatic. This is especially true for smaller cysts. Moreover, there are only few diagnostic characteristics that can be used to confirm that the cysts are the cause of the symptoms. As a consequence, a lot of controversy remains regarding the clinical importance of TC. Because of this underdiagnosed condition, patients often suffer for several years from unrecognized chronic neuropathic pain and neurological conditions. In this paper, case reports of three patients with giant and smaller symptomatic sacral cysts are presented, in which electromyographic testing was performed in order to demonstrate nerve damage. We conclude that electromyography of the sacral nerve roots can be a reasonable tool for the diagnosis of symptomatic TC, as well as for the differentiation from other pathological entities causing sacroischialgia. Moreover, using electromyography it was also documented that smaller cysts of less than 1 cm can cause nerve damage. Therefore incidence of symptomatic TC may be higher than initially thought. ispartof: Pain Practice vol:16 issue:5 pages:E81-E88 ispartof: location:United States status: published

Background Critical illness polyneuropathy or myopathy (CIP/CIM) is a frequent complication in the intensive care unit (ICU) and is associated with prolonged mechanical ventilation, longer ICU stay and increased mortality. This is an interim update of a review first published in 2009 (Hermans 2009). It has been updated to October 2011, with further potentially eligible studies from a December 2013 search characterised as awaiting assessment. Objectives To systematically review the evidence from RCTs concerning the ability of any intervention to reduce the incidence of CIP or CIM in critically ill individuals. Search methods On 4 October 2011, we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE, and EMBASE. We checked the bibliographies of identified trials and contacted trial authors and experts in the field. We carried out an additional search of these databases on 6 December 2013 to identify recent studies. Selection criteria All randomised controlled trials (RCTs), examining the effect of any intervention on the incidence of CIP/CIM in people admitted to adult medical or surgical ICUs. The primary outcome was the incidence of CIP/CIM in ICU, based on electrophysiological or clinical examination. Secondary outcomes included duration of mechanical ventilation, duration of ICU stay, death at 30 and 180 days after ICU admission and serious adverse events from the treatment regimens. Data collection and analysis Two authors independently extracted the data and assessed the risk of bias in included studies. Main results We identified five trials that met our inclusion criteria. Two trials compared intensive insulin therapy (IIT) to conventional insulin therapy (CIT). IIT significantly reduced CIP/CIM in the screened (n = 825; risk ratio (RR) 0.65, 95% confidence interval (CI) 0.55 to 0.77) and total (n = 2748; RR 0.70, 95% CI 0.60 to 0.82) population randomised. IIT reduced duration of mechanical ventilation, ICU stay and 180-day mortality, but not 30-day mortality compared with CIT. Hypoglycaemia increased with IIT but did not cause early deaths.One trial compared corticosteroids with placebo (n = 180). The trial found no effect of treatment on CIP/CIM (RR 1.27, 95% CI 0.77 to 2.08), 180-day mortality, new infections, glycaemia at day seven, or episodes of pneumonia, but did show a reduction of new shock events.In the fourth trial, early physical therapy reduced CIP/CIM in 82/104 evaluable participants in ICU (RR 0.62. 95% CI 0.39 to 0.96). Statistical significance was lost when we performed a full intention-to-treat analysis (RR 0.81, 95% CI 0.60 to 1.08). Duration of mechanical ventilation but not ICU stay was significantly shorter in the intervention group. Hospital mortality was not affected but 30- and 180-day mortality results were not available. No adverse effects were noticed.The last trial found a reduced incidence of CIP/CIM in 52 evaluable participants out of a total of 140 who were randomised to electrical muscle stimulation (EMS) versus no stimulation (RR 0.32, 95% CI 0.10 to 1.01). These data were prone to bias due to imbalances between treatment groups in this subgroup of participants. After we imputed missing data and performed an intention-to-treat analysis, there was still no significant effect (RR 0.94, 95% CI 0.78 to 1.15). The investigators found no effect on duration of mechanical ventilation and noted no difference in ICU mortality, but did not report 30- and 180-day mortality.We updated the searches in December 2013 and identified nine potentially eligible studies that will be assessed for inclusion in the next update of the review. Authors' conclusions There is moderate quality evidence from two large trials that intensive insulin therapy reduces CIP/CIM, and high quality evidence that it reduces duration of mechanical ventilation, ICU stay and 180-day mortality, at the expense of hypoglycaemia. Consequences and prevention of hypoglycaemia need further study. There is moderate quality evidence which suggests no effect of corticosteroids on CIP/CIM and high quality evidence that steroids do not affect secondary outcomes, except for fewer new shock episodes. Moderate quality evidence suggests a potential benefit of early rehabilitation on CIP/CIM which is accompanied by a shorter duration of mechanical ventilation but without an effect on ICU stay. Very low quality evidence suggests no effect of EMS, although data are prone to bias. Strict diagnostic criteria for CIP/CIM are urgently needed for research purposes. Large RCTs need to be conducted to further explore the role of early rehabilitation and EMS and to develop new preventive strategies.

PURPOSE: Muscle weakness in long-stay ICU patients contributes to 1-year mortality. Whether electrophysiological screening is an alternative diagnostic tool in unconscious/uncooperative patients remains unknown. We aimed to determine the diagnostic properties of abnormal compound muscle action potential (CMAP), sensory nerve action potential (SNAP), and spontaneous electrical activity (SEA) for Medical Research Council (MRC)-defined weakness and their predictive value for 1-year mortality. METHODS: Data were prospectively collected during the EPaNIC trial (ClinicalTrials.gov: NCT00512122). First, sensitivity, specificity, positive (PPV) and negative predictive values (NPV) of abnormal CMAP, SNAP, and SEA for weakness were determined. Subsequently, association between 1-year mortality and abnormal findings on electrophysiological screening was assessed by univariate and multivariate analyses correcting for weakness and other risk factors and the prediction model involved only a development phase. RESULTS: A total of 730 patients were electrophysiologically screened of whom 432 were tested for weakness. On day 8, normal CMAP excluded weakness with a high NPV (80.5 %). By day 15, abnormal SNAP and the presence of SEA had a high PPV (91.7 and 80.0 %, respectively). Only a reduced CMAP on day 8 was associated with higher 1-year mortality [35.6 vs 15.2 % (p < 0.001)]. This association remained significant after correction for weakness and other risk factors [OR 2.463 (95 % CI 1.113-5.452), p = 0.026]. Also among conscious/cooperative patients without weakness, reduced CMAP was independently associated with a higher likelihood of death occurring during 1 year [HR 2.818 (95 % CI 1.074-7.391), p = 0.035]. CONCLUSIONS: The diagnostic properties of electrophysiological screening vary over time. Abnormal CMAP documented early during critical illness carries information about longer-term outcome, which should be further investigated mechanistically. ispartof: INTENSIVE CARE MEDICINE vol:41 issue:12 pages:2138-2148 ispartof: location:United States status: published