Lhermitte's sign among nasopharyngeal cancer patients after radiotherapy

Neurological complications of modern radiotherapy for head and neck cancer

Radiotherapy is one of the mainstay treatment modalities for the management of non-metastatic head and neck cancer (HNC). Notable improvements in treatment outcomes have been observed in the recent decades. Modern radiotherapy techniques, such as intensity-modulated radiotherapy and charged particle therapy, have significantly improved tumor target conformity and enabled better preservation of normal structures. However, because of the intricate anatomy of the head and neck region, multiple critical neurological structures such as the brain, brainstem, spinal cord, cranial nerves, nerve plexuses, autonomic pathways, brain vasculature, and neurosensory organs, are variably irradiated during treatment, particularly when tumor targets are in close proximity. Consequently, a diverse spectrum of late neurological sequelae may manifest in HNC survivors. These neurological complications commonly result in irreversible symptoms, impair patients' quality of life, and contribute to a substantial proportion of non-cancer deaths. Although the relationship between radiation dose and toxicity has not been fully elucidated for all complications, appropriate application of dosimetric constraints during radiotherapy planning may reduce their incidence. Vigilant surveillance during the course of survivorship also enables early detection and intervention. This article endeavors to provide a comprehensive review of the various neurological complications of modern radiotherapy for HNC, summarize the current incidence data, discuss methods to minimize their risks during radiotherapy planning, and highlight potential strategies for managing these debilitating toxicities.

Neurologic Complications of Conventional Chemotherapy and Radiation Therapy

OBJECTIVE

Neurologic complications are among the most common and feared outcomes of cancer treatments. This review discusses the signs and symptoms, mechanisms, and management of the most common peripheral and central neurologic complications of chemotherapy, radiation therapy, and antiangiogenic therapy during cancer treatment and in survivors.

LATEST DEVELOPMENTS

The landscape of cancer treatments is evolving to include more targeted and biologic therapies, in addition to more traditional cytotoxic therapies and radiation therapy. With increasingly complex regimens and longer survival for patients with cancer, the early recognition and management of neurologic complications is key to improving the morbidity and mortality of patients living with cancer.

ESSENTIAL POINTS

Neurologists should be familiar with acute central and peripheral toxicities that can occur during cancer treatment and delayed toxicities that can occur years after exposure. Neurologists should be familiar with the clinical and radiologic presentations of these complications and strategies for management.

A systematic review of the symptomatic management of Lhermitte's phenomenon

INTRODUCTION

Lhermitte's phenomenon (LP) is a transient shock-like sensation that radiates down the spine into the extremities, usually with neck flexion. The potential efficacy and tolerability of various symptomatic therapies in the management of LP have not been systematically reviewed previously.

METHOD

A systematic review was conducted using PubMed, EMBASE, and the Cochrane Library from inception to August 2022 for peer-reviewed articles describing the treatment of patients with Lhermitte's phenomenon. The review adheres to the PRISMA guidelines and was registered on PROSPERO.

RESULTS

This systematic review included sixty-six articles, which included 450 patients with LP. Treatment of the underlying cause varied by aetiology. Whilst LP is most commonly considered in the context of structural pathology of the cervical cord, medication-induced LP was a common theme in the literature. The most common cause of medication-induced LP was platinum-based chemotherapy agents such as cisplatin and oxaliplatin. In medication-induced LP, symptoms typically resolved with cessation of the causative agent. Non-pharmacological treatment options were associated with mild-moderate symptomatic improvement. The most commonly used agents to treat patients with LP were carbamazepine and gabapentin, which resulted in variable degrees of symptomatic benefit.

CONCLUSIONS

No randomised studies currently exist to support the use of symptomatic therapies to treat LP. Observational data suggest that some therapies may yield a symptomatic benefit in the management of LP. However, this systematic review identified a significant paucity of evidence in the literature, which suggests that further controlled studies are needed to investigate the optimal management of this common neurologic phenomenon.

Metabolic and Toxic Myelopathies

Metabolic and toxic causes of myelopathy form a heterogeneous group of disorders. In this review, we discuss the causes of metabolic and toxic myelopathies with respect to clinical presentation, pathophysiology, diagnostic testing, treatment, and prognosis. This review is organized by temporal course (hyperacute, acute, subacute, and chronic) and etiology (e.g., nutritional deficiency, toxic exposure). Broadly, the myelopathies associated with dietary toxins (neurolathyrism, konzo) and decompression sickness present suddenly (hyperacute). The myelopathies associated with heroin use and electrical injury present over hours to days (acutely). Most nutritional deficiencies (cobalamin, folate, copper) and toxic substances (nitrous oxide, zinc, organophosphates, clioquinol) cause a myelopathy of subacute onset. Vitamin E deficiency and hepatic myelopathy cause a chronic myelopathy. Radiation- and intrathecal chemotherapy-induced myelopathy can cause a transient and/or a progressive syndrome. For many metabolic and toxic causes of myelopathy, clinical deficits may stabilize or improve with rapid identification and treatment. Familiarity with these disorders is therefore essential.

Neurological complications of systemic tumor therapy

The treatment of malignant tumors has considerably improved in recent years, and also the number of "long term cancer survivors" is increasing.The spectrum of anti-tumoral agents is increasing at a fast pace and in addition to conventional therapies such as surgery, radiotherapy, and chemotherapy, new drugs with entirely new mechanisms are appearing. Side effects of old and new drugs can affect the central and peripheral nervous system, the neuromuscular junction, and muscle. These side effects often have to be distinguished from other causes and need neurological expertise. Although the majority of patients still receive conventional therapies, several new strategies such as immune therapies are being implemented. These drugs have also drug specific side effects, which do not always follow the classical principles of "toxicity."This review focuses on the well-known and described side effects of conventional cancer therapies and adds new observations on new drugs.

Identifying risk factors for L'Hermitte's sign after IMRT for head and neck cancer

BACKGROUND

L'Hermitte's sign (LS) after chemoradiotherapy for head and neck cancer appears related to higher spinal cord doses. IMRT plans limit spinal cord dose, but the incidence of LS remains high.

METHODS

One hundred seventeen patients treated with TomoTherapy™ between 2008 and 2015 prospectively completed a side-effect questionnaire (VoxTox Trial Registration: UK CRN ID 13716). Baseline patient and treatment data were collected. Radiotherapy plans were analysed; mean and maximum spinal cord dose and volumes receiving 10, 20, 30 and 40 Gy were recorded. Dose variation across the cord was examined. These data were included in a logistic regression model.

RESULTS

Forty two patients (35.9%) reported LS symptoms. Concurrent weekly cisplatin did not increase LS risk (p = 0.70, OR = 1.23 {95% CI 0.51-2.34}). Of 13 diabetic participants (9 taking metformin), only 1 developed LS (p = 0.025, OR = 0.13 {95% CI 0.051-3.27}). A refined binary logistic regression model showed that patients receiving unilateral radiation (p = 0.019, OR = 2.06 {95% CI 0.15-0.84}) were more likely to develop LS. Higher V_40Gy (p = 0.047, OR = 1.06 {95% CI 1.00-1.12}), and younger age (mean age 56.6 vs 59.7, p = 0.060, OR = 0.96 {95% CI 0.92-1.00}) were associated with elevated risk of LS, with borderline significance.

CONCLUSIONS

In this cohort, concomitant cisplatin did not increase risk, and LS incidence was lower in diabetic patients. Patient age and dose gradients across the spinal cord may be important factors.

Dose escalation via brachytherapy boost for nasopharyngeal carcinoma in the era of intensity-modulated radiation therapy and combined chemotherapy

To investigate if dose escalation using intracavitary brachytherapy (ICBT) improves local control for nasopharyngeal carcinoma (NPC) in the era of intensity-modulated radiation therapy (IMRT) and concurrent chemoradiation treatment (CCRT). We retrospectively analyzed 232 patients with Stage T1-3 N0-3 M0 NPC who underwent definitive IMRT with or without additional ICBT boost between 2002 and 2013. For most of the 124 patients who had ICBT boost, the additional brachytherapy was given as 6 Gy in 2 fractions completed within 1 week after IMRT of 70 Gy. CCRT with or without adjuvant chemotherapy was used for 176 patients, including 88 with and 88 without ICBT boost, respectively. The mean follow-up time was 63.1 months. The 5-year overall survival and local control rates were 81.5% and 91.5%, respectively. ICBT was not associated with local control prediction (P = 0.228). However, in a subgroup analysis, 75 T1 patients with ICBT boost had significantly better local control than the other 71 T1 patients without ICBT boost (98.1% vs 85.9%, P = 0.020), despite having fewer patients who had undergone chemotherapy (60.0% vs 76.1%, P = 0.038). Multivariate analysis showed that both ICBT (P = 0.029) and chemotherapy (P = 0.047) influenced local control for T1 patients. Our study demonstrated that dose escalation with ICBT can improve local control of the primary tumor for NPC patients with T1 disease treated with IMRT, even without chemotherapy.

Lhermitte's Sign following VMAT-Based Head and Neck Radiation-Insights into Mechanism

Purpose/Objectives

We observed a number of patients who developed Lhermitte’s sign (LS) following radiation to the head and neck (H/N), since instituting volumetric modulated arc therapy (VMAT). We aimed to investigate the incidence of LS following VMAT-based RT without chemotherapy, and determine the dosimetric parameters that predict its development. We explored whether the role of inhomogeneous dose distribution across the spinal cord, causing a “bath-and-shower” effect, explains this finding.

Methods and Materials

From 1/20/2010–12/9/2013, we identified 33 consecutive patients receiving adjuvant RT using VMAT to the H/N without chemotherapy at our institution. Patients’ treatment plans were analyzed for dosimetric parameters, including dose gradients along the anterior, posterior, right, and left quadrants at each cervical spine level. Institutional Review Board approval was obtained.

Results

5 out of 33 (15.2%) patients developed LS in our patient group, all of whom had RT to the ipsilateral neck only. LS patients had a steeper dose gradient between left and right quadrants across all cervical spine levels (repeated-measures ANOVA, p = 0.030). Within the unilateral treatment group, LS patients received a higher mean dose across all seven cervical spinal levels (repeated-measures ANOVA, p = 0.046). Dose gradients in the anterior-posterior direction and mean doses to the cord were not significant between LS and non-LS patients.

Conclusions

Dose gradients along the axial plane of the spinal cord may contribute to LS development; however, a threshold dose within the high dose region of the cord may still be required. This is the first clinical study to suggest that inhomogeneous dose distributions in the cord may be relevant in humans. Further investigation is warranted to determine treatment-planning parameters associated with development of LS.

Incidence and predictors of Lhermitte's sign among patients receiving mediastinal radiation for lymphoma

PURPOSE

To prospectively examine the risk of developing Lhermitte's sign (LS) in patients with lymphoma treated with modern-era chemotherapy followed by consolidation intensity-modulated radiation therapy.

METHODS

We prospectively interviewed all patients with lymphoma who received irradiation to the mediastinum from July 2011 through April 2014. We extracted patient, disease, and treatment-related variables from the medical records of those patients and dosimetric variables from treatment-planning systems and analyzed these factors to identify potential predictors of LS with Pearson chi-square tests.

RESULTS

During the study period 106 patients received mediastinal radiation for lymphoma, and 31 (29 %) developed LS. No correlations were found between LS and any of the variables examined, including total radiation dose, maximum point dose to the spinal cord, volume receiving 105 % of the dose, and volumes receiving 5 or 15 Gy.

CONCLUSION

In this group of patients, treatment with chemotherapy followed by intensity-modulated radiation therapy led to 29 % developing LS; this symptom was independent of radiation dose and seemed to be an idiosyncratic reaction. This relatively high incidence could have resulted from prospective use of a structured interview.

Radiation therapy in neurologic disease

Radiotherapy is a primary mode of treatment of many of the disease entities seen by the neurologist. Therefore knowledge of how ionizing radiation works and when it is indicated is a crucial part of the field of Neurology. The neurologist may also be confronted with some of the side effects and complications or radiotherapy treatment. This chapter attempts to serve as a review of the current day process of radiotherapy, a brief review of biology and physics of radiation, and how it is used in the treatment diseases which are common to the Neurologist. In addition we review the more commonly seen side effects and complications of treatment which may be seen by the neurologist.

Lhermitte sign after chemo-IMRT of head-and-neck cancer: incidence, doses, and potential mechanisms

PURPOSE

We have observed a higher rate of Lhermitte sign (LS) after chemo-intensity-modulated radiotherapy (IMRT) of head-and-neck cancer than the published rates after conventional radiotherapy. We hypothesized that the inhomogeneous spinal cord dose distributions produced by IMRT caused a "bath-and-shower" effect, characterized by low doses in the vicinity of high doses, reducing spinal cord tolerance.

METHODS AND MATERIALS

Seventy-three patients with squamous cell carcinoma of the oropharynx participated in a prospective study of IMRT concurrent with weekly carboplatin and paclitaxel. Of these, 15 (21%) reported LS during at least 2 consecutive follow-up visits. Mean dose, maximum dose, and partial volume and absolute volume (in milliliters) of spinal cord receiving specified doses (≥10 Gy, ≥20 Gy, ≥30 Gy, and ≥40 Gy), as well as the pattern of dose distributions at the "anatomic" spinal cord (from the base of the skull to the aortic arch) and "plan-related" spinal cord (from the top through the bottom of the planning target volumes), were compared between LS patients and 34 non-LS patients.

RESULTS

LS patients had significantly higher spinal cord mean doses, V(30), V(40), and absolute volumes receiving 30 Gy or more and 40 Gy or more compared with the non-LS patients (p < 0.05). The strongest predictors of LS were higher V(40) and higher cord volumes receiving 40 Gy or more (p ≤ 0.007). There was no evidence of larger spinal cord volumes receiving low doses in the vicinity of higher doses (bath-and-shower effect) in LS compared with non-LS patients.

CONCLUSIONS

Greater mean dose, V(30), V(40), and cord volumes receiving 30 Gy or more and 40 Gy or more characterized LS compared with non-LS patients. Bath-and-shower effects could not be validated in this study as a potential contributor to LS. The higher-than-expected rates of LS may be because of the specific concurrent chemotherapy agents or more accurate identification of LS in the setting of a prospective study.

Neurologic complications of cancer and its treatment

The central nervous system (CNS) and peripheral nervous system (PNS) are very susceptible to cancer and its treatment. The most direct involvement of the nervous system manifests in the development of primary brain and spinal cord tumors. Many cancers exhibit a propensity toward spread to the CNS, and brain metastases are common problems seen in malignancies such as lung, breast, and melanoma. Such spread may involve the brain or spine parenchyma or the subarachnoid space. In the PNS, spread is usually through direct infiltration of nerve roots, plexi, or muscle by neighboring malignancies. In some cases, cancer has sudden, devastating effects on the nervous system: epidural spinal cord compression or cord transection from pathologic fractures of vertebra involved by cancer; increased intracranial pressure from intracranial mass lesion growth and edema; and uncontrolled seizure activity as a result of intracranial tumors (status epilepticus), which are neuro-oncologic emergencies. The best known indirect or remote effects of cancer on the nervous system are the neurologic paraneoplastic syndromes. Cancer can also result in a hypercoagulable state causing cerebrovascular complications. Treatment of cancer can have neurologic complications. The commonest of these complications are radiation-induced injury to the brain, spine, and peripheral nerves and chemotherapy-induced peripheral neuropathy. The suppressant effect of cancer and its treatment on the body's immune system can result in infectious complications within the nervous system.

Lhermitte's Sign Developing after IMRT for Head and Neck Cancer

Background. Lhermitte's sign (LS) is a benign form of myelopathy with neck flexion producing an unpleasant electric-shock sensation radiating down the extremities. Although rare, it can occur after head and neck radiotherapy. Results. We report a case of Lhermitte's developing after curative intensity-modulated radiotherapy (IMRT) for a patient with locoregionally advanced oropharyngeal cancer. IMRT delivers a conformal dose of radiation in head and neck cancer resulting in a gradient of radiation dose throughout the spinal cord. Using IMRT, more dose is delivered to the anterior spinal cord than the posterior cord. Conclusions. Lhermitte's sign can develop after IMRT for head and neck cancer. We propose an anterior spinal cord structure, the spinothalamic tract to be the target of IMRT-caused LS.

Lhermitte's sign, electric shock sensations and high dose ecstasy consumption: preliminary findings

The objectives of this study were to perform a preliminary investigation into the nature of electric shock-like experiences reported in association with the use of ecstasy tablets thought to contain methylenedioxymethamphetamines (MDMA). This included exploration of reports of electric shock-like experiences from the user's perspectives and identification of other variables that may be associated with their development. Furthermore we aimed to examine whether the well-recognised electric shock-like symptom, Lhermitte's sign (LS), is associated with ecstasy tablet use in some drug users. A single measure, cross-sectional survey was used incorporating mixed qualitative and quantitative methodology. A select group of ecstasy users (n = 35) recruited through a dance, music and lifestyle magazine completed a telephone interview. Lifetime prevalence of LS in the study population was 18% (n = 6). Development of LS was associated with use of more ecstasy tablets before a typical incident. This study indicates a relationship may exist between the use of ecstasy tablets and LS. The relationship may be dose dependent. The majority of the study population used other substances including alcohol when experiencing electrical shock sensations. LS may explain only a proportion of all electrical shock experiences among ecstasy users.

Lhermitte's sign: Review with special emphasis in oncology practice

Lhermitte's sign (LS) is characterized by electric shock like sensation, spreading along the spine in a cervico-caudal direction and also into both arms and legs, which is felt upon forward flexion of the neck. It is a myelopathy resulting from damage to sensory axons at the dorsal columns of the cervical or thoracic spinal cord and a well-known clinical sign in neurology practice. Patients with cancer may present with LS due to various causes either related to the tumor itself or to its treatment. Spinal cord tumors, radiotherapy and chemotherapy are possible causes of LS observed in oncology practice. While LS is observed with a frequency of 3.6-13% in large patient groups receiving radiotherapy for head and neck and thoracic malignancies, the true incidence of chemotherapy and spinal cord tumor induced LS is unknown with only few reported cases in the literature. In the present article, various pathologies causing Lhermitte's sign are reviewed with special emphasis on the implications of this sign in oncology practice.

Differential diagnosis of T2 hyperintense spinal cord lesions: Part A

Hyperintense spinal cord signal on T2-weighted images is seen in a wide-ranging variety of spinal cord processes including; simple MR artefacts, congenital anomalies and most disease categories. Characterization of the abnormal areas of T2 signal as well as their appearance on other MR imaging sequences, when combined with clinical context and laboratory investigations, will often allow a unique diagnosis, or at least aid in narrowing the differential diagnosis. A wide range of instructive cases is discussed here with review of the published reports focusing on pertinent MR features to aid in diagnosis.

Lhermitte's sign and vitamin B12 deficiency: case report

CONTEXT AND OBJECTIVE

Lhermitte's sign, a classical neurological sign, is a rare manifestation of vitamin B12 deficiency. The aim here was to report on a case of an elderly patient with vitamin B12 deficiency whose first clinical manifestation was the presence of Lhermitte's sign.

CASE REPORT

We describe an elderly patient with vitamin B12 deficiency who presented cognitive dysfunction, peripheral polyneuropathy and sensory ataxia, and whose first clinical manifestation was the presence of Lhermitte's sign. This sign is one of the rarest manifestations of vitamin B12 deficiency.