Qualitative and quantitative study of the highly specialized lipid tissues of cetaceans using HR-MAS NMR and classical GC

Cetacean adipose tissues contain an extremely very wide variety of acyl-chains present in triacylglycerols and / or wax esters. In addition, changes in the lipid composition across organs suggest fine stratification. It therefore remains technically challenging to describe precisely the lipid organization of these tissues. In the present study, we used in parallel HR-MAS NMR (High Resolution Magic Angle Spinning Nuclear Magnetic Resonance) and GC (gas-chromatography) to characterize and quantify the lipids and fatty acyl-chains from the blubber and melon of two odontocete species. Both methods generated very similar compositions, but each presented clear advantages. While GC underestimated the amount of short branched fatty acyl-chains, which are specific to cetacean adipose tissues and most probably of primary importance for their functioning, HR-MAS NMR allowed for their exact quantification. Conversely, when HR-MAS NMR could only discriminate a few types of fatty acyl-chain families, GC unambiguously identified and quantified most of them. In addition, this technique allowed for the determination of the wax esters molecular species. Our results further suggest that the stratification of these adipose tissues relies on changes in the triacylglycerol to wax ester ratio and in the fatty acyl composition of triacylglycerols, but not on changes in the wax esters composition. Altogether, our data show that the complementarities of these two approaches result in lipid analyses of unprecedented precision, paving the way for the detailed description of the fatty acyl composition of cetacean adipose tissues and the understanding of their functioning.

Laryngeal and phrenic nerve involvement in a patient with hereditary neuropathy with liability to pressure palsies (HNPP)

Lower cranial and phrenic nerve involvement is exceptional in hereditary neuropathy with liability to pressure palsies (HNPP). Here we report the occurrence of reversible laryngeal and phrenic nerve involvement in a patient with HNPP. The patient recalled several episodes of reversible weakness and numbness of his feet and hands since the age of 30 years. His medical history was uneventful, apart from chronic obstructive pulmonary disease (COPD). At age 44, following severe weight loss, he presented with progressive dysphonia and hoarseness. EMG of cricoarytenoid and thyroarytenoid muscles and laryngeal fibroscopy confirmed vocal cord paralysis. These speech disturbances gradually regressed. Two years later, he reported rapidly worsening dyspnea. Electroneurography showed increased distal latency of the right phrenic nerve and diaphragm ultrasonography documented reduced right hemi-diaphragm excursion. Six months later and after optimization of CODP treatment, his respiratory function had improved and both phrenic nerve conduction and diaphragm excursion were completely restored. We hypothesize that chronic cough and nerve stretching in the context of CODP, together with severe weight loss, may have triggered the nerve paralysis in this patient. Our report highlights the need for optimal management of comorbidities such as CODP as well as careful control of weight in HNPP patients to avoid potentially harmful complications.

Combined central and peripheral demyelination: Clinical features, diagnostic findings, and treatment

Combined central and peripheral demyelination (CCPD) is rare, and current knowledge is based on case reports and small case series. The aim of our study was to describe the clinical features, diagnostic results, treatment and outcomes in a large cohort of patients with CCPD. Thirty-one patients entered this retrospective, observational, two-center study. In 20 patients (65%) CCPD presented, after an infection, as myeloradiculoneuropathy, encephalopathy, cranial neuropathy, length-dependent peripheral neuropathy, or pseudo-Guillain-Barré syndrome. Demyelinating features of peripheral nerve damage fulfilling European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) electrodiagnostic criteria for CIDP were found in 23 patients (74%), and spatial dissemination of demyelinating lesions on brain MRI fulfilling the 2010 McDonald criteria for multiple sclerosis (MS) in 11 (46%). Two thirds of the patients had a relapsing or progressive disease course, usually related to the appearance of new spinal cord lesions or worsening of the peripheral neuropathy, and showed unsatisfactory responses to high-dose corticosteroids and intravenous immunoglobulins. The clinical presentation of CCPD was severe in 22 patients (71%), who were left significantly disabled. Our data suggest that CCPD has heterogeneous features and shows frequent post-infectious onset, primary peripheral nervous system or central nervous system involvement, a monophasic or chronic disease course, inadequate response to treatments, and a generally poor outcome. We therefore conclude that the current diagnostic criteria for MS and CIDP may not fully encompass the spectrum of possible manifestations of CCPD, whose pathogenesis remains largely unknown.

Evidence Based Design and healthcare: an unconventional approach to hospital design

Evidence Based Design (EBD) is a scientific analysis methodology that emphasises the use of data acquired in order to influence the design process in hospitals. It measures the physical and psychological effects of the built environment on its users. EBD uses formularization of hypothesis, testing/analyzing and outcome gathering as a framework. The design practice, in general, has always been based on a combination of legal, technical/ functional/ and aesthetical knowledge. This generalization has been shifted to another level after the implementation of EBD. In the last 30 years many case studies were collected which demonstrate the built environment's impact on users. EBD methodology can be applied to any type of building, but it is particularly used to analyze the efficiency of healthcare facilities. The Goal of this paper is to demonstrate various applications of EBD principles in healthcare buildings through case studies concerning: - reduction of infections - reduction of stress on medical staff - improved patient healing In addition to the analysis of case studies, we will also focus on official EBD researches developed by healthcare designers and professionals as "alternative solutions". These alternative "ad hoc" solutions are developed in order to answer EBD research results. The solutions that are developed from the results can answer the real needs of each hospital and improve best technological practice to reduce infection, stress and improve patient comfort. Abroad the EBD research results are studied and used by many contemporary hospital architects to develop new solutions to meet the specific requirements of any hospital project they are currently designing. This procedure demonstrates that for each outcome and key finding, there is always at least one alternative solution and, therefore, the achievement of a new hypothesis, case studies to test/measure and outcome to gather occurs. This repetitive attitude leads to a "virtuous circle" where the development of new samples produces a double- positive effect in both EBD research (in terms of new case studies to analyze) and in EBD lessons for implementation in various hospitals. Through this paper the authors state that the combined effort is needed by EBD practitioners, healthcare architects and hospital managers for the improvement and diffusion of EBD in healthcare, especially in Italy where this methodology is not widely used.

The use of DNA barcoding to monitor the marine mammal biodiversity along the French Atlantic coast

In the last ten years, 14 species of cetaceans and five species of pinnipeds stranded along the Atlantic coast of Brittany in the North West of France. All species included, an average of 150 animals strand each year in this area. Based on reports from the stranding network operating along this coast, the most common stranding events comprise six cetacean species (Delphinus delphis, Tursiops truncatus, Stenella coeruleoalba, Globicephala melas, Grampus griseus, Phocoena phocoena)and one pinniped species (Halichoerus grypus). Rare stranding events include deep-diving or exotic species, such as arctic seals. In this study, our aim was to determine the potential contribution of DNA barcoding to the monitoring of marine mammal biodiversity as performed by the stranding network.

We sequenced more than 500 bp of the 5’ end of the mitochondrial COI gene of 89 animals of 15 different species (12 cetaceans, and three pinnipeds). Except for members of the Delphininae, all species were unambiguously discriminated on the basis of their COI sequences. We then applied DNA barcoding to identify some “undetermined” samples. With again the exception of the Delphininae, this was successful using the BOLD identification engine. For samples of the Delphininae, we sequenced a portion of the mitochondrial control region (MCR), and using a non-metric multidimentional scaling plot and posterior probability calculations we were able to determine putatively each species. We then showed, in the case of the harbour porpoise, that COI polymorphisms, although being lower than MCR ones, could also be used to assess intraspecific variability. All these results show that the use of DNA barcoding in conjunction with a stranding network could clearly increase the accuracy of the monitoring of marine mammal biodiversity.

Electrophysiological patterns of oropharyngeal swallowing in multiple sclerosis

OBJECTIVE

We performed an electrophysiological study of swallowing (EPSS) in multiple sclerosis (MS) to describe oropharyngeal swallowing abnormalities and to analyze their correlations with dysphagia and with overall neurological impairment.

METHODS

Neurological examinations were quantified using the Kurtzke Functional Systems and the Expanded Disability Status Scale (EDSS). Dysphagia was evaluated using the Dysphagia in Multiple Sclerosis (DYMUS) questionnaire, while fiberoptic endoscopic evaluation of swallowing (FEES) was used to establish the degree of aspiration and penetration, graded using the penetration-aspiration scale (PAS). The EPSS measured the duration of suprahyoid/submental muscle EMG activity (SHEMG-D), the duration of the laryngeal-pharyngeal mechanogram (LPM-D), and the duration of the pause in cricopharyngeal muscle EMG activity (CPEMG-PD); it also measured the interval between onset of the suprahyoid/submental muscle EMG activity (SHEMG) and onset of the laryngeal-pharyngeal mechanogram (I-SHEMG-LPM).

RESULTS

92% of patients showed at least one electrophysiological abnormality. I-SHEMG-LPM correlated positively with the DYMUS questionnaire. I-SHEMG-LPM, SHEMG-D, and DYMUS correlated positively with the PAS. Moderate to severe bladder sphincter dysfunction was associated with a significant reduction, or absence, of CPEMG-PD.

CONCLUSION

EPSS improves our understanding of the pathophysiology of dysphagia in MS.

SIGNIFICANCE

This investigation could be useful in MS patients with swallowing abnormalities.

A European melting pot of harbour porpoise in the French Atlantic coasts inferred from mitochondrial and nuclear data

Field surveys have reported a global shift in harbour porpoise distribution in European waters during the last 15 years, including a return to the Atlantic coasts of France. In this study, we analyzed genetic polymorphisms at a fragment of the mitochondrial control region (mtDNA CR) and 7 nuclear microsatellite loci, for 52 animals stranded and by-caught between 2000 and 2010 along the Atlantic coasts of France. The analysis of nuclear and mitochondrial loci provided contrasting results. The mtDNA revealed two genetically distinct groups, one closely related to the Iberian and African harbour porpoises, and the second related to individuals from the more northern waters of Europe. In contrast, nuclear polymorphisms did not display such a distinction. Nuclear markers suggested that harbour porpoises behaved as a randomly mating population along the Atlantic coasts of France. The difference between the two kinds of markers can be explained by differences in their mode of inheritance, the mtDNA being maternally inherited in contrast to nuclear loci that are bi-parentally inherited. Our results provide evidence that a major proportion of the animals we sampled are admixed individuals from the two genetically distinct populations previously identified along the Iberian coasts and in the North East Atlantic. The French Atlantic coasts are clearly the place where these two previously separated populations of harbour porpoises are now admixing. The present shifts in distribution of harbour porpoises along this coast is likely caused by habitat changes that will need to be further studied.

An electrophysiological approach to the diagnosis of neurogenic dysphagia: implications for botulinum toxin treatment

OBJECTIVES

Botulinum toxin (BTX) injection into the cricopharyngeal (CP) muscle has been proposed for the treatment of neurogenic dysphagia due to CP hyperactivity. The aim was to determine whether an electrophysiological method exploring oropharyngeal swallowing could guide treatment and discriminate responders from non-responders, based on the association of CP dysfunction with other electrophysiological abnormalities of swallowing.

METHODS

Patients with different neurological disorders were examined: Parkinson disease, progressive supranuclear palsy, multiple system atrophy-Parkinson variant, multiple system atrophy cerebellar variant, stroke, multiple sclerosis and ataxia telangiectasia. All patients presented with clinical dysphagia, and with complete absence of CP muscle inhibition during the hypopharyngeal phase of swallowing. Each patient underwent clinical and electrophysiological investigations before and after treatment with BTX into the CP muscle of one side (15 units of Botox). Clinical and electrophysiological procedures were performed in a blind manner by two different investigators. The following electrophysiological measures were analysed: (1) duration of EMG activity of suprahyoid/submental muscles (SHEMG-D); (2) duration of laryngopharyngeal mechanogram (LPM-D); (3) duration of the inhibition of the CP muscle EMG activity (CPEMG-ID); and (4) interval between onset of EMG activity of suprahyoid/submental muscles and onset of laryngopharyngeal mechanogram (I-SHEMG-LPM).

RESULTS

Two months after treatment, 50% of patients showed a significant improvement. Patients with prolonged or reduced SHEMG-D values and prolonged I-SHEMG-LPM values did not respond to BTX. Therefore, values for which BTX had no effect (warning values) were identified.

CONCLUSIONS

This electrophysiological method can recognise swallowing abnormalities which may affect the outcome of the therapeutic approach to dysphagia with BTX treatment.

Electrophysiologic patterns of oral-pharyngeal swallowing in parkinsonian syndromes

OBJECTIVES

To assess the presence, severity, and differences in dysphagia in Parkinson disease (PD), Parkinson variant of multiple system atrophy (MSA-P), and progressive supranuclear palsy (PSP), and to study the pathophysiology of swallowing abnormalities in these disorders.

METHODS

We applied an electrophysiologic method to evaluate oral-pharyngeal swallowing. We analyzed the following measures: duration of EMG activity of suprahyoid/submental muscles (SHEMG-D); duration of laryngeal-pharyngeal mechanogram (LPM-D); duration of the inhibition of the cricopharyngeal muscle activity (CPEMG-ID); interval between onset of EMG activity of suprahyoid/submental muscles and onset of laryngeal-pharyngeal mechanogram (I-SHEMG-LPM); and swallowing reaction time (SRT).

RESULTS

The prolongation of I-SHEMG-LPM was more typical in PD, whereas the most distinctive finding both in patients with PSP and MSA-P was the reduction or the absence of CPEMG-ID early in the course of the disease.

CONCLUSIONS

Involvement of the peduncolo-pontine tegmental nucleus, with subsequent dysfunction of basal ganglia and of the medullary central pattern generator of swallowing, may account for the abnormalities detected in these parkinsonian syndromes. The method described was able to identify swallowing abnormalities also in patients without symptoms of dysphagia and to evaluate dysphagia severity in all patients.

Postinfectious inflammatory disorders: Subgroups based on prospective follow-up

BACKGROUND

Acute disseminated encephalomyelitis (ADEM) refers to a monophasic acute multifocal inflammatory CNS disease. However, both relapsing and site-restricted variants, possibly associated with peripheral nervous system (PNS) involvement, are also observed, and a systematic classification is lacking.

OBJECTIVE

To describe a cohort of postinfectious ADEM patients, to propose a classification based on clinical and instrumental features, and to identify subgroups of patients with different prognostic factors.

METHODS

Inpatients of a Neurologic and Infectious Disease Clinic affected by postinfectious CNS syndrome consecutively admitted over 5 years were studied.

RESULTS

Of 75 patients enrolled, 60 fulfilled criteria for ADEM after follow-up lasting from 24 months to 7 years. Based on lesion distribution, patients were classified as encephalitis (20%), myelitis (23.3%), encephalomyelitis (13.3%), encephalomyeloradiculoneuritis (26.7%), and myeloradiculoneuritis (16.7%). Thirty patients (50%) had a favorable outcome. Fifteen patients (25%) showed a relapsing course. Poor outcome was related with older age at onset, female gender, elevated CSF proteins, and spinal cord and PNS involvement. All but two patients received high-dose steroids as first-line treatment, with a positive response in 39 (67%). Ten of 19 nonresponders (53%) benefited from high-dose IV immunoglobulin; 9 of 10 had PNS involvement. The data were not controlled.

CONCLUSIONS

A high prevalence of "atypical variants" was found in this series, with site-restricted damage or additional peripheral nervous system (PNS) involvement. Prognosis and response to steroids were generally good, except for some patient subgroups. In patients with PNS involvement and steroid failure, a favorable effect of IV immunoglobulin was observed.

Proximal nerve conduction by high-voltage electrical stimulation in S1 radiculopathies and acquired demyelinating neuropathies

OBJECTIVE

To evaluate the reliability and sensitivity of the high-voltage electrical stimulation for studying proximal conduction of peripheral motor axons in normal subjects, S(1) radiculopathies and acquired demyelinating neuropathies.

METHODS

Twelve patients with compressive S(1) radiculopathy, 22 patients with acquired demyelinating neuropathy and 29 healthy volunteers were examined. The conduction of peripheral motor axons between lumbosacral roots and the sciatic nerve at the gluteal fold was investigated by high-voltage electrical stimulation delivered percutaneously.

RESULTS

The main electrophysiological finding in S(1) radiculopathy was an abnormal side to side difference in the amplitude of the compound motor action potential by proximal stimulation. Overall, the frequency of abnormalities detected by using high-voltage electrical stimulation was similar to that found with conventional EMG studies, and the two methods showed electrophysiological alterations in the same patients. In all patients with acquired demyelinating neuropathy, the proximal motor nerve conduction velocity from lumbosacral roots to the sciatic nerve at the gluteal fold was reduced; proximal stimulation of the motor axons revealed electrophysiological abnormalities more often than when using other electrophysiological techniques (F wave and H reflex).

CONCLUSIONS

High-voltage electrical stimulation of peripheral motor axons shows high sensitivity in detecting proximal neuropathies; it can also define the site and relevance of proximal lesions in the peripheral nervous system better than other conventional techniques.

Impaired circadian rhythmicity of nociceptive reflex threshold in cluster headache

BACKGROUND

Alteration of circadian rhythmicity involving several endocrinologic and autonomic parameters has been observed in cluster headache.

OBJECTIVES

To explore whether circadian failure of the pain control system may exist in cluster headache.

METHODS

The nociceptive flexion reflex threshold was studied in 25 patients with episodic cluster headache (14 active, 11 in remission) and 6 patients with chronic cluster headache, along with 10 normal volunteers throughout a 24-hour period. The reflex response was evoked at the level of the biceps femoris by stimulating the sural nerve at the ankle. Single and population mean cosinor methods were used to detect the circadian rhythmicity.

RESULTS

In the patients with episodic cluster headache, a significant reduction in the nociceptive flexion reflex threshold was observed in both the active subgroup and the subgroup in remission (P < .05). In these patients, persistence of a significant 24-hour rhythm during both the active period and remission was observed, but a shift of the phase was observed during clinical activity when compared with the remission period. A lack of circadian nociceptive flexion reflex threshold rhythmicity was found in the patients with chronic cluster headache.

CONCLUSIONS

Our findings suggest that in cluster headache there may be impairment of the pain control system that is associated with periodic failure of the mechanisms involved in the organization of biological rhythms.

Pelizaeus-Merzbacher disease: electrophysiological study of two sibs with the classic form and of their relatives

We examined two sibs with the classic form of Pelizaeus-Merzbacher disease (PMD) and their relatives. Electromyographic-electroneurographic studies and magnetic stimulation of motor pathways were performed. In both patients we found an absence of compound motor action potential (cMAP) after stimulation of the motor cortex and a normal conduction time by stimulating the cervical roots. Despite reported sparing of the peripheral nervous system in PMD, our conduction study of the tibial nerve revealed a slightly decreased motor nerve conduction velocity in one patient. In both patients the EMG study showed neurogenic findings. The elder sister showed a prolonged central motor conduction time. This study demonstrates abnormalities of motor corticospinal pathways also in PMD relatives suggesting that magnetic stimulation could be useful in detecting "subclinical" abnormalities in this dysmyelinating condition. Furthermore, in accordance with previous studies, we suggest that a slight involvement of the peripheral nervous system could be observed in PMD.

Effects of sleep on spinal nociceptive reflexes in humans

Controversy continues to surround the monosynaptic and polysynaptic spinal reflexes during the different stages of sleep. In animal studies both of these reflexes were found to be depressed during desynchronized sleep. In humans, the H reflex was unchanged whereas the second component of the nociceptive flexion reflex was increased. However, abolition of the H reflex and F waves during REM sleep has also been reported. The aim of this investigation was to examine the effects of different sleep stages on the polysynaptic nociceptive flexion reflex. Six healthy volunteers were studied. The RIII reflex was studied according to Willer's method (1977) during the different stages of NREM and REM sleep. The RIII reflex threshold was found to increase during stage 2 of NREM sleep. It remained higher during stages 3 and 4. During REM sleep a further increase in the reflex threshold was observed. The reflex latency was prolonged during stage 4 of NREM sleep. There was evidence of further latency prolongation during REM sleep. It was also during REM sleep that the maximum increase in the amplitude and duration of the reflex were recorded.

Periodic alternating nystagmus and vestibulo-spinal system facilitating activity

OBJECTIVE

Periodic alternating nystagmus has been associated with the instability of the velocity storage mechanism, which is known to play an important role in both the vestibulo-oculomotor and the optokinetic systems. In the present study we looked for a possible spinal equivalent to PAN.

METHODS AND RESULTS

In 3 PAN patients, the H-reflex amplitude proved to be slightly but significantly influenced by nystagmus direction, in that it was greater when the nystagmus was beating toward the stimulation side.

CONCLUSIONS

This finding suggests that projections from velocity storage may play a role not only in the ocular motor but also in assisting postural stability through the vestibulo-spinal system.

Clustering of ALS patients in central Italy due to the occurrence of the L84F SOD1 gene mutation

OBJECTIVE

To study three new apparently unrelated Italian families with ALS and several sporadic ALS patients living in the same rural area.

BACKGROUND

One Italian family with ALS carrying a superoxide dismutase 1 (SOD1) gene mutation (G41S) and no regional ALS clustering has been reported in Italy.

METHODS

Genetic analysis was performed by automated and manual sequencing of the SOD1 gene in 13 family members and in 6 of 10 unrelated patients with sporadic cases of ALS living in the same area. The authors also determined SOD1 activity in erythrocytes and lymphocytes.

RESULTS

The three families included a total of 28 affected members distributed over six generations. Despite a wide variability in age at onset and disease duration, the clinical pattern is uniform, with onset in the lower limbs, ascending progression, and predominant lower motor neuron involvement in all subjects. Generational anticipation is evident in the last two generations. All familial ALS patients and one of the six sporadic patients carry the same L84F missense point mutation in exon 4 of the SOD1 gene. SOD1 enzyme activity and SOD1 protein levels were not decreased significantly in the L84F patients.

CONCLUSION

The ALS patients carrying the L84F mutation derive from a common ancestor. This mutation is responsible for ALS clustering in the area. The L84F mutation does not modify SOD1-specific activity.

Surface mechanomyogram reflects the changes in the mechanical properties of muscle at fatigue

The contractile properties of muscle are usually investigated by analysing the force signal recorded during electrically elicited contractions. The electrically stimulated muscle shows surface oscillations that can be detected by an accelerometer; the acceleration signal is termed the surface mechanomyogram (MMG). In the study described here we compared, in the human tibialis anterior muscle, changes in the MMG and force signal characteristics before, and immediately after fatigue, as well as during 6 min of recovery, when changes in the contractile properties of muscle occur. Fatigue was induced by sustained electrical stimulation. The final aim was to evaluate the reliability of the MMG as a tool to follow the changes in the mechanical properties of muscle caused by fatigue. Because of fatigue, the parameters of the force peak, the peak rate of force production and the peak of the acceleration of force production (d2F/dt2) decreased, while the contraction time and the half-relaxation time (1/2-RT) increased. The MMG peak-to-peak (p-p) also decreased. The attenuation rate of the force oscillation amplitude and MMG p-p at increasing stimulation frequency was greater after fatigue. With the exception of 1/2-RT, all of the force and MMG parameters were restored within 2 min of recovery. A high correlation was found between MMG and d2F/dt2 in un-fatigued muscle and during recovery. In conclusion, the MMG reflects specific aspects of muscle mechanics and can be used to follow the changes in the contractile properties of muscle caused by localised muscle fatigue.

Hemoglobin near-infrared spectroscopy and surface EMG study in muscle ischaemia and fatiguing isometric contraction

BACKGROUND

To assess how muscle ischaemia and isometric fatiguing contraction influence oxygen content in striated muscle.

METHODS

We simultaneously measured changes in hemoglobin near-infrared (NIR) spectroscopy and in surface EMG before, during, and after muscle ischaemia and ischaemia plus muscle isometric fatiguing contraction. Seventeen healthy male subjects (age range: 19-40 yrs) were examined in our Clinical Neurophysiology Unit. Test I (9 subjects): hemoglobin NIR spectroscopy and stimulated surface EMG were measured for 2 minutes at rest, for 4 minutes during complete ischaemia of tibialis anterior muscle, and for twelve minutes during recovery. Test II (all subjects): hemoglobin NIR spectroscopy and surface EMG were measured for 2 minutes with the subjects performing brief non-fatiguing contractions, for 4 minutes with the subject performing maximal isometric contraction in complete ischaemia, and for twelve minutes during recovery. EMG parameters measured: median density frequency (MDF); muscle fiber conduction velocity (MFCV). NIR spectroscopy parameters measured: percentage of amplitude decrement (% AD) and nadir time (NT) during ischaemia and ischaemic effort; half-recovery time (1/2 RT) from ischaemia effort.

RESULTS

At EMG, we observed a significant shift towards lower values of both MFCV and MDF during fatiguing isometric contraction. MDF recovery was faster then MFCV recovery. At NIR spectroscopy, the 1/2 RT slowed a fast pattern in twelve subjects and a slow pattern in five. A significant relationship was found between AD% and 1/2 RT values of test I and AD% and 1/2 values of test II. We found a positive relationship between NT and 1/2 RT in test II.

CONCLUSIONS

Surface EMG and hemoglobin NIR spectroscopy can be applied simultaneously to evaluate both fatigue intensity and blood flow changes in striated muscle.

Different effect of high doses of naloxone on spinal reflexes in normal subjects and chronic paraplegic patients

There is still controversy over the effects of naloxone on spinal reflexes in view of the fact that both facilitatory and inhibitory activities have been observed. Dosage, supraspinal influences and interactions with different opiate receptors may account for the different findings. We investigated the effect of placebo (saline) and high doses of naloxone (1.66 mg/kg) on the monosynaptic (H reflex) and nociceptive polysynaptic reflex (RIII reflex) in five normal subjects and three chronic paraplegic subjects. Following the administration of naloxone, there were no changes in the RIII reflex threshold in either group. By contrast, there was a marked facilitation of the H reflex amplitude in the normal subjects, but not in the spinal cord-injured subjects after treatment with naloxone. Saline induced no changes in the RIII reflex threshold or the H reflex amplitude in either of the two groups. Our data suggest that under normal conditions the opiatergic modulation of the nociceptive reflex is not functionally active whereas the tonic inhibitory modulation of the monosynaptic reflex is mediated by descending pathways.

Hereditary motor and sensory neuropathy type II (HMSN-II) and neurogenic muscle hypertrophy: a case report and literature review

We present two siblings affected by hereditary motor and sensory type II neuropathy (HMSN-II) with neuromyotonia, and associated with muscle hypertrophy of the thighs and calves in one. We review the literature about the association between HMSN-II, neuromyotonia and muscle hypertrophy. Muscle enlargement in HMSN-II is rare and may be sporadic or under genetic control. In our patient, muscle hypertrophy was sporadic and probably due to neuromyotonia. The relationship between muscle hypertrophy and neuromyotonia can be deduced by the fact that both conditions were reduced after diphenylhydantoin treatment (200 mg/day).

Central motor conduction after magnetic stimulation in diabetes

Central motor conduction times (CMCTs), obtained by means of magnetic stimulation of the motor cortex and spinal roots, were studied in 138 patients affected by diabetes mellitus but with no signs or symptoms of central nervous system (CNS) involvement. CMCTs were significantly increased in diabetic patients (p < 0.001, t-test) with respect to normal controls, with values exceeding upper confidence limits (mean +/- 2.5 SD of controls) in about 30% of patients. There was no correlation between CMCT delay and type of diabetes (insulin-dependent or non-insulin-dependent), patient age, disease duration, degree of metabolic control compensation, presence or absence of retinopathy or nephropathy, and presence or absence of peripheral or autonomic neuropathy. CNS involvement in diabetes mellitus is discussed. Particular emphasis is given to the sensitivity and reliability of CMCTs obtained by means of magnetic stimulation as a tool in the early diagnosis of CNS functional alterations in diabetes mellitus.

Electrophysiologic study of central motor pathways in ataxia-telangiectasia

To date, corticospinal tract functional integrity in ataxia-telangiectasia has not been studied. Thorough evaluation of central motor pathways is also lacking in neuropathologic and clinical studies. Using electromagnetic stimulation, we assessed the integrity of the corticospinal tracts in eight patients with ataxia-telangiectasia. Cortical and peripheral compound motor action potentials were recorded from the abductor pollicis brevis muscle. Recordings of the shortest F-wave latency and of the compound motor action potential distal latency were made from the abductor pollicis brevis muscle after electrical stimulation of the median nerve at the wrist. A significant increase in central motor conduction time was observed in four patients, two of whom had clinical findings compatible with a pyramidal lesion. This study demonstrates involvement of the central motor pathways in ataxia-telangiectasia, which appears to be more frequent late in the course of the disease.

Neurophysiological and neuropsychological monitoring of fatigue during extreme environmental and driving conditions

Aim of the present study was to evaluate the modifications of neurophysiological and neuropsychological variables during extreme environmental and driving conditions. Eight subjects (four drivers and four passengers) were evaluated while driving a four wheels drive across the Big West Algerian Erg. The following procedures were carried out in basal conditions and at the end of the 1st, 3rd, and 5th day of driving: surface EMG of masseter and cervical para-spinal muscles during maximum isometric contraction lasting 12 sec; test of simple visual and acoustic reaction times, Cancellation test, Trial Making test. As from the second day, the drivers used appropriate dental plates. In the drivers, EMG spectrum analysis revealed a significant decrease in mean frequency values at the end of the 1st day. This finding was more relevant in masseter muscles. No significant fatigue phenomena were detected on the subsequent controls. On the contrary, the passengers showed a decrease in mean EMG frequency values. No significant modifications in the cognitive variables were detected at the end of the 1st day (initial response to stress), whereas a progressive worsening was observed in the subsequent evaluations. EMG fatigue of masseter muscles seems to be more related to psychic stress. The beneficial effects of the dental plates were also confirmed.

[Rehabilitation in multiple sclerosis: clinico-instrumental correlations]

The Authors report their experience in a patient with Multiple Sclerosis. The planning and the follow up of rehabilitative treatment were based on clinical, functional, electrophysiological and posturographic evaluation. The impairment degree was evaluated by Kurtzke's Expanded Disability Status Scale. The electrophysiological evaluation showed an abnormal recruitment flexor pattern at exteroceptive stimulus and posturography confirmed postural control disorder. The treatment was based on PNF techniques and postural feedback on standing balance platform. After rehabilitative treatment the clinical and functional improvement has been confirmed by normal exteroceptive flexion reflex and better stabilometric parameters.

"Off" painful dystonia in Parkinson's disease treated with botulinum toxin

The "off" painful dystonia (OPD), usually concerning the feet, is a type of abnormal involuntary movement, induced by the chronic use of levodopa. It is mostly observed in the advanced stage of Parkinson's disease (PD), particularly in the early morning, in the evening, and late at night. Indeed, some patients have experienced OPD also during "on" periods when dystonic posture of the foot alternates with dyskinesia. The pain probably is due to sustained muscle contraction, which causes prolonged muscle spasm, as in primary dystonia or torticollis. Dopaminergic drugs like bromocriptine, pergolide, and especially apomorphine (s.c. infusions, or bolus), can dramatically improve the OPD. Anticholinergics baclofen and lithium are alos used in the management of OPD with some benefit. On the other hand, clinical experience shows that in many cases, these therapeutic procedures are not always enough to produce the expected results. Thirty PD patients (22 men and eight women) with OPD of the foot were treated with botulinum toxin (Botox, Btx) using electromyograms to guide injections. Dystonia was evaluated using a quantitative rating scale. The selection of the muscles for Btx treatment was carried out on the basis of foot posture. We injected Btx into tibialis posterior, tibialis anterior, gastrocnemius, flexor digitorum longus, and extensores hallucis longus with a median dose 40 IU for each muscle, distributed in two sites. In all patients, the pain improved within 10 days, whereas in 21 patients, the pain disappeared completely for 4 months (range, 3-7 months); a concomitant improvement in intensity of the dystonic spasm was also observed. No side effects were reported. Seven patients with associated "on" foot dystonia described an improvement of foot posture on walking. In conclusion, in this uncontrolled study, the use of Btx in OPD seemed a promising tool to improve pain linked to foot dystonia; however, because of the well-known underlying dopaminergic defect in OPD, the Btx therapy should be considered only if the dopaminergic treatment established for the management of OPD has failed.

Twitch response of striated muscle in patients with progressive external ophthalmoplegia, mitochondrial myopathy and focal cytochrome c-oxidase deficiency

Some aspects of the contractile properties of skeletal muscle in patients with progressive external ophthalmoplegia (PEO), mitochondrial myopathy and focal cytochrome c-oxidase deficiency were investigated by studying the twitch response (TR) of the tibialis anterior muscle both at rest and after maximum isometric contraction. The results of needle electromyography were normal in four of the six examined patients, and myopathic in the remaining two. A slowing in muscle relaxation was the most frequently observed abnormality; significantly prolonged muscle contraction times and reduced twitch torque potentiation values after isometric contraction were also detected. TR abnormalities in PEO patients may be due either to a dysfunction of the contractile machinery depending upon impaired muscle energy supply or to altered muscle fiber characterized by the predominance of type I slow fiber. In addition to conventional electromyographic investigations, TR study may be a useful diagnostic tool in PEO patients.