Characterising vincristine-induced peripheral neuropathy in adults: symptom development and long-term persistent outcomes.

BACKGROUND: Decades following the introduction of vincristine as treatment for haematological malignancies, vincristine-induced peripheral neuropathy (VIPN) remains a pervasive, untreatable side-effect. However there remains a gap in understanding the characteristics of VIPN in adults. This study presents a comprehensive phenotyping of VIPN. METHODS: Adult patients (n = 57; age = 59.8 ± 14.6) were assessed cross-sectionally following completion of vincristine (months post treatment = 16.3 ± 15.6, cumulative dose = 7.6 ± 4.4), with a subset of 20 patients assessed prospectively during treatment. Patient reported measures (EORTC-QLQ-CIPN20, R-ODS) were used to profile symptoms and disability. Neurological assessment was undertaken using the Total Neuropathy Score and nerve conduction studies. Sensory threshold and fine motor tasks were also undertaken. Comparisons of data between timepoints were calculated using paired-sample t tests or Wilcoxon matched-pairs signed-rank test. Comparisons between outcome measures were calculated with independent sample t tests or Mann-Whitney U tests for non-parametric data. RESULTS: The majority of patients developed VIPN by mid-treatment (77.8%, 7.0 ± 3.3 weeks post baseline) with the prevalence remaining stable by end-of-treatment (75%, 8.1 ± 1.7 weeks post mid-treatment). By 3 months post-completion, 50% of patients still reported VIPN although there were significant improvements on neurological grading and functional assessment (P < 0.05). VIPN presented with sensorimotor involvement in upper and lower limbs and was associated with decreased sensory and motor nerve amplitudes, reduced fine-motor function and increased disability. CONCLUSION: VIPN in adults presents as a sensorimotor, upper- and lower-limb neuropathy that significantly impacts disability and function. Neuropathy recovery occurs in a proportion of patients; however, VIPN symptoms may persist and continue to affect long-term quality of life.

Axonal excitability as an early biomarker of nerve involvement in hereditary transthyretin amyloidosis.

OBJECTIVES: The treatment of hereditary transthyretin amyloidosis polyneuropathy (ATTRv-PN) has been revolutionised by genetic therapies, with dramatic improvements in patient outcomes. Whilst the optimal timing of treatment initiation remains unknown, early treatment is desirable. Consequently, the aim of the study was to develop biomarkers of early nerve dysfunction in ATTRv-PN. METHODS: Ulnar motor and sensory axonal excitability studies were prospectively undertaken on 22 patients with pathogenic hereditary transthyretin amyloid (ATTRv) gene variants, 12 with large fibre neuropathy (LF+) and 10 without (LF-), with results compared to age- and sex-matched healthy controls. RESULTS: In motor axons we identified a continuum of change from healthy controls, to LF- and LF+ ATTRv with progressive reduction in hyperpolarising threshold electrotonus (TEh40(10-20 ms): p = 0.04, TEh40(20-40 ms): p = 0.01 and TEh40(90-10 ms): p = 0.01), suggestive of membrane depolarisation. In sensory axons lower levels of subexcitability were observed on single (SubEx) and double pulse (SubEx2) recovery cycle testing in LF+ (SubEx: p = 0.015, SubEx2: p = 0.015, RC(2-1): p = 0.04) suggesting reduced nodal slow potassium conductance, which promotes sensory hyperexcitability, paraesthesia and pain. There were no differences in sensory or motor excitability parameters when comparing different ATTRv variants. CONCLUSIONS: These progressive changes seen across the disease spectrum in ATTRv-PN suggest that axonal excitability has utility to identify early and progressive nerve dysfunction in ATTRv, regardless of genotype. SIGNIFICANCE: Axonal excitability is a promising early biomarker of nerve dysfunction in ATTRv-PN.

Serum neurofilament light chain in hereditary transthyretin amyloidosis: validation in real-life practice.

BACKGROUND: Neurofilament light chain (NfL) has emerged as a sensitive biomarker in hereditary transthyretin amyloid polyneuropathy (ATTRv-PN). We hypothesise that NfL can identify conversion of gene carriers to symptomatic disease, and guide treatment approaches. METHODS: Serum NfL concentration was measured longitudinally (2015-2022) in 59 presymptomatic and symptomatic ATTR variant carriers. Correlations between NfL and demographics, biochemistry and staging scores were performed as well as longitudinal changes pre- and post-treatment, and in asymptomatic and symptomatic cohorts. Receiver-operating analyses were performed to determine cut-off values. RESULTS: NfL levels correlated with examination scores (CMTNS, NIS and MRC; all p < .01) and increased with disease severity (PND and FAP; all p < .05). NfL was higher in symptomatic and sensorimotor converters, than asymptomatic or sensory converters irrespective of time (all p < .001). Symptomatic or sensorimotor converters were discriminated from asymptomatic patients by NfL concentrations >64.5 pg/ml (sensitivity= 91.9%, specificity = 88.5%), whereas asymptomatic patients could only be discriminated from sensory or sensorimotor converters or symptomatic individuals by a NfL concentration >88.9 pg/ml (sensitivity = 62.9%, specificity = 96.2%) However, an NfL increment of 17% over 6 months could discriminate asymptomatic from sensory or sensorimotor converters (sensitivity = 88.9%, specificity = 80.0%). NfL reduced with treatment by 36%/year and correlated with TTR suppression (r = 0.64, p = .008). CONCLUSIONS: This data validates the use of serum NfL to identify conversion to symptomatic disease in ATTRv-PN. NfL levels can guide assessment of disease progression and response to therapies.

Prospective assessment of vincristine-induced peripheral neuropathy in paediatric acute lymphoblastic leukemia.

OBJECTIVE: Vincristine is a mainstay treatment for paediatric cancers, particularly acute lymphoblastic leukemia (ALL), with common toxicity including vincristine-induced peripheral neuropathy (VIPN). The present study comprehensively assessed VIPN outcomes in patients receiving vincristine treatment for ALL. METHODS: Children diagnosed with ALL commencing vincristine treatment were prospectively evaluated (baseline, post-induction, pre-reinduction, post-reinduction, follow-up). VIPN was examined clinically using the Balis sensory/motor scale, neurophysiologically using axonal excitability techniques and quality-of-life using Pediatric Quality of Life Inventory. RESULTS: Thirty-one patients were recruited to this study (age = 6.8 ± 4.4; 61.3% female). Incidence of motor VIPN (motor Balis grade > 0) symptoms were higher than sensory VIPN (sensory Balis grade > 0) at post-induction (92.0% vs 36.0%) and post-reinduction (81.8% vs 22.7%) vincristine treatment. Neurophysiological assessment also demonstrated greater change in motor axonal excitability parameters compared to sensory parameters including changes in depolarising threshold electrotonus (P < 0.0125), superexcitability and subexcitability parameters (all P < 0.0125). Follow-up assessment demonstrated persisting VIPN symptoms with reduced quality-of-life scores compared to baseline. CONCLUSIONS: Clinical and neurophysiological evaluation of VIPN suggests vincristine produces a motor-prominent sensorimotor neuropathy in children which persisted at follow-up. SIGNIFICANCE: VIPN signs and symptoms develop early in the treatment course, in line with axonal excitability profiles. Early detection of significant nerve changes may support timely implementation of neuroprotection strategies.

Clinical diagnostic utility of transcranial magnetic stimulation in neurological disorders. Updated report of an IFCN committee.

The review provides a comprehensive update (previous report: Chen R, Cros D, Curra A, Di Lazzaro V, Lefaucheur JP, Magistris MR, et al. The clinical diagnostic utility of transcranial magnetic stimulation: report of an IFCN committee. Clin Neurophysiol 2008;119(3):504-32) on clinical diagnostic utility of transcranial magnetic stimulation (TMS) in neurological diseases. Most TMS measures rely on stimulation of motor cortex and recording of motor evoked potentials. Paired-pulse TMS techniques, incorporating conventional amplitude-based and threshold tracking, have established clinical utility in neurodegenerative, movement, episodic (epilepsy, migraines), chronic pain and functional diseases. Cortical hyperexcitability has emerged as a diagnostic aid in amyotrophic lateral sclerosis. Single-pulse TMS measures are of utility in stroke, and myelopathy even in the absence of radiological changes. Short-latency afferent inhibition, related to central cholinergic transmission, is reduced in Alzheimer's disease. The triple stimulation technique (TST) may enhance diagnostic utility of conventional TMS measures to detect upper motor neuron involvement. The recording of motor evoked potentials can be used to perform functional mapping of the motor cortex or in preoperative assessment of eloquent brain regions before surgical resection of brain tumors. TMS exhibits utility in assessing lumbosacral/cervical nerve root function, especially in demyelinating neuropathies, and may be of utility in localizing the site of facial nerve palsies. TMS measures also have high sensitivity in detecting subclinical corticospinal lesions in multiple sclerosis. Abnormalities in central motor conduction time or TST correlate with motor impairment and disability in MS. Cerebellar stimulation may detect lesions in the cerebellum or cerebello-dentato-thalamo-motor cortical pathways. Combining TMS with electroencephalography, provides a novel method to measure parameters altered in neurological disorders, including cortical excitability, effective connectivity, and response complexity.

Patient-Reported Outcome Measures in Chemotherapy-Induced Peripheral Neurotoxicity: Defining Minimal and Clinically Important Changes.

BACKGROUND: Chemotherapy-induced peripheral neurotoxicity (CIPN) is a common complication of cancer treatment that produces functional disability. Increasingly, patient-reported outcome measures (PROMs) are used to assess CIPN, providing a broader symptom perspective than clinician-graded scales. Understanding when a reported change in CIPN symptoms meets the threshold for clinical significance is challenging. This study aimed to provide interpretation guidelines for validated CIPN PROMs, and thereby enable estimation of thresholds to identify clinically relevant symptoms. METHODS: Patients commencing neurotoxic cancer treatments were assessed at 3 timepoints: baseline, midtreatment, and end-of-treatment. Trajectory of CIPN development was assessed by means of CIPN PROMs, EORTC Quality of Life - Chemotherapy-Induced Peripheral Neuropathy questionnaire (QLQ-CIPN20), and Functional Assessment of Cancer Therapy/Gynecologic Oncology Group - Neurotoxicity questionnaire (FACT/GOG-NTX). Thresholds were estimated for CIPN PROMs using the NCI CTCAE sensory neuropathy scale as the clinical anchor by midtreatment and end-of-treatment. Patients were assigned to a clinical change group according to CIPN development: either no development; grade 1 neuropathy (minimally important difference [MID]); or grade 2 neuropathy (clinically important difference). Distribution-based estimates (SD, 0.5) were also evaluated as supportive evidence. RESULTS: In total, 406 patients were recruited to the study, of whom 62% (n=199/320) developed CIPN by midtreatment and 80% (n=274/343) by end-of-treatment. Anchor-based MID estimates by midtreatment were 5.06 (95% CI, 4.26-5.86) for the QLQ-CIPN20 and 3.54 (95% CI, 2.87-4.20) for the FACT/GOG-NTX. End-of-treatment MIDs were estimated to be 7.32 (95% CI, 6.23-8.40) for the QLQ-CIPN20 and 4.84 (95% CI, 3.98-5.70) for the FACT/GOG-NTX. Distribution-based MID estimations yielded lower values than anchor-based methods, at 3.73 for the QLQ-CIPN20 and 2.64 for the FACT/GOG-NTX at midtreatment and 5.52 for the QLQ-CIPN20 and 3.64 for the FACT/GOG-NTX at end-of-treatment. CONCLUSIONS: Findings from the present series aid meaningful interpretation for commonly used validated CIPN PROMs and provide thresholds that serve as guidance on how to interpret score changes, which will be useful for design and evaluation of clinical trials and clinical practice.

Metabolic and lifestyle risk factors for chemotherapy-induced peripheral neuropathy in taxane and platinum-treated patients: a systematic review.

PURPOSE: Chemotherapy-induced peripheral neurotoxicity (CIPN) is a common dose-limiting toxicity of cancer treatment causing functional impairment and impacting quality of life. Effective prevention and treatment of CIPN are lacking, and CIPN risk factors remain ill-defined. Metabolic syndrome and associated conditions have emerged as potential risk factors, due to their high prevalence and independent association with nerve dysfunction. This systematic review aimed to investigate the association between these common metabolic-lifestyle factors and CIPN. METHODS: Searches were undertaken using Medline, Embase, CINAHL, Scopus, and Web of Science databases, with additional studies identified from bibliographic references cited by original and review articles. Articles that analyzed metabolic-lifestyle risk factors associated with CIPN for patients treated with platinum- or taxane-based chemotherapy were included. RESULTS: Searches identified 6897 titles; 44 articles had full text review, with 26 studies included. Overall incidence of neuropathy ranged from 16.9 to 89.4%. Obesity had the most consistent patient-oriented evidence as a risk factor for CIPN, with moderate evidence suggesting diabetes did not increase CIPN incidence or severity. A limited number of studies supported an association with low physical activity and greater CIPN risk. CONCLUSIONS: Comorbidities and lifestyle factors, particularly obesity and low physical activity, may contribute to the development of CIPN. The implementation of sensitive outcome measures in large-scale clinical trials is required to further elucidate CIPN risk factors and evaluate if changes in lifestyle would improve long-term CIPN outcomes for cancer survivors. IMPLICATIONS FOR CANCER SURVIVORS: Better understanding of CIPN risk profiles may inform personalized medicine strategies and help elucidate pathophysiological mechanisms which could be targeted for neuroprotection.

Diagnostic utility of transcranial magnetic stimulation for neurodegenerative disease: a critical review / Utilidade diagnóstica da estimulação magnética transcraniana para doenças neurodegenerativas: uma revisão crítica

ABSTRACT. Neurodegenerative diseases pose significant challenges due to their impact on brain structure, function, and cognition. As life expectancy rises, the prevalence of these disorders is rapidly increasing, resulting in substantial personal, familial, and societal burdens. Efforts have been made to optimize the diagnostic and therapeutic processes, primarily focusing on clinical, cognitive, and imaging characterization. However, the emergence of non-invasive brain stimulation techniques, specifically transcranial magnetic stimulation (TMS), offers unique functional insights and diagnostic potential. TMS allows direct evaluation of brain function, providing valuable information inaccessible through other methods. This review aims to summarize the current and potential diagnostic utility of TMS in investigating neurodegenerative diseases, highlighting its relevance to the field of cognitive neuroscience. The findings presented herein contribute to the growing body of research focused on improving our understanding and management of these debilitating conditions, particularly in regions with limited resources and a pressing need for innovative approaches.

RESUMO. As doenças neurodegenerativas representam desafio significativo por seu impacto na estrutura cerebral, função e cognição. À medida que a expectativa de vida aumenta, a prevalência dessas doenças cresce rapidamente, resultando em substanciais encargos pessoais, familiares e sociais. Esforços têm sido feitos para otimizar os processos diagnósticos e terapêuticos, com foco principal na caracterização clínica, cognitiva e de imagem. No entanto, o surgimento de técnicas de estimulação cerebral não invasivas, especificamente a estimulação magnética transcraniana (EMT), oferece compreensão funcional e potencial diagnóstico únicos. A TMS permite a avaliação direta da função cerebral, fornecendo informações valiosas inacessíveis por outros métodos. Esta revisão teve como objetivo resumir a utilidade diagnóstica atual e potencial da EMT na investigação de doenças neurodegenerativas, destacando sua relevância para o campo da neurociência cognitiva. As conclusões aqui apresentadas contribuem para o crescente corpo de investigação centrado na melhoria da nossa compreensão e gestão dessas condições debilitantes, particularmente em regiões com recursos limitados e necessidade premente de abordagens inovadoras.

NEK1 and STMN2 short tandem repeat lengths are not associated with Australian amyotrophic lateral sclerosis risk.

Sporadic amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with a complex genetic architecture. The lengths of two short tandem repeats (STRs), at the NEK1 and STMN2 loci, were recently associated with ALS risk in cohorts of European descent. The STMN2 STR was proposed to be predictive of clinical features including the age of onset and disease duration in bulbar onset cases. We sought to investigate NEK1 and STMN2 STR lengths in a cohort of Australian sporadic ALS cases (n = 608) and neurologically healthy controls (n = 4689) of European ancestry. ExpansionHunter was used to determine NEK1 and STMN2 STR length genotypes from whole-genome sequencing data followed by PCR validation of predicted lengths. No significant association was identified between sporadic ALS risk and the length of either STR. Further, neither NEK1 nor STMN2 STR lengths were indicative of the age of onset or disease duration. We report that the NEK1 and STMN2 STRs were not associated with ALS risk or clinical features in this Australian sporadic ALS cohort.

Assessing chemotherapy-induced peripheral neuropathy with patient reported outcome measures: a systematic review of measurement properties and considerations for future use.

PURPOSE: Chemotherapy-induced peripheral neuropathy (CIPN) is a common toxicity of cancer treatment, with potential to significantly impact cancer survivors' long-term quality of life. Patient reported outcome measures (PROMs) are increasingly utilised to evaluate CIPN. However, guidance remains lacking on how to identify fit for purpose PROMs with considerations necessarily differing when used in various research and in-clinic contexts. This study aimed to evaluate evidence about CIPN PROMs measurement properties and propose considerations to optimize CIPN PROM selection for each purpose. METHODS: A systematic review was conducted to identify literature assessing measurement properties of CIPN PROMs. These were evaluated against Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) criteria and International Society for Quality of Life minimum standards. Risk of Bias (RoB) was assessed using the COSMIN RoB checklist. RESULTS: Thirty-nine papers evaluating measurement properties of 13 PROMs were included. The European Organization for Research and Treatment of Cancer Quality of Life Chemotherapy-Induced Peripheral Neuropathy Questionnaire (QLQ-CIPN20) and Functional Assessment of Cancer Therapy/Gynecologic Oncology Group-Neurotoxicity (FACT/GOG-Ntx) were the most commonly investigated PROMs and had the most measurement properties meeting established criteria. CONCLUSION: The use of the QLQ-CIPN20 and FACT/GOG-Ntx to assess CIPN in research settings has the most supporting evidence. However other considerations including study aims, endpoints and target population also factor into PROM selection and need to be considered more often when determining the most suitable outcome measure. Evidence of CIPN PROMs use in clinical practice is limited and their adoption to individual-patient level management requires more evaluation.

Development and consensus process for a clinical pathway for the assessment and management of chemotherapy-induced peripheral neuropathy.

BACKGROUND: Cancer patients treated with neurotoxic chemotherapy are at risk of developing neurological symptoms that can impact functional capacity and quality of life. However, there are no standardised pathways to assess and manage chemotherapy-induced peripheral neurotoxicity (CIPN). This study aimed to determine consensus on statements regarding a CIPN assessment and management clinical pathway. METHODS: A CIPN clinical pathway (CIPN-path) was developed and reviewed by an expert multi-disciplinary panel and consumers. Agreement with 18 statements regarding four content themes (pretreatment review, screening and assessment, management and referral, and CIPN-path feasibility) were assessed by 70 Australian respondents (68 health professionals, 2 consumers), using a 2-stage Delphi survey process to reach consensus. Respondents rated statements using a 5-point Likert scale to determine the level of agreement, with consensus defined as ≥ 80% of respondents agreeing with each statement. RESULTS: The consensus was reached for 14 of 18 items after stage 1 and all items after stage 2. Feedback was obtained for all items to refine the CIPN-path. There was an agreement on important characteristics of the CIPN-path, including pretreatment screening, regular patient-reported assessment, and a stepped-care approach to investigating and managing symptom burden. There was a lack of agreement on who should oversee CIPN assessment, which may differ according to the structure and resources of each site. CONCLUSIONS: There was an overall agreement concerning the CIPN-path to assess and manage CIPN, which may be adapted accordingly to the resources of each clinic. The CIPN-path may assist teams across different health services in identifying CIPN symptoms, aiding decision-making, and reducing morbidity from CIPN.

Novel approaches to diagnosis and management of hereditary transthyretin amyloidosis.

Hereditary transthyretin amyloidosis (ATTRv) is a severe, adult-onset autosomal dominant inherited systemic disease predominantly affecting the peripheral and autonomic nervous system, heart, kidney and the eyes. ATTRv is caused by mutations of the transthyretin (TTR) gene, leading to extracellular deposition of amyloid fibrils in multiple organs including the peripheral nervous system. Typically, the neuropathy associated with ATTRv is characterised by a rapidly progressive and disabling sensorimotor axonal neuropathy with early small-fibre involvement. Carpal tunnel syndrome and cardiac dysfunction frequently coexist as part of the ATTRv phenotype. Although awareness of ATTRv polyneuropathy among neurologists has increased, the rate of misdiagnosis remains high, resulting in significant diagnostic delays and accrued disability. A timely and definitive diagnosis is important, given the emergence of effective therapies which have revolutionised the management of transthyretin amyloidosis. TTR protein stabilisers diflunisal and tafamidis can delay the progression of the disease, if treated early in the course. Additionally, TTR gene silencing medications, patisiran and inotersen, have resulted in up to 80% reduction in TTR production, leading to stabilisation or slight improvement of peripheral neuropathy and cardiac dysfunction, as well as improvement in quality of life and functional outcomes. The considerable therapeutic advances have raised additional challenges, including optimisation of diagnostic techniques and management approaches in ATTRv neuropathy. This review highlights the key advances in the diagnostic techniques, current and emerging management strategies, and biomarker development for disease progression in ATTRv.

The impact of obesity on neuropathy outcomes for paclitaxel- and oxaliplatin-treated cancer survivors.

PURPOSE: Chemotherapy-induced peripheral neuropathy (CIPN) is a major side effect of neurotoxic cancer treatment, often impacting treatment tolerability and patient functioning. Factors predicting an individual's vulnerability for developing CIPN remain ill-defined. However, patient characteristics may contribute to CIPN risk, with obesity being a prevalent patient comorbidity. This study was aimed at evaluate if being overweight (BMI ≥ 25 kg/m2) was associated with worse symptomatic, clinical, and functional CIPN following neurotoxic cancer treatment. METHODS: Three hundred seventy-nine cancer survivors were assessed 5 (IQR 3-5) months post oxaliplatin or paclitaxel treatment via comprehensive patient-reported, clinical, and functional CIPN measures. Patients classified as overweight (BMI ≥ 25 kg/m2) were compared to those within the normal BMI range (< 25 kg/m2). Multilinear regression was conducted to evaluate the association between patient clinical factors and CIPN severity. RESULTS: Most patients reported CIPN symptoms (78%), with deficits evident on clinical examination. Overweight patients (n = 242, 63.8%) had significantly worse CIPN across symptomatic, objective clinical, and functional outcomes compared to those with a normal BMI (p < .05). In multivariate linear regression, older age (B = .088, 95%CI = .053-.122, p < .001), larger waist circumference (B = .030, 95%CI = .001-.059, p < .05), and larger BSA (B = 2.41, 95%CI = .34-04.48, p < .05) were associated with CIPN. Diabetes and BMI were significant on univariate analysis but not in the final models. CONCLUSIONS: Overweight patients represent a large proportion of cancer survivors who may be particularly impacted by CIPN, requiring closer monitoring and referral to supportive services. Accessible data such as a patient's general and abdominal obesity status may aid in formulating personalized treatment. IMPLICATIONS FOR CANCER SURVIVORS: Identifying routinely measured patient characteristics which may contribute to an individual's CIPN risk profile could assist with informing treatment decisions.

Nerve biopsy in acquired neuropathies.

A diagnosis of neuropathy can typically be determined through clinical assessment and focused investigation. With technological advances, including significant progress in genomics, the role of nerve biopsy has receded over recent years. However, making a specific and, in some cases, tissue-based diagnosis is essential across a wide array of potentially treatable acquired peripheral neuropathies. When laboratory investigations do not suggest a definitive diagnosis, nerve biopsy remains the final step to ascertain the etiology of the disease. The present review highlights the utility of nerve biopsy in confirming a diagnosis, while further illustrating the importance of a tissue-based diagnosis in relation to treatment strategies, particularly when linked to long-term immunosuppressive therapies.

Chemotherapy and peripheral neuropathy.

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a major dose-limiting side effect of many anti-cancer agents, including taxanes, platinums, vinca alkaloids, proteasome inhibitors, immunomodulatory drugs, and antibody-drug conjugates. The resultant symptoms often persist post treatment completion and continue to impact on long-term function and quality of life for cancer survivors. At present, dose reduction remains the only strategy to prevent severe neuropathy, often leading clinicians to the difficult decision of balancing maximal treatment exposure and minimal long-lasting side effects. This review examines the clinical presentations of CIPN with each class of neurotoxic treatment, describing signs, symptoms, and long-term outcomes. We provide an update on the proposed mechanisms of nerve damage and review current data on clinical and genetic risk factors contributing to CIPN development. We also examine recent areas of research in the treatment and prevention of CIPN, with specific focus on current clinical trials and consensus recommendations for CIPN management.

Nerve biopsy: Current indications and decision tools.

After initial investigation of patients presenting with symptoms suggestive of neuropathy, a clinical decision is made for a minority of patients to undergo further assessment with nerve biopsy. Many nerve biopsies do not demonstrate a definitive pathological diagnosis and there is considerable cost and morbidity associated with the procedure. This highlights the need for appropriate selection of patients, nerves and neuropathology techniques. Additionally, concomitant muscle and skin biopsies may improve the diagnostic yield in some cases. Several advances have been made in diagnostics in recent years, particularly in genomics. The indications for nerve biopsy have consequently changed over time. This review explores the current indications for nerve biopsies and some of the issues surrounding its use. Also included are comments on alternative diagnostic modalities that may help to supplant or reduce the use of nerve biopsy as a diagnostic test. These primarily include extraneural biopsy and neuroimaging techniques such as magnetic resonance neurography and nerve ultrasound. Finally, we propose an algorithm to assist in deciding when to perform nerve biopsies.

Weekly Paclitaxel-Induced Neurotoxicity in Breast Cancer: Outcomes and Dose Response.

BACKGROUND: Paclitaxel treatment produces significant peripheral neuropathy, but the time course of neuropathy development and outcomes are unclear. Dose reduction is the only strategy to prevent neurotoxicity, however, the impact of dose-reduction on neuropathy outcomes remains unknown. This study aimed to prospectively evaluated neuropathy development from weekly paclitaxel treatment and evaluate the impact of dose-reduction on post-treatment neuropathy outcomes. PATIENTS AND METHODS: Breast cancer patients receiving paclitaxel (80mg/m2 ) weekly for 12-weeks were prospectively assessed using patient reported (Functional Assessment of Cancer Therapy/Gynecologic Oncology Group-Neurotoxicity; FACTGOG-Ntx), clinical (Total Neuropathy Score clinical version; TNSc) and neurophysiological measures up to 12-months post completion. The impact of dose-reduction on post-treatment (3.6 ± 0.1 months) clinical and patient reported outcomes was evaluated in 105 weekly paclitaxel-treated patients. RESULTS: Significant neuropathy was present by 6-weeks across patient-reported, clinical, and objective neurophysiological assessments, increasing in prevalence and severity over the treatment course. Limited recovery occurred, with significant neuropathy being maintained up to 12 months (p < .05). Patients who received dose reduction had worse patient reported (FACT-GOG-Ntx: 40.2 ± .1.4) and clinical neuropathy outcomes (TNSc: 4.3 ± 0.4) compared to those who received the full dose (FACT-GOG-Ntx: 45.9 ± 0.9; TNSc: 3.3 ± 0.3, p < .05). Patients who ceased treatment early demonstrated the worse deficits (TNSc: 5.0 ± 0.6; FACT-GOG-Ntx: 37.3 ± 2.7) compared to those who received the complete dose (TNSc: 3.5 ± 0.3; FACT-GOG-Ntx: 45.3 ± 0.9, p < .05). CONCLUSION: Weekly paclitaxel produces symptomatic and objective neuropathy early in the treatment course which can persist. Dose reduction does not necessarily lead to more favorable neuropathy outcomes, with individual risk factors likely important in addition to cumulative dose. IMPLICATIONS FOR PRACTICE: Weekly paclitaxel schedules are extensively used in breast cancer. Patients may develop symptomatic and objective neuropathy early in the treatment course, with these individuals requiring closer monitoring. Furthermore, neuropathy is a long-term sequela that may impact quality of life and require appropriate supportive services. Results suggest that dose reduction does not necessarily lead to better neuropathy outcomes. Understanding schedule-specific toxicity and risk factors for neuropathy will be critical to determining individualized treatment strategies and improving quality of life in breast cancer survivors.

Neu-horizons: neuroprotection and therapeutic use of riluzole for the prevention of oxaliplatin-induced neuropathy-a randomised controlled trial.

TRIAL DESIGN: Peripheral neuropathy is a commonly reported adverse effect of oxaliplatin treatment, representing a significant limitation which may require discontinuation of effective therapy. The present study investigated the neuroprotective potential of riluzole in patients undergoing oxaliplatin treatment in a randomised-controlled trial comparing riluzole and placebo-control. METHODS: Fifty-two patients (17 females, 58.1 ± 12.7 years) receiving oxaliplatin treatment were randomised into either a treatment (50 mg riluzole) or lactose placebo group. The primary outcome measure was the total neuropathy score-reduced (TNSr). Secondary outcome measures include nerve excitability measures, 9-hole pegboard and FACT-GOG NTX questionnaire. Patients were assessed at baseline, pre-cycle 10 or 12, 4-week and 12-week post-treatment. RESULTS: Both the treatment and placebo groups developed objective and patient reported evidence of neurotoxicity over the course of oxaliplatin treatment, although there were no significant differences across any parameters between the two groups. However, across follow-up assessments, the treatment group experienced greater neuropathy, represented by a higher TNSr score at 4-week post-chemotherapy of 8.3 ± 2.7 compared with 4.6 ± 3.6 (p = 0.032) which was sustained at 12-week post-treatment (p = 0.089). Similarly, patients in the treatment group reported worse symptoms with a FACT-GOG NTX score of 37.4 ± 10.2 compared with 43.3 ± 7.4 (p = 0.02) in the placebo group at 4-week post-treatment. CONCLUSION: This study is the first to provide an objective clinical investigation of riluzole in oxaliplatin-induced peripheral neuropathy employing both functional and neurophysiological measures. Although the recruitment target was not reached, the results do not show any benefit of riluzole in minimising neuropathy and may suggest that riluzole worsens neuropathy associated with oxaliplatin treatment.