fMRI-Based Effective Connectivity in Surgical Remediable Epilepsies: A Pilot Study

Simultaneous EEG-fMRI can contribute to identify the epileptogenic zone (EZ) in focal epilepsies. However, fMRI maps related to Interictal Epileptiform Discharges (IED) commonly show multiple regions of signal change rather than focal ones. Dynamic causal modeling (DCM) can estimate effective connectivity, i.e. the causal effects exerted by one brain region over another, based on fMRI data. Here, we employed DCM on fMRI data in 10 focal epilepsy patients with multiple IED-related regions of BOLD signal change, to test whether this approach can help the localization process of EZ. For each subject, a family of competing deterministic, plausible DCM models were constructed using IED as autonomous input at each node, one at time. The DCM findings were compared to the presurgical evaluation results and classified as: "Concordant" if the node identified by DCM matches the presumed focus, "Discordant" if the node is distant from the presumed focus, or "Inconclusive" (no statistically significant result). Furthermore, patients who subsequently underwent intracranial EEG recordings or surgery were considered as having an independent validation of DCM results. The effective connectivity focus identified using DCM was Concordant in 7 patients, Discordant in two cases and Inconclusive in one. In four of the 6 patients operated, the DCM findings were validated. Notably, the two Discordant and Invalidated results were found in patients with poor surgical outcome. Our findings provide preliminary evidence to support the applicability of DCM on fMRI data to investigate the epileptic networks in focal epilepsy and, particularly, to identify the EZ in complex cases.

Expanded transcanal transpromontorial approach to the internal auditory canal and cerebellopontine angle: a cadaveric study

The aim of this paper is to describe and evaluate the feasibility of an expanded endoscopic transcanal transpromotorial approach (ExpTTA) to the internal auditory canal and the cerebellopontine angle. To this end, we performed a cadaveric dissection study in September 2015. In total, 2 heads (4 sides) were dissected focusing on anatomical landmarks and surgical feasibility. Data from dissections were reviewed and analysed for further consideration. In all 4 sides of the cadavers the procedure was feasible. In all cadavers, it was necessary to extensively drill the temporo-mandibular joint and to calibrate the external ear canal to allow adequate room to manoeuver the instruments and optics and to comfortably access the cerebellopontine angle. In addition, thorough skeletonisation of the carotid artery and the jugular bulb were necessary for the same purpose. In conclusion, ExpTTA appeared to be successful to access the internal auditory canal and cerebellopontine angle region. Potential extensive and routine application of this type of approach in lateral skull base surgery will depend on the development of technology and surgical refinements and on the diffusion of skull base endoscopic skills among otolaryngologists and neurosurgical community.

Acute endovascular treatment (< 48 hours) of uncoilable ruptured aneurysms at non-branching sites using silk flow-diverting devices

A blood blister-like (BBL) or dissecting aneurysm should be carefully considered if located at a non-branching site of the supra-clinoid internal carotid artery (ICA). Several surgical and endovascular treatment methods have been proposed but they all carry a relatively high risk of morbidity and mortality. This study evaluated the effectiveness of a novel Silk flow-diverting device (SFD) placed in the early acute stage. Three patients presenting with acute subarachnoid haemorrhage caused by small blister-like aneurysms of the carotid siphon were treated within 48 hours after admission by placement of SFDs. More than one device was placed to cover the lesion. None of the patients were premedicated and started anti-platelet therapy during the procedure. All aneurysms were successfully occluded. A good outcome was observed in two out of three treated patients. No thromboembolic or haemorrhagic event occurred during or after the procedures, or during follow-up (6-14 months). SFD prevented rebleeding and the use of these devices could be proposed as an option to treat fragile uncoilable BBL aneurysms, even in the early acute phase without anti-platelet premedication. Larger studies and long-terms results are necessary.

Intraventricular hemorrhage caused by peripheral anterior choroidal artery aneurysm rupture. A case report

Intraventricular hemorrhage is a severe ictal event secondary to several pathological conditions (anticoagulation therapies, hypertension, post-surgical, traumatic, neoplastic, vascular malformations), leading to blockage of CSF flow and possible hydrocephalus, often justifying surgical intervention. We describe an uncommon source of intraventricular hemorrhage in a 54-year-old woman caused by a peripheral anterior choroidal artery aneurysm rupture.

Neurosurgical treatment of von Hippel-Lindau-associated hemangioblastomas: benefits, risks and outcome

AIM

Von Hippel-Lindau (VHL) disease is a genetic syndrome predisposing to central nervous system (CNS) hemangioblastomas and several lesions in many organs. The cases of all VHL individuals operated on in the Neurosurgical Unit of Padua Hospital since year 2000 were reviewed in order to define which features lead to surgical treatment and to examine surgical outcome during postoperative follow-up.

METHODS

The authors evaluated 20 VHL subjects (7 males and 13 females, age at surgery 32+/-10 years) who underwent 28 operations in order to remove 48 CNS hemangioblastomas and 1 endolymphatic sac tumor. Among the 49 resected lesions, 21 (42%) were cerebellar, 9 (18%) at brainstem, 19 (38%) spinal (7 cervical, 6 dorsal, 6 at cone-cauda level), and 1 (2%) endolymphatic sac tumor in the petrous bone. Patients were graduated according to Karnofsky Performance Status (KPS) at admission, at discharge and during the last follow up visit. Genetic testing revealing the presence of a VHL disease-causing mutation was a prerequisite for inclusion in the study.

RESULTS

Nineteen individuals (95%) were symptomatic. Symptomatic hemangioblastomas were associated with a cyst or a syrinx in 22/27 circumstances (81%). Total removal, as confirmed by postoperative magnetic resonance imaging (MRI), was achieved in all but one lesion. Following surgery, at follow-up (38+/-20 months), patients improved their neurological status in 75% of cases, 20% remained stable and 5% worsened; 16 patients (80%) are able to carry on normal activity with or without minor symptoms, 3 patients require some grade of assistance, 1 patient died because of bronchopneumonia.

CONCLUSION

VHL-associated hemangioblastomas generally affect a young adult population and can be successfully removed, either when symptomatic, or when they reach a critical volume. Microsurgery of hemangioblastomas has a favourable impact on survival and quality of life of VHL patients, although it is strongly influenced by preoperative conditions. Transient surgical complications are possible, particularly with brainstem and spinal cord hemangioblastomas.

[Differences in the prevalence of work related disorders among construction workers between the end of 90s and 2006]

The aim of this work is to analyse the prevalence of occupational diseases in construction industry, comparing the results of the first years of health surveillance (1996-2000) and today's situation. We compare the prevalence of occupational diseases observed in 1348 workers during the period 1996-2000 (mean age 36,4 years, DS 11,8; mean experience in construction industry 16,9 years, DS 12,3) and the one observed in 795 different workers during 2006 (mean age 38,8 years, DS 11,1; mean experience in construction industry 18 years, DS 16,6). The prevalence of occupational diseases is respectively 12.09% and 12.83%. But analysing the single pathology it's possible to observe important differences between the two groups. In the workers observed in 2006 there is a significant reduction in prevalence of hearing loss caused by chronic exposure to noise and in prevalence of vascular disease caused by hand-arm vibrations: respectively from 94,9 to 79,2 cases/1000 workers and from 6,7 to 2.6 cases/1000 workers. Musculoskeletal diseases instead are increased from 11,1 to 37,7 cases/1000 workers, showing more attention to the problem, better diagnostics ability and more recognition by public insurance agency for occupational diseases.

Tongue lesions and isolated hypoglossal nerve palsy: a case report

We report the case of a patient with oral lesions on the upper surface of his tongue. Intraoral examination revealed marked right-sided hemiatrophy of the tongue with fasciculation, partial deviation of the tongue on the right side, and inability of the patient to completely deviate the tongue toward the left side of his mouth on protrusion. A magnetic resonance image showed presence of a tumor lesion characterized by irregular margins localized in the intradural space, with a lateral extension along the omolateral hypoglossal canal. This was consistent with the diagnosis of a hypoglossal neurinoma, later confirmed by the histopathologic examination.

The localization of facial motor impairment in sporadic Mobius syndrome

OBJECTIVE

To investigate the neurophysiologic aspects of facial motor control in patients with sporadic Möbius syndrome defined as nonprogressive congenital facial and abducens palsy.

METHODS

The authors assessed 24 patients with sporadic Möbius syndrome by performing a complete clinical examination and neurophysiologic tests including facial nerve conduction studies, needle electromyography examination of facial muscles, and recording of the blink reflex and of the trigeminofacial inhibitory reflex.

RESULTS

Two distinct groups of patients were identified according to neurophysiologic testing. The first group was characterized by increased facial distal motor latencies (DMLs) and poor recruitment of small and polyphasic motor unit action potentials (MUAPs). The second group was characterized by normal facial DMLs and neuropathic MUAPs. It is hypothesized that in the first group, the disorder is due to a rhombencephalic maldevelopment with selective sparing of small-size MUs, and in the second group, the disorder is related to an acquired nervous injury during intrauterine life, with subsequent neurogenic remodeling of MUs. The trigeminofacial reflexes showed that in most subjects of both groups, the functional impairment of facial movements was caused by a nuclear or peripheral site of lesion, with little evidence of brainstem interneuronal involvement.

CONCLUSION

Two different neurophysiologically defined phenotypes can be distinguished in sporadic Möbius syndrome, with different pathogenetic implications.

Pathological yawning as a presenting symptom of brain stem ischaemia in two patients

Two cases of brain stem stroke involving the upper pons and the ponto-mesencephalic junction presented with transient excessive pathological yawning, associated with gait ataxia and in one subject with upper limb and facial hemiparesis. A causal relation is hypothesised between the brain stem lesion and pathological yawning, possibly related to denervation hypersensitivity of a putative brain stem yawn centre. Excessive yawning may herald brain stem ischaemia.

[First aid training in collaboration with CPT and CPTA of Bergamo]

In this work it's briefly described the experience in planning and realizing of first aid at work courses for workers of the building trade, realized by the UOOML in collaboration with CPT and CPTA of Bergamo. In particular this is a report of the activity of planning and realization of courses in the months from February till September 2004.

[Assessment of the efficiency of the first aid course among construction companies in the Province of Bergamo]

The aim of this project is to value, through a specific questionnaire, the effectiveness and utility of the professional training among the construction workers responsible of the First Aid. 48 construction firms, in Province of Bergamo, were examined and 100 first aid responsible were tested through to the questionnaire. The 21% of the subjects performed a practical first aid intervention. The 84% considers the professional training courses to be globally satisfactory, and one third underlines the necessity of an annual refresher course. This study tends to confirm the validity of this program of professional training, particularly in the construction trade, that is characterized by a high accidents rate.

[Efficacy of periodic health surveillance of construction workers visited at the CPT of Bergamo]

The aim of this work is to expose the results obtained with the application of a model about efficacy in occupational medicine proposed by ALMLII. In particular we discuss the validity of some indicators of efficacy used in a large group of construction workers during health surveillance, in order to verify effectiveness and appropriateness of an occupational medicine service, as a part of the whole prevention and safety system.

The transcriptional landscape of the mammalian genome

This study describes comprehensive polling of transcription start and termination sites and analysis of previously unidentified full-length complementary DNAs derived from the mouse genome. We identify the 5' and 3' boundaries of 181,047 transcripts with extensive variation in transcripts arising from alternative promoter usage, splicing, and polyadenylation. There are 16,247 new mouse protein-coding transcripts, including 5154 encoding previously unidentified proteins. Genomic mapping of the transcriptome reveals transcriptional forests, with overlapping transcription on both strands, separated by deserts in which few transcripts are observed. The data provide a comprehensive platform for the comparative analysis of mammalian transcriptional regulation in differentiation and development.

[Variation of the judgment of the fitness to specific work in a cohort study in construction industry]

This work shows the results of a study about variation of the judgement of the fitness to specific work in the construction industry in a year. In the 8.6% of the cases, after a year from the previous examination, it was necessary to express new limitations to the job activity mainly because of the presence of illness of the musculoskeletal or cardiovascular system. Considering only workers aged over 35 years, the percentage of variation after a year grows to 12.3%.

GeneSyn: a tool for detecting conserved gene order across genomes

GeneSyn is a software tool that allows automatic detection of conserved gene order from annotated genomes.

AVAILABILITY

Available free of charge for Unix/Linux/Cygwin platforms at ftp://159.149.110.11/pub/GeneSyn_1.0/

SUPPLEMENTARY INFORMATION

ftp://159.149.110.11/pub/GeneSyn_1.0/

Small fibers peroneal mononeuropathy in a patient with Sjögren's syndrome

Sjögren's syndrome (SS) is an autoimmune epithelitis characterized by lymphocytic infiltration of exocrine glands and epithelia in multiple sites. One third of the patients present with peripheral nervous system involvement. We describe the case of a woman aged 62 affected by a peroneal nerve mononeuropathy with painful disturbances secondary to a prevalent involvement of small fibers as demonstrated by electrophysiological investigations and skin biopsy. Asymmetric peripheral nerve involvement is not uncommon in SS, though, to our knowledge, it has never been reported of a mononeuropathy involving primarily small fibers.

An algorithm for finding signals of unknown length in DNA sequences

Pattern discovery in unaligned DNA sequences is a challenging problem in both computer science and molecular biology. Several different methods and techniques have been proposed so far, but in most of the cases signals in DNA sequences are very complicated and avoid detection. Exact exhaustive methods can solve the problem only for short signals with a limited number of mutations. In this work, we extend exhaustive enumeration also to longer patterns. More in detail, the basic version of algorithm presented in this paper, given as input a set of sequences and an error ratio epsilon < 1, finds all patterns that occur in at least q sequences of the set with at most epsilonm mutations, where m is the length of the pattern. The only restriction is imposed on the location of mutations along the signal. That is, a valid occurrence of a pattern can present at most [epsiloni] mismatches in the first i nucleotides, and so on. However, we show how the algorithm can be used also when no assumption can be made on the position of mutations. In this case, it is also possible to have an estimate of the probability of finding a signal according to the signal length, the error ratio, and the input parameters. Finally, we discuss some significance measures that can be used to sort the patterns output by the algorithm.

Masseteric repetitive nerve stimulation in the diagnosis of myasthenia gravis

OBJECTIVE

(1) to develop a method for masseteric repetitive nerve stimulation (RNS) and to obtain normative data for amplitude and area decrement of the muscle (M) response. (2) To investigate myasthenia gravis (MG) patients with masseteric RNS. Masticatory muscles are frequently affected in MG, but no RNS test is available to investigate this district.

METHODS

Fifteen healthy subjects and 17 MG patients were examined. The masseteric nerve was stimulated by a monopolar needle (cathode), inserted between the mandibular incisure and the zygomatic arch, and a surface electrode (anode), on the contralateral cheek. Masseteric M response was recorded using surface electrodes on the muscle belly and below the mandibular angle. Stimuli were delivered at 3 Hz in trains of 9, at rest and after isometric effort.

RESULTS

Normal subjects: mean amplitude decrement was 0.3+/-1.2% at rest, and 1.9+/-1.3% after isometric effort.

PATIENTS

15 patients (88%) were positive on masseteric RNS; in 3 of these it was the only positive RNS test. The extent of decrement observed in masseter muscle was significantly greater than in trapezius muscle.

CONCLUSIONS

Masseteric RNS is a simple and well-tolerated procedure; it offers a new possibility in testing the cranial muscles in disorders of neuromuscular transmission.

Impaired control of an action after supplementary motor area lesion: a case study

The kinematics of the action formed by reaching-grasping an object and placing it on a second target was studied in a patient who suffered from an acute vascular left brain lesion, which affected the Supplementary Motor Area proper (SMA-proper) (Matelli M, Luppino G. Thalamic input to mesial and superior area 6 in the macaque monkey. Journal of Comparative Neurology 1996;372:59-87, Matelli M, Luppino G, Fogassi L, Rizzolatti G. Thalamic input to inferior area 6 and area 4 in the macaque monkey. Journal of Comparative Neurology 1989;280:468-488), and in five healthy control subjects. The reach kinematics of the controls was affected by the positions of both the reaching-grasping and the placing targets (Gentilucci M, Negrotti A, Gangitano M. Planning an action. Experimental Brain Research 1997;115:116-28). In contrast, the reach kinematics of the patient was affected only by the position of the reaching-grasping target. By comparing these results with those previously found in Parkinson's disease patients executing the same action (Gentilucci M, Negrotti A. Planning and executing an action in Parkinson's disease patients. Movement Disorders 1999;1:69-79, Gentilucci M, Negrotti A. The control of an action in Parkinson's disease. Experimental Brain Research 1999;129:269-277), we suggest that the anatomical "motor" circuit formed by SMA-proper (see above), Basal Ganglia (BG) and Thalamus (Alexander GE, Crutcher MD. Functional architecture of basal ganglia circuits: neural substrates of parallel processing. Trends in the Neurosciences 1990;13:266-271, Hoover JE, Strick PL. Multiple output channels in the basal ganglia. Nature 1993;259:819-821) may be involved in the control of actions: SMA-proper assembles the sequence of the action, whereas BG updates its parameters and stores them.

Trigemino-facial reflex inhibitory responses in some lower facial muscles

The effects of electrical trigeminal stimulation on activated facial muscles were studied in 20 normal subjects in order to evaluate whether excitatory or inhibitory responses are present and to investigate whether the reflex organization is similar in all the facial muscles. No inhibition was observed in frontalis, orbicularis oculi, orbicularis oris, and mentalis muscles. By contrast, a clear suppression of electromyographic (EMG) activity (late silent period or SP2) was present in the levator labii superioris, depressor anguli oris, and depressor labii inferioris muscles, with a mean latency ranging from 41.8 to 50.2 ms, and a mean duration ranging from 27.5 to 40.9 ms. An early suppression of EMG activity (early silent period or SP1) was observed, with a latency of 16 to 20 ms and a duration of 10 ms, mainly in inferior perioral muscles. Our findings show a selective trigeminal inhibitory influence upon some specific lower facial muscles.

Corticospinal excitability is specifically modulated by motor imagery: a magnetic stimulation study

Transcranial magnetic stimulation (TMS) was used to investigate whether the excitability of the corticospinal system is selectively affected by motor imagery. To this purpose, we performed two experiments. In the first one we recorded motor evoked potentials from right hand and arm muscles during mental simulation of flexion/extension movements of both distal and proximal joints. In the second experiment we applied magnetic stimulation to the right and the left motor cortex of subjects while they were imagining opening or closing their right or their left hand. Motor evoked potentials (MEPs) were recorded from a hand muscle contralateral to the stimulated cortex. The results demonstrated that the excitability pattern during motor imagery dynamically mimics that occurring during movement execution. In addition, while magnetic stimulation of the left motor cortex revealed increased corticospinal excitability when subjects imagined ipsilateral as well as contralateral hand movements, the stimulation of the right motor cortex revealed a facilitatory effect induced by imagery of contralateral hand movements only. In conclusion, motor imagery is a high level process, which, however, manifests itself in the activation of those same cortical circuits that are normally involved in movement execution.

Heteronymous H-reflex in temporal muscle motor units

An electric stimulation of the masseteric nerve elicits a heteronymous H-reflex in the temporal muscle. The characteristics of this reflex response were investigated by analysis of the firing probability changes of single motor units. Eleven healthy subjects participated in the experiments. The heteronymous H-reflex of the temporal muscle was electrically elicited by stimulation of the masseteric nerve at 120% of the intensity needed for the maximal masseteric M-wave. From 8 to 24 motor units were sampled from the temporal muscle of each subject. Peri-stimulus time histograms of motor unit recordings were built with a 0.5-ms bin width. The mean firing probability was calculated for the 20 ms preceding the stimulus. The firing probability was considered increased when it exceeded the mean by 3 standard deviations. Of 104 sampled motor units, 40 motor units showed a significant increase of the firing probability, which lasted 1 ms or less in 29 of them. In 12 out of 16 motor units, a significant increase of firing probability also persisted at a lower stimulation intensity (120% of the threshold needed to elicit a masseteric M wave). These data indicate that: (1) some temporal muscle motor units are modulated by afferents from the masseter muscle, (2) the heteronymous H-reflex has a monosynaptic component, and (3) there might be a more complex than just monosynaptic organization serving the heteronymous temporal H-reflex. For the latter conclusion regarding synaptic wiring, however, PSTH studies like the present one can offer only indirect evidence, and this question could be better studied in animals.

Isolated neuritis of the sciatic nerve in a case of Lyme disease

Lyme disease is an infectious disease caused by the spirochete Borrelia burgdorferi. The course of the disease is divided into three stages, the second of which may include various types of peripheral nervous system disturbances. We report the case of a patient with persistent deficits caused by the prevalent involvement of the sciatic nerve, confirmed by electrophysiological and neuropathological findings. The most significant bioptic results were axonal degeneration and perivascular inflammation. Damage to a single peripheral nerve as the dominant clinical expression during the course of Lyme disease is an unusual finding that has been rarely described in the literature.

Cryoglobulinaemic neuropathy manifesting with restless legs syndrome

In a series of 12 patients with essential mixed cryoglobulinaemia (EMC) and peripheral neuropathy as main feature of the disease, restless legs syndrome (RLS) was a major manifestation in four women, aged 55-65 years. In one patient RLS was a presenting manifestation of the disease, and in another patient the diagnosis of EMC was made investigating RLS and polyneuropathy, although prior rheumatological symptoms were retrospectively recognized. All patients with RLS had symmetrical sensory polyneuropathy, but non-RLS patients had also other forms of peripheral neuropathy, and symmetrical sensory polyneuropathy only in two of eight cases (P=0.03). Neurophysiological study showed that sensory action potentials of the sural nerve were more often inelicitable in non-RLS patients (six of eight) than in RLS patients (none of three). Sural nerve biopsy had no distinctive features in three RLS patients, with regard to other patients with cryoglobulinaemic neuropathy. RLS seems not uncommon in cryoglobulinaemic neuropathy, and significantly associated with symmetrical sensory polyneuropathy, whereas patients with other subtypes of cryoglobulinaemic neuropathy do not develop RLS; thus, a disorder of the sensory inputs may be important in the pathogenesis of RLS. The occurrence of RLS, especially in middle-aged women, should prompt investigations for peripheral neuropathy focusing on cryoglobulinaemic neuropathy.

Electromyographic evaluation of the spared serratus anterior after postero-lateral thoracotomy

Postero-lateral thoracotomy is the standard access in thoracic surgery, and can be carried out dividing or preserving the serratus anterior muscle. This last method, besides its advantages, is still a matter of discussion, in fact traction has been claimed to cause severe muscular damage equal to section. We have studied 20 patients (16 males and 4 females, mean age 63 years), who underwent postero-lateral thoracotomy sparing the serratus anterior, after 6 months from surgery, both clinically and by means of electromyography (EMG), to evaluate the functional status of the spared muscles. In 4 cases (20%) there wasn't any neurogenic damage nor clinical evidence of winging scapula; 3 cases (15%) had medium neurogenic damage. The remaining 13 (65%) cases had a medium neurogenic damage and only one patient showed a winging scapula, neverthless being able to lift the arm to shoulder level. Our data confirmed that retraction during surgery does not damage the serratus anterior, leaving a functionally valid muscle.

The influence of the asymmetric tonic neck reflex on the H-reflex in human temporal muscle

In contrast to limb muscles, little is known about the role of the asymmetric tonic neck reflex (ATNR) on jaw-elevator muscles. The effect of rotation of the head on the H-reflex in the anterior part of the temporal muscle after masseteric nerve stimulation was evaluated. Eight healthy volunteers (7 males and 1 female, age range 18 to 27 years, mean age 22 years) participated. The masseteric M-response and the masseteric and temporal H-reflexes were elicited by stimulating the masseteric nerve using a monopolar needle technique. The electromyographic activity of the muscles was recorded by surface electrodes. The ATNR was modified by changing position of the head: 30 degrees rotation towards the stimulated side (+N), 30 degrees rotation towards the non-stimulated side (-N) and 0 degree central position (C). The heteronymous temporal H-reflex was elicited at a stimulus intensity of 120% maximal M-response at a frequency of 1 Hz, in random series of 5 to 20 sweeps, up to 30-50 sweeps for each position. On-line averaging was performed. A significant reduction of the H-reflex amplitude was observed in the -N position (p-0.02 paired "t"-test, p = 0.015 Wilcoxon signed rank test), while a significant increase was present in the +N position (p = 0.007 PTT and WSR). Also multivariate analysis yielded a significant influence of head rotation on H-reflex amplitude (p = 0.0032). It can be concluded that the ATNR has a significant influence on the H-reflex of the human temporal muscle.