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To study the effects of a standard acute medication withdrawal program on short-term cortical plasticity mechanisms in patients with medication overuse headache (MOH). Thirteen patients with MOH and 16 healthy volunteers underwent repetitive transcranial magnetic stimulation (rTMS) over the left motor cortex; in patients with MOH, recordings were performed before and after a 3-week medication withdrawal program. Ten trains of 10 stimuli each (120% resting motor threshold) were delivered at 1 Hz or 5 Hz in two separate sessions in a randomised order. Motor evoked potential (MEP) amplitudes were measured from the right first dorsal interosseous muscle and the slope of the linear regression line from the first to the tenth stimuli was calculated for each participant. All subjects exhibited MEP amplitude inhibition in response to 1 Hz rTMS. Alternatively, the 5-Hz trains of rTMS inhibited rather than potentiated MEP amplitudes in patients with MOH. The physiological potentiating effect of 5 Hz rTMS on MEP amplitudes was restored after drug withdrawal and in proportion with the percentage reduction in monthly headache days in patients with MOH. The results suggest that acute medication withdrawal normalises brain responses in patients with MOH. Clinical improvements after medication withdrawal may reflect the reversal of neurophysiological dysfunction. Accordingly, medication withdrawal should be offered to patients with MOH as early as possible in order to prevent the development of more pronounced alterations in brain plasticity.

Background and purpose Dysphagia occurs in up to 50% of all patients with acute stroke. There is debate regarding which is the most effective screening tool in identifying aspiration in patients with acute stroke. We assessed the accuracy of the Sapienza Global Bedside Evaluation of Swallowing after Stroke (GLOBE-3S), which combines the Toronto Bedside Swallowing Screening Test (TOR-BSST©) with oxygen desaturation and laryngeal elevation measurement during swallowing. Methods We prospectively enrolled consecutive patients with stroke within 72 h of symptom onset. All patients with stroke firstly underwent a standard neurological examination, then the GLOBE-3S evaluation and finally the fiberoptic endoscopic evaluation of swallowing (FEES). Two different assessors, a neurologist and a speech pathologist, blind to both the clinical data and each other's evaluation, administered the GLOBE-3S and FEES examination. We assessed the accuracy of the GLOBE-3S in detecting post-stroke swallow impairment with aspiration using the FEES as the standard. Results We enrolled 50 patients with acute stroke, 28 of whom (56%) had swallowing impairment with aspiration at FEES evaluation. A total of 33 patients (66%) failed the GLOBE-3S evaluation. The GLOBE-3S reached a sensitivity of 100% and a specificity of 77.3% (negative predictive value, 100%; positive likelihood ratio, 4.34). The median time required for the GLOBE-3S to be performed was 297 s. Conclusions GLOBE-3S is quick to perform at the bedside and can accurately identify aspiration in patients with acute stroke. By including the measurement of laryngeal elevation and monitoring of oxygen desaturation, it could represent a highly sensitive instrument to avoid the misdiagnosis of silent aspirators.

Objective To study the effects of trains of repetitive transcranial magnetic stimulation (rTMS) over the motor cortex in patients with chronic migraine (CM) with or without medication overuse (MOH). Subjects and methods Thirty-two patients (CM [n = 16]; MOH [n = 16]) and 16 healthy volunteers (HVs) underwent rTMS recording. Ten trains of 10 stimuli each (120% resting motor threshold) were applied over the left motor cortex at 1 Hz or 5 Hz in random order. The amplitude of motor evoked potential (MEP) was evaluated from electromyographic recording in the first dorsal interosseous muscle. The slope of the linear regression line for the 10 stimuli for each participant was calculated using normalized data. Results rTMS-1 Hz had a normal depressive effect on MEP amplitude in all groups. rTMS-5 Hz depressed instead of potentiating MEP amplitudes in MOH patients, with a significantly different response from that in HVs and CM patients. The slope of the linear regression of MEP amplitudes was negatively correlated with pain intensity in CM patients, and with the duration of overuse headache in MOH patients. Conclusions This different plastic behaviour suggests that MOH and CM, despite exhibiting a similar clinical phenotype, have different neurophysiological learning processes, probably related to different pathophysiological mechanisms of migraine chronification.

To evaluate trigemino-cervical-spinal reflexes (TCSRs) in a group of migraine patients during the pain-free period.TCRSs are part of a complex nocifensive response involving the cervical and the upper limb muscles, and are modulated by supraspinal inhibitory pathways; it may, thus, be possible to use TCRSs to explore the trigeminal system in migraineurs.A total of 43 migraine patients without aura (MWoA, 32 patients) or with typical aura (MWA, 11 patients) and 30 age- and sex-matched healthy subjects took part in the study. TCRSs were obtained by stimulating the supraorbital nerve and recorded from the semispinalis capitis muscle and the biceps brachii. The latency (L, msec), area (A, mVms) and recovery cycle of the reflexes were recorded. The effects of heterotopic painful stimulation on the neurophysiological parameters were studied by a validated cold pressor test (CPT).No significant changes were found between either migraine patients and controls or MWoA and MWA patients in the mean values in the L and A of TCRSs (t-test, P.05). The recovery curve of the trigemino-cervical reflexes (TCRs) was significantly faster in migraine patients than in controls, while no differences were found in the trigemino-spinal reflexes (TSRs) (t-test, P.01). Activation of the diffuse inhibitory controls through the CPT induced a significant reduction in the TCRs and TSRs area in both migraine patients and controls (paired t-test, P.01), though the extent of this reduction did not differ significantly between migraineurs and controls (t-test, P.05).Our data suggest that the pain-free period in migraine patients is characterized by a hyperexcitability of the trigeminal pathways and of their anatomical and functional connections with the upper cervical cord neurons, and that this abnormal hyperexcitability does not appear to be due to a lack of a supraspinal inhibitory modulation.

Transcranial magnetic stimulation (TMS) of the motor cortex of one hemisphere (conditioning stimulus, CS) inhibits EMG responses evoked in distal hand muscles by a magnetic stimulus given at appropriate interval later over the opposite hemisphere (test stimulus, TS). The common interpretation attributes this effect to an inhibition produced at cortical level via a transcallosal route. The variability of cortical excitability as measured by the interhemispheric paired-pulse (PP) technique has been assessed in healthy subjects in order to compare sub- and supra-threshold intensity of CS (80% versus 120% of individual motor threshold, MT). Within- and between-subject variability relating, respectively, to interhemispheric and gender differences were also assessed. Results point to an efficacy of a magnetic CS on one hemisphere in inhibiting EMG responses of the abductor digiti minimi (ADM) stimulated by a TS delivered over the opposite hemisphere in a range of intervals centered at 12ms. These reductions were produced by the 120% suprathreshold CS, while the 80% subthreshold CS did not affect EMG responses. Females showed a higher transcallosal inhibition than males, suggesting gender differences in interhemispheric connectivity that concern the anterior half of the trunk of the corpus callosum.

Neurophysiological investigations have demonstrated that there are unique fluctuations in the migraine brain functional activity between the ictal and interictal periods. Here we investigated the possibility that there are fluctuations over time also in whole brain morphometry of patients affected by episodic migraine without aura (MO). Twenty-four patients with untreated MO underwent 3T MRI scans during ( n = 10) or between attacks ( n = 14) and were compared to a group of 15 healthy volunteers (HVs). We then performed voxel-based-morphometry (VBM) analysis of structural T1-weighted MRI scans to determine if changes in brain structure were observed over the course of the migraine cycle. Interictally, MO patients had a significantly lower gray matter (GM) density within the right inferior parietal lobule, right temporal inferior gyrus, right superior temporal gyrus, and left temporal pole than did HVs. Ictally, GM density increased within the left temporal pole, bilateral insula, and right lenticular nuclei, but no areas exhibited decreased GM density. These morphometric GM changes between ictal and interictal phases suggest that abnormal structural plasticity may be an important mechanism of migraine pathology. Given the functional neuroanatomy of these areas, our findings suggest that migraine is a condition associated with global dysfunction of multisensory integration and memory processing.

Motor deficits affect patients with Alzheimer's disease only at later stages. Recent studies demonstrate that the primary motor cortex is affected by neuronal degeneration accompanied by the formation of amyloid plaques and neurofibrillary tangles. It is conceivable that neuronal loss is compensated by reorganization of the neural circuitries occurring along the natural course of the disease, thereby maintaining motor performances in daily living. Cortical motor output to upper limbs was tested via motor-evoked potentials from forearm and hand muscles elicited by transcranial magnetic stimulation of motor cortex in 16 patients with mild Alzheimer's disease without motor deficits. Motor cortex excitability was increased, and the center of gravity of motor cortical output, as represented by excitable scalp sites, showed a frontal and medial shift, without correlated changes in the site of maximal excitability (hot-spot). This may indicate functional reorganization, possibly after the neuronal loss in motor areas. Hyperexcitability might be caused by a dysregulation of the intracortical GABAergic inhibitory circuitries and selective alteration of glutamatergic neurotransmission. Such findings suggest that motor cortex hyperexcitability and reorganization allows prolonged preservation of motor function during the clinical course of Alzheimer's disease.

The most common mononeuropathy in the lower extremity involves the nerve. We retrospectively evaluated the etiological predisposing factors and clinical-neurophysiological features of 36 patients affected by peroneal mononeuropathy (PM). In 30 patients, a clear predisposing factor was identified. PM was more frequently perioperative (11 cases), associated with axonal involvement. Unexpectedly, PM was not only due to surgery close to the peroneal region, but was mostly associated with hip surgery and, rarely, with thoracic-abdominal surgery. A postural predisposing factor of PM was also frequently observed, usually associated with a pure conduction block. Conversely, most patients with bedridden predisposing factor presented axonal involvement, which was rarely associated with conduction block. In 25 of 36 PM cases, a long-term follow-up lead to an improvement (12 cases) or to good recovery (13 cases) of PM. In conclusion, our study shows that: (1) in most PM cases it is possible to identify a predisposing factor; (2) there is a good correlation between predisposing factor and neurophysiological involvement, and (3) PM usually has usually a good prognosis.

We report the clinical, serological, and neurophysiological findings in seven patients with foodborne botulism caused by ingestion of black olives in water. The clinical picture was characterized by mild symptoms with a long latency of onset and by involvement of cranial and upper limb muscles; only one patient, a child, developed respiratory failure. Spores of Clostridium botulinum were found in stools in some but not all cases. Conventional neurophysiological tests had low sensitivity; abnormal findings were present only in the patient with severe clinical involvement, in whom compound muscle action potentials (CMAPs) appeared reduced. Repetitive nerve stimulation at a high rate showed pseudofacilitation and not true posttetanic facilitation, but single-fiber electromyography (SFEMG) showed abnormalities of neuromuscular transmission in every case. Neurophysiological evaluation, particularly SFEMG, is important because it allows rapid identification of abnormal neuromuscular transmission while bioassay studies are in progress.

Despite intensive neurophysiological research, evidence is lacking to show whether abnormal cortical excitability in migraine reflects a primary cortical disturbance or reduced control by thalamo-cortical loops. One way to contribute to the scientific discussion on this topic is to deliver transcranial magnetic stimulation (TMS) and test the cortical silent period (SP) recorded in facial muscles. The facial-muscle SP is a purely cortical phenomenon that reflects the excitability of inhibitory interneurons, and can disclose changes in cortical inhibition even in patients without documented primary lesions of the motor cortices. To test the interictal excitability of cortical motor inhibitory interneurons in migraine, we investigated the facial-SP in patients with migraine with and without aura between attacks. In 26 patients and 15 age-matched controls, high-intensity magnetic stimuli were delivered with a round coil centered at the vertex during a maximal muscle contraction. Electromyographic responses were recorded from surface electrodes placed over the subjects' perioral muscles. Facial SPs were significantly shorter in patients than in controls. The SP shortening provides neurophysiological evidence showing hypoexcitability of cortical inhibitory neurons in patients with migraine between attacks. Despite a possible primary deficit of cortical inhibitory interneurons in migraine, we favor the interpretation of a secondary disfacilitation by hypoactive thalamo-cortical loops. Based on this interpretation, the interictal reduced cortical inhibition documented by the shortened SP could be considered the motor counterpart of the reduced preactivation excitability level in the sensory cortices purported to explain why cortical evoked responses habituate poorly in patients with migraine.

Familial hemiplegic migraine (FHM) is a rare subtype of migraine with aura with an autosomal dominant pattern of inheritance. Six FHM families underwent extensive clinical and genetic investigation. The authors identified a novel ATP1A2 mutation (E700K) in three patients from one family. In the patients, attacks were triggered by several factors including minor head trauma. In one subject a 3-day coma developed after a cerebral angiography. Overall, the phenotype of the patients closely resembles that of previously reported cases of FHM type II. The E700K variant might be regarded as the cause of the disease in this family, but this was not tested functionally.

Purpose The use of inferior alveolar nerve somatosensory evoked potentials may represent an objective means of evaluating sensory nerve function in the maxillofacial region. The aim of this work was to confirm the existence of a standard sequence of prominent events in the trigeminal somatosensory evoked potentials (TSEPs) of inferior alveolar nerve (IAN) waveform, examine those components and their normal variability by statistical analysis, and discuss TSEPs’ nervous origin and some patterns of TSEPs’ abnormalities due to dysfunctional nerves. Materials and Methods TSEPs were obtained following electrical stimulation (square wave pulses 0.2 millisecond [ms] in duration, 4 to 6.5 mA, 0.7/second repetition rate, 200 averages) of the gum at the mental foramen level via intraoral surface electrodes and recorded from the contralateral central scalp sites. Results We successfully recognized steady waveforms of sufficient quality and consistently recorded a “W”-shaped response: latency onset and peak of the initial deflection of positive polarity were approximately 12 ms and 20 ms, respectively. Negative and positive deflections followed with respective peak latencies at around 26 ms and 36 ms. One side of the lower lip can be compared with the contralateral side and patients may serve as their own control in cases of unilateral nerve injury. The anaesthetic block showed the total abolition of responses. Reproducible TSEP waveform was only obtained during nerve stimulation and not during masseter muscle stimulation. Conclusions TSEPs, obtained with the present technique, may represent an objective, low-invasive, and reliable way of testing sensory nerve function in the maxillofacial region.

A rapidly progressing dementia, followed by focal neurological signs, and evidence of periodic sharp wave complexes (PSWC) in the EEG may lead to the clinical suspicion of Creutzfeldt–Jakob disease (CJD). Different clinical variants of CJD have been described in the past, with prominent extrapyramidal or occipital lobe involvement, all included in the sporadic form of CJD (sCJD). Familiar and iatrogenic forms of CJD are also known. More recently a new variant has been described, vCJD [1], casually linked to bovine spongiform encephalopathy (BSE) and it has attracted increasing attention toward each form of rapidly progressing dementia; likewise the differential diagnosis between sCJD vs. vCJD is not always easy. Magnetic resonance imaging (MRI) too seems to have a peculiar role in differentiating sCJD from vCJD, even if the role of MRI in the diagnosis of CJD is still debated. Diffusion MRI is expected to play an important role in the clinical setting of CJD, contributing to formulation of an early diagnosis, especially in cases with unusual clinical presentation. In fact, the sensitivity of diffusion MRI is superior to that of conventional MRI (T1, T2, FLAIR) in detecting specific basal ganglia and cortical abnormalities early in the course of CJD [2] and these abnormalities correlate well with areas of the most severe and characteristic neuropathological changes [3]. We describe a case of autopsy–proven sCJD, with an unusual clinical course without dementia as a presenting symptom and discuss the role of diffusion MRI and laboratory tests in making an early diagnosis.

Intracortical facilitation and inhibition, as assessed by the paired-pulse transcranial magnetic stimulation technique with a subthreshold conditioning pulse followed by a suprathreshold test pulse, was studied upon awakening from REM and slow-wave sleep (SWS). Ten normal subjects were studied for four consecutive nights. Intracortical facilitation and inhibition were assessed upon awakening from SWS and REM sleep, and during a presleep baseline. Independently of sleep stage at awakening, intracortical inhibition was found at 1-3-ms interstimulus intervals and facilitation at 7-15-ms interstimulus intervals. Motor thresholds were higher in SWS awakenings, with no differences between REM awakenings and wakefulness, while motor evoked potential amplitude to unconditioned stimuli decreased upon REM awakening as compared to the other conditions. REM sleep awakenings showed a significant increase of intracortical facilitation at 10 and 15 ms, while intracortical inhibition was not affected by sleep stage at awakening. While the dissociation between motor thresholds and motor evoked potential amplitudes could be explained by the different excitability of the corticospinal system during SWS and REM sleep, the heightened cortical facilitation upon awakening from REM sleep points to a cortical motor activation during this stage.

Transcranial magnetic stimulation (TMS) of the motor cortex of one hemisphere (conditioning stimulus (CS)) inhibits EMG responses evoked in distal hand muscles by a later magnetic stimulus given at an appropriate interval, over the opposite hemisphere (test stimulus (TS)). This effect is commonly attributed to an inhibition produced at cortical level via a transcallosal route. The present study assessed the reproducibility of the transcallosal inhibition effects in different sessions in healthy subjects. Within- and between-subject variability, relating to interhemispheric differences was also evaluated. A magnetic CS on one hemisphere effectively inhibited EMG responses of the abductor digiti minimi stimulated by a TS delivered over the opposite hemisphere in a range of intervals centered at 12 ms. Even though group effects were reproduced in separate sessions, the high between- and within-subject variability yielded low test-retest correlations. This differentiation forces the definition of reproducibility (or repeatability), as the replication of the same mean curves of EMG reduction, and of reliability, as the between- or within-subject correlations between values of specific EMG measures. © 2003 Elsevier Science Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Objective : To evaluate the usefulness, sensitivity and specificity of a new neurophysiological test for partial conduction block. Methods . In 17 patients (17 nerves) with clinical pictures strongly suggesting the presence of motor conduction block and 20 healthy subjects (40 nerves), motor nerve conduction studies were performed with the conventional surface technique and with a new technique developed by us: the single fiber EMG (SFEMG) conduction block test. Moreover, we also evaluated patients with other neurological diseases. The recent American Association of Electrodiagnostic Medicine (AAEM) consensus criteria for partial conduction block were used for the standard conduction block tests. Results : According to AAEM consensus criteria, 5/17 cases presented ‘definite' partial conduction block and 6 presented ‘probable' partial conduction block. In contrast, 16/17 cases (94%) presented evidence of conduction block at the SFEMG conduction block test. The 5/6 cases that did not fulfill in the AAEM criteria and that presented abnormal findings at SFEMG nerve conduction test could be considered affected by minimal conduction block. The sensitivity of this new test was greater than conventional test. The specificity was 100% (no abnormal findings in healthy subjects or patients with diseases other than neuropathy). Conclusions : The SFEMG conduction block test is a sensitive, complementary, technique for diagnosis of minimal conduction block in patients with normal findings in standard nerve conduction studies.

To assess the relationship between peripheral nerve involvement and the patient’s perception of his own quality of life, we studied 36 consecutive out-patients affected by insulin-dependent diabetes mellitus without other diabetic complications other than neuropathy (20 men, 16 women; mean age 39.1 years). We used clinical (Semmes-Weinstein, vibration perception threshold, muscle strength, osteotendinous reflexes), neurophysiological (sural, peroneal and ulnar nerves), metabolic (glycosylated haemoglobin) and patient-oriented (SF-36 and NASS questionnaires) measurements. Patient-oriented physical scores were significantly related to: (1) neurophysiological findings of the inferior limbs; (2) conventional measurements of sensitivity; (3) metabolic assessment. Conversely, patient-oriented mental scores were significantly related only to metabolic assessment. The patient-oriented measure provided an important perspective of the severity of the disease often closely related with the biological parameters and suggested new ways of interpreting conventional biological measurements. In particular, the peripheral nerve picture appeared strictly related with the physical aspects of the patients’ quality of life, while the metabolic picture appeared related with both the mental and physical aspects of the quality of life.

We examined the relationships between diabetic peripheral nerve involvement and patients' own perception of quality of life in a multidimensional study based on outcome research recommendations. The study enrolled 50 consecutive outpatients with type 1 diabetes mellitus (23 men, 27 women; mean age, 40.1 years). The patients were evaluated with validated clinical tests (e. g. Semmes-Weinstein, vibration perception threshold, muscle strength), neurophysiological tests (sural, peroneal and ulnar nerves) and patient-oriented (SF-36 and NASS) questionnaires. Patient-oriented physical scores were significantly related with: (1) neurophysiological findings of the lower limbs; (2) conventional measurements of sensitivity. Conversely, patient-oriented mental scores were not related with these findings. The patient-oriented questionnaires provided an important perspective of the severity of the disease, often closely related with the biological parameters. They offered new interpretations to conventional biological measurements. In particular, the peripheral nerve picture was strictly related to the physical aspects of the patients' quality of life, and not with the mental aspects.

Objective : The aim of this study was to verify the action of Botulinum toxin type-A (BoNT-A) by means of neurophysiological techniques, in patients presenting lower limb spasticity and requiring BoNT-A injections in the calf muscles, due to the poor response to medical antispastic treatment. Subjects and method : Patients presenting paraparesis were enrolled. They underwent clinical evaluation for spasticity according to the Ashworth scale and neurophysiological recordings including: motor evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) of the leg area; compound motor action potential (cMAP) to tibial nerve stimulation, F-wave, and H-reflex before the treatment and 24 h, 2 weeks and 1 month after the injection of BoNT-A. In all patients, gastrocnemius was treated and in some cases soleus or tibialis posterior muscles were also injected. Results : In all patients, BoNT-A injections induced a clear clinical improvement as showed by the reduced spasticity values of the Ashworth scale. A significant increment of MEP latency and central conduction time (CCT) duration were observed 2 weeks after the treatment only in the injected muscles. Conclusions : Prolonged MEP latencies and CCT after BoNT-A injections is probably due to a central alteration in responsiveness of spinal motor neurons to descending impulses from the corticospinal tracts. Such changes represent objective parameters heralding clinical efficacy of treatment.

We simultaneously performed near infrared spectroscopy (NIRS) and transcranial Doppler (TCD) to evaluate the effects of hypercapnia as well as of scalp ischemia on the blood flow at two different depth levels within the brain and of the scalp vessels. A decrease in the backscattered light intensity, meaning an increment of blood volume, was detected at the end of hypercapnia in all healthy subjects. This decrement was partly masked by ischemia in the cutaneous vessels. In 2 patients with a monohemispheric lesion in the middle cerebral artery (MCA) territory, an increase in NIRS response was found in the healthy hemisphere, while in the stroke side the CO2-induced changes were negligible. TCD data showed a similar increment of blood flow velocity to the hypercapnia in both hemispheres, with no differences between the affected and normal side in 1 patient, whereas in the second one, no increment was observed on the affected side, probably due to internal carotid artery stenosis. The two methods nicely integrate: TCD mainly tests subcortical changes in the MCA flow, while NIRS is exquisitely sensitive to cortical arterioles and capillary blood flow modifications.

Motor evoked potentials (MEPs) to magnetic transcranial stimulation (TCS) were simultaneously and bilaterally recorded from flexor carpi radialis (FCR) and extensor communis digitorum (ECD) muscles in seven healthy and trained subjects. Latencies and amplitudes characteristics of MEPs were investigated under the following randomised conditions: muscular and mental relaxation; mental simulation, during absolute muscular relaxation, selective flexion or extension of the right or left wrist muscles; arithmetical calculation with muscular relaxation. Unspecific, diffuse facilitatory effects on MEPs amplitude were induced by mental non motor activity (arithmetical calculation). A further specific and lateralised amplitude potentiation on the agonist muscle acting as 'prime mover' for the mentally simulated movement was consistently found in all the subjects, without significant latency changes. Inhibitory effects on antagonists were evident only in two subjects.

Background and purpose The thalamus seems to be profoundly involved in the cyclical recurrence of migraine clinical and neurophysiological features. Here possible structural changes in the thalamus of migraineurs were searched for by means of diffusion tensor (DT) magnetic resonance imaging (MRI). This MRI technique provides quantitative data on water molecule motion as a marker of tissue microstructure. Methods Twenty-four untreated migraine without aura (MO) patients underwent DT-MRI scans (3-T Siemens Gyroscan) during (n = 10) and between attacks (n = 14) and were compared with a group of 15 healthy volunteers (HVs). Fractional anisotropy (FA) and mean diffusivity (MD) were examined. Results During the interictal phase MO patients had a significantly higher FA and slightly lower MD values in bilateral thalami compared with HVs. During attacks, all MRI quantitative measurements in migraineurs were similar to those found in HVs. Right thalamic FA was positively correlated with the number of days since the last migraine attack in pooled patient data (r = 0.626, P = 0.003). Conclusions These higher thalamic FA values noted during the interictal period which normalized during an attack are probably related to plastic peri-ictal modifications in regional branching and crossing of fibres. Whether these changes could be considered as the anatomical counterpart of the cyclical functional fluctuations previously observed in the neurophysiology of migraine remains to be determined.

We report a mentally retarded 30-year-old woman with partial trisomy of chromosome 9 (46, XX-6, +der(6)t(6,9)pat) who has had epilepsy since age 11 months. She had been treated with various combinations of drugs. After 1 year of treatment with valproate (VPA) and ethosuximide (ESM), the patient developed arthralgias, muscle weakness, fatigue, and fever. Laboratory examination showed increased sedimentation rate, hypergammaglobulinemia, and high titers of antinuclear antibodies (ANA). The possibility of VPA-induced systemic lupus erythematosus (SLE) was considered. This diagnosis was supported by detection of antihistone antibodies and the HLA-DR4 antigen. VPA dosage was tapered and discontinued, with accompanying resolution of clinical, immunological and hematological signs of SLE 6 weeks after VPA discontinuation. This is the fourth reported case of VPA-induced SLE.

We studied retrospectively the intraoperative preresection electrocorticograms (ECoGs) of 72 patients undergoing surgery for medically intractable, mostly complex partial, temporal lobe seizures (TLS). Quantification of interictal epileptiform discharges (EDs) detected visually at each electrode location in 2 min recording epochs included computations of ED rates (EDs/min) and cumulative voltages (CuVs) (μV/min). Of 6388 EDs, 81% involved the infratemporal surface, 18% the lateral temporal surface and 1% the orbital frontal area. Forty-eight patients (67%) demonstrated multiple (up to 5 or more), temporally independent foci. Dominant foci in medial and lateral infratemporal locations were about equally common and were significantly more frequent than in lateral temporal locations. Rankings of ED CuVs and rates at individual cortical locations defined 4 areas of “relative interictal cortical epileptogenicity.” These were arranged in an orderly pattern with the anterior parahippocampal gyrus and the inferomedial surface of the temporal tip displaying the highest and the lateral temporal and posterior infratemporal cortices showing the lowest propensity to the interictal epileptiform discharge. Individual areas were not characterized by distinct clinical seizure manifestations. Preresection ECoGs provide information on the epileptogenic dysfunction that involves most of the temporal lobe of patients with medically intractable TLS.

Background Recent evidence indicates that peripheral tissue markers can provide information regarding changes affecting cellular metabolism in Alzheimer disease (AD). We previously reported that serum copper levels can discriminate subjects with AD from normal control subjects (with 60% sensitivity and 95% specificity) and from patients with vascular dementia (with 63% sensitivity and 85% specificity). Objective To study the correlation between AD and serum levels of transition metals and markers of peripheral oxidative stress. Design Case study. Setting General hospital inpatient wards and outpatient clinics. Patients A pair of elderly monozygotic female twins discordant for AD. Main Outcome Measures Biochemical analyses of peripheral-blood transition metals and indicators of oxidative stress and neurologic and neuropsychological assessments of clinical status for presence of cognitive impairment and AD. Results Serum copper and total peroxide levels were both 44% higher in the twin with greater cognitive impairment and a diagnosis of AD. Conclusions The cases reported support the hypothesis of a major involvement of copper and oxidative abnormalities in AD.

Early auditory evoked potentials and electroencephalograms were recorded in 10 rabbits during hypoxic hypoxia (5% O2 in N2 gas mixture) and after reoxygenation. In all experiments EEG flattening preceded the disappearance of the early evoked potential, whose recovery after reoxygenation was more rapid than that of the EEG. Significant increases in P3-P4 and P1-P3 interpeak latencies were observed during hypoxic conditions before the complete flattening of the early auditory evoked potential. In addition, negative relationships were found between the P3-P4 interpeak latency increase and mean arterial pressure reduction, and between the former and metabolic acidosis.

Study Objectives: The aim of the study is to assess, in humans, transcallosal inhibition upon awakening from rapid eye movement (REM) and non-REM sleep, by paired-pulse transcranial magnetic stimulation (TMS). Design: During the daytime, a baseline session of motor evoked potentials (MEPs) was recorded. During the nighttime, the TMS sessions were administered just before sleep onset and upon awakenings from REM and stage 2 sleep, both in the early and final part of night. Setting: The sleep research laboratory at the University of Rome "La Sapienza." Participants: Ten right-handed subjects participated in the experiment for 4 consecutive sleep-recording nights. Interventions: N/A. Measurements and Results: During the daytime, a robust transcallosal inhibition was found; the MEP amplitude reduction ranged from 35% to 40%. During the nighttime, a decrease of transcallosal inhibition from right-to-left motor cortex, as compared to that from left-to-right motor cortex, was observed. The direct assessment of MEP changes, as a function of sleep stage and of the time of night, pointed to a drop of transcallosal inhibition after awakening from REM sleep. Therefore, the inhibitory activity of transcallosal fibers observed after non-REM awakening almost disappeared after REM sleep awakenings. Conclusions: The drastic drop of transcallosal inhibition after awakenings from REM sleep represents the first evidence in humans of a change of interhemispheric connectivity mediated by the corpus callosum during this sleep stage and may open new avenues for a better understanding of some aspects of sleep mechanisms (ie, dreaming function and dream mentation). Abbreviations: REM, rapid eye movement; MEP, motor evoked potentials; TMS, transcranial magnetic stimulation; EEG, electroencephalogram; ADM muscle, Abductor Digiti Minimi muscle; ISI, interstimulus intervals; MT, motor threshold; IHPP paradigm, interhemispheric paired pulse paradigm; ANOVA, analysis of variance.