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Objective This study aimed to measure health-related quality of life (HRQOL) in children and adolescents with tuberous sclerosis complex (TSC) and quality of life (QOL) and depressive symptoms among caregivers. Methods Adequate metrics were used to assess HRQOL in children and adolescents with TSC (4-18 years, KINDLR) as well as QOL (EQ-5D) and symptoms of depression (BDI-II) among caregivers. Predictors for reduced HRQOL and depressive symptoms were identified by variance analysis, ordinal regression, and bivariate correlation. Results The mean HRQOL score was 67.9 ± 12.7, and significantly lower values were associated with increasing age, attending special needs education, TSC-associated psychiatric symptoms, and drug-related adverse events. The mean QOL of caregivers was 85.4 ± 15.7, and caregiver's sex, TSC mutation locus, familial TSC clustering, special needs education, degree of disability, care dependency, presence of TSC-associated psychiatric symptoms, and TSC severity were significant predictors of lower QOL. Depressive symptoms were identified in 45.7% of caregivers, associated with female sex of the caregiver, familial TSC clustering, special needs education, and presence of TSC-associated psychiatric symptoms of the child. Multivariate regression analysis revealed adolescence and drug-related adverse events as significant predictors for lower HRQOL in TSC children, and TSC2 variants predicted lower QOL and depressive symptoms in caregivers. Conclusion Compared with other chronic diseases, such as headache, diabetes or obesity, children with TSC have significantly lower HRQOL, which further decreases during adolescence. A decreased HRQOL of patients correlates with a lower QOL and increased symptoms of depression of their caregivers. These results may improve the comprehensive therapy and care of children and adolescents with TSC and their families and caregivers. Trial registration DRKS, DRKS00016045. Registered 01 March 2019, http://www.drks.de/DRKS00016045.

Seizures are a primary and early disease manifestation of Tuberous Sclerosis Complex (TSC). We aimed to describe the age-stratified patterns of antiseizure drug (ASD) treatments among children, adolescents, and adults with TSC in Germany. Additionally, we reviewed real-world and clinical study evidence regarding ASD utilization in patients with TSC.We evaluated the pattern of routine ASD use and everolimus prescriptions based on a 2019 multicenter survey of 268 individuals with TSC-associated epilepsy. We contextualized the results with a structured review of real-world and clinical study evidence.TSC-associated epilepsy treatment comprises a wide variety of ASDs. In this German sample, the majority of patients were treated with polytherapy, and lamotrigine (34.7%), valproate (32.8%), oxcarbazepine (28.7%), vigabatrin (19.0%), and levetiracetam (17.9%) were identified as the most-commonly used ASDs. In addition, everolimus was used by 32.5% of patients. In adherence to current TSC guidelines, the disease-modifying ASD vigabatrin was widely used in children (58% below the age of 5 years), whereas treatment in adults did not necessarily reflect guideline preference for (partial) GABAergic ASDs.The selection of ASDs for patients with TSC-associated epilepsy follows well-evaluated recommendations, including the guidelines regarding vigabatrin use in children. Several characteristics, such as the comparatively high frequency of valproate use and polytherapy, reflect the severity of TSC-associated epilepsy.

This study was undertaken to quantify epilepsy-related costs of illness (COI) in Germany and identify cost-driving factors.COI were calculated among adults with epilepsy of different etiologies and severities. Multiple regression analysis was applied to determine any epilepsy-related and sociodemographic factors that serve as cost-driving factors.In total, 486 patients were included, with a mean age of 40.5 ± 15.5 years (range = 18-83 years, 58.2% women). Mean 3-month COI were estimated at €4911, €2782, and €2598 for focal, genetic generalized, and unclassified epilepsy, respectively. The mean COI for patients with drug-refractory epilepsy (DRE; €7850) were higher than those for patients with non-DRE (€4720), patients with occasional seizures (€3596), or patients with seizures in remission for1 year (€2409). Identified cost-driving factors for total COI included relevant disability (unstandardized regression coefficient b = €2218), poorer education (b = €2114), living alone (b = €2612), DRE (b = €1831), and frequent seizures (b = €2385). Younger age groups of 18-24 years (b = -€2945) and 25-34 years (b = -€1418) were found to have lower overall expenditures. A relevant disability (b = €441), DRE (b = €1253), frequent seizures (b = €735), and the need for specialized daycare (b = €749) were associated with higher direct COI, and poorer education (b = €1969), living alone (b = €2612), the presence of a relevant disability (b = €1809), DRE (b = €1831), and frequent seizures (b = €2385) were associated with higher indirect COI.This analysis provides up-to-date COI data for use in further health economics analyses, highlighting the high economic impacts associated with disease severity, disability, and disease-related loss of productivity among adult patients with epilepsy. The identified cost drivers could be used as therapeutic and socioeconomic targets for future cost-containment strategies.

Background The approval of everolimus (EVE) for the treatment of angiomyolipoma (2013), subependymal giant cell astrocytoma (2013) and drug-refractory epilepsy (2017) in patients with tuberous sclerosis complex (TSC) represents the first disease-modifying treatment option available for this rare and complex genetic disorder. Objective The objective of this study was to analyse the use, efficacy, tolerability and treatment retention of EVE in patients with TSC in Germany from the patient’s perspective. Methods A structured cross-age survey was conducted at 26 specialised TSC centres in Germany and by the German TSC patient advocacy group between February and July 2019, enrolling children, adolescents and adult patients with TSC. Results Of 365 participants, 36.7% (n = 134) reported the current or past intake of EVE, including 31.5% (n = 115) who were taking EVE at study entry. The mean EVE dosage was 6.1 ± 2.9 mg/m2 (median: 5.6 mg/m2, range 2.0–15.1 mg/m2) in children and adolescents and 4 ± 2.1 mg/m2 (median: 3.7 mg/m2, range 0.8–10.1 mg/m2) in adult patients. An early diagnosis of TSC, the presence of angiomyolipoma, drug-refractory epilepsy, neuropsychiatric manifestations, subependymal giant cell astrocytoma, cardiac rhabdomyoma and overall multi-organ involvement were associated with the use of EVE as a disease-modifying treatment. The reported efficacy was 64.0% for angiomyolipoma (75% in adult patients), 66.2% for drug-refractory epilepsy, and 54.4% for subependymal giant cell astrocytoma. The overall retention rate for EVE was 85.8%. The retention rates after 12 months of EVE therapy were higher among adults (93.7%) than among children and adolescents (88.7%; 90.5% vs 77.4% after 24 months; 87.3% vs 77.4% after 36 months). Tolerability was acceptable, with 70.9% of patients overall reporting adverse events, including stomatitis (47.0%), acne-like rash (7.7%), increased susceptibility to common infections and lymphoedema (each 6.0%), which were the most frequently reported symptoms. With a total score of 41.7 compared with 36.8 among patients not taking EVE, patients currently being treated with EVE showed an increased Liverpool Adverse Event Profile. Noticeable deviations in the sub-items ‘tiredness’, ‘skin problems’ and ‘mouth/gum problems’, which are likely related to EVE-typical adverse effects, were more frequently reported among patients taking EVE. Conclusions From the patients’ perspective, EVE is an effective and relatively well-tolerated disease-modifying treatment option for children, adolescents and adults with TSC, associated with a high long-term retention rate that can be individually considered for each patient. Everolimus therapy should ideally be supervised by a centre experienced in the use of mechanistic target of rapamycin inhibitors, and adverse effects should be monitored on a regular basis.

Background Tuberous sclerosis complex (TSC) is a monogenetic, multisystemic disease characterised by the formation of benign tumours that can affect almost all organs, caused by pathogenic variations in TSC1 or TSC2. In this multicentre study from Germany, we investigated the influence of sociodemographic, clinical, and therapeutic factors on quality of life (QoL) among individuals with TSC. Methods We assessed sociodemographic and clinical characteristics and QoL among adults with TSC throughout Germany using a validated, three-month, retrospective questionnaire. We examined predictors of health-related QoL (HRQoL) using multiple linear regression analysis and compared the QoL among patients with TSC with QoL among patients with other chronic neurological disorders. Results We enrolled 121 adults with TSC (mean age: 31.0 ± 10.5 years; range: 18–61 years, 45.5% [n = 55] women). Unemployment, a higher grade of disability, a higher number of organ manifestations, the presence of neuropsychiatric manifestations or active epilepsy, and a higher burden of therapy-related adverse events were associated with worse QoL, as measured by two QoL instruments (EuroQoL-5 dimensions [EQ-5D] and Quality of Life in Epilepsy Patients [QOLIE-31]). Neuropsychiatric and structural nervous system manifestations, the number of affected organs, and therapy-related adverse events were also associated with higher depression, as measured by the Neurological Disorders Depression Inventory for Epilepsy (NDDI-E). In multiple regression analysis, more severe therapy-related adverse events (large effect, p p p = 0.003) were independently associated with worse HRQoL, explaining 65% of the variance (p p Conclusions Active epilepsy, neuropsychiatric manifestations (such as anxiety and depression), and therapy-related adverse events are important independent predictors of worse quality of life among adults with TSC. Generic quality of life in TSC with several manifestations is similar to uncontrolled severe chronic diseases and significantly negatively correlates with TSC severity. Trial registration DRKS, DRKS00016045. Registered 01 March 2019.

Summary Objectives The aim of the present study was to evaluate the safety and efficacy of the add-on treatment of stiripentol (STP) in adult patients with severely pharmacoresistant focal or multifocal epilepsy. Methods Data on adult patients treated with STP from March 2007 to July 2020 and with at least one clinical follow-up (FU) were retrospectively reviewed. Data on tolerability, efficacy and concomitant medication were evaluated at baseline, 6 months (5.5 ± 1.6 months (mean ± SD)) and 12 months (13.1 ± 3.9 months (mean ± SD)). Results Data of 22 patients (54.5% male, mean age 34.4 ± 17.79 years (mean ± SD), including mean duration of epilepsy 17.6 ± 25.5 years (mean ± SD), median seizure frequency 30 ± 20 (median ± MAD) per month, and 63.6% being severely intellectually disabled, with 3 to 18 previous anti-seizure-drugs (ASD), were collected. After 6 months, 72.7% of the patients were still taking STP, and 31% of the patients were responders, including 13% who were seizure-free. The 12-month retention rate was 54.4 %, the response rate was 36.4% and 13.6% of patients were seizure-free at the 12-month FU. Reasons for discontinuation were increased seizure frequency, hyperammonaemia and encephalopathy. Conclusion STP seems to be a useful option in the treatment of patients with severely pharmacoresistant epilepsy. Prospective trials are necessary to examine the efficacy of STP in adult patients with pharmacoresistant focal epilepsy.

Background Transcutaneous auricular vagus nerve stimulation (taVNS) has been investigated regarding its therapeutic properties in several several conditions such as epilepsy, migraine and major depressive disorder and was shown to access similar neural pathways as invasive vagus nerve stimulation. While the vagus nerve's role in gut motility is physiologically established, the effect of taVNS has scarcely been investigated in humans and yielded conflicting results. Real-time gastric magnetic resonance imaging (rtMRI) is an established reproducible method to investigate gastric motility non-invasively. Objective To investigate the influence of taVNS on gastric motility of healthy participants using rtMRI. Methods We conducted a randomized, double-blind study using high-frequency (HF) stimulation at 25Hz or low-frequency (LF) taVNS at 1Hz after ingestions of a standardized meal in 57 healthy participants. The gastric motility index (GMI) was determined by measuring the amplitude and velocity of the peristaltic waves using rtMRI. Results After HF taVNS, GMI was significantly higher than after LF stimulation (p = 0.005), which was mainly attributable to a higher amplitude of the peristaltic waves (p = 0.003). Conclusion We provide evidence that 4-h of taVNS influences gastric motility in healthy human participants for the first time using rtMRI. HF stimulation is associated with higher amplitudes of peristaltic waves in the gastric antrum compared to LF stimulation. Further studies are needed to investigate the effect of different frequencies of taVNS and its therapeutic properties in conditions with impaired gastric motility.

ObjectivesBrivaracetam (BRV) is the latest approved antiepileptic drug and acts as a synaptic vesicle protein 2A ligand. The aim of the present study was to evaluate the efficacy and tolerability of BRV in the clinical setting.DesignRetrospective, observational multicentre study.SettingWe retrospectively collected clinical data of patients who received BRV in 10 epilepsy centres using a questionnaire that was answered by the reporting neurologist.ParticipantsData of 615 epilepsy patients treated with BRV were included in the study.Primary and secondary outcome measuresEfficacy regarding seizure frequency and tolerability of BRV were evaluated. Descriptive statistics complemented by X2 contingency tests and effect sizes were performed.ResultsOverall, 44% of the patients had a decreased, 38% a stable and 18% an increased seizure frequency. 17% of patients achieved seizure freedom after initiation of BRV. The seizure frequency decreased in 63% of 19 patients with BRV monotherapy. 27% reported adverse effects, but only 10% of patients with monotherapy. Brivaracetam was significantly more often associated with decreased seizure frequency in levetiracetam (LEV) naïve patients (p=0.012), but BRV also led to a decreased seizure frequency in 42% of patients who had been treated with LEV before, including 17% of patients who were completely seizure free. Adverse effects under LEV improved in 62% and deteriorated in 2% of patients after the switch to BRV. At latest follow-up (mean±SD = 26.3±6.5 months), 68% were still on BRV.ConclusionsThe present study shows that results of the phase III studies on BRV match data from real life clinical settings. Brivaracetam seems to be a useful alternative in patients who have suffered adverse effects while taking LEV.

Emergency treatment with benzodiazepines is indicated in prolonged seizures, seizure clusters and status epilepticus. The aim of this study was to evaluate the use of emergency medication in adult patients with epilepsy. All adult epilepsy patients attending the epilepsy outpatient clinics of the university hospitals in Frankfurt and Marburg in 2015 were asked to participate in this questionnaire-based, retrospective survey. A total of 481 patients with a mean age of 43.4 years (range 18–94 years, 54% female) participated in the study. Among them, 134 patients (27.9%) reported on the prescription of an emergency medication during the last year. Patients receiving emergency medication were younger and exhibited a lower age at epilepsy onset, a higher seizure frequency and a higher number of regularly taken antiepileptic drugs. The most frequently taken emergency drugs were oral lorazepam tablets (65.7%; n = 88 out of 134), followed by buccal midazolam (23.9%, n = 32) and rectal diazepam (17.9%, n = 24). The most common indications for administering the emergency medication were seizures continuing for several minutes (35.1%, n = 47), but almost the same number of patients (33.6%, n = 45) stated that the rescue medication was given during or after every seizure. Regarding adverse events, sedation was named as a major (18.7%, n = 25) or moderate (29.1%; n = 39) problem by a substantial number of patients. Difficulties in administration were reported by 17 (13%) patients. Two-thirds assessed the efficacy of their emergency medication as good (50.7%, n = 68) or as very good (15.7%, n = 21). For multivariate logistic regression analysis, aspects such as young age at onset, active epilepsy, structural etiology, presence of generalised tonic–clonic seizures, past medical history of status epilepticus and living with another person independently predicted prescription of emergency medication. In most cases, unsuitable benzodiazepines with slow absorption due to oral administration were prescribed, or buccal midazolam solution was used off-label in adults. Furthermore, inappropriate use of emergency medication at every seizure was reported by a substantial number of participating patients.

Objective The objective of this study was to evaluate effectiveness, retention, and tolerability of brivaracetam (BRV) in genetic generalized epilepsies (GGE) in clinical practice. Methods A multicenter, retrospective cohort study recruiting all patients that started BRV in 2016 and 2017. Results A total of 61 patients (mean age = 29.8, range = 9-90 years, 41 female [67%]) were treated with BRV. They were difficult to control, with 2.4 failed antiepileptic drugs (AEDs) in the past, taking 1.9 AEDs on average at baseline. The length of exposure to BRV ranged from 7 days to 24 months, with a mean retention time of 7.9 months, resulting in a total exposure time to BRV of 483 months. The retention rate was 82% at 3 months and 69% at 6 months. Efficacy at 3 months was 36% (50% responder rate), with 25% seizure-free for 3 months. Patients with juvenile myoclonic epilepsy showed a responder rate of 60%, with 40% being free of any seizures. Long-term 50% responder rate was present in 17 patients (28%; 11 seizure-free [18%]) for >6 months and in 14 patients (23%; 10 seizure-free [16%]) for >12 months. Treatment-emergent adverse events were observed in 26% of the patients, with the most common being somnolence, ataxia, and psychobehavioral adverse events. Use of intravenous BRV with bolus injection of 200-300 mg in two females with absence status epilepticus was well tolerated, but did not result in cessation of status epilepticus. Significance Use of BRV in GGE is well tolerated, and 50% responder rates are similar to those observed in the regulatory trials for focal epilepsies. An immediate switch from levetiracetam (LEV) to BRV at a ratio of 15:1 is feasible. The occurrence of psychobehavioral adverse events seems less prominent than under LEV, and a switch to BRV can be considered in patients with LEV-induced adverse events.

Emergency treatment with benzodiazepines is indicated in prolonged seizures, seizure clusters and status epilepticus.The aim of this study was to evaluate the use of emergency medication in adult patients with epilepsy.All adult epilepsy patients attending the epilepsy outpatient clinics of the university hospitals in Frankfurt and Marburg in 2015 were asked to participate in this questionnaire-based, retrospective survey.A total of 481 patients with a mean age of 43.4 years (range 18-94 years, 54% female) participated in the study. Among them, 134 patients (27.9%) reported on the prescription of an emergency medication during the last year. Patients receiving emergency medication were younger and exhibited a lower age at epilepsy onset, a higher seizure frequency and a higher number of regularly taken antiepileptic drugs. The most frequently taken emergency drugs were oral lorazepam tablets (65.7%; n = 88 out of 134), followed by buccal midazolam (23.9%, n = 32) and rectal diazepam (17.9%, n = 24). The most common indications for administering the emergency medication were seizures continuing for several minutes (35.1%, n = 47), but almost the same number of patients (33.6%, n = 45) stated that the rescue medication was given during or after every seizure. Regarding adverse events, sedation was named as a major (18.7%, n = 25) or moderate (29.1%; n = 39) problem by a substantial number of patients. Difficulties in administration were reported by 17 (13%) patients. Two-thirds assessed the efficacy of their emergency medication as good (50.7%, n = 68) or as very good (15.7%, n = 21). For multivariate logistic regression analysis, aspects such as young age at onset, active epilepsy, structural etiology, presence of generalised tonic-clonic seizures, past medical history of status epilepticus and living with another person independently predicted prescription of emergency medication.In most cases, unsuitable benzodiazepines with slow absorption due to oral administration were prescribed, or buccal midazolam solution was used off-label in adults. Furthermore, inappropriate use of emergency medication at every seizure was reported by a substantial number of participating patients.

Objectives To assess first clinical experiences with brivaracetam (BRV) in the treatment of epilepsies. Methods Data on patients treated with BRV from February to December 2016 and with at least one clinical follow-up were collected from electronic patient records. Data on safety and efficacy were evaluated retrospectively. Results In total, 93 patients were analyzed; 12 (12.9%) received BRV in monotherapy. The mean duration to follow-up was 4.85 months (MD = 4 months; SD = 3.63). Fifty-seven patients had more than one seizure per month at baseline and had a follow-up of more than 4 weeks; the rate of ≥50% responders was 35.1% (n = 20) in this group, of which five (8.8%) patients were newly seizure-free. In 50.5% (47/93), patients were switched from levetiracetam (LEV) to BRV, of which 43 (46.2%) were switched immediately. Adverse events (AE) occurred in 39.8%, with 22.6% experiencing behavioral and 25.8% experiencing non-behavioral AE. LEV-related AE (LEV-AE) were significantly reduced by switching to BRV. The discontinuation of BRV was reported in 26/93 patients (28%); 10 of those were switched back to LEV with an observed reduction of AE in 70%. For clinical reasons, 12 patients received BRV in monotherapy, 75% were seizure–free, and previous LEV-AE improved in 6/9 patients. BRV-related AE occurred in 5/12 cases, and five patients discontinued BRV. Conclusion BRV seems to be a safe, easy, and effective option in the treatment of patients with epilepsy, especially in the treatment of patients who have psychiatric comorbidities and might not be good candidates for LEV treatment. BRV broadens the therapeutic spectrum and facilitates personalized treatment.

Limb ataxia is seen as a sign of ipsilateral cerebellar dysfunction. However, imaging studies have shown a bilateral cerebellar activation during unilateral hand movements. We questioned whether unilateral cerebellar lesions affect pointing movements not only of the ipsilateral hand but also of the contralateral hand. Horizontal saccadic pointing movements of 10 patients with unilateral cerebellar infarctions (infarctions of the posterior inferior or superior cerebellar artery) were compared with those of 19 controls. The movements were recorded with an infrared video motion analysis system. The peak velocity, time lag, and dysmetria of the ipsilateral and contralateral hands were calculated. Patients with cerebellar infarctions had significantly slower movements not only for the ipsilateral but also for the contralateral arm. The time lag of these movements in patients was also significantly larger for both arms. In contrast, there was no significant difference in dysmetria at the endpoints. These findings indicate that both ipsilateral and contra-lateral movements of patients with unilateral cerebellar lesions are slightly impaired.

Little is known about how the brain binds together signals from multiple sensory modalities to produce unified percepts of objects and events in the external world. Using event-related functional magnetic resonance imaging (fMRI) in humans, we measured transient brain responses to auditory/visual binding, as evidenced by a sound-induced change in visual motion perception. Identical auditory and visual stimuli were presented in all trials, but in some trials they were perceived to be bound together and in others they were perceived as unbound unimodal events. Cross-modal binding was associated with higher activity in multimodal areas, but lower activity in predominantly unimodal areas. This activation pattern suggests that a reciprocal and 'competitive' interaction between multimodal and unimodal areas underlies the perceptual interpretation of simultaneous signals from multiple sensory modalities.

We investigated whether the intersession variability of serial fMRI studies correlates between two activation modalities, i.e. a standardized visual and a standardized motor task. Six volunteers were scanned in at least weekly intervals. The number of pixels activated as well as the activation amplitude varied widely. The maximal difference of the number of pixels activated was 1150%, of the activation amplitude 250%. In three volunteers, the variability was highly correlated between the two tasks. Three other volunteers showed one outlier each. We conclude that the intersession variability is due to global factors affecting the whole brain, but that due to unpredictable outliers, using a standardized task to normalize the data of interest is of limited value.

We report our 6 months of experience with adjunctive lacosamide in 25 patients with pharmacoresistant focal epilepsy. Baseline characteristics of our patients were similar to those of the populations in the three clinical trials that evaluated lacosamide for refractory focal epilepsy. One patient experienced sustained seizure freedom for 5 months; two more patients had nonsustained periods of seizure freedom of 1 and 4 months. A total of eight patients (32%) reported a greater than 50% reduction in seizure frequency. Thirteen patients (52%) reported side effects during the titration, mostly dizziness, fatigue, nausea, and gait instability. In five patients (20%), these disappeared during the maintenance phase and/or with dose reduction. Two patients lost more than 10% of their body weight. Otherwise, in terms of efficacy and adverse effects, our data mirror the profile of lacosamide described in the three clinical trials. Substantial weight loss may occur in individual patients.

Skilled gestures require the integrity of the neural networks involved in storage, retrieval, and execution of motor programs. Premotor cortex and/or parietal cortex lesions frequently produce deficits during performance of gestures, transitive more than intransitive. The dorsal stream links object information with object action, suggesting that mechanical knowledge of tool use is stored focally in the brain. Using event-related fMRI, we explored activity during instructed-delay transitive and intransitive hand gestures. The comparison between planning-preparation and execution of gestures demonstrated a temporal rostral to caudal gradient of activation in the ventral premotor cortex (PMv) and inferior to superior gradient of activation in the posterior parietal cortex (PPc). Comparison between transitive and intransitive gestures established a functional specificity within the dorsal stream for mechanical knowledge. Results demonstrate that not only PPc but also the PMv acts in the processing of sensorimotor information during gestures. This might be the substrate underlying selective deficits in ideomotor apraxia patients.

Imagining motor acts is a cognitive task that engages parts of the executive motor system. While motor imagery has been intensively studied using neuroimaging techniques, most studies lack behavioral observations. Here, we used functional MRI to compare the functional neuroanatomy of motor execution and imagery using a task that objectively assesses imagery performance. With surface electromyographic monitoring within a scanner, 10 healthy subjects performed sequential finger-tapping movements according to visually presented number stimuli in either a movement or an imagery mode of performance. We also examined effects of varied and fixed stimulus types that differ in stimulus dependency of the task. Statistical parametric mapping revealed movement-predominant activity, imagery-predominant activity, and activity common to both movement and imagery modes of performance (movement-and-imagery activity). The movement-predominant activity included the primary sensory and motor areas, parietal operculum, and anterior cerebellum that had little imagery-related activity (−0.1 ∼ 0.1%), and the caudal premotor areas and area 5 that had mild-to-moderate imagery-related activity (0.2 ∼ 0.7%). Many frontoparietal areas and posterior cerebellum demonstrated movement-and-imagery activity. Imagery-predominant areas included the precentral sulcus at the level of middle frontal gyrus and the posterior superior parietal cortex/precuneus. Moreover, activity of the superior precentral sulcus and intraparietal sulcus areas, predominantly on the left, was associated with accuracy of the imagery task performance. Activity of the inferior precentral sulcus (area 6/44) showed stimulus-type effect particularly for the imagery mode. A time-course analysis of activity suggested a functional gradient, which was characterized by a more “executive” or more “imaginative” property in many areas related to movement and/or imagery. The results from the present study provide new insights into the functional neuroanatomy of motor imagery, including the effects of imagery performance and stimulus-dependency on brain activity.

To clarify the precise location and timing of the mo tor cortical activation in voluntary movement, dipole source analysis integrating multiple constraints wa conducted for the movement-related cortical potentia (MRCP). Six healthy subjects performed single self paced extensions of the right index finger at about 15-intervals during EEG and event-related fMRI acquisi tions. EEG was recorded from 58 scalp electrodes, and fMRI of the entire brain was obtained every 2.6 s. Coordinates of the two methods were coregistered us ing anatomical landmarks. During dipole source mod eling, a realistic three-layer head model was used as a volume conductor. To identify the number of uncorre lated source s in the MRCP, principal component (PC analysis was performed, which was consistent with the existence of six sources in the left (Lt SM1) and right (Rt SMI) sensorimotor and medial frontocentral (MFC) areas. After dipoles were seeded at the acti vated spots revealed by fMRI, dipole orientations were fixed based on the interpretation of the topography of distribution of the PC. The strength of the six dipoles (three dipoles in Lt SMI, two in Rt SMI, and one in MFC) was then computed over time. Within the bilat eral SM1, activation of the precentral gyrus occurs bilaterally with similar strength from -1.2 s, followed by that of the precentral bank from -0.5 s with con tralateral preponderance. Subsequently, the postcen tral bank becomes active only on the contralateral side at 0.1 s after movement. Activation of the MFC shows timing similar to that of the bilateral precentral gyri These deduced patterns of activation are consis tent with previous studies of electrocorticography in humans.

By using the (14C)2-deoxyglucose method1, inhibition has been shown to be a metabolically active process at the level of the synapse2,3. This is supported by recent results from magnetic resonance spectroscopy that related the changes in neuroenergetics occurring with functional activation to neurotransmitter cycling4. However, inhibitory synapses are less numerous and strategically better located than excitatory synapses, indicating that inhibition may be more efficient, and therefore less energy-consuming, than excitation. Here we test this hypothesis using event-related functional magnetic resonance imaging in volunteers whose motor cortex was inhibited during the no-go condition of a go/no-go task, as demonstrated by transcranial magnetic stimulation. Unlike excitation, inhibition evoked no measurable change in the blood-oxygenation-level-dependent signal in the motor cortex, indicating that inhibition is less metabolically demanding. Therefore, the ‘activation’ seen in functional imaging studies probably results from excitation rather than inhibition.

Long-term deprivation of visual input for several days or weeks leads to marked changes in the excitability and function of the occipital cortex. The time course of these changes is poorly understood. In this study, we addressed the question whether a short period of light deprivation (minutes to a few hours) can elicit such changes in humans. Noninvasive transcranial magnetic stimulation (TMS) of the human occipital cortex can evoke the perception of flashes or spots of light (phosphenes). To assess changes in visual cortex excitability following light deprivation, we measured the minimum intensity of stimulation required to elicit phosphenes (phosphene threshold) and the number of phosphenes elicited by different TMS stimulus intensities (stimulus-response curves). A reduced phosphene threshold was detected 45 min after the onset of light deprivation and persisted for the entire deprivation period (180 min). Following re-exposure to light, phosphene thresholds returned to predeprivation values over 120 min. Stimulus-response curves were significantly enhanced in association with this intervention. In a second experiment, we studied the effects of light deprivation on functional magnetic resonance imaging (fMRI) signals elicited by photic stimulation. fMRI results showed increased visual cortex activation after 60 min of light deprivation that persisted following 30 min of re-exposure to light. Our results demonstrated a substantial increase in visual cortex excitability. These changes may underlie behavioral gains reported in humans and animals associated with light deprivation.