Spinal Cord Decompression Sickness Research Articles

Therapeutic management of severe spinal cord decompression sickness in a hyperbaric center.

Spinal cord decompression sickness (scDCS) unfortunately has a high rate of long-term sequelae. The purpose of this study was to determine the best therapeutic management in a hyperbaric center and, in particular, the influence of hyperbaric treatment performed according to tables at 4 atm (Comex 30) or 2.8 atm abs (USNT5 or T6 equivalent). This was a retrospective study that included scDCS with objective sensory or motor deficit affecting the limbs and/or sphincter impairment seen at a single hyperbaric center from 2010 to 2020. Information on dive, time to recompression, and in-hospital management (hyperbaric and medical treatments such as lidocaine) were analyzed as predictor variables, as well as initial clinical severity and clinical deterioration in the first 24 h after initial recompression. The primary endpoint was the presence or absence of sequelae at discharge as assessed by the modified Japanese Orthopaedic Association score. 102 divers (52 ± 16 years, 20 female) were included. In multivariate analysis, high initial clinical severity, deterioration in the first 24 h, and recompression tables at 4 atm versus 2.8 atm abs for both initial and additional recompression were associated with incomplete neurological recovery. Analysis of covariance comparing the effect of initial tables at 2.8 versus 4 atm abs as a function of initial clinical severity showed a significantly lower level of sequelae with tables at 2.8 atm. In studying correlations between exposure times to maximum or cumulative O2 dose and the degree of sequelae, the optimal initial treatment appears to be a balance between administration of a high partial pressure of O2 (2.8 atm) and a limited exposure duration that does not result in pulmonary oxygen toxicity. Further analysis suggests that additional tables in the first 24-48 h at 2.8 atm abs with a Heliox mixture may be beneficial, while the use of lidocaine does not appear to be relevant. Our study shows that the risk of sequelae is related not only to initial severity but also to clinical deterioration in the first 24 h, suggesting the activation of biological cascades that can be mitigated by well-adapted initial and complementary hyperbaric treatment.

Hyperbaric treatment deviations for U.S. Navy divers: Spinal DCS

Introduction The United States Navy (USN) developed and refined standardized oxygen treatment tables for diving injuries, but USN tables may not address all situations of spinal decompression sickness (DCS). We describe a detailed recompression treatment regimen that deviated from standard USN protocol for an active-duty USN diver with a severe, delayed presentation of spinal cord DCS. Case Report A USN diver surfaced from his second of three dives on a standard Navy ‘no-Decompression’ Air SCUBA dive (Max depth 101 fsw utilizing a Navy Dive Computer) and developed mid-thoracic back pain, intense nausea, paresthesias of bilateral feet, and penile erection. Either not recognizing the constellation of symptoms as DCS and after resolution of the aforementioned symptoms, he completed the third planned dive (essentially an in-water recompression). Several hours later, he developed paresthesias and numbness of bilateral feet and legs and bowel incontinence. He presented for hyperbaric treatment twenty hours after surfacing from the final dive and was diagnosed with severe spinal DCS. Based on the severity of clinical presentation and delay to treatment, the initial and follow-on treatments were modified from standard USN protocol. MRI of the spine four days after initial presentation demonstrated a 2∙2 cm lesion at the T4 vertebral level extending caudally. Follow-up examinations over two years demonstrated almost complete return of motor and sensory function; however, the patient continued to suffer fecal incontinence and demonstrated an abnormal post-void residual urinary volume. An atypical presenting symptom, a discussion of MRI findings, and clinical correlations to the syndrome of spinal DCS are discussed throughout treatment and long-term recovery of the patient.

Influence of prehospital management on the outcome of spinal cord decompression sickness in scuba divers

BackgroundDecompression sickness (DCS) with spinal cord involvement has an unfortunately high rate of long-term sequelae. The objective of this study was to determine the association of prehospital variables on the...

F102. The influence of initial tibial somatosensory evoked potentials as a prognostic factor in spinal cord decompression sickness

Introduction Somatosensory evoked potentials (SSEPs) are the electrical potentials generated in sensory pathways at peripheral, spinal, subcortical and cortical levels of the nervous system. This study aims to determine tibial SSEPs as the potential risk or prognostic factor associated with the development of severe diving-related spinal cord DCS. Methods 68 injured divers(abnormal tibial SSEPs n = 34, normal tibial SSEPs n = 34) presenting symptoms of spinal cord DCS were retrospectively included from Seoul Medical Center. Diving information, time interval between symptom onset and hyperbaric treatment were studied. The initial severity of spinal cord DCS was rated with the Boussuges severity score and muscle power examination and the presence of sequelae was evaluated at 2 weeks. The tables used in the initial treatment for spinal cord DCS included US navy table6 or table6a. Results There were no significant differences between each treatment group in age, diving experience, depth of dive. bottom time of dive, onset to treatment, Boussuges’s score and the grade of motor power before the treatment. The motor power improvements of DCS patients with normal tibial SSEPs were more frequently occurred compared to those with abnormal tibial SSEPs (58.9% vs 35.3%, p = 0.029). Conclusion Initial tibial SSEPs might be useful prognostic factor in spinal cord DCS.

Relationship between clinical and radiologic findings of spinal cord injury in decompression sickness.

Decompression sickness may involve the central nervous system. The most common site is spinal cord. This study was conducted to determine the relationship between magnetic resonance(MR) imaging findings of spinal damage. We conducted a retrospective review of 12 patients (male=10, female=2) who presented with spinal cord symptoms. We investigated their clinical features, neurological findings and radiologic findings. The depth and bottom time of the dive were 34.5 meters (range 22-56) and 22.7 minutes (range 10-55) respectively. Most divers ascended within appropriate time frame as shown by the decompression tables. The most frequent initial symptoms were lower limb weakness (n=12), followed by sensory disturbances (n=10) and bladder dysfuction (n=5). The chief radiologic abnormalities were continuous (n=3), or non-continuous (n=5) high-signal intensity on T2-weighted images at posterior paramedian portion of the spinal cord, mainly thoracic level. There were no abnormal findings in the remaining four (4) patients, and they showed good prognosis. All patients were treated with hyperbaric oxygen therapy and some received high-dose dexamethasone. On discharge, five (5) patients had made a full recovery, seven (7) had some residual neurological sequelae, and all patients except one (1) regained normal bladder function. Spinal cord decompression sickness is a neurological emergency. Early recognition and treatment may minimize neurological damage. Initial normal finding in MR imaging was a good predictor for prognosis in spinal decompression sickness.

Clinical characterization and treatment of acute spinal cord decompression sickness after repeated dives

To analyze and summarize the characteristics and treatment of acute spinal cord decompression sickness. To explore the factors that influence the treatment effect. 77 cases of acute spinal cord decompression sickness patients should be divided into 4 groups according to the pressurized treatment and drug treatment options. They were group I, group II, group III and group IV. At the same time they were get hyperbaric oxygen therapy and other treatment. The evaluation index, were Frankel function classification and paraplegia index. There were 17 factors that affected the treatment effect. The rate of early cure was 57.14% (44/77). The rate of late cure was 74.03% (57/77). Their difference was statistically significant (P<0.05). In 3 months and 1 year the cure rate of group IV and group B were the highest. But there was no difference between them(P>0.05). They were higher than group ii and group I (P<0.05). The Frankel function classification in 3months and 1 year in each group was higher than before treatment (P<0.05). The paraplegia index in 3 months and 1 year in each group was lower than before treatment (P<0.05). In 3 months and 1 year the Frankel function classification was increased gradually and the paraplegia index was decreased gradually in group I , group II, group III (P<0.05). In group IV and group III the Frankel function and the paraplegia index had not significant difference (P>0.05). Among the 17 factors that affect the treatment effect there are 9 factors that affect the proportion of the large. The first choice of treatment method for the patients with acute spinal cord decompression sickness would be group III. Drug therapy was also imporpant. At the same time the hyperbaric oxygen therapy and other treatments were taken. Although the cure rate was not high in this article. But most of the cure is within 3 months. Within 1 year.the cure rate still could be improved. 9 factors that affect the efficacy of acute spinal cord decompression sickness was more noteworthy.

Gene expression profile of type II spinal cord decompression sickness.

This study was an experimental, controlled, animal study. This study was to determine the changes of molecular pathology in spinal cord decompression sickness (SC-DCS) based on a rabbit model of SC-DCS with the aid of an all-gene expression profile chip. Qingdao, Shandong Province, China. A gene expression profile chip containing 43 803 genes was used to compare the gene expressions in the spinal cords of four male New Zealand white rabbits in the SC-DCS and control groups, respectively. Selected differentially expressed genes were identified with quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry. The chip hybridization results showed that the SC-DCS group had nine upregulated and seventeen downregulated genes, compared with the control group. These genes were mainly related to inflammation, ion channels, the cell cycle, material transfer and apoptosis. The qRT-PCR results showed that parathyroid hormone and tumor necrosis factor alpha (TNF-α) genes were upregulated compared with the control group (P<0.01). However, the acyl-CoA synthetase and voltage-gated channel genes were downregulated (P<0.05). The immunohistochemical staining results confirmed that there were significantly greater expression levels of TNF-α in the spinal cord tissues of the SC-DCS group compared with the control group. The spinal cord lesions of SC-DCS involve multiple gene changes in the rabbit; however, the significance of these findings needs further research. Meanwhile, the gene expression profile chip results provide us with a better understanding of the pathogenesis of DCS.

Relation between cervical and thoracic spinal canal stenosis and the development of spinal cord decompression sickness in recreational scuba divers

Retrospective case-control study. The intent of this study was to investigate the relationships between vertebral degenerative changes resulting in spinal canal stenosis, spinal cord lesions and the development of spinal cord decompression sickness (DCS) in scuba divers. Referral hyperbaric facility, Toulon, France. We examined 33 injured divers less than 50 years old by cervical and thoracic MRI and compared them with 34 matched control divers. The number of intervertebral disk abnormalities and the degree of canal compression were analyzed on T2-weighted sagittal images using a validated grading system developed recently. The presence and the distribution of hyperintense cord lesions in relation with the accident and the recovery status at 6 months were also assessed. Canal spinal narrowing was more common in injured divers than in controls (79% vs. 50%, OR=3.7 [95% CI, 1.3-10.8], P=0.021). We found a significant linear association between the extent of canal stenosis, multisegmental findings and the development of spinal cord decompression sickness. MRI intramedullary lesions were significantly more frequent in divers with incomplete recovery (OR=16 [95% CI, 2.6-99], P=0.0014), but statistical analysis failed to demonstrate a significant relationship between canal compression, signal cord abnormalities and a negative clinical outcome. These results suggest that divers with cervical and thoracic spinal canal stenosis, mainly due to disk degeneration, are at increased risk for the occurrence of spinal cord decompression sickness.

MRI in spinal cord decompression sickness

Spinal cord decompression sickness (DCS) is a rare condition that can lead to spinal cord infarction. Despite the low incidence of diving-related DCS, we have managed to collect the data and MRI findings of seven patients who have been diagnosed with and treated for DCS in our local hyperbaric facility. This study describes the clinical presentation, MRI spinal cord findings, treatment administered and outcome of these patients. The patient medical records, from 1997 to 2007, were retrospectively reviewed. All patients with a final diagnosis of DCS and who underwent examination were included. The images were independently reviewed by two radiologists who recorded the location and number of lesions within the spinal cord. The Frankel grading was used to assess the initial and clinical outcome response. Patchy-increased T2W changes affecting several levels at the same time were found. Contrary to the popular notion that venous infarction is the leading cause of DCS, most of our patients also demonstrated affliction of grey matter, which is typically seen in an arterial pattern of infarction. Initial involvement of multiple (>6) spinal cord levels was associated with a poor outcome. Patients who continued to have multiple neurological sequelae with less than 50% resolution of symptoms despite recompression treatment were also those who had onset of symptoms within 30 min of resurfacing. DCS is probably a combination of both arterial and venous infarction. Short latency to the onset of neurological symptoms and multilevel cord involvement may be associated with a poorer outcome.

Prognostic Factors of Spinal Cord Decompression Sickness in Recreational Diving: Retrospective and Multicentric Analysis of 279 Cases

This study aims to determine the potential risk factors associated with the development of severe diving-related spinal cord decompression sickness (DCS). Two hundred and seventy nine injured recreational divers (42 ± 12 years; 53 women) presenting symptoms of spinal cord DCS were retrospectively included from seven hyperbaric centers in France and Belgium. Diving information, symptom latency after surfacing, time interval between symptom onset and hyperbaric treatment were studied. The initial severity of spinal cord DCS was rated with the Boussuges severity score, and the presence of sequelae was evaluated at 1 month. Initial recompression treatment at 2.8 ATA with 100% oxygen breathing or deeper recompression up to 4 or 6 ATA with nitrogen or helium-oxygen breathing mixture were also recorded. Twenty six percent of DCS had incomplete resolution after 1 month. Multivariate analysis revealed several independent factors associated with a bad recovery: age ≥ 42 [OR 1.04 (1-1.07)], depth ≥ 39 m [OR 1.04 (1-1.07)], bladder dysfunction [OR 3.8 (1.3-11.15)], persistence or worsening of clinical symptoms before recompression [OR 2.07 (1.23-3.48)], and a Boussuges severity score >7 [OR 1.16 (1.03-1.31)]. However, the time to recompression and the choice of initial hyperbaric procedure did not significantly influence recovery after statistical adjustment. Clinical symptoms of spinal cord DCS and their initial course before admission to the hyperbaric center should be considered as major prognostic factors in recovery. A new severity score is proposed to optimize the initial clinical evaluation for spinal cord DCS.

Prise en charge des accidents de décompression médullaire en plongée sous-marine : actualités en 2010

The outcome of spinal cord decompression sickness after scuba diving is unpredictable during the 24 first hours with a high risk of incomplete recovery. The treatment is defined on first aid normobaric oxygen when neurological symptoms occur, rehydration and prompt recompression in hyperbaric chamber. The presence of initial motor impairment, the aggravation of symptoms during the transfer to the hyperbaric facility and the emergence of sphincter dysfunction are predictive of poor prognosis whatever the treatment undertaken.

Neurological Symptoms After a Provocative Dive: Spinal DCS or Anterior Spinal Artery Syndrome?

Reported here is a 37-yr-old professional diving instructor who had developed complaints of back pain and weakness in the lower extremities after diving. He was eventually diagnosed as having spinal cord decompression sickness along with a likely diagnosis of anterior spinal artery (artery of Adamkiewicz) syndrome. Additionally, since the transthoracic echocardiography revealed patent foramen ovale, we hypothesized that it might have been a potential route for gas bubbles to occlude the anterior spinal artery in this diver.

Risk factors and treatment outcome in scuba divers with spinal cord decompression sickness

Purpose This study was designed to determine the recompression strategy and the potential risk factors associated with the development of severe diving-related spinal cord decompression sickness (DCS). Material and Methods Sixty-three injured recreational divers (52 men and 11 women; 46 ± 12 years) presenting with symptoms of spinal involvement were retrospectively included. Diving information, symptom latency after dive completion, and time interval between symptom onset and hyperbaric treatment were studied. The severity of spinal cord DCS was rated numerically for both the acute event and 1-month later. Initial recompression treatment at 2.8 atmosphere absolute (ATA) with 100% oxygen breathing or deeper recompression at 4 atmosphere absolute with nitrogen-oxygen or helium-oxygen breathing mixture was also noted. Results Twenty-one divers (33%) had incomplete resolution after 1 month. The clinical severity at presentation was the only independent predictor of poor outcome (odd ratio, 2.68; P < .033). Time to treatment did not influence the recovery with a similar median delay (3 hours) between the divers with or without long-term sequelae. Choice of recompression procedure was not also a determinant factor for treatment outcome. Conclusion The initial clinical course before treatment is a major prognostic factor of spinal cord DCS. Delay to recompression less than 3 hours and use of deep treatment tables did not improve outcome in DCS divers.

MRI Findings and Clinical Outcome in 45 Divers with Spinal Cord Decompression Sickness

Decompression sickness (DCS) affecting the spinal cord is the most dangerous form of diving-related injury with potential sequelae. This study was conducted to evaluate the relationship between spinal cord lesions on MRI and clinical findings in divers with spinal DCS. We studied 45 cases of DCS that were referred to our hyperbaric facility with clinical evidence of spinal involvement during the period 2002-2007. The study included only patients who underwent MRI within 10 d of injury. The severity of spinal DCS for each patient was rated numerically for both the acute event and 1 mo later. The presence or absence of back pain was also noted. Spinal cord lesions were significantly more frequent in divers with severe DCS, and did not occur in any diver who experienced a favorable outcome (sensitivity = 67%, specificity = 100%, negative predictive value = 77%, positive predictive value = 100%). The presence of vertebral degenerative changes that impinged on the spinal cord was strongly associated with MRI abnormalities, but not with a negative outcome. Acute back pain was associated with hyperintense lesions and persistence of neurological sequelae [OR = 14 (95% CI, 3.1 to 63.5)]. The results show that MRI could be helpful in predicting clinical outcome in divers with spinal cord DCS. The presence of medullary compressive factors and vertebral back pain after surfacing indicate increased likelihood of severe myelopathy with incomplete recovery.

Relation Between Right-to-Left Shunts and Spinal Cord Decompression Sickness in Divers

The role of right-to-left shunting (RLS) in spinal cord decompression sickness (DCS) remains uncertain and could differ according to the distribution of lesion in spinal cord with a higher risk of upper spinal cord involvement in divers presenting a large patent foramen ovale. The aims of this study were to assess the prevalence of RLS with transcranial doppler ultrasonography in 49 divers referred for spinal cord DCS and compare it with the prevalence of RLS in 49 diving controls, and to determine a potential relation between RLS and lesion site of spinal cord. The proportion of large RLS was greater in DCS divers than in healthy control divers (odds ratio, 3.6 [95 % CI, 1.3 to 9.5]; p = 0.017). Shunting was not associated with the increased incidence of cervical spinal cord DCS (OR, 1.1 [95 % CI, 0.3 to 3.9]; p = 0.9) while a significant relationship between large RLS and spinal cord DCS with thoracolumbar involvement was demonstrated (OR, 6.9 [95 % CI, 2.3 to 20.4]; p < 0.001). From the above results, we conclude that the risk of spinal cord DCS in divers with hemodynamically relevant RLS is higher than in divers without RLS, particularly in their lower localization.

MRI diagnosis of acute spinal cord decompression sickness

Objective To describe MRI findings of acute spinal cord decompression sickness.Methods MRI findings of 5 cases with clinical definite acute spinal cord decompression sickness were retrospectively analyzed.The main clinical informations included underwater performance history against regulations,short-term complete or incomplete spinal cord injury symptoms after fast going out of water,sensory disability and urinary and fecal incontinence,etc.Results Spinal cord vacuole sign was found in all 5 cases.Iso-signal intensity(n=3),high signal intensity(n=1),and low signal intensity (n=1)was demonstrated on T1 WI,and high signal intensity(n=5)was found on T2 WI.Owl eye sign was detected in 3 cases,and lacune foci were seen in 2 cases.Conclusion MRI findings of acute spinal cord decompression sickness had some characteristics,and it was easy to diagnose by combining diving history with clinical manifestations. Key words: Spinal cord diseases; Decompression sickness; Magnetic resonance imaging

Spinal cord decompression sickness associated with scuba diving: correlation of immediate and delayed magnetic resonance imaging findings with severity of neurologic impairment—a report on 3 cases

Background There are few reports detailing an association between immediate and delayed changes in MR imaging findings and severity of neurologic impairment in patients with spinal cord DCS. We report on the cases of 3 patients diagnosed with spinal cord DCS presenting with severe neurologic symptoms after scuba diving. Case Description Of 175 patients with DCS referred to the Tokyo Metropolitan Ebara Hospital Department of Neurosurgery, 3 were determined by MR imaging and neurologic examination to have a spinal cord injury. Hyperbaric oxygen, methylprednisolone, and rehabilitation therapies were applied to these patients. We examined whether the severity of the patients' neurologic dysfunction, classified according to Fränkel's grade, was associated with the extent of abnormal signals depicted by spinal MR imaging in these patients at the acute phase and monthly follow-up points. T2-weighted MR imaging performed within 24 hours of the onset of the patients' neurologic symptoms revealed signals of increased intensity located predominantly in the dorsolateral regions, involving spinal segments 1 through 4, and a neurologic examination upon admission revealed severe sensory and motor dysfunction (Fränkel's grade A) in all 3 patients. The abnormal signals on MR images at 1 month postinjury were markedly decreased in size as compared with those at the acute phase. However, neurologic function showed minimal or no improvement (Fränkel's grade A or B). Conclusion In patients with spinal cord DCS, the improvement in MR imaging findings was not associated with improved clinical status. This discrepancy suggests that intricate pathophysiologic changes, reversible and persistent damage subsequent to initial cord injuries (ie, edematous and neurotoxic lesions), underlie the disease and affect the clinical course.

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Helium-oxygen therapy in the emergency department

Helium is an inert gas with unique physical properties that allow it to be used for various respiratory emergencies. Because of its low specific gravity and low viscosity, the passage of helium through the respiratory tract is smoother, more laminar, and less turbulent than either air or oxygen. These properties have prompted the use of helium and oxygen in patients with airway obstructions due to tumor, foreign body, edema, or bronchoconstriction. Helium-oxygen has been used to facilitate bronchoscopy through small diameter endotracheal tubes and to increase the effectiveness of high-frequency jet ventilation. Helium has been successful in the treatment of spinal cord decompression sickness seen in divers. Helium-oxygen mixtures are commercially available and may be useful in the emergency department to treat patients with airway obstruction. This article reviews literature concerning the use of helium-oxygen gas mixtures in the emergency department. Additional research conducted in the future may further define the use of this unique gas mixture in the emergency department.

Assessment of spinal cord trauma using evoked potentials in a rat model of decompression sickness

A rapid quantitative technique for assessing spinal cord trauma in a rat model of decompression sickness is described. Evoked potentials are measured from the lower limbs of rats before and after dives with compressed air in a hyperbaric chamber. Under chloral hydrate anesthesia, the sciatic nerve is stimulated at the sciatic notch with needle electrodes and platinum/iridium electrodes are used to record the action potentials from the plantar muscles. Analysis showed that the sensory reflex response was markedly depressed in the rats soon after diving and did not recover for up to 5 days. The motor response was similarly affected although to a lesser degree. The latency of the reflex response also became prolonged after 3 days. The significant and complex pattern of neurological dysfunction shown by this electrophysiologic technique validates the use of the rat model for the study of spinal cord decompression sickness. This technique should aid studies aimed at testing new therapies for this disease.