A patient with limb girdle muscular dystrophy carries a TRIM32 deletion, detected by a novel CGH array, in compound heterozygosis with a nonsense mutation.

Limb girdle muscular dystrophy 2H is a rare autosomal recessive muscular dystrophy, clinically highly variable, caused by mutations in the TRIM32 gene. Here we describe a 35-years-old who experienced progressive muscle weakness. The muscle biopsy revealed an unspecific pattern of atrophic and hypertrophic fibers; the immunohistochemistry for several proteins was normal. Comparative genomic hybridization (CGH) analysis showed a heterozygous deletion of the entire TRIM32 gene. On the other allele we identified the R316X nonsense mutation. The genetic diagnosis of LGMD2H in this case was reached by using a novel high throughput diagnostic tool.

Time and frequency domain analysis of surface myoelectric signals during electrically-elicited cramps.

OBJECTIVES: To examine if different frequencies of electrical stimulation trigger different sized cramps in the abductor hallucis muscle and to analyze their surface electromyographic (EMG) behaviour in both time and frequency domains. METHODS: Fifteen subjects were studied. Stimulation trains of 150 pulses were applied to the muscle motor point. Frequency was increased (starting from 4pps with 2-pps steps) until a cramp developed. Current intensity was 30% higher than that eliciting maximal M-waves. After the first cramp ("threshold cramp"), a 30-minute rest was provided before a second cramp ("above-threshold cramp") was elicited with a frequency increased by 50% with respect to that eliciting the first cramp. RESULTS: We found greater EMG amplitude and a compression of the power spectrum for above-threshold cramps with respect to threshold cramps. M-wave changes (ranging between small decreases of M-wave amplitude to complete M-wave disappearance) occurred and progressively increased throughout stimulation trains. Significant positive correlations were found between estimates of EMG amplitude during cramps and estimated reductions of M-wave amplitude. CONCLUSIONS: Varying frequencies of electrical stimulation triggered different sized cramps. Moreover, decreases in M-wave amplitude were observed during both threshold and above-threshold stimulations. The choice of the stimulation frequency has relevance for optimizing electrical stimulation protocols for the study of muscle cramps in both healthy and pathological subjects.

A novel KCNA1 mutation identified in an Italian family affected by episodic ataxia type 1.

Episodic ataxia type 1 (EA1) is a rare human neurological syndrome characterized by continuous myokymia and attacks of generalized ataxia that can be triggered by abrupt movements, emotional stress and fatigue. An Italian family has been identified where related members displayed continuous myokymia, episodes of ataxia, attacks characterized by myokymia only, and neuromyotonia. A novel missense mutation (F414C), in the C-terminal region of the K(+) channel Kv1.1, was identified in the affected individuals. The mutant homotetrameric channels were non-functional in Xenopus laevis oocytes. In addition, heteromeric channels resulting from the co-expression of wild-type Kv1.1 and Kv1.1(F414C), or wild-type Kv1.2 and Kv1.1(F414C) subunits displayed reduced current amplitudes and altered gating properties. This indicates that the pathogenic effect of this KCNA1 mutation is likely to be related to the defective functional properties we have identified.

[Evaluation of professional exposure to chloride vinyl monomer and vinyl idene chloride for a pharmaceutical packaging worker]. / Valutazione dell'esposizione professionale a cloruro di vinile monomero e cloruro di vinilidene di un lavoratore addetto al confezionamento farmaci.

The study was conducted by Judicial Policy investigations of Prosecution's Office. The event was connected by a professional founded suspicion disease of a pharmaceutical worker. First information coming from the Authority indicated a chloride vinyl monomer (CVM) exposure. We applied a chemical risk assessment method to estimate real professional exposure. The method was based on the productive cycle, physical and chemical and toxicological properties. The method combined to environmental data permitted to formulate etiological hypothesis. The worker during drugs packaging was exposed to CVM and vinylidene chloride (CVDM) caused by blister warming and by glue deposition. We explain the evaluations by which we could consider the pollutant different distribution in workplaces.

High plasma creatine kinase: review of the literature and proposal for a diagnostic algorithm.

The condition of persistently high plasma CK levels is frequently encountered in asymptomatic patients with normal neurological examination. This condition may be the unique manifestation of several neuromuscular disorders, whose diagnosis is now possible using new diagnostic techniques. However, even if these patients are intensely investigated, specific diagnoses are not always forthcoming. Because of the lack of a widely accepted diagnostic protocol, hyperCKaemia in asymptomatic subjects is a potentially difficult clinical problem. In this paper we review the literature on conditions associated with variations in plasma CK levels and the literature on investigations carried out in asymptomatic persons with high CK to identify neuromuscular diseases. In the light of these data, and the deliberations of a working group of the Italian Association of Myology, we propose a diagnostic algorithm to guide the diagnostic work-up of persons presenting with persistently high levels of plasma CK. This algorithm has been discussed and approved by the Committee of the Italian Association of Myology.

[Biological and chemical risks in haemodialysis centres]. / Il rischio biologico e chimico in emodialisi.

Haemodialysis technique was introduced in 1965 for people afflicted to chronic renal insufficiency, permitting them to survive. The method purifies patient blood who is connected to the equipment by tubes. The equipment uses saline solutions and water and it operates by osmotic pressure and by filtration. In this paper biological and chemical occupational risks are analysed. Main biological risks are caused by haematic viruses such as HIV, HBV, HCV. Chemical risks are mainly caused by disinfection products such as acid, basic and saline solutions. Workers exposed to chemical and biological risks are nursing staff, doctors, assistants, maintenance men. The paper analyses these risks and it shows prevention and protection solutions to reduce significantly the risks. The S.Pre.S.A.L. (Prevention and Protection Service in Work Places) operators of ASL RMC (Health Local Agency of Rome) visited six haemodialysis centres situated in Rome in the ASL RMC territory. They verified the application of safety and healthy measures by use of a check list about risk assessment, the lay-out, the equipment, the preventive and protective measures and the application of law. Experimental data were organized in relation of legislative accomplishments and technical measures. The aim of our work was to improve workers' safety in the haemodialysis centres, proposing the better technical solutions to realise this objective.

Clinical features and neurophysiological follow-up in a case of Brown-Vialetto-Van Laere syndrome.

Brown-Vialetto-Van Laere syndrome is a rare disease of unknown origin commonly considered as part of the large group of motor neuron diseases. The course is quite variable: it may be quickly fatal or protracted, with relapsing phases followed by periods of arrest and even partial improvement. We describe a case of Brown-Vialetto-Van Laere syndrome with strong family history for sensorineural hearing impairment. The patient came to our medical attention for severe respiratory failure and leg weakness. The clinical conditions partially improved with recovery of spontaneous respiration and mild increase in muscle strength. The neurophysiological studies performed on our patient showed evidence of nerve damage with subsequent improvement. Our study raises the possibility that the disorder is due to primary nerve damage, which can better justify the intermittent course of the disease, the partial clinical regression and the neurophysiological improvement, never detected in typical motor neuron disorders.

Brainstem neurodegeneration correlates with clinical dysfunction in SCA1 but not in SCA2. A quantitative volumetric, diffusion and proton spectroscopy MR study.

Magnetic resonance (MR) techniques enable in vivo measurement of the atrophy of the brainstem and cerebellum in spinocerebellar ataxia type 1 (SCA1) and 2 (SCA2) patients, which is accompanied by a decrease in the concentration of N-acetyl aspartate (NAA) or of the NAA/creatine ratio in the pons and cerebellum. Mean diffusivity (D) is emerging as an additional sensitive and quantitative MR parameter to investigate brain diseases. In order to explore differences between the MR features of SCA1 and SCA2 and correlate the MR and clinical findings in the two conditions, we examined 16 SCA1 patients, 12 SCA2 patients and 20 healthy control subjects. The MR protocol included T1-weighted 3D gradient echo sequences, single-voxel proton spectroscopy of the right cerebellar hemisphere (dentate and peridentate region) and of the pons with a PRESS sequence and an external reference quantitation method, and (in nine patients with SCA1 and nine patients with SCA2) diffusion-weighted echo-planar images with reconstruction of the D maps. The patients were evaluated with the Inherited Ataxia Clinical Rating Scale (IACRS). Compared with control subjects, the SCA1 and SCA2 patients showed a decrease (P < 0.01) in the volume of the brainstem and cerebellum and in the concentration of NAA in the pons and cerebellar hemisphere, whereas D of the brainstem and cerebellum was increased. No significant difference was observed between the SCA1 and SCA2 patient groups. No correlation between cerebellar volume and dentate and peridentate NAA concentration was found in SCA1 or SCA2 patients. The volume of the brainstem, D of the brainstem and cerebellum and the concentration of NAA in the pons were correlated (P < 0.05) with the IACRS score in SCA1 but not in SCA2. This discrepancy is in line with the clinical observation that the clinical deficit has a later onset and faster progression in SCA1 and an earlier onset and slower progression in SCA2, and suggests that neurodegeneration of the brainstem is a comparatively more rapid process in SCA1. In conclusion, our study indicates that SCA1 and SCA2 substantially exhibit the same MR features. The correlation in SCA1 between clinical severity and quantitative volumetric, diffusion MRI and proton MR spectroscopy findings in the brainstem indicates that these measurements might be employed for longitudinal studies and hopefully as surrogate markers in future pharmacological trials of this condition.

Stiff person syndrome does not always occur with maternal passive transfer of GAD65 antibodies.

The authors report the presence of high titer antibodies to glutamic acid decarboxylase (anti-GAD65) until age 24 months in two asymptomatic newborns of a woman with stiff-person syndrome (SPS). No signs of SPS were detectable in the two children at ages 6 and 8 years. This observation indicates that other cofactors are involved in the pathogenesis of SPS.

The role of gustatory flushing in Frey's syndrome and its treatment with botulinum toxin type A.

After parotid surgery, gustatory sweating and flushing occur more frequently, the former reportedly in 15-100% of cases, while no reliable data are available for the latter. Although botulinum toxin (BoNT) is effective in controlling sweating, little is known about its effect on flushing. In 17 patients suffering from Frey's syndrome after parotid surgery, we studied the gustatory flushing phenomenon as compared to gustatory sweating, analyzing their frequency, area, type of stimulus and response to BoNT administration. Cutaneous blood flow (CBF) was monitored by laser Doppler flowmetry (LDF) on affected and unaffected areas of the cheek in basal conditions and after meals, before and then 1 month after starting the BoNT injections. The Minor test was used to identify the sweating area. Flushing was observed in 7 of 17 patients after masticatory activity, spicy meals or citrus fruits. No clinical data correlated with any presence of flushing. Flushing regressed completely after BoNT administration and CBF reached similar values in the affected and unaffected sites. No adverse effects were observed. BoNT administration proved an effective and safe treatment for gustatory sweating and flushing in patients with Frey's syndrome.

Hyperhidrosis and sympathetic skin response in chronic alcoholic patients.

Palmoplantar hyperhidrosis is frequently observed in patients with a clinical history of chronic abnormal alcoholic intake. It can be related to peripheral or central mechanisms such as abnormal spontaneous activity in peripheral damaged fibres; receptor hypersensitivity; compensatory incremented activity in segmentary anhidrosis; or impairment of central sweat control. With the aim of quantifying this phenomenon and of identifying its possible origin, sympathetic skin response (SSR) analysis was performed in 20 chronic alcoholic patients with clinical diffuse acral hyperhidrosis, compared with 30 normal subjects and 2 patients affected by primary palmoplantar hyperhidrosis (PPH). SSRs were recorded by disc electrodes place on the hands and feet, simultaneously. At the hand level two recording sites were selected: palm-dorsum proximally and ventral-dorsal tip of the third finger distally. Attention was paid to the number of SSR after a single endogenous or exogenous stimulus. The alcoholic patients were divided into two groups, with and without mild polyneuropathy. Both patient groups showed synchronous SSR at recording sites, with the same pattern and the normal delay between upper and lower arms. In the control group one response was generally related to a single stimulus; if more responses were elicited an evident adaptation was shown; in the two groups of patients an increase of the waves was observed in all the recording sites without any adaptation. The SSR profile described in alcoholic patients was observed also in PPH. The pattern of SSR waves in alcoholic patients seems to suggest a possible central origin of this type of hyperhidrosis.

Different time courses of recovery after poisoning with botulinum neurotoxin serotypes A and E in humans.

Botulinum toxin serotypes A and E (BoNT/A and /E) cleave the carboxy-terminus of synaptosomal associated protein-25 (SNAP-25) removing nine and 26 residues, respectively. To investigate the effect of these lesions of the same target molecule, 11 volunteers were injected with 3 IU of BoNT/A in the extensor digitorum brevis (EDB) muscle of one foot and with 3 IU of BoNT/E in the contralateral one. In addition, seven volunteers were similarly injected with mixtures of BoNT/A + BoNT/E. Compound muscular action potential (CMAP) was measured at different time intervals and the percentage variation of CMAP (%CMAP) was calculated. Unexpectedly, a much faster recovery of %CMAP after BoNT/E injections was observed. Double poisoned EBD muscles recovered similarly to BoNT/E. So, a larger deletion of the SNAP-25 molecule caused by BoNT/E leads to a faster functional recovery.

On the action of botulinum neurotoxins A and E at cholinergic terminals.

Botulinum neurotoxins type A and E (BoNT/A and /E) are metalloproteases with a unique specificity for SNAP-25 (synaptosomal-associated protein of 25 kDa), an essential protein component of the neuroexocytotic machinery. It was proposed that this specificity is based on the recognition of a nine-residue sequence, termed SNARE motif, which is common to the other two SNARE proteins: VAMP (vesicle-associated membrane protein) and syntaxin, the only known substrates of the other six clostridial neurotoxins. Here we report on recent studies which provide evidence for the involvement of the SNARE motif present in SNAP-25 in its interaction with BoNT/A and /E by following the kinetics of proteolysis of SNAP-25 mutants deleted of SNARE motifs. We show that a single copy of the motif is sufficient for BoNT/A and /E to recognise SNAP-25. While the copy of the motif proximal to the cleavage site is clearly involved in recognition, in its absence, other more distant copies of the motif are able to support proteolysis. We also report on studies of poisoning human neuromuscular junctions with either BoNT/A or BoNT/E and describe the unexpected finding that the time of recovery of function after poisoning is much shorter in the case of type E with respect to type A intoxication. These data are discussed in terms of the different sites of action of the two toxins within SNAP-25.