Magnetic resonance imaging in cancer-related lumbosacral plexopathy

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.

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.

Multiple Cranial Neuropathies in a Patient with Diffuse Large B-cell Lymphoma: Case Report and Review of Literature

Neuropathies can occur in patients with diffuse large B-cell lymphoma (DLBCL) at any stage of the disease as a presenting symptom or during later stages of illness. A wide spectrum of neurological association is known to occur with DLBCL, ranging from cranial nerve palsies to peripheral neuropathies. Evaluation of cranial and peripheral neuropathies in patients with DLBCL requires meticulous clinical, imaging, and electrodiagnostic testing. A 75-year-old right-handed female with a known history of multiple cranial neuropathies and DLBCL presented with acute dysphagia and upper extremity weakness of one-week duration. On evaluation, she was found to have right vagal nerve palsy. Cerebrospinal fluid (CSF) analysis along with flow cytometry testing showed CD19 and CD20 positive B cells, confirming neoplastic infiltration of CSF. We describe the case and review the literature of the association of cranial nerve palsies with DLBCL.

Plexus and peripheral nerve metastasis

Cancer in the form of solid tumors, leukemia, and lymphoma can infiltrate and metastasize to the peripheral nervous system, including the cranial nerves, nerve roots, cervical, brachial and lumbosacral plexuses, and, rarely, the peripheral nerves. This review discusses the presentation, diagnostic evaluation, and treatment options for metastatic lesions to these components of the peripheral nervous system and is organized based on the anatomic distribution. As skull base metastases (also discussed in Chapter 14) result in cranial neuropathies, these will be covered in detail, as well as cancers that directly infiltrate the cranial nerves. Particular emphasis is placed on the clinical, imaging, and electrodiagnostic features that differentiate neoplastic plexopathies from radiation-induced plexopathies. Neurolymphomatosis, in which malignant lymphocytes invade the cranial nerves, nerve roots, brachial and lumbosacral plexuses, and peripheral nerves, is a rare manifestation of lymphoma and leukemia. Diagnoses of neurolymphomatosis are often missed or delayed given its varied presentations, resulting in poorer outcomes. Thus this disease will also be discussed in depth.

Neuropathies associated with lymphoma†

Neuropathy occurs with various manifestations as a consequence of lymphoma, and an understanding of the etiology is necessary for proper treatment. Advances in medical imaging have improved the detection of peripheral nerve involvement in lymphoma, yet tissue diagnosis is often equally important. The neoplastic involvement of the peripheral nervous system (PNS) in lymphoma can occur within the cerebrospinal fluid (CSF), inside the dura, or outside of the CSF space, affecting nerve root plexuses and peripheral nerves. The infiltration of either cranial or peripheral nerves in lymphoma is termed neurolymphomatosis (NL). These infiltrations can occur as mononeuropathy, multifocal neuropathy, symmetric neuropathies, or plexopathies. In rare cases, intravascular lymphoma (IL) can affect the PNS and an even rarer condition is the combination of NL and IL. Immune-mediated and paraneoplastic neuropathies are important considerations when treating patients with lymphoma. Demyelinating neuropathies, such as Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy, occur more frequently in non-Hodgkin's lymphoma than in Hodgkin's disease. Paraproteinemic neuropathies can be associated with lymphoma and paraneoplastic neuropathies are rare. While the treatment of lymphomas has improved, a knowledge of neurotoxic, radiotherapy, neoplastic, immune-mediated and paraneoplastic effects are important for patient care.

Lumbosacral plexopathy

PURPOSE OF REVIEW

This article provides an up-to-date review of the clinical features and pathogenesis of different types of lumbosacral plexopathy and a clinical approach to their evaluation and management. Often, the pathologic involvement is not limited to the plexus and also involves the root and nerve levels. These conditions are called lumbosacral radiculoplexus neuropathies.

RECENT FINDINGS

The pathophysiology of diabetic and nondiabetic lumbosacral radiculoplexus neuropathy has been elucidated; it is ischemic injury due to a perivascular inflammatory process and microvasculitis. The clinical and neurophysiologic features of these two entities have been found to be similar, consisting of acute or subacute onset of pain and paresthesia followed by profound motor weakness asymmetrically involving the lower limbs and associated with weight loss. A lower limb and motor predominant neuropathy without pain also occurs in diabetes mellitus and has been shown to be a form of diabetic lumbosacral radiculoplexus neuropathy and not diabetic chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). The pathophysiology of some cases of postsurgical lumbosacral plexopathies has recently been shown also to be inflammatory from microvasculitis, and treatment with immunotherapy in a timely fashion may be desirable.

SUMMARY

Many pathophysiologic processes, such as neoplastic, traumatic, infectious, radiation, and inflammatory/microvasculitic processes, can affect the lumbosacral plexus causing lumbosacral plexopathy. The clinical symptoms and signs depend on the part of the plexus involved and the temporal course. Management depends on the cause of the lumbosacral plexopathy. Many cases of lumbosacral plexopathy previously thought to be idiopathic have been shown to be caused by ischemic injury from microvasculitis; despite lack of evidence for efficacy in improving neurologic deficits, the authors of this article include immunotherapy in their management of patients with this condition.

Perineural tumor spread of bladder cancer causing lumbosacral plexopathy: an anatomic explanation

We present two cases of biopsy-proven neoplastic lumbosacral plexopathy from perineural spread of bladder cancer: one patient presented with predominantly sciatic nerve involvement and the second predominantly with obturator nerve involvement. These two patterns of perineural spread from bladder cancer were supported by imaging in our cases and solidified by review of the literature. Based on the innervation of the bladder, we provide an anatomic explanation for this observation. To our best knowledge, such an anatomic, mechanistic basis for perineural tumor spread in bladder cancer has not yet been described.

High-resolution 3-T MR neurography of the lumbosacral plexus

The lumbosacral plexus comprises a network of nerves that provide motor and sensory innervation to most structures of the pelvis and lower extremities. It is susceptible to various traumatic, inflammatory, metabolic, and neoplastic processes that may lead to lumbrosacral plexopathy, a serious and often disabling condition whose course and prognosis largely depend on the identification and cure of the causative condition. Whereas diagnosis of lumbrosacral plexopathy has traditionally relied on patients' medical history, clinical examination, and electrodiagnostic tests, magnetic resonance (MR) neurography plays an increasingly prominent role in noninvasive characterization of the type, location, and extent of lumbrosacral plexus involvement and is developing into a useful diagnostic tool that substantially affects disease management. With use of 3-T MR imagers, improved coils, and advanced imaging sequences, which provide exquisite spatial resolution and soft-tissue contrast, MR neurography provides excellent depiction of the lumbrosacral plexus and its peripheral branches and may be used to confirm a diagnosis of lumbrosacral plexopathy with high accuracy or provide superior anatomic information should surgical intervention be necessary.

Pelvic radiculopathies, lumbosacral plexopathies, and neuropathies in oncologic disease: a multidisciplinary approach to a diagnostic challenge

The purpose of this article is to familiarize the reader with the anatomy of the major pelvic nerves and the clinical features of associated lumbosacral plexopathies. To demonstrate this we illustrate several cases of malignant lumbosacral plexopathy on computed tomography, magnetic resonance imaging, and positron emission tomography/computed tomography. A new lumbosacral plexopathy in a patient with a prior history of abdominal or pelvic malignancy is usually of malignant etiology. Biopsies may be required to definitively differentiate tumour from posttreatment fibrosis, and in cases of inconclusive sampling or where biopsies are not possible, follow-up imaging may be necessary. In view of the complexity of clinical findings often confounded by a history of prior surgery and/or radiotherapy, a multidisciplinary approach between oncologists, neurologists, and radiologists is often required for what can be a diagnostic challenge.

Diagnosis of brachial and lumbosacral plexus lesions

To most doctors, brachial and lumbosacral plexopathies are known as difficult disorders, because of their complicated anatomy and relatively rare occurrence. Both the brachial, lumbar, and sacral plexuses are extensive PNS structures stretching from the neck to axillary region and running in the paraspinal lumbar and pelvic region, containing 100000-200000 axons with 12-15 major terminal branches supplying almost 50 muscles in each limb. The most difficult part in diagnosing a plexopathy is probably that it requires an adequate amount of clinical suspicion combined with a thorough anatomical knowledge of the PNS and a meticulous clinical examination. Once a set of symptoms is recognized as a plexopathy the patients' history and course of the disorder will often greatly limit the differential diagnosis. The most common cause of brachial plexopathy is probably neuralgic amyotrophy and the most common cause of lumbosacral plexopathy is diabetic amyotrophy. Traumatic and malignant lesions are fortunately rarer but just as devastating. This chapter provides an overview of both common and rarer brachial and lumbosacral plexus disorders, focusing on clinical examination, the use of additional investigative techniques, prognosis, and treatment.

Adenocarcinoma of the prostate involving the lumbosacral plexus: MRI evidence to support direct perineural spread

BACKGROUND

Prostate adenocarcinoma, which may recur despite aggressive treatment, has the potential to spread to the lumbosacral plexus. This intraneural involvement is not widely known and is thought to be from direct perineural spread. We hypothesized that high-resolution imaging could provide supportive evidence for this mechanism.

METHODS

The clinical data and imaging studies (magnetic resonance imaging, MRI, and positron emission tomography/computed tomography, PET/CT) of patients evaluated at our institution between 2004 and 2009 for lumbosacral plexopathy due to intraneural prostate carcinoma were retrospectively reviewed.

RESULTS

Four patients presenting with painful lumbosacral plexopathy were found to have intraneural lumbosacral prostate adenocarcinoma. Two patients had involvement of the lumbosacral plexus ipsilateral to the lobe of the prostate most involved with adenocarcinoma at prostatectomy. High-resolution MRI and PET/CT studies revealed similar findings: abnormal soft tissue signal was followed from the prostate (n = 1) or prostatic bed (n = 3) area along the expected course of the pelvic plexus to the level of the sciatic notch, where it involved the sacral spinal nerves and sciatic nerve. Imaging findings were consistent with neoplastic infiltration, which was confirmed at biopsy in three patients.

CONCLUSIONS

The potential for prostate adenocarcinoma to spread to the lumbosacral plexus has, to our knowledge, not been readily appreciated. Because the imaging findings are often subtle, we believe that intraneural lumbosacral plexus involvement may not be uncommon. This study, with the use of high-resolution MRI and PET/CT studies, supports the direct perineural spread of prostate adenocarcinoma via the pelvic plexus to the lumbosacral plexus. This mechanism could also explain cases of leptomeningeal and/or dural-based prostate metastases.

Neurotoxicity of radiation therapy

Direct or incidental exposure of the nervous system to therapeutic irradiation carries the risk of symptomatic neurologic injury. Central nervous system toxicity from radiation includes focal cerebral necrosis, neurocognitive deficits, and less commonly cerebrovascular disease, myelopathy, or the occurrence of a radiation-induced neoplasm. Brachial or lumbosacral plexopathy are the most common syndromes of radiation toxicity affecting the peripheral nervous system. This article focuses on the clinical features, diagnosis, and management options for patients with radiation neurotoxicity.

Causes of lumbosacral plexopathy

The lumbosacral plexus represents the nerve supply to the lower back, pelvis and legs. This review will focus on diseases and disorders affecting the pathway as demonstrated by magnetic resonance imaging (MRI) and computed tomography (CT). We stress the need to review the lumbosacral plexus in patients with non-specific symptoms such as back, hip, pelvic pain, and in those who present with sciatica unaccompanied by demonstrable intervertebral disc prolapse. We illustrate that the imaging appearances may be non-specific and re-inforce the importance of the clinical history and the use of tissue sampling to achieve an accurate diagnosis.

Peripheral nervous system involvement in patients with cancer

Involvement of the peripheral nervous system (PNS) is common in patients with cancer and any part, including motor neurons, sensory ganglia, nerve roots, plexuses, cranial and peripheral nerves, and neuromuscular junctions, can be affected. Different mechanisms can initiate damage associated with cancer-related PNS disorders. These include tumour infiltration, toxicity of treatments, metabolic and nutritional perturbations, cachexia, virus infections, and paraneoplastic neurological syndromes. The type of cancer, lymphoma, or solid tumour is a further determinant of a PNS disorder. In this Review we discuss the different causes and mechanisms of disorders of the PNS in patients with cancer and we will focus on their assessment and diagnosis.

Regional Cancer Pain Syndromes

Cancer pain often presents in a body region. This review summarizes articles from 1999-2004 relevant to cancer pain syndromes in the head and neck, chest, back, abdomen, pelvis, and limbs. Although the evidence is limited, progress is being made in further development of the evidence base to support and guide current practice.

Neoplastic lumbosacral radiculoplexopathy in prostate cancer by direct perineural spread: An unusual entity

Neoplastic lumbosacral plexopathy occurs with some abdominal and pelvic malignancies. Patients present with severe pain radiating from the low back down to the lower extremities, and this progresses to weakness. Neoplastic lumbosacral plexopathy is virtually always associated with known malignancy or obvious pelvic metastatic disease. Uncommonly, prostate cancer can present as a lumbosacral plexopathy occurring through direct pelvic spread. We describe two cases of lumbosacral radiculoplexopathy from infiltrative prostate cancer without evidence of other pelvic or extraprostatic spread. The probable etiology of tumor spreading along prostatic nerves into the lumbosacral plexus (i.e., perineural spread) is discussed as are the potential mechanisms for this unusual mode of cancer dissemination.

Metastases to the peripheral nervous system

Cancer metastasis can affect any part of the nervous system. When the peripheral nervous system is involved, the usual targets are cranial nerves, nerve roots and plexi. However, peripheral nerves and muscles can also be affected by compression or infiltration of neoplastic cells. This review focuses in the diagnosis and treatment of metastatic complications of cancer involving plexi, peripheral nerves and muscles.

Lymphoma and peripheral neuropathy: a clinical review

Lymphoma occasionally affects the peripheral nervous system. When it does, the diagnosis can be elusive since many patients present without known lymphoma. Most peripheral nerve complications are due to non-Hodgkin's lymphoma (NHL), which infiltrates nerves causing axonal damage. This disorder can affect nerve roots and cranial nerves, often associated with lymphomatous meningitis. NHL may also infiltrate peripheral nerves and cause plexopathy, mononeuropathy, or generalized neuropathy. These neuropathies may resemble an asymmetric mononeuropathy multiplex or a generalized disorder such as chronic inflammatory demyelinating polyradiculoneuropathy. When NHL infiltrates diffusely, the term neurolymphomatosis is used. Hodgkin's lymphoma (HL), by contrast, rarely infiltrates nerves. More often, HL causes immunological disorders of the peripheral nervous system such as inflammatory plexopathy or Guillain-Barré syndrome. Other rare lymphomas such as intravascular lymphoma and Waldenstrom's macroglobulinemia can also affect peripheral nerves in specific ways. In addition, other malignant and nonmalignant lymphoproliferative disorders enter into the differential diagnosis of lymphomatous neuropathy. This review discusses the multiple peripheral nerve presentations of lymphoma from the clinician's point of view and provides a guide to the evaluation and diagnosis of these uncommon, challenging disorders.

The management of malignant psoas syndrome: case reports and literature review

Malignant psoas syndrome (MPS) was first described in 1990, and is characterized by proximal lumbosacral plexopathy, painful fixed flexion of the ipsilateral hip, and radiological or pathological evidence of ipsilateral psoas major muscle malignant involvement. There have been 23 case reports of MPS in medical journals. Despite being associated with a severe and difficult pain, there is no definitive approach to management presented in the palliative care literature. We review the relevant clinical features and the subsequent multidisciplinary pain management in relation to four new cases of malignant involvement of the psoas muscle, and the 23 case reports in the literature. We propose that MPS comprises a continuum of symptoms and signs related to the degree of anatomical destruction with associated inflammatory reaction and muscle spasm, and also the degree of lumbosacral plexopathy causing neuropathic pain. A protocol is presented for the management of the complex pain issues of MPS directed at likely mechanisms. The treatment options include opioids, agents for neuropathic pain, muscle relaxants to manage psoas muscle spasm, and anti-inflammatory agents to reduce peritumoral edema. Direct anti-tumor measures also need to be considered. Further prospective study is needed to validate the proposed methods of assessment and treatment.

Neuromuscular complications of cancer

Neuromuscular complications of cancer are common and can affect any component of the peripheral nervous system from peripheral nerve cell body to muscle. Perhaps the most common complication is a length-dependent symmetric axonal polyneuropathy that is often multifactorial in etiology, resulting from metabolic and treatment effects of the primary malignancy. However, neuromuscular disorders may also be the presenting complaint in many conditions, including disorders caused by malignant infiltration of nerve and disorders cause by paraneoplastic syndromes. Although many of the paraneoplastic conditions are poorly responsive to treatment, not all are, and one hopes that prompt diagnosis of the underlying malignancy will lead to improved patient outcome. Recognition of iatrogenic neuromuscular complications is also important to modify treatment protocols when possible and thus decrease the risk of long-term neurologic disability.

Regional pain syndromes in cancer patients

Pain is one of the cardinal presenting symptoms in cancer patients and often seems to progress in the natural history of the disease. In light of the past neglect of this problem, it is becoming crucial for clinicians and researchers in the fields of oncology, pain management, and others dealing with this patient population to have a thorough understanding of the often complex pain syndromes that are relevant to managing cancer. In this article we briefly review the important topics related to cancer pain syndromes with some emphasis on those that typically generate localized pain.

Sectional neuroanatomy of the lower limb I: lower back and hip

This series of two articles is structured to provide anatomically accurate functional schematics of the motor and sensory innervation of the lower back, hip, and lower limb. This first paper provides radiographically oriented schematic axial sections of the lower back and hip in which the muscles are appropriately color-coded to match the peripheral nerves. A companion color-coded summary table allows prediction of unique patterns of denervation from 25 lesion sites. These are divided into three categories (roots T12 to S4, four plexal quadrants, and 11 sectional levels). Correlation between an imaging abnormality at one of these lesion sites and the predicted denervation pattern ensures the lesion is, in fact, clinically significant. The next article will continue this color-coded approach into the lower limb.

Diagnostic investigations in cancer pain

Defining the specific cause of pain in patients with cancer often has substantial therapeutic and prognostic implications. This process often requires the use of specific diagnostic investigations. Here we critically review the diagnostic investigations used in the evaluation of common pain problems in patients with cancer. Familiarity with this information facilitates the development of efficient and rational diagnostic strategies.

Cancer pain: a neurological perspective

Nerve pain in cancer is common, mainly manifested by a radiculopathy associated with vertebral metastasis, by a plexopathy caused by lymph-node involvement or, more rarely, by trigeminal involvement in cancer of the head and neck. Less frequent types of nerve pain can occur as late effects of antitumour therapy, including surgery, radiation and chemotherapy. The distinction between a nociceptive and a non-nociceptive nerve pain helps in determining the most appropriate symptomatic management.

Acute lower extremity paralysis following radiation therapy for cervical cancer

BACKGROUND

Acute lower extremity paralysis secondary to lumbosacral plexopathy is a rare but severe complication that may follow pelvic radiotherapy for cervical cancer.

CASE

A 49-year-old female with newly diagnosed stage IIIB cervical cancer developed progressive bilateral lower extremity paralysis and pelvic pain only 10 weeks following completion of radiation therapy for cervical cancer with no evidence of metastasis or progression of disease. Her bladder and bowel function were not affected. Following extensive workup, the most likely etiology was presumed radiation-induced lumbosacral plexopathy.

CONCLUSION

Although metastatic carcinoma is more commonly the reason for progressive lower extremity weakness with pelvic pain in women with advanced cervical cancer, radiation-induced lumbosacral plexopathy, a rare but devastating complication, may be the cause. Diagnosis is by exclusion.