Reorganization of motor modules for standing reactive balance recovery following pyridoxine-induced large-fiber peripheral sensory neuropathy in cats.

Task-level goals such as maintaining standing balance are achieved through coordinated muscle activity. Consistent and individualized groupings of synchronously activated muscles can be estimated from muscle recordings in terms of motor modules or muscle synergies, independent of their temporal activation. The structure of motor modules can change with motor training, neurological disorders, and rehabilitation, but the central and peripheral mechanisms underlying motor module structure remain unclear. To assess the role of peripheral somatosensory input on motor module structure, we evaluated changes in the structure of motor modules for reactive balance recovery following pyridoxine-induced large-fiber peripheral somatosensory neuropathy in previously collected data in four adult cats. Somatosensory fiber loss, quantified by postmortem histology, varied from mild to severe across cats. Reactive balance recovery was assessed using multidirectional translational support-surface perturbations over days to weeks throughout initial impairment and subsequent recovery of balance ability. Motor modules within each cat were quantified by non-negative matrix factorization and compared in structure over time. All cats exhibited changes in the structure of motor modules for reactive balance recovery after somatosensory loss, providing evidence that somatosensory inputs influence motor module structure. The impact of the somatosensory disturbance on the structure of motor modules in well-trained adult cats indicates that somatosensory mechanisms contribute to motor module structure, and therefore may contribute to some of the pathological changes in motor module structure in neurological disorders. These results further suggest that somatosensory nerves could be targeted during rehabilitation to influence pathological motor modules for rehabilitation.NEW & NOTEWORTHY Stable motor modules for reactive balance recovery in well-trained adult cats were disrupted following pyridoxine-induced peripheral somatosensory neuropathy, suggesting somatosensory inputs contribute to motor module structure. Furthermore, the motor module structure continued to change as the animals regained the ability to maintain standing balance, but the modules generally did not recover pre-pyridoxine patterns. These results suggest changes in somatosensory input and subsequent learning may contribute to changes in motor module structure in pathological conditions.

Severe Acquired Hypokalemic Paralysis in a Bodybuilder After Self-Medication With Triamterene/Hydrochlorothiazide.

BACKGROUND: Severe hypokalemia with severe neurological impairment and electrocardiogram (ECG) abnormalities due to the misuse of triamterene/hydrochlorothiazide (HCTZ) in a bodybuilder has not yet been reported. CASE REPORT: A 22-year-old bodybuilder developed acute generalized muscle cramps, sensory disturbance of the distal lower and upper limbs, quadriparesis, and urinary retention. These abnormalities were attributed to severe hypokalemia of 1.8 mmol/L (normal range 3.4-4.5 mmol/L) due to misuse of triamterene/HCTZ together with fluid restriction. He was cardiologically asymptomatic, but ECG revealed a corrected QT (QTc) interval of 625 ms. On intravenous application of fluids along with intravenous and oral substitution of potassium, his condition rapidly improved, such that the sensory disturbances, quadriparesis, and bladder dysfunction completely resolved within 2 days after admission. CONCLUSIONS: Self-medication with diuretics along with fluid restriction may result in severe hypokalemia, paralysis, and ECG abnormalities. Those responsible for the management of bodybuilding studios and competitions must be aware of the potential severe health threats caused by self-medication with diuretics and anabolic steroids. Although triamterene is potassium-sparing, it may enhance the potassium-lowering effect of HCTZ.

Clinical diagnosis of sensory neuropathy in HIV patients treated with tenofovir: A 6-month follow-up study.

BACKGROUND: Sensory neuropathy (SN) is a common and often painful neurological condition associated with HIV-infection and its treatment. However, data on the incidence of SN in neuropathy-free individuals initiating combination antiretroviral therapies (cART) that do not contain the neurotoxic agent stavudine are lacking. AIMS: We investigated the 6-month incidence of SN in ART naïve individuals initiating tenofovir (TDF)-based cART, and the clinical factors associated with the development of SN. METHODS: 120 neuropathy-free and ART naïve individuals initiating cART at a single center in Johannesburg, South Africa were enrolled. Participants were screened for SN using clinical signs and symptoms at study enrolment and approximately every 2-months for a period of ~6-months. Diagnostic criteria for symptomatic SN was defined by the presence of at least one symptom (pain/burning, numbness, paraesthesias) and at least two clinical signs (reduced vibration sense, absent ankle reflexes or pin-prick hypoaesthesia). Diagnostic criteria for asymptomatic SN required at least two clinical signs only (as above). RESULTS: A total of 88% of the cohort completed three visits within the 6-month period. The 6-month cumulative incidence of neuropathy was 140 cases per 1000 patients (95% CI: 80-210) at an incidence rate of 0.37 (95% CI: 0.2-0.5) per person year. Height and active tuberculosis (TB) disease were independently associated with the risk of developing SN (P < .05). INTERPRETATION: We found that within the first 6 months of starting cART, incident SN persists in the post-stavudine era, with 11 (9%) of individuals developing asymptomatic SN, and 9 (8%) developing symptomatic SN.

Lateral femoral cutaneous nerve block with different volumes of Ropivacaine: a randomized trial in healthy volunteers.

BACKGROUND: Nerve block of the lateral femoral cutaneous nerve (LFCN) is a predominantly sensory block. It reduces pain following total hip arthroplasty (THA), but the non-responder rate is high. We hypothesized, that an increased volume of ropivacaine, would result in greater coverage of incisions used for THA. METHODS: We conducted a randomized, blinded trial in 20 healthy volunteers. Participants were randomized to receive bilateral LFCN-blocks with 8 mL ropivacaine 0.75% on the left side and 16 mL ropivacaine 0.75% on the right side, or vice versa. Allocation was blinded to both participants and outcome assessors. Before nerve block performance, incision lines for posterior and lateral THA approaches were depicted with invisible ultraviolet-paint, thereby securing sufficient blinding during outcome assessment. The blocked area was mapped using temperature and mechanical discrimination tests. Quadriceps muscle strength was monitored. Primary outcome was coverage of the posterior incision line assessed by temperature discrimination test. RESULTS: We found no difference in coverage of the posterior or lateral incision lines when comparing LFCN-blocks with 8 mL versus 16 mL of ropivacaine. The blocked area was significantly larger in the 16 mL group, assessed by both temperature discrimination test (p = 0.012) and mechanical discrimination test (p = 0.034). We observed no difference between groups regarding quadriceps muscle strength (p = 1.0). CONCLUSIONS: A LFCN-block with increased volume of ropivacaine from 8 mL to 16 mL did not result in a greater coverage of posterior or lateral incision lines used for THA, but in a larger blocked sensory area. TRIAL REGISTRATION: Clinicaltrials.gov: NCT03138668 . Registered 3rd of May 2017.

Second-generation antipsychotic drugs and short-term somatic serious adverse events: a systematic review and meta-analysis.

BACKGROUND: Antipsychotic drugs might cause acutely occurring, serious side-effects and thus contribute to the increased physical morbidity and mortality observed in patients with severe mental health disorders. We examined this hypothesis by doing a meta-analysis of International Conference on Harmonisation-Good Clinical Practice-defined serious adverse events occurring in placebo-controlled trials of antipsychotics. METHODS: For this systematic review and meta-analysis, we included randomised controlled trials (RCTs) comparing second-generation antipsychotics with placebo. We searched MEDLINE, Embase, Cochrane CENTRAL, BIOSIS, PsycINFO, PubMed, ClinicalTrials.gov, and WHO International Clinical Trials Registry Platform for trials published in any language from database inception up until Jan 27, 2017. Trials were included without limitations in population (diagnostic category, age, sex, ethnicity), dosing regimen, blinding status, duration, or publication year. Only psychological studies lasting less than 1 day and trials done in mainland China were excluded. We contacted pharmaceutical companies, drug regulatory authorities, and study investigators for additional data. The primary outcome was the number of patients with at least one somatic serious adverse event. We estimated minimum and maximum numbers of patients with the outcome in each study group and synthesised the results with odds ratios (ORs) in a common-effects meta-analysis. This study is registered with PROSPERO, number CRD42016033930. FINDINGS: We identified 597 RCTs, comprising 108 664 participants, that met the inclusion criteria. 314 trials (67 642 participants) with details on individual serious adverse events available constituted the main dataset for meta-analysis. 88% of these were 13 weeks (approximately 3 months) or shorter in duration (median 6 weeks, IQR 4-9). At least one somatic serious adverse event occurred in 698 (1·63%) to 862 (2·02%) of 42 600 patients on antipsychotics, and in 343 (1·37%) to 419 (1·67%) of 25 042 patients on placebo. The odds ratios (ORs) were 1·24 (95% CI 1·08-1·42) and 1·24 (1·10-1·41) based on the minimum and maximum estimate, respectively. In predefined subgroup analyses we found evidence suggesting a larger effect in older patients (>65 years; OR 1·56, 95% CI 1·22-1·98; 1·58, 1·25-1·99) as compared with adults (18-65 years; 1·09, 0·91-1·29; 1·10, 0·95-1·28); likewise in children or adolescents (<18 years) although the evidence was more uncertain (1·49, 0·81-2·75; 1·54, 0·85-2·77). Of 597 included RCTs, 30 (5%), 358 (60%), and 209 (35%) were rated at high, moderate, or low risk of bias, respectively. τ2 was zero for both analyses of the primary outcome (minimum estimate, maximum estimate). A Bayesian sensitivity analysis using external information on heterogeneity gave similar results. INTERPRETATION: We found evidence that antipsychotics cause short-term somatic serious adverse events on top of somatic serious adverse events occurring independent of treatment. This effect appears to be mainly driven by results in older patients. Hence, clinicians should be aware that antipsychotics are potentially toxic, particularly when treating patients sharing risk factors with the older population. FUNDING: German Ministry of Education and Research.

Risk prediction and impaired tactile sensory perception among cancer patients during chemotherapy.

OBJECTIVES: to estimate the prevalence of impaired tactile sensory perception, identify risk factors, and establish a risk prediction model among adult patients receiving antineoplastic chemotherapy. METHOD: historical cohort study based on information obtained from the medical files of 127 patients cared for in the cancer unit of a private hospital in a city in Minas Gerais, Brazil. Data were analyzed using descriptive and bivariate statistics, with survival and multivariate analysis by Cox regression. RESULTS: 57% of the 127 patients included in the study developed impaired tactile sensory perception. The independent variables that caused significant impact, together with time elapsed from the beginning of treatment up to the onset of the condition, were: bone, hepatic and regional lymph node metastases; alcoholism; palliative chemotherapy; and discomfort in lower limbs. CONCLUSION: impaired tactile sensory perception was common among adult patients during chemotherapy, indicating the need to implement interventions designed for early identification and treatment of this condition.

Sensory axonal polyneuropathy due to 2,4-dinitrophenol.

A 24-year-old man developed subacute onset of numbness and pain in the upper and lower limbs. Physical examination demonstrated decreased pinprick sensation, but was otherwise normal. Blood and cerebrospinal fluid parameters were normal except for mild hepatic dysfunction. No data were suggestive of connective tissue disease. Nerve conduction studies demonstrated sensory neuropathy. A detailed medical interview revealed that the patient had been taking self-imported 2,4-dinitrophenol (DNP) for 2 months to decrease body weight. Six months after discontinuing DNP, subjective symptoms and liver dysfunction resolved completely, and the patient was diagnosed with drug-induced peripheral neuropathy and hepatopathy. There are no case reports of health risks posed by DNP in Japan, and even worldwide, cases of peripheral neuropathy due to DNP are rare. Obtaining a detailed drug history is important, as is providing information on the dangers of self-imported medicines.

Ipsilateral and contralateral sensory changes in healthy subjects after experimentally induced concomitant sensitization and hypoesthesia.

BACKGROUND: In unilateral neuropathic pain. e.g. after peripheral nerve injury, both positive and negative sensory signs occur often, accompanied by minor but equally directed contralateral sensory changes. To mimic this feature, we experimentally aimed to induce concomitant c-fibre sensitization and block in healthy subjects and analyzed the bilateral sensory changes by quantitative sensory testing (QST) using the protocol of the German Research Network on Neuropathic Pain. METHODS: Twenty eight healthy subjects were firstly randomized in 2 groups to receive either topical capsaicin (0.6%, 12 cm2, application duration: 15 min.) or a lidocaine/prilocaine patch (25/25 mg, 10 cm2, application duration: 60 min.) on the right volar forearm. Secondly, 7-14 days later in the same area either at first capsaicin (for 15 min.) and immediately afterwards local anesthetics (for 60 min.) was applied (Cap/LA), or in inversed order with the same application duration (LA/Cap). Before, after each application and 7-14 days later a QST was performed bilaterally. STATISTICS: Wilcoxon-test, ANOVA, p < 0.05. RESULTS: Single application of 0,6% capsaicin induced thermal hypoesthesia, cold hypoalgesia, heat hyperalgesia and tactile allodynia. Lidocaine/prilocaine alone induced thermal and tactile hypoesthesia as well as mechanical and cold hypoalgesia, and a heat hyperalgesia (to a smaller extent). Ipsilaterally both co-applications induced a combination of the above mentioned changes. Significant contralateral sensory changes occurred only after the co-application with concomitant sensitization and hypoesthesia and comprised increased cold (Cap/LA, LA/Cap) and mechanical detection as well as cold pain threshold (LA/Cap). CONCLUSION: The present experimental model using combined application of capsaicin and LA imitates partly the complex sensory changes observed in patients with unilateral neuropathic pain and might be used as an additional surrogate model. Only the concomitant use both agents in the same area induces both positive and negative sensory signs ipsilaterally as well as parallel contralateral sensory changes (to a lesser extent). TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT01540877 , registered on 23 February 2012.

Risk prediction and impaired tactile sensory perception among cancer patients during chemotherapy / Predição de risco e incidência de percepção sensorial tátil alterada em pacientes oncológicos durante quimioterapia / Predicción de riesgo e incidencia de percepción sensorial táctil alterada en pacientes oncológicos durante quimioterapia

ABSTRACT Objectives: to estimate the prevalence of impaired tactile sensory perception, identify risk factors, and establish a risk prediction model among adult patients receiving antineoplastic chemotherapy. Method: historical cohort study based on information obtained from the medical files of 127 patients cared for in the cancer unit of a private hospital in a city in Minas Gerais, Brazil. Data were analyzed using descriptive and bivariate statistics, with survival and multivariate analysis by Cox regression. Results: 57% of the 127 patients included in the study developed impaired tactile sensory perception. The independent variables that caused significant impact, together with time elapsed from the beginning of treatment up to the onset of the condition, were: bone, hepatic and regional lymph node metastases; alcoholism; palliative chemotherapy; and discomfort in lower limbs. Conclusion: impaired tactile sensory perception was common among adult patients during chemotherapy, indicating the need to implement interventions designed for early identification and treatment of this condition.

RESUMO Objetivos: Estimar a prevalência de percepção sensorial tátil alterada, identificar os fatores de risco e estabelecer modelo de predição de risco para seu desenvolvimento, em pacientes adultos, submetidos à quimioterapia antineoplásica. Método: Coorte histórica realizada a partir de informações obtidas em prontuários de 127 pacientes atendidos em uma unidade oncológica de um hospital privado de um município de Minas Gerais, Brasil. Os dados foram analisados por estatística descritiva, bivariada, com análise de sobrevida e multivariada por regressão de Cox. Resultados: Dos 127 pacientes analisados 57% desenvolveu percepção sensorial tátil alterada. As variáveis independentes que impactaram, de forma significativa e conjunta, com o tempo para ocorrência do desfecho foram: metástases óssea, hepática e de linfonodo regional, alcoolismo, quimioterapia paliativa e desconforto nos membros inferiores. Conclusão: A percepção sensorial tátil alterada foi um achado comum em pacientes adultos durante o tratamento quimioterápico, apontando para a necessidade da implementação de intervenções que visem identificar precocemente e prevenir ou tratar o problema.

RESUMEN Objetivos: estimar la prevalencia de percepción sensorial táctil alterada, identificar los factores de riesgo y establecer un modelo de predicción de riesgo para su desarrollo, en pacientes adultos sometidos a quimioterapia antineoplásica. Método: estudio de cohorte histórica, realizado a partir de informaciones obtenidas de fichas médicas de 127 pacientes atendidos en unidad oncológica de un hospital privado, en municipio de Minas Gerais, Brasil. Los datos fueron analizados con estadística descriptiva, bivariada, con análisis de sobrevivencia y multivariado con la regresión de Cox. Resultados: de los 127 pacientes analizados, 57% desarrollaron percepción sensorial táctil alterada. Las variables independientes que causaron impacto de forma significativa, y conjuntamente con el tiempo para ocurrencia del resultado, fueron: metástasis ósea, hepática y de linfoma regional; alcoholismo; quimioterapia paliativa; e, incomodidad en los miembros inferiores. Conclusión: la percepción sensorial táctil alterada fue un hallazgo común en pacientes adultos durante el tratamiento quimioterápico, lo que apunta para la necesidad de la implementación de intervenciones que objetiven identificar precozmente y prevenir o tratar el problema.

Quantitative Sensory Testing at Baseline and During Cycle 1 Oxaliplatin Infusion Detects Subclinical Peripheral Neuropathy and Predicts Clinically Overt Chronic Neuropathy in Gastrointestinal Malignancies.

PURPOSE: Oxaliplatin neurotoxicity has a spectrum of manifestations from an often reversible acute neurotoxicity to a more irreversible "stocking and glove" chronic neuropathy that is associated with high morbidity. Quantitative sensory testing (QST) is a noninvasive psychometric testing method that can potentially be used in the clinic setting to measure subclinical neurologic changes early on to identify patients that will experience chronic oxaliplatin-induced peripheral neuropathy at 1 year. PATIENTS AND METHODS: Thirty patients with gastrointestinal malignancies who were receiving oxaliplatin were recruited. QST and patient-reported outcomes were assessed at baseline; during infusion cycles 1, 2, 4, and 6; and at 1 year. National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE), version 4.0, chronic neuropathy scores were assessed at the 1-year time point. The variables at each time point were evaluated for prediction of 1-year chronic neuropathy scores. RESULTS: We found that patients with preexisting subclinical neuropathy were more likely to experience grades 2 and 3 chronic neuropathy than were those who did not have this condition (heat detection threshold, Spearman correlation coefficient (rs) = 0.39; P = .037; pellet retrieval time, rs = 0.47; P = .024). Patients in whom thermal and cutaneous sensory deficits developed with cycle 1 infusion were also more likely to experience grades 2 and 3 neuropathy at 1 year (cold detection threshold, rs = 0.50; P = .007; heat detection threshold, rs = 0.39; P = .042; cutaneous detection threshold, rs = 0.42; P = .043). CONCLUSION: QST provides a noninvasive, commercially available, and feasible clinical test to select patients, even before oxaliplatin treatment, who are likely to experience moderate to severe chronic peripheral neuropathy.

Diseases of abnormal sensitivity to cold in children on psychostimulant drugs.

BACKGROUND: Oral psychostimulant (PS) drugs, the pharmacologic treatment of choice for attention-deficit/hyperactivity disorder (ADHD), have been associated with diseases of abnormal sensitivity to cold (DASC) such as Raynaud phenomenon and acrocyanosis. OBJECTIVES: In a cohort of pediatric patients with DASC, we sought to identify prevalence and clinical features of patients on PS drugs. METHODS: A 6-year retrospective chart review (2005-2011) of Ste-Justine University Hospital Center DASC patients with and without exposure to PS drugs was performed. Clinical data were analyzed with descriptive statistical methods. RESULTS: Of 43 patients with DASC, 11 (25%) were exposed to PS drugs. In this group males were overrepresented, there was no evidence of collagen vascular diseases, serologic findings were not significant and the mean duration of PS intake was of 2.5 years. DASC age of onset was similar in both exposed and nonexposed patients. The incidence of more than one DASC type was greater in teenager patients with a positive family history of autoimmune and/or collagen vascular diseases. LIMITATIONS: This study is limited by its small population size, short follow-up period and its retrospective nature. CONCLUSION: Physicians should be aware of PS drugs as possible triggers for DASC.

A multicenter, non-randomized, phase II study of docetaxel and carboplatin administered every 3 weeks as second line chemotherapy in patients with first relapse of platinum sensitive epithelial ovarian, peritoneal or fallopian tube cancer.

BACKGROUND: In patients with ovarian cancer relapsing at least 6 months after end of primary treatment, the addition of paclitaxel to platinum treatment has been shown to improve survival but at the cost of significant neuropathy. In the first line setting, the carboplatin-docetaxel combination was as effective as the combination of carboplatin and paclitaxel but with less neurotoxicity. This study was initiated to evaluate the feasibility of carboplatin with docetaxel as second line treatment in patients with ovarian, peritoneal or fallopian tube cancer. METHODS: Patients with stage IC-IV epithelial ovarian, peritoneal or fallopian tube cancer were enrolled at the first relapse after at least 6 months since completion of the first line treatment. Docetaxel 75 mg/m2 was given as an one hour IV infusion followed immediately by carboplatin (AUC=5) given as a 30-60 min. IV infusion on day 1 and repeated every 3 weeks for 6-9 courses. Primary endpoint was toxicity; secondary endpoints were response rate and the time to progression. RESULTS: A total of 74 patients were included. Of these, 50 patients received 6 or more cycles, 13 received 3-5 courses and 11 received less than 3 courses. A total of 398 cycles were given. Grade 3/4 neutropenia was seen in 80% (59 of 74) patients with an incidence of febrile neutropenia of 16%. Grade 2/3 sensory peripheral neuropathy occurred in 7% of patients, but no grade 4 sensory peripheral neuropathy was observed. Sixty patients were evaluable for response. The overall response rate was 70% with 28% complete responses in the response evaluable patient population. Median progression-free survival was 12.4 months (95% CI 10.4-14.4). CONCLUSIONS: The three-weekly regimen of docetaxel in combination with carboplatin was feasible and active as second-line treatment of platinum-sensitive ovarian, peritoneal and Fallopian tube cancer. The major toxicity was neutropenia, while the frequency of peripheral neuropathy was low.

Signs and symptoms of methylmercury contamination in a First Nations community in Northwestern Ontario, Canada.

In 1970, fish caught in the English-Wabigoon River system in northwestern Ontario, Canada, were found to be contaminated with mercury coming from a chlor-alkali plant in the province. In the 1970s, patients exhibiting some of the symptoms of the Hunter-Russell syndrome (e.g. paresthesias, visual field constriction, ataxia, impaired hearing, and speech impairment) were reported by some researchers. However attempts to diagnose the patients as suffering from methylmercury poisoning proved to be controversial. In order to research the presence of methylmercury contamination, and show that the patients, through eating contaminated fish, were suffering from methylmercury poisoning, we studied the results of subjective complaints, neurological findings, and quantitative somatosensory measurements gathered in Grassy Narrows Indian Reservation, Ontario, in March, 2010. At that time, the population of the Grassy Narrows settlement was around 900. Ninety-one residents volunteered to be examined. From them, we selected 80 people who were older than 15 years old, and divided them into two groups. Canadian Younger (CY): 36 residents who were from 16 to 45 years old. Canadian Older (CO): 44 residents who were from 46 to 76 years old. We compared them to Japanese Exposed (JE): 88 methylmercury exposed residents from the Minamata district in Japan, and Japanese Control (JC): 164 control residents from non-polluted areas in Japan. Complaints and abnormal neurological findings were more prevalent and quantitative sensory measurements were worse in the two Canadian groups and the Japanese Exposed group than in the Japanese Control group. Complaints, neurological findings and quantitative sensory measurements were similar in Canadian Older and Japanese Exposed. The results for Canadian Younger fell between those of Canadian Older and Japanese Control. These findings indicate that the clinical signs and symptoms of the residents of Grassy Narrows are almost the same as those recorded for Minamata disease in Japan.

Unilateral contrast neurotoxicity as a stroke mimic after cerebral angiogram.

Contrast neurotoxicity (CN) following exposure to iodinated contrast is uncommon, and usually presents as cortical blindness due to bilateral occipital lobe involvement. Unilateral cortical dysfunction due to CN could mimic an acute stroke and has been rarely described. We report the case of an 89-year-old female who developed a transient dense/complete left homonymous-hemianopsia and left-sided tactile extinction after undergoing a right internal carotid (ICA) artery rotational angiogram with a standard high-volume iodinated contrast injection for 3D visualization a 6×4-mm right posterior communicating artery aneurysm with a fetal posterior cerebral artery (PCA) incorporated in the neck. This was associated with transient fullness and loss of gray-white matter differentiation in the right occipital and parietal lobes. The potential mechanism of CN in our case was the injection of a high volume of contrast in the ICA for the rotational angiogram. The presence of a right fetal PCA possibly allowed the contrast to reach the right occipital lobe. CN manifesting as an acute focal neurologic syndrome should be considered in the setting of recent iodinated contrast exposure.

Severe adverse reactions to dental local anaesthetics: prolonged mandibular and lingual nerve anaesthesia.

BACKGROUND: Prolonged anaesthesia may occur following dental local anaesthetic blocks. This paper reviews the possible mechanisms of injury. Direct injury to the nerve by the needle, although commonly thought to be the mechanism, is unlikely. It is much more likely that the injury is from neurotoxicity and/or interference with the vascularization of the nerve. METHODS: Estimation of the frequency of injury was complicated by the fact that although local anaesthetics are prescription-only (S4) drugs, they are supplied without prescription by dental supply houses. Unlike all other S4 drugs, there is no statutory requirement to record supply. The pharmaceutical and supply houses relied on that and 'commercial confidentiality' to not supply information. RESULTS: An informed estimate of 1 in 27 415 was made but this figure has wide confidence limits. Management of cases of prolonged anaesthesia following local anaesthetic injection is discussed. CONCLUSIONS: Patients who suffer this uncommon complication suffer considerable distress and feel injured, so care must be exhibited in their management. Specialist referral is recommended.

Can milnacipran used for neuropathic pain in patients with advanced cancer cause neuromuscular and somatosensory disorders?

BACKGROUND: Milnacipran is one of the classes of drugs that are serotonin and norepinephrine reuptake inhibitors (SNRIs). It is a promising drug for the treatment of neuropathic pain in patients with advanced cancer. However, we found that neuromuscular and somatosensory disorders occurred when milnacipran was used as an adjuvant analgesic. CASE REPORT: A 66-year-old woman with a history of neuropathic pain was given 15 mg of milnacipran after dinner. The next morning she developed stiffness of the fingers, numbness in the mandible, and the soles of her feet felt swollen. Milnacipran was discontinued and her symptoms disappeared immediately. We managed this case, which was becoming severe, by discontinuing milnacipran on early detection of symptoms. DISCUSSION: This is the first report that demonstrates an adverse reaction of milnacipran when used as an analgesic adjuvant, and not as an antidepressant drug, for neuropathic pain in patients with advanced cancer. The analgesic effect of SNRIs will likely be used in the management of neuropathic pain in the future; however, clinicians should be aware of the early adverse reactions to these agents.

Axial kinesthesia is impaired in Parkinson's disease: effects of levodopa.

Integration of sensory and motor inputs has been shown to be impaired in appendicular muscles and joints of Parkinson's disease (PD) patients. As PD advances, axial symptoms such as gait and balance impairments appear, which often progresses to complete inability stand or walk unaided. The current study evaluates kinesthesia in the axial musculature of PD patients during active postural control to determine whether impairments similar to those found in the appendages are also present in the hip and trunk. Using axial twisting, we quantified the detection threshold and directional accuracy of the hip relative to the feet (i.e. Hip Kinesthesia) and the hip relative to the shoulders (i.e. Trunk Kinesthesia). The relation of kinesthetic threshold to disease progression as measured by UPDRS and the effect of levodopa treatment on kinesthesia were assessed in 12 PD compared to age-matched controls. Subjects stood unaided while passively twisted at a very low constant rotational velocity (1 degrees /s). The results showed that accuracy in determining the direction of axial twisting was reduced in PD relative to healthy control subjects in the hip (PD-ON: 81%; PD-OFF: 91%; CTL=96%) and trunk (PD-ON: 81%; PD-OFF: 88%; CTL=95%). Thresholds for perception of axial twisting were increased when PD subjects were ON levodopa versus OFF in both the hip (p<0.01) and the trunk (p<0.05). The magnitude of decrease in sensitivity due to being ON levodopa was significantly correlated with the increase in UPDRS motor scores (Hip: r=0.90, p<0.01 and Trunk: r=0.60, p<0.05). This effect was not significantly correlated with equivalent levodopa dosage. PD subjects with disease onset on the left side of their body showed significantly higher axial thresholds than subjects with right PD onset (p<0.05). In conclusion, deficits in axial kinesthesia seem to contribute to the functional impairments of posture and locomotion in PD. Although levodopa has been shown to improve appendicular kinesthesia, we observed the opposite in the body axis. These findings underscore the dissociable neurophysiological circuits and dopaminergic pathways that are known to innervate these functionally distinct muscle groups.

Randomised double-blind, placebo-controlled trial of the effects of the 'party pills' BZP/TFMPP alone and in combination with alcohol.

The objective of this study was to determine the clinical effects of party pills containing benzylpiperazine (BZP) and trifluoromethylphenylpiperazine (TFMPP) when taken alone and in combination with alcohol. The study was a randomised, double-blind, placebo-controlled trial conducted in a hospital-based clinic in Wellington, New Zealand. Thirty-five volunteers who had previously used party pills containing BZP were included in this trial. Participants received one of the following four treatments: 300 mg/74 mg BZP/TFMPP and placebo, 300 mg/74 mg BZP/TFMPP and 57.6 g (6 units) alcohol, placebo and 57.6 g (6 units) alcohol and double placebo. The primary outcome variable was a measure of driving performance, the standard deviation of lateral position (SDLP) measured at 6.5 h. Secondary measures included adverse events, cardiovascular effects, psychological function and delayed effects on sleep. The study was stopped early, after 35 of the planned 64 subjects had undertaken testing, because of severe adverse events that occurred in four of 10 BZP/TFMPP-only subjects, three of seven combined BZP/TFMPP and alcohol subjects, none of the 6 placebo subjects, and none of the 12 alcohol-only subjects. The overall rate of severe adverse events (defined as causing considerable interference with usual activity and/or rated by subject as severe) in those receiving BZP/TFMPP was seven of 17 (41.2%, 95% CI 18.4-67.1). The severe events included agitation, anxiety, hallucinations, vomiting, insomnia and migraine. BZP/TFMPP significantly improved the driving performance, decreasing SDLP at -4.2 cm (95% CI -6.8 to -1.6, P = 0.002). The effect of alcohol was to increase SDLP: 2.3 cm (95% CI -0.3 to 4.9, P = 0.08). BZP/TFMPP also resulted in increased heart rate and blood pressure and in difficulty in getting to sleep. BZP/TFMPP alone or with alcohol carries a significant risk of severe adverse events when taken in similar doses to those recommended by manufacturers.

Retardation in somatosensory cortex development induced by postnatal BrdU treatment in mice.

Cerebral dysgeneses are in the background of several neurological and mental disturbances. The aim of the present study was to investigate structural and activity changes following disturbed postnatal neuronal development in mice. Newborn C57Bl6 mice were exposed to 5-bromo-2'-deoxyuridine (BrdU: daily 50 microg/g body weight) during a period between postnatal days P0-P5 or P0-P11, respectively, and neuronal malformation and malfunctioning of somatosensory (barrel field) cortex was analyzed in adolescent animals. Alterations in histological architecture of interneuronal and glial elements were studied and correlated with electrophysiological modifications. Between P30 and P35 days litters underwent ex vivo electrophysiological experiments to examine the changes in basic excitability and in synaptic efficacy. Parallel immunohistochemistry was performed to detect BrdU, GABA and GFAP. There were no BrdU immunopositive cell nuclei in control animals, but marked staining was observed in both BrdU treated groups. Lessening in the number of GABAergic neurons was observed in the treated groups. GFAP immunohistochemical analysis has shown an increased number of activated astroglial cells in treated animals. Reduction of the number of GABAergic neurons was observed in the treated groups. Electrophysiological recordings on cortical slices showed increased excitability in the treated groups.