Diabetic and nondiabetic lumbosacral radiculoplexus neuropathies: new insights into pathophysiology and treatment

Brachial and Lumbosacral Plexopathies

The brachial and lumbosacral plexuses are complex neural structures that transmit sensory, motor, and autonomic information between the spinal cord and the extremities. Plexus disorders can be particularly disabling because lesions in the plexus usually affect large groups of nerve fibers originating from several spinal levels. Electrodiagnostic studies are often required to confirm a plexus lesion and determine the extent of injury and prognosis. Magnetic resonance is the imaging modality of choice for detecting intrinsic nerve abnormalities; recently, high-resolution ultrasound has emerged as an alternative method for dynamic evaluation and visualization of internal nerve architecture. Once a plexopathy is confirmed, the list of possible etiologies is relatively limited and includes traumatic and nontraumatic causes. Treatment relies on symptom management and physical rehabilitation unless a treatable underlying condition is found. Surgical approaches, including nerve grafts or tendon transfers, may improve limb function when spontaneous recovery is suboptimal.

The overlap of diabetic and inflammatory neuropathies: Epidemiology, possible mechanisms, and treatment implications

Diabetic polyneuropathy is the common neuropathy of diabetes. However, several inflammatory neuropathies may occur during diabetes. Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) represents the most treatable example. There has been uncertainty about a higher risk of CIDP in subjects with diabetes. Contradicting earlier reports, subsequent epidemiological studies failed to confirm an association. However, more recent studies from different populations have shown a two-fold relative risk of concurrent diabetes with CIDP. Recognition of CIDP is important in diabetes as treatment response rates have been reported as comparable with or without diabetes. However, with diabetes, the clinical presentation of CIDP and the resulting disability may be more severe due to additional axonal loss from pre-existing diabetic polyneuropathy and delayed diagnosis. An association of nodo-paranodopathy has similarly been described with a three-fold relative risk of concurrent diabetes in seropositive subjects, particularly those harbouring anti-contactin 1 antibodies. Although rare, recognition of nodo-paranodopathy, with characteristic clinical features, in the context of diabetes is likewise important in view of treatment implications. Other inflammatory neuropathies in diabetes are the painful or painless, cervical, or lumbar, radiculoplexus neuropathies. These need distinguishing from variant, multifocal forms of CIDP, as are not treatable, although remit spontaneously over months or years. There are reports of possible association of Guillain-Barré syndrome (GBS), and particularly of greater GBS severity, with diabetes. Finally, vasculitic neuropathy may also occur in diabetes and requires early suspicion, urgent investigations and immunosuppressant treatment. As the worldwide prevalence of diabetes rises, prompt recognition of its concurrent inflammatory neuropathies, is essential.

Clinical Reasoning: An Unusual Etiology of Lumbosacral Plexopathy in a Patient With HIV

We present a compelling case of uncontrolled diabetes, who initially presented as diabetic lumbosacral radiculoplexus neuropathy (DLRPN), with radicular pain in the right lower limb (LL) followed by asymmetric weakness of both LLs (right greater than left) with wasting in the medial compartment of the right thigh and significant sensory loss in the bilateral sural and right saphenous nerve distribution. Electrophysiology was suggestive of right lumbosacral radiculoplexus neuropathy. Incidentally, the patient tested positive for HIV-1 at our tertiary care center. CSF analysis revealed markedly elevated protein levels (>400 mg/dL) with lymphocytosis, a red flag for DLRPN. This observation led to further workup. Nerve biopsy showed large collections of perivascular endoneurial and epineurial lymphoid inflammatory cells, which favored an alternative diagnosis. This case highlights the intricate interplay between HIV infection, diabetes, and neurologic manifestations, challenging the initial clinical suspicion of DLRPN. This study emphasizes the importance of considering atypical presentations of neuropathy, especially in the context of coexisting medical conditions, and emphasizes the significance of comprehensive diagnostic workup, including CSF studies and nerve biopsy, for an accurate diagnosis.

Mitochondrial dysfunction in diabetic neuropathy: Impaired mitophagy triggers NLRP3 inflammasome

Diabetic neuropathy is one of the challenging complications of diabetes and is characterized by peripheral nerve damage due to hyperglycemia in diabetes. Mitochondrial dysfunction has been reported as one of the key pathophysiological factor contributing to nerve damage in diabetic neuropathy, clinically manifesting as neurodegenerative changes like functional and sensorimotor deficits. Accumulating evidence suggests a clear correlation between mitochondrial dysfunction and NLRP3 inflammasome activation. Unraveling deeper molecular aspects of mitochondrial dysfunction may provide safer and effective therapeutic alternatives. This review links mitochondrial dysfunction and appraises its role in the pathophysiology of diabetic neuropathy. We have also tried to delineate the role of mitophagy in NLRP3 inflammasome activation in experimental diabetic neuropathy.

A Severe Case of Diabetic Lumbosacral Radiculoplexus Neuropathy: A Diagnosis of Exclusion

Diabetic lumbosacral radiculoplexus neuropathy (DLSRPN), also known as diabetic amyotrophy, is a rare disease of exclusion that is difficult to diagnose due to its non-specific clinical presentation of neuropathy, autonomic symptoms, and potential weight loss. Due to this, many differential diagnoses are raised before making a diagnosis of such an uncommon disease. However, once the diagnosis is made, the management of this disease can vary. Here, we would like to discuss the etiology, pathophysiology, diagnosis, and management of this disease, as well as present a rare case of diabetic lumbosacral radiculoplexus neuropathy in a 50-year-old male.

Bruns Garland Syndrome as the first presentation of type 2 diabetes: two case reports and a practical approach to diagnosis

BACKGROUND

Diabetes is a global health problem causing a significant burden on the healthcare systems both due to the disease itself and associated complications. Diabetic radiculoplexus neuropathies or Bruns-Garland syndrome constitutes a rare form of microvascular complications, more commonly affecting the lumbosacral plexus and, very rarely, the cervical plexus. We describe two Sri Lankan males who presented with diabetic lumbosacral radiculoplexus neuropathy and diabetic cervical radiculoplexus neuropathy as the initial manifestation of diabetes.

CASE DESCRIPTION

Case 1: a 49-year-old Sri Lankan hotel chef presented with subacute painful weakness and wasting of the left upper arm for 3 months and weight loss. Left upper limb proximal muscles were wasted with diminished power and reflexes. A nerve conduction study showed comparative amplitude reduction. An electromyogram revealed positive sharp waves, frequent fibrillations, and high amplitude polyphasic motor unit potentials with reduced recruitment in proximal muscles of left upper limb. Case-2: a 47-year-old Sri Lankan carpenter presented with subacute progressive asymmetrical painful weakness and wasting of bilateral thighs for 5 months and weight loss. Lower limb proximal muscles were wasted with reduced power and knee jerks. The nerve conduction study was normal. The electromyogram was similar to case 1 involving both quadratus femoris muscles, which was more prominent on the left side. The work up for an underlying etiology revealed only elevated fasting blood glucose and HbA1c, suggesting a new diagnosis of diabetes associated with neurological symptoms. Patient 1 was diagnosed with diabetic cervical radiculoplexus neuropathy and patient 2 with diabetic lumbosacral radiculoplexus neuropathy. Both showed significant improvement following optimization of glycemic control together with symptomatic treatment and physiotherapy.

CONCLUSION

Diagnosis of diabetic radiculoplexus neuropathy requires a comprehensive workup to rule out other sinister pathologies. This case report has a dual importance; it describes diabetic radiculoplexus neuropathy as the very first manifestation of two previously healthy people, giving rise to a new diagnosis of diabetes and, at the same time, reporting on diabetic cervical radiculoplexus neuropathy, which is extremely rare and has never been previously reported in Sri Lanka.

Clinicopathologic Findings in Patients With Paraneoplastic Neuropathies and Antibodies Strongly Associated With Cancer

BACKGROUND AND OBJECTIVES

Pathologic descriptions of peripheral nerve involvement in paraneoplastic neuropathies are sparse, mostly from autopsies focusing on CNS and dorsal root ganglia tissues. Here, we describe the clinicopathologic features of peripheral nerve biopsies in patients with paraneoplastic neurologic syndromes to expand the currently limited knowledge.

METHODS

Retrospective review of the Mayo Clinic electronic medical record from 1995 to 2022 for patients identified to have subacute onset neuropathy with paraneoplastic antibodies identified in our neuroimmunology laboratory having available nerve biopsies performed at the time of diagnosis. Patients with another cause of neuropathy not linked to their subacute onset were excluded.

RESULTS

Nineteen patients met inclusion criteria: 4 with amphiphysin antibodies, 6 with antineuronal nuclear antibody (ANNA)-1 only, 3 with both ANNA-1 and collapsin response-mediator protein 5 (CRMP-5), 2 with ANNA-2, and 4 with CRMP-5 antibodies only. Fifteen biopsies had reduced the density of myelinated nerve fibers-4 with multifocality. Subperineurial edema was present in 17 biopsies. Prominent epineurial perivascular inflammation was present in 3 biopsies, all belonging to patients with a lumbosacral radiculoplexus neuropathy (LRPN) phenotype.

DISCUSSION

Axonal loss, subperineurial edema, and an absence of prominent inflammation are the most common findings in nerve biopsies of patients with paraneoplastic antibodies strongly associated with cancer. The LRPN phenotype was the only subset with inflammatory collections. Paraneoplastic autoantibody testing should be considered in patients with subacute onset neuropathies, with or without interstitial inflammatory findings.

Focal inflammatory neuropathies

This chapter focuses on neuropathies that present with focal involvement of nerve roots, plexus, and/or peripheral nerves associated with autoimmune and inflammatory mechanisms that present with focal involvement of nerve roots, plexus and/or peripheral nerves. The clinical presentation, diagnosis, and treatment of focal autoimmune demyelinating neuropathies, focal nonsystemic vasculitic disorders (diabetic and nondiabetic radiculoplexus neuropathies, postsurgical inflammatory neuropathy, and neuralgic amyotrophy), and focal neuropathies associated with sarcoidosis and bacterial and viral infections are reviewed.

Ultrasound assessment of the brachial plexus nerve root cross-sectional areas in asymptomatic patients with type 2 diabetes

Type 2 diabetes mellitus (T2D) is one of the most common metabolic diseases and is often associated with cervical radiculoplexus neuropathies. Magnetic resonance imaging is the modality of choice for evaluating the brachial plexus, however, the use of ultrasound for its evaluation has increased and has been shown to be an additional reliable method. We aimed to compare the cross-sectional areas of the C5, C6, and C7 nerve roots of the brachial plexus, at the interscalene groove, in asymptomatic patients with T2D to that of an asymptomatic control cohort without T2D. A total of 25 asymptomatic patients with T2D were recruited from outpatient clinics. A total of 18 asymptomatic subjects without T2D were also recruited from hospital staff volunteers to form the control cohort. High-resolution ultrasound imaging of the bilateral C5, C6, and C7 nerve roots of the brachial plexus was performed in the short axis, at the level of the interscalene grooves. The nerve root cross-sectional areas were recorded and compared. In the patients with T2D, HbA1c and fasting blood glucose (FBG) levels were obtained as well as the duration of T2D in years and correlated with cross-sectional areas. The cross-sectional areas of C6 and C7 were significantly smaller in the T2D cohort. Additionally, HbA1c, and FBG levels as well as the duration of T2D were negatively correlated with the C5, C6, and C7 cross-sectional areas. Our study demonstrated smaller brachial plexus nerve root cross-sectional areas in asymptomatic patients with T2D which negatively correlated with HbA1c, and FBG levels as well as the duration of T2D.

Painless nondiabetic lumbosacral radiculoplexus neuropathy with complete recovery: a case report

BACKGROUND

Lumbosacral radiculoplexus neuropathy, also known as amyotrophy, is an uncommon monophasic disorder characterized by inflammation of the lumbosacral nerve roots and plexuses. Lumbosacral radiculoplexus neuropathy is usually associated with diabetes mellitus, is typically painful at presentation, and often associated with long-term residual neurologic deficits. We report a case of painless, nondiabetic lumbosacral radiculoplexus neuropathy in a young Chinese woman, who made a full recovery after treatment with intravenous immunoglobulin, adding an atypical case to the scarce literature on lumbosacral radiculoplexus neuropathy.

CASE PRESENTATION

A 35-year-old Chinese woman presented to our emergency department with 1-week history of painless left lower limb weakness and numbness. Examination revealed weakness confined to the left lower limb but spanning various nerves and myotomes, with abnormal sensation. Clinical localization to the lumbosacral plexus was supported by neurodiagnostic tests, and magnetic resonance imaging of the lumbosacral plexus showed that the nerve roots were also involved. After treatment with intravenous immunoglobulin for nondiabetic lumbosacral radiculoplexus neuropathy, the patient had a full recovery.

CONCLUSION

Our patient's case highlights that lumbosacral radiculoplexus neuropathy, an already rare disorder, can occur in the absence of diabetes mellitus and pain, making it even harder to recognize. A systematic and meticulous clinical approach, supported by intelligent selection of adjunctive tests, is required for localization and diagnosis. With an accurate diagnosis, our case also demonstrates that appropriate and prompt treatment can lead to complete recovery, despite previous reports suggesting a high prevalence of long-term residual deficits after lumbosacral radiculoplexus neuropathy.

Lumbosacral plexopathy secondary to discectomy and fixation

Lumbosacral plexopathy (LSP) is a rare entity characterized by acute onset of pain followed by sensory and motor deficits, reflex changes and muscle atrophy. The diagnosis is based on clinical and EMG findings. LSP can result from pelvic tumors, infections, trauma, abdominopelvic or spinal surgery, radiation, intravenous drug abuse, diabetic neuropathy, vasculitis or maybe idiopathic. We present a case report of LSP following spinal surgery treated by pulse steroid and immunotherapy.

Autoimmune Axonal Neuropathies

OBJECTIVE

This article reviews autoimmune axonal neuropathies, their characteristic clinical features, disease and antibody associations, appropriate ancillary testing, treatment, and prognosis.

LATEST DEVELOPMENTS

In 2021, the American College of Rheumatology and the Vasculitis Foundation released new summary guidelines for the treatment of antineutrophil cytoplasmic autoantibody-associated vasculitides. In addition, novel autoantibodies have been recently identified; they are often paraneoplastic and associated with axonal neuropathies.

ESSENTIAL POINTS

Recognition of autoimmune axonal neuropathies is important because of the potential for effective treatment to either reverse deficits or slow the progression of disease. It is necessary to properly assess for associations with other systemic disorders (eg, systemic vasculitis, connective tissue disease, neoplasm) so that adequate treatment for both neurologic and non-neurologic aspects of the disease can be initiated.

Radiation-Induced Lumbosacral Plexopathy

Lumbosacral plexopathy (LSP) encompasses a group of disorders affecting post-ganglionic fibers derived from the L1-S4 roots. The differential diagnosis is challenging and includes other neuropathies of medullary, radicular, or peripheral origin. Defining the etiology is equally crucial, as LSP management relies on its cause. A thorough clinical history should address potential neoplastic disease (new-onset, progression, or relapse), diabetes mellitus, lumbar or pelvic trauma, and previous exposure to radiation. This is the case of a 78-year-old male, with a history of prostatic adenocarcinoma, treated with image-guided radiation therapy and hormone therapy five years before, with no evidence of relapse on follow-up. The patient presented with bilateral weakness, numbness, and paresthesia of lower limbs, gradually progressing over a three-month period, and followed by an acute worsening with inability to stand or walk. He also referred to distal mild edema, episodic hematuria, and urinary incontinence. Physical examination revealed paraparesis affecting proximal and distal leg muscles, along with bilateral hypoesthesia, impaired deep tendon reflexes, and proprioception below knee level. Pelvic, dorsal, and lumbosacral MRI excluded neoplastic lesions but identified somatic fracture of L5 without medullary or conus medullaris compromise. These findings did not explain the clinical picture. Further neurophysiologic studies characterized sensory-motor deficits as post-ganglionic, with specific spontaneous discharges of the muscle fibers, known as myokymia. These findings were consistent with radiation-induced LSP and were supported by MRI. Radiation-induced cystitis was also documented in pelvic MRI and urethral cystoscopy. This case highlights the clinical picture and differential diagnosis of radiation-induced LSP. Despite more typical symptoms and course, a neoplastic origin should always be carefully investigated and excluded. Radiation protocol should be carefully accessed, and its complications should not be overlooked, as they might cause severe morbidity.

Central and Peripheral Nervous System Complications of Vasculitis Syndromes from Pathology to Bedside: Part 2-Peripheral Nervous System

PURPOSE OF REVIEW

Peripheral nervous system vasculitides (PNSV) are a heterogeneous group of disorders with a clinical subset that may differ in prognosis and therapy. We provide a comprehensive update on the clinical assessment, diagnosis, complications, treatment, and follow-up of PNSV.

RECENT FINDINGS

Progress in neuroimaging, molecular testing, and peripheral nerve biopsy has improved clinical assessment and decision-making of PNSV, also providing novel insights on how to prevent misdiagnosis and increase diagnostic certainty. Advances in imaging techniques, allowing to clearly display the vessel walls, have also enhanced the possibility to differentiate inflammatory from non-inflammatory vascular lesions, while recent histopathology data have identified the main morphological criteria for more accurate diagnosis and differential diagnoses. Overall, the identification of peculiar morphological findings tends to improve diagnostic accuracy by defining a clearer boundary between systemic and non-systemic neuropathies. Therefore, the definition of epineurium vessel wall damage, type of vascular lesion, characterization of lymphocyte populations, antibodies, and inflammatory factors, as well as the identification of direct nerve damage or degeneration, are the common goals for pathologists and clinicians, who will both benefit for data integration and findings translation. Nevertheless, to date, treatment is still largely empiric and, in some cases, unsatisfactory, thus often precluding precise prognostic prediction. In this context, new diagnostic techniques and multidisciplinary management will be essential in the proper diagnosis and prompt management of PNSV, as highlighted in the present review. Thirty to fifty percent of all patients with vasculitis have signs of polyneuropathy. Neuropathies associated with systemic vasculitis are best managed according to the guidelines of the underlying disease because appropriate workup and initiation of treatment can reduce morbidity. Steroids, or in severe or progressive cases, cyclophosphamide pulse therapy is the standard therapy in non-systemic vasculitic neuropathies. Some patients need long-term immunosuppression. The use of novel technologies for high-throughput genotyping will permit to determine the genetic influence of related phenotypes in patients with PNSV.

Autoimmune polyneuropathies

The autoimmune peripheral neuropathies with prominent motor manifestations are a diverse collection of unusual peripheral neuropathies that are appreciated in vast clinical settings. This chapter highlights the most common immune-mediated, motor predominant neuropathies excluding acute, and chronic inflammatory demyelinating polyradiculoneuropathy (AIDP and CIDP, respectively). Other acquired demyelinating neuropathies such as distal CIDP and multifocal motor neuropathy will be covered. Additionally, the radiculoplexus neuropathies, resulting from microvasculitis-induced injury to nerve roots, plexuses, and nerves, including diabetic and nondiabetic lumbosacral radiculoplexus neuropathy and neuralgic amyotrophy (i.e., Parsonage-Turner syndrome), will be included. Finally, the motor predominant peripheral neuropathies encountered in association with rheumatological disease, particularly Sjögren's syndrome and rheumatoid arthritis, are covered. Early recognition of these distinct motor predominant autoimmune neuropathies and initiation of immunomodulatory and immunosuppressant treatment likely result in improved outcomes.

Adult and childhood vasculitis

Vasculitis refers to heterogeneous clinicopathologic disorders that share the histopathology of inflammation of blood vessels. Unrecognized and therefore untreated, vasculitis of the nervous system leads to pervasive injury and disability, making this a disorder of paramount importance to all clinicians. There has been remarkable progress in the pathogenesis, diagnosis, and treatment of primary CNS and PNS vasculitides, predicated on achievement in primary systemic forms. Primary neurological vasculitides can be diagnosed with assurance after intensive evaluation that incudes tissue confirmation whenever possible. Clinicians must choose from among the available immune modulating, suppressive, and targeted immunotherapies to induce and maintain remission status and prevent relapse, unfortunately without the benefit of RCTs, and tempered by the recognition of anticipated medication side effects. It may be said that efforts to define a disease are attempts to understand the very concept of the disease. This has been especially evident in systemic and neurological disorders associated with vasculitis. For the past 100 years, since the first description of granulomatous angiitis of the brain, the CNS vasculitides have captured the attention of generations of clinical investigators around the globe to reach a better understanding of vasculitides involving the central and peripheral nervous system. Since that time it has become increasingly evident that this will necessitate an international collaborative effort.

Lumbosacral Radiculoplexus Neuropathy After COVID-19

INTRODUCTION

Lumbosacral Radiculoplexus Neuropathy (LRPN) is a subacute, painful, paralytic, asymmetric immune-mediated lower-limb neuropathy associated with weight loss and diabetes mellitus (called DLRPN). Approximately one-third of LRPN cases have a trigger. Our purpose is to show that COVID-19 can trigger LRPN.

CASE REPORT

We describe the clinical, neurophysiological, radiologic, and pathologic findings of a 55-year-old man who developed DLRPN after severe acute respiratory syndrome coronavirus-2 infection. Shortly after mild coronavirus disease 2019 (COVID-19), the patient developed severe neuropathic pain (allodynia), postural orthostasis, fatigue, weight loss, and weakness of bilateral lower extremities requiring wheelchair assistance. One month after COVID-19, he was diagnosed with type 2 diabetes mellitus. Neurological examination showed bilateral severe proximal and distal lower extremity weakness, absent tendon reflexes, and pan-modality sensation loss. Electrophysiology demonstrated an asymmetric axonal lumbosacral and thoracic radiculoplexus neuropathies. Magnetic resonance imaging showed enlargement and T2 hyperintensity of the lumbosacral plexus. Cerebral spinal fluid (CSF) showed an elevated protein (138 mg/dL). Right sural nerve biopsy was diagnostic of nerve microvasculitis. He was diagnosed with DLRPN and treated with intravenous methylprednisolone 1 g weekly for 12 weeks. The patient had marked improvement in pain, weakness, and lightheadedness and at the 3-month follow-up was walking unassisted.

CONCLUSION

COVID-19 can trigger postinfectious inflammatory neuropathies including LRPN.

Is diabetes the risk factor for poor neurological recovery after cervical spine surgery? A review of the literature

The poor prognosis of cervical spine surgery is mainly manifested as poor neurological recovery and the presence of new upper extremity dysfunction that promotes significant psychological and physiological burdens on patients. Many factors influence the prognosis of cervical spine surgery, including the age of patients, the time and mode of surgery, and the surgical technique used. However, in clinical studies, it has been observed that patients with diabetes have a higher probability of poor prognosis after surgery. Therefore, we review the pathophysiology of diabetic neuropathies and discuss its impact on cervical nerve system function, especially in cervical nerve roots and upper limb peripheral nerve conduction.

Current perspectives on the diagnosis, assessment, and management of vasculitic neuropathy

INTRODUCTION

Vasculitic neuropathy can present associated with both primary and secondary systemic vasculitis as a result from underlying diseases such as rheumatic diseases and infections, Moreover, confined vasculitis in the peripheral nervous system may be present. Thus, the diagnosis and management of vasculitic neuropathy require multidisciplinary approaches.

AREAS COVERED

Current views as well as relevant clinical research on the diagnosis, assessment, and management of vasculitic neuropathy are reviewed to suggest appropriate treatment strategies. We searched PubMed and Google Scholar for reports published between July 2017 and July 2022.

EXPERT OPINION

For the treatment of vasculitic neuropathy, determining the causative primary disease is important and often requires diagnosis by tissue biopsy. Due to the scarce research on the treatment of vasculitic neuropathy, treatment is empirically based on findings from studies of systemic vasculitides involving other organs, particularly antineutrophil cytoplasmic antibody-associated vasculitis. In addition to conventional glucocorticoids and immunosuppressive agents, complement-targeted therapy, anti-B-cell therapy, and disease-specific molecular targeted therapies have recently gained relevance. Future research is needed to develop new patient-specific therapeutic options.

Diabetic Mononeuropathies and Diabetic Amyotrophy

This brief review describes the etiology, pathophysiology, clinical features, therapy and prognosis of the diabetic mononeuropathies and diabetic amyotrophy and neuropathic cachexia. Mononeuropathies include cranial neuropathies, of which the oculomotor nerve is most commonly affected, and are thought to be due to microvascular occlusion. Peripherally, entrapment neuropathies occur in both the upper and lower limbs and are due to compression of an already damaged nerve in anatomically restricted channels. Diabetic radiculopathies occur in the dermatones of the thorax and abdomen, mimicking intraabdominal or intrathoracic pathology. I also describe the features of the rare but very distinctive diabetic amyotrophy and neuropathic cachexia. Overall, the prognosis from these conditions is excellent with residual pain or muscle weakness being rare with the exception of diabetic amyotrophy where the prognosis is dependent upon cooperation with intensive rehabilitation. Therapies include "watchful waiting," physical therapy and rarely surgical intervention, which may be urgently needed for nerve decompression and reversal of motor defects.

Optical coherence tomography of the retina combined with color Doppler ultrasound of the tibial nerve in the diagnosis of diabetic peripheral neuropathy

OBJECTIVE

To investigate the value of the retinal nerve fiber layer (RNFL) thickness in the optic disc and the cross-sectional area (CSA) of lower limb nerves in the diagnosis of diabetic peripheral neuropathy (DPN) separately and in combination.

METHODS

A total of 140 patients with type 2 diabetes were enrolled, including 51 patients with DPN (DPN group) and 89 patients without DPN (NDPN group). Clinical data and biochemical parameters were collected. Electromyography/evoked potential instrument was performed for nerve conduction study. Optical coherence tomography was performed to measure the RNFL thickness of the optic disc. Color Doppler ultrasound was performed to measure CSA of lower limb nerves.

RESULTS

The RNFL thickness was lower and the CSA of the tibial nerve (TN) in the DPN group was larger than that in the NDPN group. The album/urine creatinine ratio, diabetic retinopathy, and CSA of TN at 3 cm were positively correlated with DPN. The RNFL thickness in the superior quadrant of the optic disc was negatively correlated with DPN. For RNFL thickness to diagnose DPN, the area under the curve (AUC) of the superior quadrant was the largest, which was 0.723 (95% confidence interval [CI]: 0.645-0.805), and the best cutoff value was 127.5 μm (70.5% sensitivity, 72.1% specificity). For CSA of TN to diagnose DPN, the AUC of the distance of 5 cm was the largest, which was 0.660 (95% CI: 0.575-0.739), and the best cutoff value was 13.50 mm² (82.0% sensitivity, 41.6% specificity). For the combined index, the AUC was greater than that of the above two indicators, which was 0.755 (95% CI: 0.664-0.846), and the best cutoff value was 0.376 (64.3% sensitivity, 83.0% specificity).

CONCLUSIONS

Patients with DPN have a reduction of the RNFL thickness and an increase in the CSA of TN, and these two changes are related to DPN. The RNFL thickness of the optic disc and the CSA of TN can be used as diagnostic indicators of DPN, and the combination of the two indicators has a higher diagnostic value.

Case report: Corticosteroids-induced acute diabetic peripheral neuropathy

A 62-year-old man was diagnosed as IgA nephropathy. He had a pancreatic tumor operation 19 years ago and had a normal plasma glucose test every year. One month after the medication of prednisolone acetate was administered his fasting plasma glucose elevated to 7.1mmol/L while he manifested symptoms of thirst, frequent urination, and weight loss. Approximately 3 months after the steroids, he started complaining of numbness, weakness, and muscle cramp in his lower extremities, blood tests showed elevated plasma glucose and electromyography (EMG) revealed impairment of the peripheral nerves in the lower extremity, diabetic peripheral neuropathy was diagnosed. Mecobalamin and Acupuncture were employed and steroids were discontinued, 8 months later he recovered part of his strength and sensation. This case presents a specific adverse drug reaction of corticosteroids that causes diabetes mellitus and subsequently leads to peripheral neuropathy in an acute onset.

Risk factors for Lumbosacral Radiculoplexus Neuropathy

INTRODUCTION/AIMS

Recently, our group found an association between diabetes mellitus (DM) and lumbosacral radiculoplexus neuropathy (LRPN) in Olmsted County, Minnesota; we found a higher risk (OR: 7.91) for developing LRPN in diabetic compared to non-diabetic patients. However, the influence of other comorbidities and anthropomorphic variables was not studied.

METHODS

Demographic and clinical data from 59 LRPN patients and 177 age-sex matched controls were extracted using the Rochester LRPN epidemiological study. Differences between groups were compared by Chi-square/Fisher's exact test or Wilcox sum rank. Univariate and multivariate logistic regression analysis were performed.

RESULTS

Factors predictive of LRPN on univariate analysis were DM (OR 7.91; CI 4.11-15.21), dementia (OR 6.36; CI 1.13-35.67), stroke (OR 3.81; CI 1.32-11.01), dyslipidemia (OR 2.844; CI 1.53-5.27), comorbid autoimmune disorders (OR 2.72; CI 1.07-6.93), hypertension (OR 2.25; CI 1.2-4.13), obesity (OR 2.05; CI 1.11-3.8), BMI (OR 1.1; CI 1.04-1.15), and weight (OR 1.02; CI 1.009-1.037). On multivariate logistic regression analysis only DM (OR 8.03; CI 3.86-16.7), comorbid autoimmune disorders (OR 4.58; CI 1.45-14.7), stroke (OR 4.13; CI 1.2-14.25) and BMI (OR 1.07; CI 1.01-1.13) were risk factors for LRPN.

DISCUSSION

DM is the strongest risk factor for the development of LRPN, followed by comorbid auto-immune disorders, stroke and higher BMI. Altered metabolism and immune dysfunction seem to be the most influential factors in the development of LRPN. This article is protected by copyright. All rights reserved.

Approach to Limb Weakness

"Approach to limb weakness" provides an overview of the pathways of the motor system and the type of weakness seen with pathology at each level from the cortex to the muscle. This article provides the clinical pearls needed to identify different patterns of weakness and accurately localize the level of weakness. It offers important pointers that help distinguish among the different etiologies of weakness at each level, as well as various diagnostic approaches and treatments of diseases that lead to limb weakness. The diagnoses discussed are meant to be representative and not exhaustive, as a complete differential for each pattern of weakness is beyond the scope of this article.

High-Resolution Ultrasonography in the Assessment of Lumbar Radiculoplexus Neuropathy in Diabetics: Preliminary Results of a Case-Control Study

Background  The traditional diagnosis of lumbar radiculoplexus neuropathy (LRN) is based on a classical sequence of symptoms and targeted electrodiagnostic examination by means of electromyography. Ultrasonography reliably indicates the level of lumbar radiculopathy by assessing edema mesial to the site of compression. Materials and Methods  This case-control study was undertaken at a tertiary care hospital between July 2017 and June 2019 on 15 diabetic patients with symptoms of LRN. Fifteen healthy volunteers with no symptoms or clinical signs of LRN were included in the control group. The diameter (D) and transverse diameter (TD) of L1 nerve root (L1NR), L2NR, L3NR, and L4NR were measured, and their cross-sectional areas (CSAs) were calculated based on location in the lateral zone, where the NRs were visualized. On high-resolution ultrasonography, femoral nerve was localized lateral to the femoral artery in the femoral triangle beneath the inguinal ligament. Additionally, the CSA (calculated as CSA [mm ² ] = D × TD × π/4), the diameter (mm), and transverse diameter (mm) of bilateral femoral nerves at the level of L3-L4 were calculated. Results  The difference attributed to CSAs between affected NRs in LRN group and unaffected NRs in controls at levels L1-L4 was considered statistically significant ( p  < 0.05). Receiver operating characteristic analysis revealed mean values to be 8 mm ² (CSA) for L1NR, 11.2 mm ² (CSA) for L2NR, 13.6 mm2 (CSA) for L3NR, and 17.8 mm ² (CSA) for L4NR. There was significant difference between ΔCSA of LRN patients and controls at L1 to L4 levels ( p  < 0.05). CSA measurements of lateral femoral cutaneous nerve (8 mm ² ) and femoral nerve (58 mm ² ) performed on high-resolution ultrasonography were significantly larger on the affected side as compared with the unaffected side. Conclusion  Radiculoplexus neuropathy of the lumbar plexus can be reliably diagnosed on high-resolution ultrasonography that can reveal nerve thickening. The laterality of affected NRs was significantly greater in LRN group when compared with controls.

Electrodiagnostic Assessment of Plexopathies

Disorders of the brachial and lumbosacral plexus are complex and may occur as a consequence of trauma, compression, inflammatory disorders, malignant infiltration, or delayed effects of radiation therapy. An understanding of plexus anatomy and surrounding structures will allow the electromyographer to facilitate an efficient and comprehensive assessment of the plexus. A careful and thorough electrodiagnostic assessment allows for localization within the plexus and may provide important information about underlying pathology and prognosis.

Progressive muscle weakness and amyotrophy during pregnancy as the first manifestation of systemic lupus erythematosus: A case report and review of literature

BACKGROUND

Systemic lupus erythematosus is a common autoimmune disease involving multiple systems. Clinical involvement of the central and peripheral nervous systems is not unusual, but peripheral neuropathy in systemic lupus erythematosus with chronic inflammatory demyelinating polyneuropathy is uncommon. Our study aimed to illustrate the clinical features, diagnosis, and treatment of systemic lupus erythematosus combined with chronic inflammatory demyelinating polyneuropathy, and to aid in the identification of peripheral neuropathy in systemic lupus erythematosus.

METHODS

This article reports a case of systemic lupus erythematosus with onset in pregnancy, with chronic inflammatory demyelinating polyneuropathy as the first manifestation. We then analyze the identification of common peripheral neuropathy in systemic lupus erythematosus in detail, based on a literature review of confirmed cases of systemic lupus erythematosus combined with chronic inflammatory demyelinating polyneuropathy.

RESULTS

A 34-year-old woman presented progressive muscle weakness and muscular atrophy in the extremities during pregnancy, 3 years previously. At 4 months after onset, she had completely lost the ability to hold objects and walk, and had slight numbness in the limbs, without paresthesia. Her condition was misdiagnosed as "motor neuron disease" at the time. Three years after onset, her condition was revisited because of nephrotic syndrome, and she was diagnosed with nephrotic syndrome and peripheral nerve injury caused by systemic lupus erythematosus. After immunosuppressive treatment with corticosteroids and intravenous cyclophosphamide, her symptoms of muscle weakness were markedly improved. This article summarizes the characteristics of systemic lupus erythematosus combined with chronic inflammatory demyelinating polyneuropathy that have been reported in the literature, from the aspects of morbidity, disease progression, nerve injury, laboratory examinations, and treatment response.

CONCLUSIONS

Our identification of a common peripheral neuropathy in systemic lupus erythematosus will help to improve clinicians' understanding of various peripheral neuropathies in systemic lupus erythematosus. It will also aid in the early diagnosis and treatment of such patients, thus improving their long-term prognosis.

A Comprehensive Review of Neuronal Changes in Diabetics

There has been an exponential rise in diabetes mellitus (DM) cases on a global scale. Diabetes affects almost every system of the body, and the nervous system is no exception. Although the brain is dependent on glucose, providing it with the energy required for optimal functionality, glucose also plays a key role in the regulation of oxidative stress, cell death, among others, which furthermore contribute to the pathophysiology of neurological disorders. The variety of biochemical processes engaged in this process is only matched by the multitude of clinical consequences resulting from it. The wide-ranging effects on the central and peripheral nervous system include, but are not limited to axonopathies, neurodegenerative diseases, neurovascular diseases, and general cognitive impairment. All language search was conducted on MEDLINE, COCHRANE, EMBASE, and GOOGLE SCHOLAR till September 2021. The following search strings and Medical Subject Headings (MeSH terms) were used: "Diabetes Mellitus," "CNS," "Diabetic Neuropathy," and "Insulin." We explored the literature on diabetic neuropathy, covering its epidemiology, pathophysiology with the respective molecular pathways, clinical consequences with a special focus on the central nervous system and finally, measures to prevent and treat neuronal changes. Diabetes is slowly becoming an epidemic, rapidly increasing the clinical burden on account of its wide-ranging complications. This review focuses on the neuronal changes occurring in diabetes such as the impact of hyperglycemia on brain function and structure, its association with various neurological disorders, and a few diabetes-induced peripheral neuropathic changes. It is an attempt to summarize the relevant literature about neuronal consequences of DM as treatment options available today are mostly focused on achieving better glycemic control; further research on novel treatment options to prevent or delay the progression of neuronal changes is still needed.

Rare diabetic neuropathies: It is not only distal symmetrical polyneuropathy

The prevalence of diabetes mellitus is increasing at an epidemic level, leading to a consequent increase of its chronic complications, including neuropathy. Diabetic neuropathy constitutes a heterogeneous group of disorders with distinct clinical presentations and pathophysiological mechanisms. These distinct forms may be categorised according to their clinical presentation as symmetrical (distal symmetrical polyneuropathy, autonomic and acute sensory neuropathy) and focal or multifocal (radiculoplexus neuropathies, entrapment syndromes, cranial palsies and other mononeuropathies). Additionally, people with diabetes may have neuropathies due to causes other than diabetes. The commonest forms of diabetic neuropathy are distal symmetrical polyneuropathy and autonomic neuropathy. However, clinicians should be aware that people with diabetes may suffer from less common forms of neuropathy and should be able to recognise their symptoms and signs. The recognition of the rare diabetic neuropathies is crucial, as they often lead to different clinical outcomes and require different management. The aim of the present narrative, non-systematic review is to outline the rare types of diabetic neuropathies.

Postoperative lumbar paraspinal compartment syndrome

Lower lumbar paraspinal muscles constitute a compartment as they are surrounded by distinct fascial and bony boundaries. Lumbar paraspinal compartment syndrome is a rare entity, often caused by intense exercise, but also can be a postoperative complication. We present a 60-year-old man with low back pain, numbness in the left lower back and radicular pain in the left lower extremity, which started after a surgery that involved prolonged positioning on the left side 7 years before, and persisted to the day of evaluation. There was an immediate transient rise in the creatine kinase after surgery. Electromyography showed a left lower lumbar-sacral plexopathy and a lumbar spine MRI revealed fatty infiltration of the lower lumbar-sacral paraspinal muscles. The emergence of radicular lower limb pain was likely due to the compression of the proximal portion of lumbar-sacral plexus during the acute stage of rhabdomyolysis.

Lumbosacral Radiculoplexus Neuropathy: Neurologic Outcomes and Survival in a Population-Based Study

OBJECTIVE

To determine whether patients in the community with lumbosacral radiculoplexus neuropathy (LRPN) have milder neuropathy than referral patients, we characterized the outcomes and survival of population-based compared to referral-based LRPN cohorts.

BACKGROUND

Previously, we found that the incidence of LRPN is 4.16/100,000/y, a frequency greater than other inflammatory neuropathies. The survival of patients with LRPN is uncharacterized.

METHODS

Sixty-two episodes in 59 patients with LRPN were identified over 16 years (2000-2015). Clinical findings were compared to previous referral-based LRPN cohorts. Survival data were compared to those of age- and sex-matched controls.

RESULTS

At LRPN diagnosis, median age was 70 years, median Neuropathy Impairment Score (NIS) 22 points, 92% had pain, 95% had weakness, 23% were wheelchair-bound, and median modified Rankin Scale score (mRS) was 3 (range 1-4). At last follow-up, median NIS improved to 17 points (p < 0.001) with 56% having ≥4 points improvement, 16% were wheelchair-bound, and median mRS was 2. Compared to referral-based LRPN cohorts, community patients with LRPN had less impairment, less bilateral disease (37% vs 92%), and less wheelchair usage (23% vs 49%). LRPN survival was 86% at 5 years and 55% at 10 years. Compared to age- and sex-matched controls, patients with LRPN had 76% increased risk of death (p = 0.016). In multivariate analysis, diabetes, age, stroke, chronic kidney disease, peripheral artery disease, and coronary artery disease were significant mortality risk factors but LRPN was not.

CONCLUSION

LRPN is a painful, paralytic, asymmetric, monophasic, sometimes bilateral pan-plexopathy that improves over time but leaves patients with impairment. Although having LRPN increases mortality, this increase is probably due to comorbidities (diabetes) rather than LRPN itself.

Radiographic lumbosacral vertebral abnormalities and constipation in cats

Background and Aim:

Lumbosacral intervertebral disk disease (IVDD) in cats usually develops concurrent with constipation, spondylosis deformans, and sacralization. However, the prevalence of lumbar IVDD in cats was considered low, and there was less information on the incidence of non-traumatic lumbosacral vertebral abnormalities that may affect large bowel dysfunction. This study aimed to retrospectively investigate the relationship between non-traumatic lumbosacral vertebral abnormalities, both congenital and acquired, and large bowel dysfunction in cats.

Materials and Methods:

Of 3108 cats that were presented to the Diagnostic Imaging Unit, the Small Animal Teaching Hospital, Faculty of Veterinary Science, Chulalongkorn University, between March 2016 and February 2018, 1365 cats met the inclusion criteria. All abdominal radiographs were reviewed, and all subsequent data were recorded, including the presence of congenital or acquired lumbosacral lesions, number of lumbar vertebrae, and length of the second, fifth, and last lumbar vertebrae, including the type of lumbar abnormalities. Moreover, radiographic information relating to constipation and megacolon was also collected.

Results:

Non-traumatic lumbosacral vertebral abnormalities were observed in 29.74% of cats. The most common congenital lumbosacral vertebral abnormalities were six lumbar vertebrae, sacralization, and lumbarization, whereas most common acquired lumbosacral abnormalities were bone spur, narrowing disk space, spondylosis deformans, and lumbosacral degeneration, respectively. Cats with abnormal lumbosacral vertebrae are prone to have more problems with the large bowel (p=0.0057; odds ratio=1.731). Moreover, congenital and acquired lumbosacral abnormalities were also at risk of large bowel abnormalities (p=0.0069; odds ratio=1.920 and p<0.0001; odds ratio=4.107, respectively).

Conclusion:

This study revealed the evidence and distribution of the variation in feline lumbar anatomy and also elucidated that cats with abnormal lumbar vertebral columns were more likely to have problems with distal gastrointestinal tracts than those without.

Peripheral Neuropathies Associated With Vasculitis and Autoimmune Connective Tissue Disease

PURPOSE OF REVIEW

This article discusses peripheral neuropathies associated with vasculitis (isolated or in the setting of systemic vasculitis) and autoimmune connective tissue disease and provides a brief overview of their diagnostic evaluation and management.

RECENT FINDINGS

The classification of systemic vasculitic neuropathy and nonsystemic vasculitic neuropathy continues to evolve. Classification according to the presence of antineutrophil cytoplasmic antibodies and their subtypes facilitates prognostication and management. Recent research on antineutrophil cytoplasmic antibody-associated vasculitis has added to our understanding of its neurologic complications. The treatment of vasculitis is also evolving, and new nonsystemic vasculitic neuropathy classification has impacted the treatment and management of this disorder. New classification criteria for Sjögren syndrome (which commonly causes neurologic complications) facilitate accurate and timely diagnosis.

SUMMARY

Vasculitis and autoimmune connective tissue disease are underrecognized and treatable causes of peripheral neuropathy. Furthermore, peripheral neuropathy may reveal an underlying rheumatologic or vasculitic disorder. Rapid recognition and treatment are essential. Familiarity with the diagnosis and treatment of neuropathies in the setting of connective tissue disease and vasculitis reduces morbidity and, in some cases, mortality.

Diabetes and Metabolic Disorders and the Peripheral Nervous System

PURPOSE OF REVIEW

This article provides an up-to-date review of the manifestations of neuropathy seen in the setting of diabetes and other metabolic disorders.

RECENT FINDINGS

Although a number of metabolic disorders cause or are associated with peripheral neuropathy, the neuropathies associated with glucose dysregulation make up the vast majority of cases. Recent investigations have determined major differences in the neuropathies associated with type 1 and type 2 diabetes. Neuropathy in type 1 diabetes is closely linked to glycemic control, whereas neuropathy in type 2 diabetes is linked to dyslipidemia, central obesity, hypertension, insulin resistance, and glucose control. Although length-dependent axonal distal symmetric polyneuropathy is the most common clinical presentation, diabetes is also associated with acute, asymmetric, painless, and autonomic neuropathies.

SUMMARY

The prevalence of diabetes and metabolic syndrome is increasing across the globe. The need to recognize and treat the wide array of clinical manifestations of neuropathy detected in individuals with metabolic disorders will continue to grow. As a consequence, an increasing number of well-trained physicians who can manage these patients is needed. At present, treatment is largely focused on prevention and symptomatic management. Investments into funding for both basic and clinical science are necessary to bring novel therapeutic interventions into clinical practice.

Clinical spectrum and diagnosis of diabetic neuropathies

Neuropathy is the most prevalent microvascular complication of diabetes mellitus; it encompasses distal symmetric polyneuropathy, autonomic neuropathy, radiculoplexus neuropathy, mononeuropathy, and treatment-induced neuropathy. The prevalence rate of diabetic neuropathy in Korea was reported to be approximately 43%, which is similar to rates in other countries. However, the precise pathogenic mechanism underlying diabetic neuropathy is still obscure, and many clinical trials have failed to develop methods to prevent or reduce the progression of diabetic neuropathy. Nevertheless, early diagnosis and proper management of diabetic neuropathy are essential to alleviate disabling symptoms and to improve the quality of life of patients. This review discusses clinical manifestations and classification of diabetic neuropathies, bedside neurological examination, and electrophysiological tests.

Idiopathic Lumbosacral Neuropathy Syndrome: Case Report

Idiopathic lumbosacral plexitis or lumbosacral radiculoplexus neuropathy is a disease characterized by nerve damage in lumbar and/or sacral plexus without trauma, mass effect or diabetic complications. A 47-year-old male patient with right groin pain and loss of right leg muscle strength is presented in this case report. Neuropathy was detected in the L4 nerve root by electromyography and magnetic resonance neurrographic imaging. The underlying cause was investigated; however, it is linked to the idiopathic outcome. Idiopathic lumbosacral neuropathy is a lumbosacral plexus disease in which no underlying pathology plays a role in causing severe pain and muscle weakness. Patients should be avoided urgently operation because of the sudden onset symptoms.

Brachial and lumbosacral plexopathies: A review

Diseases of the brachial and lumbosacral plexus are uncommon and complex. The diagnosis of plexopathies is often challenging for the clinician, both in terms of localizing a patient's symptoms to the plexus as well as determining the etiology. The non-specific clinical features and similar presentations to other root, nerve, and non-neurologic disorders emphasize the importance of a high clinical index of suspicion for a plexopathy and comprehensive clinical evaluation. Various diagnostic tests, including electrodiagnostic (EDX) studies, neuroimaging (including ultrasound, MRI, or PET), serologic studies, and genetic testing, may be used to confirm a plexopathy and assist in identifying the underlying etiology. EDX testing plays an important role in confirming a plexopathy defining the localization, pathophysiology, chronicity, severity, and prognosis. Given the complexity of the plexus anatomy, multiple common and uncommon NCS and an extensive needle examination is often required, and a comprehensive, individualized approach to each patient is necessary. Treatment of plexopathies often focuses on symptomatic management although, depending on the etiology, specific targeted treatments may improve outcome. This article reviews the clinical features, EDX approaches, and evaluation and treatment of brachial and lumbosacral plexopathies.

Neuralgic amyotrophy: a paradigm shift in diagnosis and treatment

Neuralgic amyotrophy (NA), also known as Parsonage-Turner syndrome, is characterised by sudden pain attacks, followed by patchy muscle paresis in the upper extremity. Recent reports have shown that incidence is much higher than previously assumed and that the majority of patients never achieve full recovery. Traditionally, the diagnosis was mainly based on clinical observations and treatment options were confined to application of corticosteroids and symptomatic management, without proven positive effects on long-term outcomes. These views, however, have been challenged in the last years. Improved imaging methods in MRI and high-resolution ultrasound have led to the identification of structural peripheral nerve pathologies in NA, most notably hourglass-like constrictions. These pathognomonic findings have paved the way for more accurate diagnosis through high-resolution imaging. Furthermore, surgery has shown to improve clinical outcomes in such cases, indicating the viability of peripheral nerve surgery as a valuable treatment option in NA. In this review, we present an update on the current knowledge on this disease, including pathophysiology and clinical presentation, moving on to diagnostic and treatment paradigms with a focus on recent radiological findings and surgical reports. Finally, we present a surgical treatment algorithm to support clinical decision making, with the aim to encourage translation into day-to-day practice.

Diabetic Lumbosacral Radiculoplexus Neuropathy (Diabetic Amyotrophy)

Diabetic lumbosacral radiculoplexus neuropathy, also known as diabetic amyotrophy, has a characteristic course of sudden onset of unilateral pain in the thigh and hip, which may spread to the other side in weeks to months and proceeds with progressive lower extremity weakness, often resulting in the inability to walk unassisted. The syndrome is typically monophasic, and most patients will recover at least to some degree. Less typical features include lack of pain, distal predominant weakness, absence of diabetes, and upper extremity involvement. This article provides a series of interesting cases to highlight the diagnostic challenges and discusses management decision making.

Spectrum of diabetic neuropathies

The diabetic state results in neuropathy. The main causative mechanism is hyperglycemia, although microvascular involvement, hypertriglyceridemia, as well as genetic and immune mechanisms may be contributory. There is a growing spectrum of types of diabetic neuropathies that differ based on the type of fibers involved (e.g. myelinated, unmyelinated, autonomic, somatic), distribution of nerves involved, and mechanisms of neuropathy. The most common type is distal sensory neuropathy (DSN), which affects the distal ends of large myelinated fibers, more often sensory than motor, and is often asymptomatic. The next-most common is distal small fiber neuropathy (DSFN), which largely affects the unmyelinated fibers and carries the phenotype of burning feet syndrome. Diabetic autonomic neuropathy (DAN) occurs when widespread involvement of autonomic unmyelinated fibers occurs, and patients can be incapacitated with orthostatic hypotension as well as neurogenic bladder and bowel involvement. Radiculoplexus diabetic neuropathy causes proximal weakness and pain, usually in the lower extremity, and has a combination of immune, inflammatory, and vascular mechanisms. The nerve roots and plexus are involved. These patients present with proximal weakness of a subacute onset, often with severe pain and some autonomic failure. Finally, rapid and sustained reduction of blood glucose can result in treatment-induced diabetic neuropathy (TIND), which largely affects the sensory and autonomic fibers. This occurs if HbA1c is rapidly reduced within 3 months, and the likelihood is proportional to the original A1c and the size of the reduction.

Polyneuropathie im Alter

Das periphere Nervensystem ist im Laufe des Alternsprozesses Veränderungen unterworfen. So kommt es unter anderem zu einer Abschwächung von Muskeleigenreflexen und Propriozeption. Davon abzugrenzen sind Polyneuropathien als krankhafte Veränderungen des peripheren Nervensystems. Die jährliche Inzidenz von Polyneuropathien wird auf 118/100.000 geschätzt, die Prävalenz liegt bei etwa 1 %, für ältere Populationen werden 7 % angegeben. Die Ursachen sind vielfältig und ähnlich den Ursachen von Neuropathien des jüngeren Alters: Neben metabolischen, immunvermittelten, hereditären, toxischen und infektiösen Ätiologien können Polyneuropathien Ausdruck von Systemerkrankungen sein. Entsprechend der Altersverteilung der verschiedenen Ursachen sind Neuropathien im Zusammenhang mit Diabetes, monoklonalen Gammopathien und Malignomen im Alter häufiger. Allerdings nimmt der Anteil der kryptogenen Neuropathien, also ohne eindeutige Ursache, mit dem Alter zu. Bei alten Menschen führen Polyneuropathien zu einer zusätzlichen Beeinträchtigung der Mobilität und einem erhöhten Sturzrisiko, was auch die Abklärung funktioneller Fähigkeiten erforderlich macht.

Postsurgical Neuropathy: A Descriptive Review

Postsurgical neuropathies represent an infrequent but potentially devastating complication of surgery that may result in significant morbidity with medicolegal implications. Elucidation of this phenomenon has evolved over the past few decades, with emerging evidence for not only iatrogenic factors contributing to this process but also inflammatory causes. This distinction can be important; for instance, cases in which inflammatory etiologies are suspected may benefit from further investigations including nerve biopsy and may benefit from treatment in the form of immunotherapy. In contrast, postsurgical neuropathies due to perioperative causes including anesthesia, traction, compression, and transection will not benefit in the same manner. This article summarizes early and current literature surrounding the frequency of new neurologic deficits after various surgical types, potential causes including anatomical and inflammatory considerations, and roles for treatment. To capture the scope of the issue, a literature review was conducted for human studies in English via MEDLINE and EMBASE from January 1, 1988 to March 31, 2018. Search terms included anesthesia and/or surgical procedures, operative, peripheral nervous system diseases, trauma, mononeuropathy, polyneuropathy, peripheral nervous system, nerve compression, neuropathy, plexopathy, postoperative, postsurgical, perioperative, complication. We excluded case series with less than 10 patients and review papers. We then narrowed the studies to those presented highlighting key concepts in postsurgical neuropathy.

Diffusion tensor imaging of diabetic amyotrophy

OBJECTIVE

To qualitatively and quantitatively characterize the nerves of patients with diabetic amyotrophy (DA) using magnetic resonance neurography (MRN) with diffusion tensor imaging (DTI).

MATERIALS AND METHODS

Forty controls and 13 DA cases were analyzed. 1.5-Tesla and 3.0-Tesla MRN with DTI was used. Qualitative data from 13 patient records were recorded. Region of interest (ROI) measurements were taken of bilateral L3 through S2 lumbosacral nerve roots, femoral nerves, and sciatic nerves. An ANOVA and multiple linear regression analysis were performed. An intraclass correlation coefficient (ICC) was calculated between two readers.

RESULTS

In DA cases, abnormalities of the lumbosacral nerve roots (n = 11 patients), sciatic (n = 10), femoral (n = 13), and obturator nerves (n = 4) were seen; denervation changes of the abdominopelvic muscles were also identified. Quantitatively, minimum and mean nerve signals on B600 were significantly less than controls (p < 0.001). Minimum and mean ADC values were significantly greater in cases than in controls (p < 0.001 and p = 0.002 respectively). Mean fractional anisotropy (FA) values were significantly lower in cases than in controls (p = 0.041). There were no significant differences in the minimum FA values between cases and controls. Minimum and mean ADCs correlated positively with highest recorded hemoglobin A1 (HbA1c) while controlling for sex, age, and BMI (β = 0.518, p < 0.001 and β = 0.302, p = 0.020 respectively). ICCs were 0.892 (B600), 0.717 (ADC), and 0.730 (FA).

CONCLUSION

Neuromuscular lesions secondary to DA are qualitatively and quantitatively identified on MRN with DTI, and a positive correlation of ADC levels with serum HbA1c levels exists. Thus, MRN with DTI can be employed as a non-invasive diagnostic tool, if DA is suspected.

Overview of the Vasculitides

The systemic vasculitides are heterogeneous clinicopathologic disorders that share the common feature of vascular inflammation. The resulting disorder can vary depending on involvement of specific organs, caliber of blood vessels, the underlying inflammatory process, and individual host factors. The cumulative result is diminished blood flow, vascular alterations, and eventual occlusion with variable ischemia, necrosis, and tissue damage. An international revised nomenclature system provides the necessary nosology and findings relevant to classify each of the vasculitides. This article is an introduction and overview of the clinical presentation, differential diagnosis, laboratory evaluation, and treatment of systemic and nervous system vasculitides.

Epidemiology of Peripheral Neuropathy and Lower Extremity Disease in Diabetes

PURPOSE OF REVIEW

Diabetic peripheral neuropathy eventually affects nearly 50% of adults with diabetes during their lifetime and is associated with substantial morbidity including pain, foot ulcers, and lower limb amputation. This review summarizes the epidemiology, risk factors, and management of diabetic peripheral neuropathy and related lower extremity complications.

RECENT FINDINGS

The prevalence of peripheral neuropathy is estimated to be between 6 and 51% among adults with diabetes depending on age, duration of diabetes, glucose control, and type 1 versus type 2 diabetes. The clinical manifestations are variable, ranging from asymptomatic to painful neuropathic symptoms. Because of the risk of foot ulcer (25%) and amputation associated with diabetic peripheral neuropathy, aggressive screening and treatment in the form of glycemic control, regular foot exams, and pain management are important. There is an emerging focus on lifestyle interventions including weight loss and physical activity as well. The American Diabetes Association has issued multiple recommendation statements pertaining to diabetic neuropathies and the care of the diabetic foot. Given that approximately 50% of adults with diabetes will be affected by peripheral neuropathy in their lifetime, more diligent screening and management are important to reduce the complications and health care burden associated with the disease.