Severity Of Nerve Damage Research Articles

Evaluation of peripheral nerve injury according to the severity of damage using 18F-FDG PET/MRI in a rat Model of sciatic nerve injury

ABSTRACT Objectives We ascertained that the PET scan may be a valuable imaging modality for the noninvasive, objective diagnosis of neuropathic pain caused by peripheral nerve injury through the previous study. This study aimed to assess peripheral nerve damage according to severity using18F-FDG PET/MRI of the rat sciatic nerve. Methods Eighteen rats were divided into three groups: 30-second (G1), 2-minute (G2), and 5-minute (G3) crushing injuries. The severity of nerve damage was measured in the third week after the crushing injury using three methods: the paw withdrawal threshold test (RevWT), standardized uptake values on PET (SUVR), and intensity analysis on immunohistochemistry (IntR). Results There were significant differences between G1 and G3 in both SUVR and IntR (p = 0.012 and 0.029, respectively), and no significant differences in RevWT among the three groups (p = 0.438). There was a significant difference in SUVR (p = 0.012), but no significant difference in IntR between G1 and G2 (p = 0.202). There was no significant difference between G2 and G3 in SUVR and IntR (p = 0.810 and 0.544, respectively). Discussion Although PET did not show results consistent with those of immunohistochemistry in all respects, this study demonstrated that PET uptake tended to increase with severe nerve damage. If this research is supplemented by further experiments, PET/MRI can be used as an effective diagnostic modality.

Diagnostic Relevance of Electromyographic Values and their Role in Forecasting the Conservative Treatment in Patients with Carpal Tunnel Syndrome

Summary. Instrumental investigation and electromyography (EMG), one of the most widespread and informative of its methods, still remains widely used for differentiated diagnostics with any other disorder, compressive-ishemic focal neuropathy (CIFN) of the median nerve (MN) ) at the level of the carpal tunnel (CT) diagnosis verification and determination of the severity of damage to the MN. The clinical diagnosis of this pathologyis better know as carpal tunnel syndrome (CTS). Objective: To study the diagnostic relevance of electromyographic values in the Ukrainian population of CTS patients and their role in forecasting the efficiency of conservative treatment of this disorder.
 Materials and methods: 128 patients (204 extremities) with the clinical signs of CTS, who formed the Main Group (MG) underwent electromyography (EMG). The mean age of the patients was 58.2±12.5 years old; among them were 105 (82 %) women and 23 (18 %) men; 77 persons with a bilateral and 51 with a unilateral process. The control group (CG) included 30 volunteers (54 extremities) without any claims and signs of neurological symptoms. The mean age was 45.1±7.8 years old; among them were 23 (77.6%) women and 7 (23,3%) men. To determine the EMG predictors of the effectiveness of clinical outcomes after paraneural corticosteroid injection (PCI) 58 extremities MG were examined.For the EMG examination, we used the «Viking Quest» machine by Nicollet, the USA. Applying relevant methods, we investigated the following: median motor distal latency (DMLm) and CMAP of M. abductor pollicis brevis (APB); median sensory distal onset (MOL-D2), median sensory distal peak latency (MPL-D2), median SNAP amplitude digit 2, median sensory conduction velocity between wrist and digit 2 (mSNCV); difference in median sensory onset latency (digit 1) (MSL-D1) to radial sensory onset latency (digit 1) (RSL-D1) – MD1-RD1; difference in median nerve distal motor latency (2nd lumbrical)to the ulnar nerve distal motor latency (2nd interossei) – 2LI-DML; interrelation of the amplitudes of CMAP APB obtained by the stimulation of the MN on the level of the lower third of forearm to the amplitude of CMAP APB – on the level of the lower third of a palm (wrist to palm amplitude ratio); the sensory ulnar nerve conduction velocity (uSNCV).
 Results: The analysis of mean values of the core EMG values has demonstrated the significant differences between MG and CG, with different directions of changes, typical of the CTS. Relying on the data collected while studying people from the CG (the discovered referential and abnormal values) and the ROC analysis, we have established the sensitivity and specificity of EMG values: DMLm – 73.5% and 96.3%; MPL-D2 – 81.9% and 100%; mSNCV– 93.9% and 100%; MD1-RD1 – 62.5% and 100%; MSL-D1– 83.3% and 96.9%; 2LI-DML – 88.2% and 100%, respectively (AUC=0,91-0.96). Based on the results of the ROC analysis, determined that the most prognostically significant EMG predictor of clinical outcome after PCI was median SNAP amplitude digit 2 (sensitivity 90,9% and specificity 92%, AUC=0,95.
 Conclusions: The EMG is the objective and informative method to diagnose CIFN of the MN at the level of the CT, severity of nerve damage in CTS patients and predicting of clinical outcome after PCI.

Inhibitory effect of parthenolide on peripheral nerve degeneration.

Traumatic axonal damage disrupts connections between neurons, leading to the loss of motor and sensory functions. Although damaged peripheral nerves can regenerate, recovery depends on the variety and severity of nerve damage. Thus, many phytochemicals have been studied for their ability to reduce peripheral nerve degeneration, and among them, Parthenolide (PTL), which is extracted from Feverfew has effects against production of free radicals, inflammation, and apoptosis. Thus, we conducted a study to investigate whether PTL has an inhibitory effect on peripheral nerve degeneration during peripheral nerve damage. To verify the effect of PTL on peripheral nerve degeneration process, a morphological comparison of peripheral nerves with and without PTL was performed. PTL significantly reduced the quantity of fragmented ovoid formations at 3DIV (days in vitro). Immunostaining for MBP revealed that the ratio of intact myelin sheaths increased significantly in sciatic nerve with PTL compared with absence of PTL at 3DIV. Furthermore, nerve fibers in the presence of PTL maintained the continuity of Neurofilament (NF) compared to those without at 3DIV. Immunostaining for LAMP1 and p75 NTR showed that the expression of LAMP1 and p75 NTR decreased in the nerve after PTL addition at 3DIV. Lastly, immunostaining for anti-Ki67 revealed that PTL inhibited Ki67 expression at 3DIV compared to without PTL. These results confirm that PTL inhibits peripheral nerve degenerative processes. PTL may be a good applicant to inhibit peripheral nerve degeneration. Our study examined the effect of Parthenolide in preventing degeneration of peripheral nerves by inhibiting the breakdown of peripheral axons and myelin, also inhibiting Schwann cell trans-dedifferentiation and proliferation.

P‑hydroxybenzyl alcohol ameliorates neuronal cerebral ischemia‑reperfusion injury by activating mitochondrial autophagy through SIRT1.

Mitochondrial autophagy serves a key role in clearing damaged mitochondria. P‑hydroxybenzyl alcohol (pHBA) can improve neuronal injury induced by cerebral ischemia‑reperfusion (I/R). However, the mechanism of pHBA improving I/R damage through the mitochondrial pathway remains unclear. A rat model of middle cerebral artery occlusion and reperfusion (MCAO/R) was used in the present study. The rats were treated with sirtuin 1 (SIRT1) inhibitor EX527 and pHBA for 7 days, followed by reperfusion. At 24h after reperfusion, the infarct size was calculated and the severity of nerve damage was evaluated. Hematoxylin and eosin and Nissl staining revealed cellular changes in the ischemic penumbra. Changes in mitochondrial structure were observed using electron microscopy. Mitochondrial function was evaluated by detecting mitochondrial membrane potential (MMP), mitochondrial permeability transition pore (mPTP) and ATP levels using commercially available kits. In addition, the ischemic penumbra tissues were used for immunofluorescence staining for p62 and LC3 proteins. The expression of SIRT1 and mitochondrial autophagy‑related proteins, PTEN‑induced kinase 1 (PINK1) and Parkin, were detected by western blotting. Finally, apoptosis was analyzed by TUNEL staining and the expression of apoptosis‑related proteins (Bax, Bcl‑2 and Caspase‑3) by western blotting. The results suggested that postoperative pHBA treatment may reduce the size of cerebral infarction and damage to the nervous system, and may improve cell damage in the ischemic penumbra of MCAO/R rats. Compared with rats in the untreated MCAO/R group, the mitochondrial structure of the pHBA‑treated group was improved, the levels of MMP and ATP were increased, and the degree of opening of mPTP was decreased. Simultaneously, immunofluorescence and western blotting results showed that compared with the MCAO/R group, the number of LC3‑ and TUNEL‑positive cells increased, the number of p62‑positive cells decreased, SIRT1 and autophagy protein (PINK1, Parkin and LC3 II/I) expression levels increased and p62 expression decreased in the pHBA group. However, these improvements were blocked by treatment with EX527. In summary, results from the present study suggested that pHBA may improve neuronal injury in the ischemic penumbra of MCAO/R rats through SIRT1‑activated mitochondrial autophagy and mitochondrial‑mediated neuronal apoptosis.

Imaging Review of Peripheral Nerve Injuries in Patients with COVID-19

With surging numbers of coronavirus disease 2019 (COVID-19) patients throughout the world, neuromuscular complications and rehabilitation concerns are becoming more apparent. Peripheral nerve injury can occur in COVID-19 patients secondary to post-infectious inflammatory neuropathy, prone positioning-related stretch/compression injury, systemic neuropathy, or nerve entrapment from hematoma. Imaging of peripheral nerves in COVID-19 patients may help characterize nerve pathology, identify site and severity of nerve damage, and potentially elucidate mechanisms of injury thereby aiding the medical diagnosis and decisionmaking process. This review article aims to provide a first comprehensive summary of the current knowledge of COVID-19 and peripheral nerve imaging.

Quantitative and qualitative sensory testing results are associated with numbness rather than neuropathic pain in patients with post-implant trigeminal neuropathy: a cross-sectional pilot study

Purpose: This study aimed to characterize the sensory profile of patients with post-implant trigeminal neuropathy and identify the association between subjective symptoms and objective signs including psychophysical testing and radiographic imaging. This study further evaluated to the association between quantitative sensory testing (QST)/qualitative sensory testing (QualST) and the severity of nerve injury graded by radiographic imaging.Materials and methods: This retrospective study included 34 patients diagnosed with post-implant trigeminal neuropathy. Data on the neuropathic pain symptom inventory (NPSI), thermal and electric QST, bedside QualST, and cone beam computed tomography (CBCT) was collected and the association between these variables were analysed.Results: Numbness was the most common subjective symptom and evoked pain was the most frequent neuropathic pain. There was no significant correlation between negative and positive symptoms. Spearman’s rank correlation analyses indicated that objective findings including QST/QualST correlated with a sensory loss profile rather than a gain of function profile. Moderate positive correlations between some positive symptoms and the score of QualST were observed. The Mann–Whitney U test showed that subjective symptoms did not differ according to the severity of nerve damage according to CBCT, but the electric QST and QualST was discriminative.Conclusions: This study suggests that QST/QualST associated with the severity of nerve damage according to CBCT might be useful in assessing numbness in patients with negative and positive symptoms after implant surgery, but may be of marginal utility in the evaluation of neuropathic pain within the limitation of this cross-sectional study with small sample size.

Clinical and instrumental characteristics of traumatic lesions of peripheral nerves of limbs

Traumatic injuries of peripheral nerves are caused by domestic, iatrogenic, industrial or military injuries. The estimated frequency of traumatic neuropathies in peacetime in Europe is 1 per 1000, with the highest prevalence among young people of working age. In modern local armed conflicts, the frequency and severity of gunshot injuries increased significantly. In connection with the widespread use of personal protective equipment (helmet, body armor), there is a relative increase in injuries to the limbs. Damage to the peripheral nerve can significantly reduce the patient’s quality of life and lead to severe disability with significant social and personal consequences. A deep understanding of the pathophysiology and molecular basis of damage to the peripheral nerves, achievements in the field of damage topography contributed to the development of microsurgical techniques of treatment. At the same time, there are quite a lot of unresolved issues related to clarifying the mechanisms of degeneration and regeneration in traumatic injuries of peripheral nerves. To determine and select a further tactic for the treatment of traumatic neuropathy, it is necessary to clarify the level, nature and severity of nerve damage. In order to improve the treatment of peripheral nerve injuries, in addition to the clinical-neurological examination, a wide range of additional modern instrumental research techniques are used: electroneuromyography, ultrasound investigation, magnetic resonance tomography.

Chronic Pelvic Pain: The Neuropathic Pain Basis

Chronic pelvic pain (CPP) in both genders has been chiefly the province of surgical subspecialists. Morphologic end-organ processes have been studied for decades without significant advances in understanding the etiology of CPP or developing adequate therapeutic outcomes. The neurogenic basis of CPP has received little attention. Several peripheral nerves may be the source. The largest of these is a pudendal nerve and is the most important because it is a mixed nerve and affects sensory and motor symptoms in both the somatic and autonomic nervous systems. Nerve compression and stretch are the two most important etiologic factors. Practitioners can diagnose these painful neuropathies by a careful symptom history and physical examination. The most important diagnostic tool is sensory examination of the pudendal territory using pinprick. Various neurophysiologic tests can confirm pudendal neuropathy. The smaller peripheral nerves affect CPP. Because pudendal neuropathy is a tunnel syndrome related to cumulative, repetitive microtrauma, it can be treated accordingly. Treatment options include nerve protection, medications (analeptics, tricyclic amines), perineural infiltrations of local anesthetics with or without corticosteroids, and, in a significant minority, decompression of the pudendal nerves. The smaller nerves often respond to a program of postural correction and perineural anesthetic blockades. All patients require attention to central sensitization. Treatment success depends on the duration of symptoms, etiology, and severity of nerve damage. The last item can only be evaluated at surgery. Complete cures of CPP, treated using each modality, can be measured by validated symptom scores for as long as 13 years. To progress in the diagnosis and treatment of CPP, interspecialty studies are needed that distinctly separate neurogenic from nonneurogenic CPP. To date, this has not been done. Thus, diagnostic, etiologic, and treatment conclusions are quite limited. CPP provides a rich foundation for clinical research for neurologists. Key Words: abdominal cutaneous neuropathy, chronic pelvic pain, interstitial cystitis, irritable bowel syndrome, middle cluneal neuropathy, neurogenic pelvic pain, pudendal neuropathy, sexual dysfunction, thoracolumbar junction syndrome

Nerves Around the Shoulder: What the Radiologist Should Know?

Peripheral neuropathies of the shoulder are common and could be related to traumatic injury, shoulder surgery, infection or tumour but usually they result from an entrapment syndrome. Imaging plays an important role to detect the underlying causes, to assess the precise topography and the severity of nerve damage. The key points concerning the imaging of nerve entrapment syndrome are the knowledge of the particular topography of the injured nerve, and the morphology as well signal modifications of the corresponding muscles. Magnetic Resonance Imaging best shows these findings, although Ultrasounds and Computed Tomography sometimes allow the diagnosis of neuropathy.

Chronic Pelvic Pain: The Neuropathic Pain Basis

Chronic pelvic pain (CPP) in both genders has been chiefly the province of surgical subspecialists. Morphologic end-organ processes have been studied for decades without significant advances in understanding the etiology of CPP or developing adequate therapeutic outcomes. The neurogenic basis of CPP has received little attention. Several peripheral nerves may be the source. The largest of these is a pudendal nerve and is the most important because it is a mixed nerve and affects sensory and motor symptoms in both the somatic and autonomic nervous systems. Nerve compression and stretch are the two most important etiologic factors. Practitioners can diagnose these painful neuropathies by a careful symptom history and physical examination. The most important diagnostic tool is sensory examination of the pudendal territory using pinprick. Various neurophysiologic tests can confirm pudendal neuropathy. The smaller peripheral nerves affect CPP. Because pudendal neuropathy is a tunnel syndrome related to cumulative, repetitive microtrauma, it can be treated accordingly. Treatment options include nerve protection, medications (analeptics, tricyclic amines), perineural infiltrations of local anesthetics with or without corticosteroids, and, in a significant minority, decompression of the pudendal nerves. The smaller nerves often respond to a program of postural correction and perineural anesthetic blockades. All patients require attention to central sensitization. Treatment success depends on the duration of symptoms, etiology, and severity of nerve damage. The last item can only be evaluated at surgery. Complete cures of CPP, treated using each modality, can be measured by validated symptom scores for as long as 13 years. To progress in the diagnosis and treatment of CPP, interspecialty studies are needed that distinctly separate neurogenic from nonneurogenic CPP. To date, this has not been done. Thus, diagnostic, etiologic, and treatment conclusions are quite limited. CPP provides a rich foundation for clinical research for neurologists. Key Words: abdominal cutaneous neuropathy, chronic pelvic pain, interstitial cystitis, irritable bowel syndrome, middle cluneal neuropathy, neurogenic pelvic pain, pudendal neuropathy, sexual dysfunction, thoracolumbar junction syndrome

Apport de l’électroneuromyographie dans les paralysies faciales périphériques

In case of peripheral facial palsy, electroneuromyogram of the facial nerve provides an indication of the nature (myelinic and/or axonal) and severity of nerve damage, thereby facilitating establishment of a prognosis, which is favorable for myelin damage, and guarded for severe axonal damage. The initial examination must be carried out during the second week. In case of severe axonal damage, examination results can be monitored at the third, and more particularly the sixth and the twelfth months. Stable neurophysiological data between the sixth and the twelfth months signal damage stability and open the way to possible palliative surgery. In the event of trigeminal damage, neurophysiological exploration furthers analysis of temporal muscle innervation. ENMG can confirm and precisely indicate peripheral hemifacial spasm.

Report of 121 Cases of Bell's Palsy Referred to the Emergency Department.

According to the high incidence of Bell's palsy (IFP) and lack of clinical data regarding different aspects of disease, the present study investigated 121 Iranian patients with peripheral facial paralysis referred to the emergency department. In this retrospective study, all patients with peripheral facial paralysis, referred to the emergency department of Poursina hospital, Rasht, Iran, from August 2012 to August 2013, were enrolled. For all patients with diagnosis of Bell's palsy variables such as age, sex, occupation, clinical symptoms, comorbid disease, grade of paralysis, and the severity of the facial palsy were reviewed and analyzed using STATA version 11.0. 121 patients with peripheral facial paralysis were assessed with a mean age of 47.14±18.45 years (52.9% male). The majority of patients were observed in the summer (37.2%) and autumn (33.1%) and the recurrence rate was 22.3%. The most common grades of nerve damage were IV and V based on House-Brackman grading scale (47.1%). Also, the most frequent signs and symptoms were ear pain (43.8%), taste disturbance (38.8%), hyperacusis (15.7%) and increased tearing (11.6%). There were not significant correlations between the severity of palsy with age (p= 0.08), recurrence rate (p=0.18), season (p=0.9), and comorbid disease including hypertension (p=0.18), diabetes (p=0.29), and hyperlipidemia (p=0.94). The patients with any of following symptoms such as ear pain (p<0.001), taste disturbance (p<0.001), increased tearing (p=0.03), and Hyperacusis (p<0.001) have more severe palsy. There was equal gender and occupational distribution, higher incidence in fourth decade of life, higher incidence in summer and autumn, higher grade of nerve damage (grade V and VI), and higher incidence of ear pain and taste disturbance in patients suffered from IFP. In addition, there was significant association between severity of nerve damage and presence of any simultaneous symptoms.

Injury of the inferior alveolar nerve after overfilling of the root canal with endodontic cement: a case report

The inferior alveolar nerve (IAN) contains mainly sensory fibers. Within the mandibular canal, the IAN runs forward in company of the inferior alveolar artery, and together they are called the inferior alveolar neurovascular bundle. Disturbances of the IAN and mental nerve will predominantly give sensitivity symptoms in the soft tissue of the lower lip and chin. We present a case report of endodontic overfilling involving the mandibular canal. A 52-year-old woman was seen in our outpatient clinic for pain and numbness in the left lower lip and chin, which developed following an endodontic treatment for her mandibular left second premolar. The panoramic radiograph showed radiopaque material in the inferior alveolar canal region, with an extension from the left canine to the second premolar. This case report shows an unusual complication of mandibular second premolar root canal overfilling. The patient underwent treatment with corticosteroids, and after 2 months, the clinical examination revealed an improved clinical situation with a disappearance of the hypoesthesia but with a persistence of the pain. After 4 months, the pain had almost entirely disappeared. In conclusion, even if in our case no surgical treatment was used and although spontaneous resorption has been described for some materials, early surgical exploration with removal of the material and decompression of the IAN is suggested, irrespective of the material used, because the severity of nerve damage can increase with the duration of the injury.

A Sciatic Nerve Lesion Secondary to Compression by a Heterotopic Ossification in the Hip and Thigh Region—An Electrodiagnostic Approach

A sciatic nerve lesion secondary to compression by a heterotopic ossification is rare. Operative release of the encased sciatic nerve in some cases may restore the function of the nerve partially or completely. However, in some cases the injury may be permanent. An electrophysiologic study is very useful to determine the location and severity of nerve damage, including axonal loss, demyelination, or both. An electrophysiologic study can emphasize the portion of the sciatic nerve that has been involved the most (lateral versus medial or peroneal versus tibial). In some cases an electrophysiologic study can suggest whether surgery should be postponed if a recovery pattern from the nerve injury is obvious. The prognostic value of follow-up studies is considerable. The authors reviewed literature available to them since 1971 and found 6 cases, including their own. This is the first attempt to put together all the information available in the literature about this condition.

Neurosensory differences after wire and rigid fixation in patients with mandibular advancement

Purpose: The purpose of this analysis was to compare the frequency and severity of nerve damage with rigid and wire fixation in patients participating in a prospective, randomized clinical trial. Patients and Methods: One hundred twenty-six patients who required a bilateral sagittal split osteotomy and mandibular advancement were randomly assigned to receive either rigid or wire fixation. Tactile sensation in the mental nerve region bilaterally was determined presurgically and throughout the subsequent 2 years by using monofilament detection and brush stroke direction. Neurosensory levels were compared between the types of fixation over time. Results: Evaluation with monofilament detection showed no significant difference between types of fixation throughout the 2-year follow-up. However, brush stroke determination showed significantly greater hypesthesia with rigid compared with wire fixation from 8 weeks through 2 years postoperatively. Conclusion: Rigid fixation resulted in more anesthesia in the mental nerve distribution than wire fixation when tested with brush stroke direction. However, increased anesthesia was not present when measured with monofilament determination. © 2000 American Association of Oral and Maxillofacial Surgeons

Missile injuries of the sciatic nerve

Missile injuries of the sciatic nerve are not common in civil practice. We analysed a war series of 55 cases operated on in a period from 1991 to 1995. Nerve continuity was preserved at least partially in 76.4% of cases, but only 13.3% of cases had preserved some nerve function. Surgical results were analysed in 45 cases followed for more than two years. The rates of useful functional recovery were 86.7% for tibial division, 53.3% for peroneal division and 86.7% for the sciatic nerve complex. On the basis of the obtained results we were able to make the following conclusions: (1) missile injuries to the sciatic nerve are characterised by partially preserved nerve continuity and complete functional loss in the majority of cases, (2) surgery should be performed 3 to 6 months after injury, (3) reconstruction of tibial division is the major goal of surgical repair, (4) the extent and severity of nerve damage and the type of surgical procedure are the main prognostic factors and (5) failures of surgical repair are usually related to nerve grafting at gluteal level.

Posttraumatic autoimmune reaction in peripheral nerve: Effect of a single injury

This study was conducted to show that local autoimmune reactions could be observed in rat sciatic nerve after a single injury. Furthermore, we attempted to correlate the intensity of the immunological reaction with the severity of nerve damage, with the type of surgical treatment and with the degree of functional recovery. Through the use of direct immunofluorescence techniques, we found that the severity of the initial damage was associated with the intensity of the local immunological response assessed 2.5 months after surgery. There was an association between type of surgical treatment and intensity of the autoimmune reaction. A correlation between autoimmune reaction and degree of long-term functional impairment was not immediately clear. The probable factors that underlie these results are discussed.