Anti-aquaporin-4 antibody in Chinese patients with central nervous system inflammatory demyelinating disorders

Objective

To determine seroprevalence of aquaporin-4 (AQP4) antibody in Chinese patients with central nervous system (CNS) inflammatory demyelinating disorders.

Methods

AQP4 antibody was detected by anti-AQP4 antibody assay. We measured seroprevalence in 200 patients with neuromyelitis optica (NMO, n = 44), multiple sclerosis (MS, n = 46), transverse myelitis (TM, n = 44), optic neuritis (ON, n = 13), acute disseminated encephalomyelitis (ADEM, n = 2), and other neurological diseases (OND, n = 51).

Results

AQP4 antibody seropositivity was 88.6% in patients with NMO, 4.3% in patients with MS, 30.8% in patients with ON and 51.7% in patients with LETM (longitudinally extensive TM). No patients with acute partial TM, ADEM, OND were positive for AQP4 antibody. Sensitivity of the test was 88.6% (95% CI 80–95) in patients with NMO. Specificity is 97.9% (95% CI 95.1–100) in 46 MS patients, with 51 OND patients as the control group. If the patients with recurrent ON, LETM were considered high risk for NMO (n = 37) and the remaining patients (n = 119) were considered controls, the sensitivity of this assay would be 48.6% (95% CI 33.4–64.1) and the specificity 97.5% (95% CI 94.7–100).

Conclusion

This study confirms that AQP4 antibody is a sensitive and specific biomarker for discrimination between NMO and other CNS autoimmune diseases.     

Altered antioxidant defense system in clinically stable patients with schizophrenia and their unaffected siblings

Objective

To determine Red Blood Cell (RBC) antioxidant enzyme activities and plasma Thiobarbituric Acid Reactive Substances (TBARS) in clinically stable patients with schizophrenia and their unaffected siblings.

Methods

A case-control study carried out on three groups: 60 schizophrenic patients treated with neuroleptics, 33 of their unaffected siblings and 30 healthy controls with no family psychiatric history. Biological markers were measured on fasting patients after a period of tobacco abstinence: RBC antioxidant enzyme activities – superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) – by spectrophotometry and plasma levels of TBARS by spectrofluorimetry.

Results

RBC SOD and CAT activities were significantly lower in schizophrenic patients and their unaffected siblings compared to the control group (P < 0.001). Schizophrenic patients also had significantly lower RBC GSH-Px activity than controls (P = 0.03), whereas their unaffected siblings had significantly higher RBC GSH-Px activity than controls (P = 0.04). Plasma TBARS were higher in schizophrenic patients than their unaffected siblings: 2.1 ± 0.8 μmol/l vs. 1.7 ± 0.6 μmol/l (P = 0.06).

Conclusions

Our results showed a decrease in antioxidant enzyme activities and an increase in lipid peroxidation confirming the existence of oxidative stress in schizophrenic patients treated with neuroleptics. Additionally, this suggests that the increase in GSH-Px activity in unaffected siblings would be a protective mechanism against oxidative stress and damage. Other studies are necessary to confirm these findings.     

Clinicopathological review of patients with and without multiple sclerosis treated by partial sensory rhizotomy for medically refractory trigeminal neuralgia: a 12-year retrospective study

Background

Trigeminal nerve root entry zone demyelination has been implicated as a cause of trigeminal neuralgia (TN) in multiple sclerosis (MS) and patients with nerve root vascular compression. We have examined the relationship between pathology and treatment outcome in patients with and without MS, treated for intractable TN by partial sensory rhizotomy (PSR).

Methods

We reviewed the operative records, electron microscopic biopsy findings and post-operative satisfaction and pain scores of 23 MS and 47 non-MS patients who underwent PSR between 1992 and 2004.

Results

The MS and non-MS patients had similar ages of onset of TN, duration of symptoms, age at surgery and proportions with typical and atypical symptoms. Demyelination was present in 16 MS and 23 non-MS patients (p = 0.129), and a compressing vessel in 5 MS and 23 non-MS patients (p = 0.039). Of those with demyelination, vascular compression was documented in 3 MS and 15 non-MS patients (p = 0.008). Pain and satisfaction scores were similar in both groups. Recurrent TN was more commonly associated with a compressing vessel (p = 0.019).

Conclusions

TN is frequently associated with nerve root entry zone demyelination in MS and patients with nerve root vascular compression. The characteristics of the TN and response to PSR are similar in both groups. Persistent vascular compression increases the risk of recurrent TN after PSR.     

Bandpass filter settings differentially affect measurement of P50 sensory gating in children and adults

Objective

This study investigated the effect of four different bandpass filter settings on measures of the P50 component and the signal-to-noise ratios (SNR) of averaged ERPs obtained from a sensory gating paradigm employing paired-click stimuli.

Methods

Participants were adults (n = 18) 20–55 years old and children (n = 25) 5–10 years old who were free of neurological disorders.

Results

Results show that the filter settings (0.23–75 Hz, 10–50 Hz, 10–75 Hz, and 10–200 Hz) differentially affected the P50 amplitude, noise power and SNR measures of the conditioning and test clicks, and P50 T/C ratios.

Conclusions

The 10–50 Hz filter setting may be optimal in studies that include only adults as these settings resulted in the smallest mean P50 T/C ratio, a reasonable standard deviation (SD) for the ratio, and the highest SNRs. The 10–200 Hz filter may be the best for studying young children as this setting had the smallest mean and SD of P50 T/C ratios for these participants.

Significance

In studies that include both adults and children investigators are advised to use the 10–200 Hz filter setting because the smaller variability of sensory gating in the child group helps ensure better homogeneity of variance measures between the groups.     

Mismatch negativity and low frequency oscillations in schizophrenia families

Objective

Theta-alpha range oscillations have been associated with MMN in healthy controls. Our previous studies showed that theta-alpha activities are highly heritable in schizophrenia patients’ families. We aimed to test the hypothesis that theta-alpha activities may contribute to MMN in schizophrenia patients and their family members.

Methods

We compared MMN and single trial oscillations during MMN in 95 patients, 75 first-degree relatives, 87 controls, and 34 community subjects with schizophrenia spectrum personality (SSP) traits.

Results

We found that (1) MMN was reduced in patients (p < 0.001) and SSP subjects (p = 0.047) but not in relatives (p = 0.42); (2) there were augmented 1–20 Hz oscillations in patients (p = 0.02 to <0.001) during standard and deviant stimuli; (3) theta-alpha (5–12 Hz) oscillations had the strongest correlation to MMN in controls and relatives (ΔR² = 21.4–23.9%, all p < 0.001), while delta (<5 Hz) showed the strongest correlation to MMN in schizophrenia and SSP trait subjects; and, (4) MMN (h² = 0.56, p = 0.002) and theta-alpha (h² = 0.55, p = 0.004) were heritable traits.

Conclusions

Low frequency oscillations have a robust relationship with MMN and the relationship appears altered by schizophrenia; and schizophrenia patients showed augmented low frequency activities during the MMN paradigm.

Significance

The results encourage investigation of low frequency oscillations to elucidate the neurophysiological pathology underlying MMN abnormalities in schizophrenia.     

Factors affecting the diagnostic delay in amyotrophic lateral sclerosis

Background

Although amyotrophic lateral sclerosis (ALS) is a relentlessly progressive disorder, early diagnosis allows a prompt start with the specific drug riluzole and an accurate palliative care planning. ALS at onset may however mimic several disorders, some of them treatable (e.g., multifocal motor neuropathy) or epidemiologically more frequent (e.g., cervical myelopathy).

Objective

To study the delay from onset to diagnosis in a cohort of ALS patients and to the variables that may affect it.

Methods

We performed a retrospective analysis of the diagnostic delays in a cohort of 260 patients affected by ALS (M/F = 1.32) followed at our tertiary referral ALS Center between 2000 and 2007.

Results

The median time from onset to diagnosis was 11 months (range: 6–21) for the whole ALS cohort, 10 months (range: 6–15) in bulbar-onset (n = 65) and 12 months (range: 7–23) in spinal-onset (n = 195) patients (p = 0.3). 31.1% of patients received other diagnoses before ALS and this led to a significant delay of the correct diagnosis in this group (other diagnoses before ALS, n = 81: median delay, 15 months [9.75–24.25] vs ALS, n = 179, median delay, 9 months [6–15.25], p < 0.001).

Conclusions

The diagnostic delay in ALS is about one year, besides the growing number of tertiary centres and the spread of information about the disease through media and internet. Cognitive errors based on an incorrect use of heuristics might represent an important contributing factor. Furthermore, the length of the differential diagnosis from other disorders and delays in referral to the neurologist seems to be positively associated with the delay in diagnosis.     

Decreased resting energy expenditure in patients with Duchenne muscular dystrophy

Background

Skeletal muscle metabolism is a major determinant of resting energy expenditure (REE). Although the severe muscle loss that characterizes Duchenne muscular dystrophy (DMD) may alter REE, this has not been extensively investigated.

Methods

We studied REE in 77 patients with DMD ranging in age from 10 to 37 years using a portable indirect calorimeter, together with several clinical parameters (age, height, body weight (BW), body mass index (BMI), vital capacity (VC), creatine kinase, creatinine, albumin, cholinesterase, prealbumin), and assessed their influence on REE. In addition, in 12 patients maintaining a stable body weight, the ratio of energy intake to REE was calculated and defined as an alternative index for the physical activity level (aPAL).

Results

REE (kcal/day, mean ± SD) in DMD patients was 1123 (10–11 years), 1186 ± 188 (12–14 years), 1146 ± 214 (15–17 years), 1006 ± 136 (18–29 years) and 1023 ± 97 (?30 years), each of these values being significantly lower than the corresponding control (p < 0.0001). VC (p < 0.001) was the parameter most strongly associated with REE, followed by BMI (p < 0.01) and BW (p < 0.05). The calculated aPAL values were 1.61 (10–11 years), 1.19 (12–14 years), 1.16 (15–17 years), and 1.57 (18–29 years).

Conclusion

The REE in DMD patients was significantly lower than the normal value in every age group, and strongly associated with VC. Both the low REE and PAL values during the early teens, resulting in a low energy requirement, might be related to the obesity that frequently occurs in this age group. In contrast, the high PAL value in the late stage of the disease, possibly due to the presence of respiratory failure, may lead to a high energy requirement, and thus become one of the risk factors for development of malnutrition.     

Evaluation of clinical parameters during and after treatment of attack in patients with clinically isolated syndrome: Comparison of the results with that of multiple sclerosis patients

Objectives

The aim of the present study was to examine the changes in the measurement of functions during and after pulse methylprednisolone (MP) treatment during a clinically isolated syndrome (CIS) attack, using the multiple sclerosis functional composite (MSFC) and Expanded Disability Status Scale (EDSS), and to compare the results with that of MS patients.

Patients and method

The present study included 44 patients with CIS and 26 patients with clinically definite multiple sclerosis (MS), as the control group. All patients were having an acute attack and were treated with 1000-mg intravenous methylprednisolone. The scales were administered before-and after-treatment, and at 30 days after treatment.

Results

A 5-days treatment was adequate in 36.9% of CIS patients and 62.5% of MS patients (p = 0.003). A moderate correlation was found between Auditory Consonant Trigram Test (ACT) and paced auditory serial addition test in CIS patients before-treatment. A poor correlation was found between EDSS scores and ACT in CIS patients at all measurement periods. The level of correlation between EDSS and ACT scores was similar in MS patients.

Conclusion

Although MS and CIS patients show similar response to corticosteroid treatment and had similar fatigue characteristics, overall cognitive functioning was better in CIS patients.     

Effect of concentration and mode of intrathecal baclofen administration on soleus H-reflex in patients with muscle hypertonia

Objectives

Assess spinal reflex excitability after increasing intrathecal baclofen (ITB) flow by manipulation of drug concentration and mode of administration.

Methods

The effect of concentration was assessed by comparing changes in H-reflex (H/M ratio) 1–6 h after a 50 μg ITB bolus at 50 μg/ml concentration administered manually via lumbar puncture (LP, duration 1–2 min, n = 27) to a 50 μg bolus at 500 μg/ml concentration programmed through the pump and delivered via intrathecal catheter (IC, duration 10 min) above simple continuous dose (25–100 μg/day, n = 16). The effect of mode of administration was assessed by comparing peak changes in H/M ratio after 50 μg IC bolus above simple continuous dose (complex continuous mode, n = 27) to simple continuous mode only (n = 22) at equivalent daily doses (75–150 μg/day).

Results

H/M decrease was faster and overall greater after LP than IC bolus (mean 1-h 77% vs. 63%, p = 0.012; 1–6 h 91% vs. 82%, p < 0.001, respectively). H/M ratio also decreased significantly more with complex (91%) than simple continuous mode of administration (78%, p = 0.025).

Conclusions

Lower ITB concentration and complex continuous mode of administration lead to greater decrease in H/M ratio.

Significance

Decreased spinal reflex excitability after adjustment of drug and pump parameters to increase ITB flow may result in better clinical response.     

Non-conventional risk factors were associated with infarct patterns in ischemic stroke

Objective

Diffusion-weighted imaging (DWI) infarct patterns can play a useful role in the management of ischemic stroke patients, particularly in identifying index stroke mechanisms. Novel vascular risk factors like high sensitivity C-reactive protein (hs-CRP) and the metabolic syndrome have recently been shown to be of prognostic importance following ischemic stroke. We aimed to determine the relationship between these novel factors and infarct patterns noted on DWI.

Methods

A total of 886 patients with acute cerebral infarcts within the MCA territory were prospectively studied. Using the DWI data the patients were divided into four groups: cortical, small (<1 cm) superficial, border-zone, and deep infarcts patterns. The independent associations of various infarct DWI patterns vs. hs-CRP and presence of the metabolic syndrome were evaluated after adjusting for the confounders.

Results

hs-CRP was highest among patients with cortical infarcts, while the metabolic syndrome was most frequent in patients with border-zone infarcts. Compared to the lowest quartile of hs-CRP level, those in the highest quartile were more likely to have the cortical pattern (OR, 3.55; 95% CI, 1.92–6.56; P < 0.001), and less likely to have the deep infarct pattern (OR, 0.49; 95% CI, 0.29–0.81; P = 0.006) in logistic regression analyses. There was an independent association between presence of the metabolic syndrome and the border-zone pattern (OR, 1.75; 95% CI, 1.12–2.73; P = 0.013).

Conclusions

hs-CRP levels and metabolic derangements are independently associated with infarct pattern in acute ischemic stroke, and may be the potential targets for lessening the clinical impact of certain infarct patterns.     

Evaluation of ability for basic movement scale for children type T (ABMS-CT) for disabled children

Background

The objective of this pilot study was to test the validity and reliability of a new scale, the Ability for Basic Movement Scale for Children Type T (ABMS-CT).

Methods

Forty-nine pediatric patients with disabilities (aged 1.00–15.17 years; 29 males and 20 females) participated in this prospective study. To prove the validity and reliability of the ABMS-CT, subjects were administered the ABMS-CT by two physicians. In addition to the ABMS-CT score, data on age, diagnosis, and results of the Functional Independence Measure for Children (WeeFIM) were recorded.

Results

Spearman’s rank correlation coefficient analysis showed that the ability to perform basic movements according to the individual scores for each item on the ABMS-CT and the total scores of the ABMS-CT correlated significantly with the total scores of the motor and cognitive WeeFIM, respectively (r = 0.753–0.892, p = 0.0001). The five items on the ABMS-CT had appropriate internal consistency (Cronbach’s α = 0.966). Inter-rater reliability analysis indicated that the “oral and facial area”, “hands and fingers”, “one leg”, “both legs”, and “stairs” items on the ABMS-CT had almost perfect reliability (κ = 0.854–0.925).

Conclusion

This study provides evidence for the validity and reliability of the ABMS-CT with regard to assessment of the functional ability for complex movements in disabled pediatric patients even if they can walk independently.     

Factors predicting quality of life in a group of Polish subjects with multiple sclerosis: accounting for functional state, socio-demographic and clinical factors

Objectives

Quality of life (QoL) has presently a firmly established position as an important endpoint in medical care. Multiple sclerosis (MS) is a chronic neurological disease with considerable effect on patients’ QoL. QoL of MS patients from many European countries has already been assessed but little is known on health-related QoL of Polish subjects with MS. Few studies have taken into consideration multiple predictors of QoL. The aim of this study was to elicit the most relevant factors that determine QoL of Polish group of MS patients. Socio-demographic and clinical factors as well as the influence of disability level were analyzed in this study.

Patients and methods

173 MS patients and 86 healthy controls underwent assessment using the Mini Mental Status Examination, WHOQOL-100, Beck Depression Inventory and Fatigue Severity Scale. Data were analyzed by a stepwise linear regression analysis.

Results

MS patients had significantly worse global QoL and worse QoL in physical and psychological health domains, lower level of independence, worse social relations and were less satisfied with the surrounding environment they lived in compared with healthy controls (p < 0.05). MS subjects had also higher level of depression and fatigue compared to healthy controls (p < 0.05).

Conclusions

The study determined that the strongest predictors of global QoL of Polish MS patients were depression, disability level and fatigue.     

Topography of maturational changes in EEG burst spectral power of the preterm infant with a normal follow-up at 2years of age

Objective

To quantify the electroencephalography (EEG) burst frequency spectrum of preterm infants by automated analysis and to describe the topography of maturational change in spectral parameters.

Methods

Eighteen preterm infants <32 weeks gestation and normal neurological follow-up at 2 years underwent weekly 4-h EEG recordings (10–20 system). The recordings (n = 77) represent a large variability in postmenstrual age (PMA, 28–36 weeks). We applied an automated burst detection algorithm and performed spectral analysis. The frequency spectrum was divided into δ1 (0.5–1 Hz), δ2 (1–4 Hz), θ (4–8 Hz), α (8–13 Hz) and β (13–30 Hz) bands. Spectral parameters were evaluated as a function of PMA by regression analysis. Results were interpolated and topographically visualised.

Results

The majority of spectral parameters show significant change with PMA. Highest correlation is found for δ and θ band. Absolute band powers decrease with increasing PMA, while relative α and β powers increase. Maturational change is largest in frontal and temporal region.

Conclusions

Topographic distribution of maturational changes in spectral parameters corresponds with studies showing ongoing gyration and postnatal white matter maturation in frontal and temporal lobes.

Significance

Computer analysis of EEG may allow objective and reproducible analysis for long-term prognosis and/or stratification of clinical treatment.     

Upper extremity motor measures of Tap Test response in Normal Pressure Hydrocephalus

Objective

The Tap Test (TT) is a commonly used method for predicting shunt responsiveness in patients with Normal Pressure Hydrocephalus (NPH). The present study investigates whether measures of upper extremity motor function are useful for assessing response to spinal fluid drainage.

Methods

42 subjects undergoing evaluations for idiopathic NPH (iNPH) participated in this study. A standardized gait evaluation, a neuropsychological battery, and objective tests of upper extremity motor functions were administered. A Neurologist skilled in NPH assessment independently rated patients as TT Responders (n = 26) or Non-Responders (n = 16) based on clinical impression of change 2–4 h after 40–50 cm³ drainage of spinal fluid by lumbar puncture (LP). In the subset of subjects who underwent shunt placement, operative outcome was also evaluated.

Results

TT Responders improved significantly more than TT Non-Responders in Upper Extremity Coordination/Speed tasks (p < .001). The groups did not differ on other neuropsychological measures post-LP. A possible association was observed between pre- and post-TT changes in Upper Extremity Coordination/Speed and post-shunt improvement. Among Upper Extremity Coordination/Speed measures, Line Tracing displayed the greatest sensitivity (76%) to change post-LP.

Conclusions

Our data suggest that measures of upper extremity motor functions may be useful as measures of Tap Test response in patients with iNPH. These upper extremity motor tasks can be rapidly administered (<5 min) in clinical practice and may provide an additional dimension beyond gait and cognition for evaluating response to LP.     

Association of genetic polymorphisms in the type II deiodinase gene with bipolar disorder in a subset of Chinese population

Objective

Genetic factors play a critical role in the etiology of bipolar disorder (BPAD). Previous studies suggested an association between thyroid dysfunction and BPAD. We hypothesize that genetic variations in the type II deiodinase (DIO2) gene that possibly alter the bioactivity of thyroid hormones are associated with BPAD.

Method

A case–control association study was conducted in a subset of Chinese Han population. Two single nucleotide polymorphisms (SNP), open reading frame a (ORFa)-Gly3Asp (rs12885300) and Thr92Ala (rs225014) with potential functions on the activity of DIO2, were selected. The frequencies of allele, genotype and haplotype of the two SNPs were compared between the BPAD patients and the control group.

Results

Statistical significance between the BPAD patients and the control group was observed for the allele (χ² = 7.746, P = 0.005, df = 1) and genotype frequencies (χ² = 8.158, P = 0.017, df = 2) at the locus of ORFa-Gly3Asp, and for the allele (χ² = 15.838, P = 7.00e−005, df = 1) and genotype frequencies (χ² = 17.236, P = 0.0002, df = 2) at Thr92Ala. Distribution of allele 3Gly and 92Ala were significantly higher in the BPAD patients, with odds ratios of 1.489 [95% confidence interval (CI) = 1.124–1.973] and 1.616 [95% CI = 1.275–2.048], respectively. Individuals with two copies of the variant 3Gly or 92Ala were at greater risk of BPAD than individuals with one copy (dose–response manner). Haplotypes ORFa-3Asp-92Ala and ORFa-3Gly-92Ala indicated higher susceptibility for BPAD with odds ratios of 3.759 (95% CI = 2.013–7.020) and 1.292 (95% CI = 1.017–1.642), respectively, while ORFa-3Asp-92Thr probably played a protective role with an odds ratio of 0.395 (95% CI = 0.284–0.549).

Conclusion

Data generated from this study supported our hypothesis that genetic variations of the DIO2 gene were associated with BPAD and suggested further consideration on the possible involvement of these functionally active variants in the pathophysiology of BPAD.     

Surgical treatment of unruptured intracranial aneurysms in a low-volume hospital--outcome and review of literature

Background

The aim of this study was to evaluate surgical outcome of unruptured intracranial aneurysms (UIAs) in a low-volume hospital and compare the results with the recent literature.

Methods

A retrospective review of all consecutive craniotomies for UIA from July 1999 through June 2009 was performed. Morbidity was defined as modified Rankin Scale (mRS) ≥ 3 and evaluated six weeks after surgery. Cognitive function was evaluated at rehabilitation-to-home discharge. A PubMed database search (2001–2011) seeking retrospective, single-center studies reporting on surgical outcome of UIAs was performed.

Results

There were 47 procedures performed in 42 patients to treat 50 UIAs (mean of 5 annual craniotomies). The mean age was 54.7 ± 12.1 years and mean aneurysm size was 7.6 ± 4.0 mm. Favorable outcome (mRS 0–2) at six weeks after surgery was achieved in 45 of 47 procedures (95.7%). Aneurysm size ≥ 12 mm was statistically significant related to adverse outcome defined as mRS change ≥ 1 (71% vs. 29%; p = 0.018). Five patients (10.6%) with favorable neurological outcome (mRS 2) presented with cognitive impairment at rehabilitation-to-home discharge. There was no significant difference in overall morbidity and mortality comparing low- and high-volume hospitals (4.0% vs. 4.8%; p = 0.85).

Conclusions

Low-volume hospitals may achieve good results for surgical treatment of UIAs. The results indicate that defining numeric operative volume thresholds is not feasible to guide centralization of aneurysm treatment.     

Age-related changes in the control of perturbation-evoked and voluntary arm movements

Objective

This study examined how handrail location predictability affects perturbation-evoked arm responses in young and older adults and whether age-related changes in perturbation-evoked arm responses are specific to mechanisms associated with reactive postural control.

Methods

Young and older adults reached for a handrail in response to a support surface translation (perturbation-evoked) or to a visual cue (voluntary). For both movement tasks, the handrail location was made predictable or unpredictable to the participant. Electromyographic (EMG) activity and kinematics of the reaching arm were recorded to quantify the arm response.

Results

Posterior deltoid EMG activity during perturbation-evoked and voluntary movements were delayed by 15–74 ms (p < 0.001) and 16% smaller (p = 0.024) when the handrail was in an unpredictable compared to a predictable location. While ageing resulted in a 12–16 ms delayed initiation of EMG activity during perturbation-evoked reaching (p = 0.003), the effects of handrail predictability and movement task did not interact with age.

Conclusions

Age-related differences in perturbation-evoked arm responses are independent of both handrail location predictability and movement task.

Significance

Age-related differences in perturbation-evoked arm responses cannot be solely attributed to declines in reactive postural control. Rather, ageing leads to a deterioration of neural mechanisms common to both perturbation-evoked and voluntary arm movements.     

Motor unit firing in amyotrophic lateral sclerosis and other upper and lower motor neurone disorders

Objective

Motor unit recruitment order and firing rate was investigated in healthy subjects, and in small numbers of patients 50 years ago. We aimed to investigate firing rate in different disorders, testing the same target muscle with normal strength, to evaluate possible application in diagnosing upper motor neuron (UMN) lesion.

Methods

We studied motor unit firing in the tibialis anterior muscle in six groups of subjects; normal subjects (n = 45), patients with amyotrophic lateral sclerosis (ALS) (n = 36), primary lateral sclerosis (PLS) (n = 21), progressive muscular atrophy (PMA) (n = 14), various upper motor neurone lesions (n = 16) and polyneuropathy (n = 42). In all these subjects the tibialis anterior muscle was of normal strength. Motor units were recruited during slight contraction in order to study 2–5 motor units at each recording site, using a standard concentric needle electrode, so that 20–22 motor units were recorded in each muscle. We analysed the coefficient of variation (CV) for amplitude, area, duration and firing rate in these motor units, and the correlation between motor unit potential size and recruitment order.

Results

The mean MU firing rate in this task was similar in each group. No recruitment order was disclosed within the limits of the study task. The CV of firing rate was decreased in UMN and PLS groups. ALS patients with marked spasticity showed a lower CV of motor unit firing rate. The CV of amplitude, area and duration was similar between groups.

Conclusions

These results in tibialis anterior indicate that physiological modulation of lower motor neuron (LMN) firing rate is decreased in patients with lower limb spasticity. The variability of MU discharges tends to be greater in diseases affecting the LMN.

Significance

These results suggest that, notwithstanding the simplicity of the task we have used, the physiological variability of motor unit firing may be a useful variable in assessing UMN involvement in motor system disorders.     

Systemic arterial inflammation, measured with 18FDG-PET, is common amongst subjects with both recent and prior cerebrovascular disease

Objective

To compare systemic arterial inflammation in subjects with recent ischaemic stroke or TIA and controls with prior cerebrovascular disease.

Methods

Systemic arterial inflammation was prospectively measured by ¹⁸F-fluorodeoxygluose positron emission tomography in 11 cases with recent ischaemic stroke or TIA, and 11 sex matched controls with prior cerebrovascular disease.

Results

Hot spots (both carotid and non-carotid) of localised ¹⁸FDG uptake were found in more than half of all patients with either recent (n = 6) or prior (n = 8) cerebrovascular disease. There was no significant difference in the total number of hotspots, or hotspots at specific sites, in cases compared with controls. Mean standard uptake values (SUV) were similar in the carotid arteries and aorta of cases and controls, and showed a trend toward higher values in the femoral arteries of the controls (median 1.8; IQR 1.6–2.2) compared to cases (median 1.5; IQR 1.4–1.7).

Conclusion

Arterial inflammation was common, and appeared similar, in patients with recent stroke/TIA, and controls with stroke/TIA more than two years previously.     

History of depressive and/or anxiety disorders as a predictor of treatment response: A post hoc analysis of a 12-week, randomized, double-blind, placebo-controlled trial of paroxetine controlled release in patients with fibromyalgia

Background

Despite of a high comorbidity of depressive and/or anxiety disorders with fibromyalgia, information on the clinical implications of this comorbidity is limited but antidepressants are commonly prescribed to treat fibromyalgia in clinical practice. We investigated whether a history of depressive and/or anxiety disorders was associated with response to paroxetine controlled release (CR) in the treatment of fibromyalgia.

Methods

One hundred sixteen (116) fibromyalgia subjects were randomized to receive paroxetine CR or placebo for 12 weeks. The primary outcome was treatment response defined as ≥ 25% reduction in the Fibromyalgia Impact Questionnaire (FIQ) score. In multivariate logistic regression, we determined if a history of depression and/or anxiety disorders was an independent predictor of response to paroxetine CR.

Results

In logistic regression, the history of depression and/or anxiety did not predict treatment response as measured by ≥ 25% reduction in Fibromyalgia Impact Questionnaire (FIQ) score (OR = 0.66, 95% CI = .29–1.49, Wald = 0.97, p = 0.32), while the drug status (paroxetine CR) was significantly associated with treatment response (OR = 2.57, CI = 1.2–5.61, Wald = 5.5, p = 0.02).

Conclusion

A significant proportion of patients with fibromyalgia had a history of anxiety and or depressive disorders. However response to treatment of fibromyalgia symptoms with paroxetine CR was not associated with a history of depressive and/or anxiety disorders. Our findings need to be confirmed in more adequately-powered and well-designed subsequent studies.