Syringomyelia Associated with Chiari 1 Malformation in Adults: Positive Outcome Predictors after Posterior Fossa Decompression with Duraplasty

BACKGROUND

Syringomyelia (Syr) in patients with Chiari 1 malformation (CM1) may be attributable to abnormal dynamics of cerebrospinal fluid (CSF) in the upper cervical segment; fourth ventricle enlargement has been reported in association with a worse clinical and radiological presentation, independently of the posterior fossa volume. In this study, we analyzed presurgery hydrodynamic markers to evaluate if their changes could be associated with clinical and radiological improvement after posterior fossa decompression and duraplasty (PFDD). As a primary endpoint, we aimed to correlate improvement in the fourth ventricle area with positive clinical outcomes.

METHODS

In total, in this study, we enrolled 36 consecutive adults with Syr and CM1 who were followed by a multidisciplinary team. All the patients were prospectively evaluated with clinical scales and neuroimaging, including CSF flow, the fourth ventricle area, and the Vaquero Index by using a phase-contrast MRI before (T0) and after surgical treatment (T1-Tlast, with a range of 12-108 months). The CSF flow at the craniocervical junction (CCJ), the fourth ventricle area, and the Vaquero Index changes were statistically analyzed and compared to the clinical and quality of life improvement after surgery. The good outcome prediction ability of presurgical radiological variables was tested.

RESULTS

Surgery was associated with positive clinical and radiological outcomes in more than 90% of cases. The fourth ventricle area significantly reduced after surgery (T0-Tlast, p = 0.0093), but no significant associations with clinical improvement were found. The presurgical presence of CSF flow at the CCJ was able to predict a good outcome (AUC = 0.68, 95% CI 0.50-0.87 and LH+ = 2.1, IC 95% 1.16-3.07) and was also significantly associated with post-surgical pain relief (rho = 0.61 and p = 0.0144).

CONCLUSIONS

Presurgery CSF flow at the CCJ is proposed as a radiological marker with the ability to predict a positive outcome after PFDD in adults with syringomyelia and CM1. Measurements of the fourth ventricle area could be useful additional information for evaluating surgical long-term follow-up; further experience on larger cohorts is required to better define the prognostic yield of this radiological parameter.

Chiari Malformation Type 1 and Syringomyelia: Why Do Patients Claim for International Guidelines? Commentary on the 2021 Chiari and Syringomyelia Consensus Document

The diagnosis of Chiari malformation type 1 (CM1) and Syringomyelia (Syr) has become increasingly common during the past few years. Contemporarily, the body of literature on these topics is growing, although randomized controlled studies on significant case series to drive guidelines are missing in the pediatric and adult populations. As a result of the different opinions about surgical indications and techniques raised by CM1-Syr, an increasing number of well-informed but disoriented patients is emerging. To bridge this gap, an International Consensus Conference on CM1-Syr held in Milan in November 2019 aimed to find a consensus among international experts, to suggest some recommendations that, in the near future, could lead to guidelines. Here, we comment on the most relevant recommendations about the definition, diagnosis, surgical management, failures and re-intervention, and outcome. We also focus on some "wrong" indications or techniques that, although widely disapproved by the experts, and negatively experienced by many patients, are still largely in use.

Neurophysiological Correlates in Patients with Syringomyelia and Chiari Malformation: The Cortico-Diaphragmatic Involvement

Purpose. Brainstem syndromes have frequently been reported in Chiari syndrome and in syringobulbia; previous studies have shown that determining the central motor conduction time (CMCT) along the circuit of the phrenic nerve makes the assessment of the voluntary control of the respiratory pathway possible. In our study, we evaluated the transcranial magnetic stimulation (TMS) of the phrenic nerve in patients affected by Chiari syndrome and/or syringomyelia (Syr) with the aim of identifying subclinical neurophysiological alterations. Methods. One hundred patients (75 females; average age: 51 ± 13.08 SD; range: 18–76) affected by Chiari syndrome and/or Syr without dyspnea were selected. The magnetic stimulation of the second motor neuron correlating with the phrenic nerve was performed using cervical magnetic stimulation (C5-MEP); the cortical MEP after magnetic stimulation (Cz-MEP) was recorded by magnetic stimulation of the motor cortex (areas corresponding to the diaphragm). The CMCT was calculated. The differences between the patients and controls were calculated (Student’s t test). Results. In 13% of the patients, the Cz-MEP were absent bilaterally, and the CMCT was not evaluable. In all these cases, bulbar/cervical Syr was present at MRI; in 10 of them, this was associated with CM1. A bilateral response was obtained in all the other patients (87%), and the CMCTs were normal. All the patients with alterations/absence of Cz-MEP presented bulbar/cervical Syr at MRI. The C5-MEP latency was prolonged or absent in 48%; of these, 84% presented bulbar/cervical Syr associated with CM1 at MRI. The C5-MEP latency values were significantly higher in the group of patients. Conclusions. Neurophysiological alterations of the diaphragmatic pathway were recorded in a group of Chiari syndrome and, particularly, in bulbar/cervical Syr. Future studies with larger cohorts of patients are needed to further assess the specific role of the TMS of the phrenic nerve in CM/Syr patients.

Diagnosis and treatment of Chiari malformation type 1 in children: the International Consensus Document

BACKGROUND

Chiari malformation type 1 (CM1) is a rare condition where agreed classification and treatment are still missing. The goal of this study is to achieve a consensus on the diagnosis and treatment of CM1 in children.

METHODS

A multidisciplinary panel formulated 57 provisional statements based on a review of the literature. Thirty-four international experts (IE) participated in a Delphi study by independently rating each statement on a 4-point Likert scale ("strongly disagree," "disagree," "agree," "strongly agree"). Statements that were endorsed ("agree" or "strongly agree") by < 75% of raters were re-formulated, or new statements were added, and another Delphi round followed (up to a maximum of three).

RESULTS

Thirty-five IE were contacted and 34 agreed to participate. A consensus was reached on 30/57 statements (52.6%) after round 1. Three statements were added, and one removed. After round 2, agreement was reached on 56/59 statements (94.9%). Finally, after round 3, which took place during the 2019 Chiari Consensus Conference (Milan, Italy), agreement was reached on 58/59 statements (98.3%) about four main sections (Definition and Classification, Planning, Surgery, Isolated Syringomyelia). Only one statement did not gain a consensus, which is the "definition of radiological failure 24 month post-surgery."

CONCLUSIONS

The consensus document consists of 58 statements (24 on diagnosis, 34 on treatment), serving clinicians and researchers following children with CM1. There is a clear need for establishing an international network and registry and to promote collaborative studies to increase the evidence base and optimize the long-term care of this patient population.

The management of Chiari malformation type 1 and syringomyelia in children: a review of the literature

In anticipation of the "Chiari and Syringomyelia Consensus Conference" held in Milan in 2019, we performed a systematic literature review on the management of Chiari malformation type 1 (CM1) and syringomyelia (Syr) in children.We aimed to summarize the available evidence and identify areas where consensus has not been reached and further research is needed.In accordance with PRISMA guidelines, we formulated seven questions in Patients-Interventions-Comparators-Outcomes (PICO) format. Six PICOs concerned CM1 children with/without additional structural anomalies (Syr, craniosynostosis, hydrocephalus, tethered cord, and cranio-vertebral junction anomalies), and one PICO Syr without CM1. We searched Medline, Embase, Cochrane, and NICE databases from January 1, 1999, to May 29, 2019. Cohort studies, controlled and randomized clinical trials (CCTs, RCTs), and systematic reviews were included, all pertinent only to patients ≤ 18 years of age.For CM1, 3787 records were found, 460 full texts were assessed and 49 studies (46 cohort studies, one RCT, and two systematic reviews) were finally included. For Syr, 376 records were found, 59 full texts were assessed, and five studies (one RCT and four cohort studies) were included. Data on each PICO were synthetized narratively due to heterogeneity in the inclusion criteria, outcome measures, and length of follow-up of the included studies.Despite decades of experience on CM1 and Syr management in children, the available evidence remains limited. Specifically, there is an urgent need for collaborative initiatives focusing on the adoption of shared inclusion criteria and outcome measures, as well as rigorous prospective designs, particularly RCTs.

Migraine in Chiari 1 Malformation: a cross-sectional, single centre study

In Chiari 1 Malformation (CM1) the most frequent symptom is exertional headache, but other headache types have been reported, such as migraine. This cross-sectional study is aimed to examine the prevalence of migraine in a group of CM1 headache patients and to compare clinical-demographic characteristics between migraine and non-migraine patients. 427 adults were enrolled at the multidisciplinary Chiari Center in Torino. 230 headache patients were classified, based on radiological criteria. Frequencies (absolute/percentage values) were calculated in the whole sample for: migraine presence (with and without aura), gender, age, radiologic phenotypes and headache clinical characteristics. The association between CM1 diagnosis and headache characteristics (independent variables) and migraine diagnosis (dependent variable) was estimated by logistic regression models. Seventy-eight patients (67 females) out of 230 presenting headache had a migraine (34%), 44/78 (56%) with aura; in 58/78 (74%) migraine was comorbid with secondary headache attributable to CM1. Migraine prevalence in patients with isolated CM1 (52/120, 43.3%) was higher (p = 0.0016) than in all the other patients (26/110, 23.6%). Although migraine was prevalent in females (86%; 6:1 female:male ratio), age classes and gender were not risk factors for migraine at multivariate analysis, while migraine was associated with isolated CM1 phenotype (OR = 2.6). This study shows a high prevalence of migraine in CM1 patients and a significant association between migraine and isolated CM1. In patients with radiological evidence of CM1, particularly in the absence of neurological signs, a careful headache clinical characterization, according to the International Headache Society criteria, may be advised.

Syringomyelia and Chiari Syndrome Registry: advances in epidemiology, clinical phenotypes and natural history based on a North Western Italy cohort

BACKGROUND

Syringomyelia and Chiari Syndrome are classified as rare diseases, but current known occurrence in Europe is missing. The increased ability to diagnose these pathologies by magnetic resonance imaging and its widespread availability has led to an increase of reported cases, often asymptomatic, with the need to standardize definitions, diagnostic criteria and treatments.

AIMS

We present shared Interregional Recommendations developed with the primary aim to estimate Syringomyelia and Chiari Syndrome prevalence and incidence in North Western Italy, with special reference to symptomatic forms.

METHODS

An agreement for the standardization of definitions, classifications, diagnostic criteria and surgical Recommendations was reached by the multidisciplinary Interregional Piemonte and Valle d'Aosta Chiari-Syringomyelia Consortium (Delphi method); next, in 2011 a census for Syringomyelia and Chiari Malformation was performed through the Interregional Piemonte and Valle d'Aosta Rare Disease Registry, integrated by a dedicated form in order to estimate prevalence and incidence.

RESULTS

436 patients, 292 females, met shared interregional diagnostic criteria. Syringomyelia prevalence was estimated in 4.84:100 000; Chiari Malformation prevalence was 7.74:100 000; incidence was 0.82:100 000 and 3.08:100 000 respectively. Demographics, neuroradiological parameters and aetiology were reported (in symptomatic and asymptomatic forms). Finally, symptoms and signs, familiar and natural history were analyzed.

CONCLUSIONS

First Italian epidemiological data (prevalence, incidence) on Chiari and syringomyelia was collected, according to shared diagnostic Recommendations. Future perspectives include the adoption of these Recommendations at national level to standardize the access to diagnosis and care process and promote multicenter clinical trials.

Comorbidities, anthropometric, demographic, and lifestyle risk factors for ulnar neuropathy at the elbow: A case control study

We performed a prospective multicenter case-control study to explore the association between ulnar neuropathy at elbow (UNE) and body and elbow anthropometric measures, demographic and lifestyle factors, and comorbidities. Cases and controls were consecutively enrolled among subjects admitted to four electromyography labs. UNE diagnosis was made on clinical and neurographic findings. The control group included all other subjects without signs/symptoms of ulnar neuropathy and with normal ulnar nerve neurography. Anthropometric measurements included weight, height, waist, hip circumferences, and external measures of elbow using a caliper. The participants filled in a self-administered questionnaire on personal characteristics, lifestyle factors, and medical history. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) by fitting unconditional logistic regression models adjusted by center and education level. We enrolled 220 cases (males 61.8%; mean age 51.7 years) and 460 controls (47.4% males; mean age 47.8 years). At multivariable analysis, UNE was associated to male gender (OR = 2.4, 95%CI = 1.6-3.7), smoking habits (>25 pack-years (OR = 2.3, 95%CI = 1.3-4.1), body mass index (OR = 1.05, 95%CI 1.01-1.10), polyneuropathies (OR = 4.1, 95%CI 1.5-11.5), and leaning with flexed elbow on a table/desk (OR = 1.5, 95%CI 1.0-2.2). Cubital groove width (CGW) turned out to be negatively associated with UNE (OR = 0.80, 95%CI = 0.74-0.85). Our study suggests that some personal factors especially anthropometric measures of the elbow may play a role in UNE pathogenesis as the measures of wrist in CTS. We demonstrated that for each millimeter of smaller CGW the risk of idiopathic UNE increases of 25%.

The external elbow measure as surrogate of the anatomical width of cubital groove and possible risk factor of ulnar neuropathy at the elbow

Introduction: There are no studies on elbow anthropometry in ulnar neuropathy at the elbow (UNE). We aimed to test the interrater agreement of external elbow measurements with caliper, the matching of external width of cubital groove (WCG) measures with those obtained through conventional radiography (XR) and ultrasonography (US). The final aim was to evaluate the differences of anthropometric elbow and body measures between UNE cases and controls with multicenter prospective study.Materials and methods: After common training of five observers for external elbow and body anthropometric measurements, we assessed the interrater agreement of measures in a single blind measurement session in 16 healthy volunteers. Then we verified if external WCG measures in eight and four of the above 16 subjects matched with those obtained with US and XR. Finally, we enrolled 40 consecutive idiopathic UNE cases in four electromyographic labs matched for sex and age with 40 controls to evaluate the differences of anthropometric measures.Results: There was high interrater agreement of all anthropometric body and elbow measures (Kendal's and interclass correlation coefficients between 0.84 and >0.9). We found high relations between WCG caliper measures and those obtained with US and XR (r > 0.9). WCG was smaller in cases than in controls (13.2 vs.15.7 mm, p < 0.001). There were no differences in body anthropometric measures (BMI and waist-to-hip ratio).Conclusion: The external measurement of WCG is reliable and reproducible and may be risk factor of UNE. Future studies should be performed in lager samples evaluating the relations with lifestyle and occupational factors.

A Delphi consensus statement of the Neuropathic Pain Special Interest Group of the Italian Neurological Society on pharmacoresistant neuropathic pain

To improve patient care and help clinical research, the Neuropathic Pain Special Interest Group of the Italian Neurological Society appointed a task force to elaborate a consensus statement on pharmacoresistant neuropathic pain. The task force included 19 experts in neuropathic pain. These experts participated in a Delphi survey consisting of three consecutive rounds of questions and a face-to-face meeting, designed to achieve a consensus definition of pharmacoresistant neuropathic pain. In the three rounds of questions, the participants identified and described the main distinguishing features of pharmacoresistance. In the face-to-face meeting the participants discussed the clinical features determining pharmacoresistance. They finally agreed that neuropathic pain is pharmacoresistant when "the patient does not reach the 50% reduction of pain or an improvement of at least 2 points in the Patient Global Impression of Change, having used all drug classes indicated as first, second, or third line in the most recent and widely agreed international guidelines, for at least 1 month after titration to the highest tolerable dose." Our consensus statement might be useful for identifying eligible patients for invasive treatments, and selecting patients in pharmacological trials, thus improving patient care and helping clinical research.

Prevalence of Neuropathic Pain in Patients with Traumatic Brachial Plexus Injury: A Multicenter Prospective Hospital-Based Study

Objective

Prevalence and clinical characteristics of neuropathic pain due to traumatic brachial plexus injury.

Design

Observational epidemiological study.

Setting

Hospital-based multicenter study.

Subjects

One hundred seven prospectively enrolled patients with brachial plexus injury.

Methods

All the patients underwent clinical examination and neurophysiological testing for a definitive diagnosis of the brachial plexus lesion. The DN4 questionnaire was used to identify neuropathic pain, and the Neuropathic Pain Symptom Inventory (NPSI) to evaluate the different symptoms of neuropathic pain. The SF36 questionnaire and the Beck Depression Inventory (BDI) were used to assess quality of life and mood disturbances in patients with neuropathic pain.

Results

Of the 107 enrolled patients, 74 had pain (69%); neuropathic pain, as assessed by means of the DN4, was identified in 60 (56%) of these patients. According to the NPSI, the most frequent and severe pain type was the spontaneous burning pain. Clinical and neurophysiological findings showed that pain is unrelated to age but is associated with the severity of peripheral nerve damage. The SF36 questionnaire and BDI showed that neuropathic pain impairs quality of life and causes depression.

Conclusions

Our study provides information on the prevalence, characteristics, and variables associated with neuropathic pain due to traumatic brachial plexus injuries that might provide a basis for improving the clinical management of this condition.

Teleconsulting for Minor Head Injury: The Piedmont Experience

We evaluated the benefits of teleconsulting for patients hospitalised with minor head injuries in centres without neurosurgery. In the Piedmont region, 1462 consultation requests were received at specialist centres in 2009, relating to 519 patients with a minor head injury diagnosis (ICD 850–854). These were compared with the details of 1895 patients admitted with the same diagnosis during 2009, but for whom no consultations were requested. The mortality risk in the two groups was estimated using logistic regression, after adjusting for the principal confounding factors (sex, age, seriousness of the patient's injury at diagnosis, referral centre). The estimated risk of death for patients for whom no consultation was requested was an odds ratio of 1.32 (95% CI 1.08 to 1.74) compared to those who received a teleconsultation. However, after adjusting for the confounding factors, the risk was not significant (odds ratio = 1.25, 95% CI 0.83 to 1.91). A stratified analysis identified a significant effect for elderly people, aged over 70 years, in whom the odds ratio was 1.14 (95% CI 1.04 to 1.82). The results confirm the benefits of telemedicine, in particular for elderly patients, when teleconsultation is requested in the case of minor head injury.

Chiari and Syringomyelia Consortium: a model of multidisciplinary and sharing path for rare diseases

Piemonte and Valle d'Aosta Interregional Network for Rare Diseases (RD) is a model of "diffuse" network; it involves all the health system specialists devoted to the diagnosis, the therapy and the follow-up of a RD. The Consortium is a multidisciplinary team operating throughout the Region composed of volunteer Physicians and Biologists that promotes periodical meetings to develop shared protocols. In 2008 the Specialist-Technical Committee for the Interregional RD Network approved the set up of the "Chiari and Syringomyelia Consortium" (CSC) with two specific objectives: to identify the shared diagnostic criteria and to develop the interdisciplinary diagnostic-therapeutic-assistance path (DTAP) to be used interregionally. Other objectives are: to define the prevalence of the pathologies (both symptomatic and asymptomatic, both in adults and children) and to improve collaboration between the patient Associations and the Physicians.

High prevalence of neuropathies in patients with end-stage liver disease

OBJECTIVES

Peripheral neuropathy has been reported in association with end-stage liver disease, but there is only a limited number of reports on the incidence and features of these neuropathies.

MATERIALS AND METHODS

In this study, 83 patients awaiting liver transplantation were evaluated for the presence of peripheral and autonomic neuropathy.

RESULTS

Sixty-five percent of the patients had evidence of neuropathy, in agreement with peripheral NCS or cardiovascular autonomic function test. The neuropathy was more frequent in patients with advanced hepatic failure, evaluated with the MELD score. The most frequent abnormalities in nerve conduction studies were sensory-motor neuropathies and sensory neuropathies, with a length-dependent pattern.

CONCLUSION

Peripheral neuropathy and autonomic neuropathy are common in patients with end-stage liver disease with different etiology and correlate with the severity of the liver disease.

Validation of the Italian version of the Neuropathic Pain Symptom Inventory in peripheral nervous system diseases

The aim of this study was to validate the Italian version of the Neuropathic Pain Symptom Inventory (NPSI) in patients with neuropathic pain due to peripheral nerve diseases, and also to evaluate the validity of a new NPSI score: a frequency weighted NPSI score (NPSI-FW). First, the original version of the NPSI was translated into Italian. Then the validity and reliability of the Italian NPSI (I-NPSI) were tested in 392 Italian patients consecutively referred to 16 Italian outpatient services for peripheral nerve diseases, by correlating the I-NPSI scores with other pain scales. The repeatability and responsiveness were assessed. A significant correlation between the I-NPSI scores and all the other pain measures was seen. Reproducibility and responsiveness were good. Our study shows the validity of the I-NPSI and demonstrates its reliability for assessing neuropathic pain in patients with peripheral nerve diseases. The I-NPSI scores represent reliable measurements to assess neuropathic symptoms and effectiveness of treatment on them.

Clinical and electrophysiological correlations in type 2 diabetes mellitus at diagnosis

The purpose of this study was to evaluate, in newly diagnosed type 2 diabetes mellitus (DM): (1) the prevalence and staging of peripheral neuropathy, as well as its possible relationship with metabolic profile; (2) the clinical value of both the Diabetic Neuropathy Index (DNI) and the Diabetic Neuropathy Score (DNS), and their reciprocal concordance, as a screening method for neuropathy. Thirty-nine newly diagnosed DM subjects underwent: neurological examination, nerve conduction studies (NCS), quantitative sensory system and cardiovascular autonomic function assessments. Peripheral neuropathy was observed in 72% of the subjects (its staging was similar to that of patients with longer disease history), while another 10% of them showed a borderline neuropathy. The Deep Breathing test was abnormal in 28% of the patients; postural hypotension was found in 6%. The same proportion (82%) of subjects who scored positively on the DNI showed altered NCS, while the quantitative sensory system assessments had a low sensitivity in order to detect the neuropathy. No correlation was found between metabolic indexes and DNI/DNS parameters. The high prevalence of peripheral and autonomic function alterations suggests that each newly diagnosed diabetic subject should be screened for neuropathy by the DNI, to reduce the negative prognostic influence of this complication.

A further critical evaluation of requests for electrodiagnostic examinations

The aim of this study was to evaluate the impact of electrophysiological (EDX) tests in the clinical management and diagnosis of patients, and the appropriateness of the referral diagnosis. A study was carried out in three electrodiagnostic services in the Torino area, over a 12-month period. In our study 3,900 individuals (2,340 females, 1,560 males) were evaluated. Patients underwent EDX examinations including nerve conduction study, electromyography and repetitive stimulation test. Most patients had been sent for EDX tests by specialists. Specialists suspected mainly polyneuropathy, whilst general practitioners suspected mainly carpal tunnel syndrome. Seventy-two percent of the requests were correctly formulated, 55% by general practitioners and 77% by specialists. There was a concordance between the results of the EDX tests and diagnostic hypothesis 40% of the time. This study confirms the usefulness and diagnostic impact of EDX examinations and evidences the amount of time and resources wasted as a result of incorrect or incomplete requests.

Pain affects the quality of life of neuropathic patients

The aim of this study was to verify the extent to which the presence of pain affects the quality of life (QoL) of neuropathic patients. The patients were selected in our Department of Peripheral Nervous System Diseases. We enrolled 120 consecutive patients with chronic polyneuropathy who had not received continuous pain therapy during the two months preceding study entry, and administered them the Total Neuropathy Score (TNS), the official Italian version of the SF-36 and the Italian Pain Questionnaire (QUID). Our main finding was that the QoL is affected not only by the presence of neuropathy, but also by the presence and intensity of pain: the physical aspect of the QoL correlated only weakly with the TNS, but pain was closely related to a worsening in this parameter; moreover, the mental domains of the SF-36 were only correlated with pain. Pain per se worsens the QoL of neuropathic patients, regardless of disease severity.

Somatosensory- and motor-evoked potential monitoring during spine and spinal cord surgery

STUDY DESIGN

Prospective, observational study.

SETTING

Regional Trauma Center, Torino, Italy.

OBJECTIVES

Complex spinal surgery carries a significant risk of neurological damage. The aim of this study is to determine the reliability and applicability of multimodality motor-evoked potentials (MEPs) and somatosensory-evoked potentials (SEPs) monitoring during spine and spinal cord surgery in our institute.

METHODS

Recordings of MEPs to multipulse transcranial electrical stimulation (TES) and cortical SEPs were made on 52 patients during spine and spinal cord surgery under propofol/fentanyl anaesthesia, without neuromuscular blockade.

RESULTS

Combined MEPs and SEPs monitoring was successful in 38/52 patients (73.1%), whereas only MEPs from at least one of the target muscles were obtained in 12 patients (23.1%); both MEPs and SEPs were absent in two (3.8%). Significant intraoperative-evoked potential changes occurred in one or both modalities in five (10%) patients. Transitory changes were noted in two patients, whereas three had persistent changes, associated with new deficits or a worsening of the pre-existing neurological disabilities. When no postoperative changes in MEP or MEP/SEP modalities occurred, it was predictive of the absence of new motor deficits in all cases.

CONCLUSION

Intraoperative combined SEP and MEP monitoring is a safe, reliable and sensitive method to detect and reduce intraoperative injury to the spinal cord. Therefore, the authors suggest that a combination of SEP/MEP techniques could be used routinely during complex spine and/or spinal cord surgery.

Electrophysiological findings of peripheral neuropathy in newly diagnosed type II diabetes mellitus

This study was aimed at assessing the electrophysiological signs of peripheral neuropathy in diabetes mellitus (DM) type II patients at diagnosis. Nerve conduction studies (NCS) of median, ulnar, peroneal, tibial and sural nerves were performed in 39 newly diagnosed DM subjects and compared to those of 40 healthy controls. Metabolic indices were also investigated. Electrophysiological alterations were found in 32 (82%) of the DM patients, and more than half of them (62.2%) showed multiple (two to five) abnormal parameters. Because most of the subjects (84.4%) had from two to five nerves involved, these alterations were widespread in the seven nerves evaluated. Forty-two percent of the patients had NCS alterations suggestive of distal median mononeuropathy, implying that metabolic factors in DM make the median nerve more susceptible to focal entrapment. A reduced sensory nerve action potential (SNAP) amplitude was observed in the median nerve in 70% of the patients, in the ulnar in 69% and in the sural nerve only in 22%. In the presence of a decrease in the SNAP amplitude of the ulnar or median nerve, the SNAP amplitude of the sural nerve was normal in 82 or 80% of the subjects, respectively. This finding may be in keeping with a distal involvement of the sensory fibres, as explored by routine median or ulnar NCS. No correlation was found between metabolic indices and NCS parameters. In conclusion, a high percentage of newly diagnosed DM patients show signs of neuropathy, and upper limb nerve sensory NCS seem to be more sensitive in detecting it than lower limb NCS.

Subclinical electrophysiological alterations of phrenic nerve in chronic inflammatory demyelinating polyneuropathy

Alterations of the phrenic nerve (PN) and pulmonary function tests (PFTs) have been described in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). This study was aimed at assessing the relationship between PN and respiratory function in CIDP patients without clinical signs of respiratory failure. Bilateral PN and right median nerve conduction studies were carried out along with blood gas analysis and PFTs: maximal inspiratory pressure; maximal expiratory pressure; forced vital capacity. The amplitude of the compound muscle action potential of the PN was seen to be altered in 19/24 (79%) patients and latency in 22 (92%). Eighteen patients (75%) showed at least one abnormal PFTs or CO2 partial pressure value. Electrophysiological alterations of the PN were observed in a high percentage of the CIDP patients studied. No statistically significant correlation was observed between PN and PFTs alterations.

Thalidomide sensory neurotoxicity: a clinical and neurophysiologic study

The clinical and neurophysiologic data from 65 patients taking thalidomide were reviewed. Thalidomide sensory neurotoxicity was found to be cumulative dose dependent but occurs only when the total dose is relatively high (>20 g). The risk of developing sensory neuropathy is around 10% below this threshold but increases with higher doses.

Thalidomide neuropathy: clinical, electrophysiological and neuroradiological features

OBJECTIVE

Thalidomide is a promising therapy for multiple myeloma. Sensory neuropathy is a side effect of thalidomide and resulted to be partially reversible in 50% of cases, suggesting a sensory ganglionopathy. Spinal cord magnetic resonance imaging (MRI) was found to be useful in the diagnosis of sensory ganglionopathies and we use it to determine if thalidomide neuropathy has features of a ganglionopathy.

MATERIAL AND METHODS

Six patients with multiple myeloma developed thalidomide-induced polyneuropathy. Nerve conduction studies, somatosensory-evoked potentials (SEPs) and cervical and dorsal spinal cord MRI were obtained in all.

RESULTS

All patients had a sensory neuropathy, with clinical or electrophysiological abnormalities involving all four limbs. Spinal cord MRI showed high signal intensity in the posterior columns in only one patient, with abnormal central conduction time at SEPs.

CONCLUSION

Our results suggest that thalidomide can induce either an axonal length-dependent neuropathy or, less frequently, a ganglionopathy.

Intracranial stimulation of the facial nerve: normative values with magnetic coil in 240 nerves

This study was aimed at defining normative values of latency and amplitude of the compound muscle action potential (CMAP) from the orbicularis oculi muscle, obtained by transcranial magnetic stimulation. We evaluated the dependence of latency and amplitude on the age of the subjects, in order to calculate cut-off values for each age decade. A total of 120 healthy normal subjects, aged 15-78 years, were studied. CMAP from the orbicularis oculi muscle, pars inferior, was excited by means of transcranial magnetic stimulation of the homolateral scalp. A suitable mathematical model was developed to evaluate the mean variation of the latency and amplitude of CMAP for each age decade in the studied population. Mean values were, respectively, 4.62+/-0.40 ms for latency and 4.17+/-0.72 mV for amplitude. We found an increase in latency of about 0.12 ms for every ten years, that became 0.15 ms if referring only to subjects over 20 years, and a decrease in amplitude of 0.18 mV each ten years. Normality interval values for the latency and amplitude were calculated for each age decade. Our data, obtained in a representative population for range of age of evaluated subjects, provide normality values and variability coefficients useful for future confronting works.

Intravenous immunoglobulin as first treatment in diabetics with concomitant distal symmetric axonal polyneuropathy and CIDP

The authors investigated the impact of IVIg as first line treatment of diabetic patients suffering from chronic inflammatory demyelinating polyneuropathy (CIDP) concomitant with distal symmetric axonal polyneuropathy. Nine patients with these clinical and electrophysiological features were treated with IVIg (0.4 g/Kg/day for 5 days). Clinical and electrophysiological evaluations were performed before and after treatment. Following IVIg treatment there was no significant improvement in clinical deficit. However, there was a significant and persistent decrease in the Rankin scale score and an improvement in the demyelinating feature on nerve conduction studies. Our findings suggest that IVIg had small but detectable beneficial effects on diabetic patients with CIDP and a high degree of axonal damage.

Terminal latency index in polyneuropathy with IgM paraproteinemia and anti-MAG antibody

Criteria for the diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP) are met by the polyneuropathy associated with immunoglobulin M (IgM) paraproteinemia and anti-myelin-associated glycoprotein (MAG) antibody (MAG-CIDP). However, MAG-CIDP differs from other types of CIDP, mainly in its poorer response to treatment. The utility of terminal latency index (TLI) as an electrophysiological marker for MAG-CIDP has been debated. In this study we confirmed its diagnostic usefulness and evaluated TLI threshold values for motor nerves investigated in routine nerve conduction studies. Median, ulnar, peroneal, and tibial TLIs of 11 subjects with MAG-CIDP, 18 with CIDP, and 76 healthy controls were compared, and threshold values for MAG-CIDP evaluated as the lowest value with a likelihood ratio higher than 10. Mean TLI values and TLIs of all but the peroneal nerve were significantly lower in MAG-CIDP. Median nerve TLI of 0.26 and ulnar nerve TLI of 0.33 were identified as the threshold TLI values for MAG-CIDP.