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Biomedical subjects

Carlo Alberto Tassinari

Publications and source records attributed to Carlo Alberto Tassinari.

At least 19 recordsLinked to original sources
PubMed2006

CAP, epilepsy and motor events during sleep: the unifying role of arousal.

Arousal systems play a topical neurophysiologic role in protecting and tailoring sleep duration and depth. When they appear in NREM sleep, arousal responses are not limited to a single EEG pattern but are part of a continuous spectrum of EEG modifications ranging from high-voltage slow rhythms to low amplitude fast activities. The hierarchic features of arousal responses are reflected in the phase A subtypes of CAP (cyclic alternating pattern) including both slow arousals (dominated by the <1Hz oscillation) and fast arousals (ASDA arousals). CAP is an infraslow oscillation with a periodicity of 20-40s that participates in the dynamic organization of sleep and in the activation of motor events. Physiologic, paraphysiologic and pathologic motor activities during NREM sleep are always associated with a stereotyped arousal pattern characterized by an initial increase in EEG delta power and heart rate, followed by a progressive activation of faster EEG frequencies. These findings suggest that motor patterns are already written in the brain codes (central pattern generators) embraced with an automatic sequence of EEG-vegetative events, but require a certain degree of activation (arousal) to become visibly apparent. Arousal can appear either spontaneously or be elicited by internal (epileptic burst) or external (noise, respiratory disturbance) stimuli. Whether the outcome is a physiologic movement, a muscle jerk or a major epileptic attack will depend on a number of ongoing factors (sleep stage, delta power, neuro-motor network) but all events share the common trait of arousal-activated phenomena.

Arousal↗
PubMed2006

Lesionectomy in epileptogenic gangliogliomas: seizure outcome and surgical results.

We retrospectively analysed seizure outcome and surgical results in a series of 21 patients with ganglioglioma treated with lesionectomy. The 21 patients (13 males, eight females) had a history of epilepsy longer than 1 year and post-operative follow up of at least 1 year. Information on the duration of the seizures, type and frequency was retrieved from medical records. In all patients, surgery was limited to the tumour. The interval between onset of seizures and surgery ranged from 1 to 35 years (mean 11). Patient age ranged from 6 to 61 years (mean 27.5). Fifteen patients (71.4%) had complex partial seizures and six had simple partial seizures. Secondary generalisation was present in 10 patients (47.6%). Seizure frequency varied from several per day to one per month. Sixteen tumours were temporal (76.1%; 11 temporo-mesial, five temporo-lateral), and five were extratemporal (23.8%). The mean follow-up period was 5.4 years (range: 1.25-10 years). No tumour progression was observed. No patient died during surgery or the post-operative course. Fourteen patients (66.6%) were Engel class I (five temporo-mesial, five temporo-lateral, four extratemporal) and seven (33.3%) were Engel class II. Post-operative complications were observed in six patients (28.6%), two of whom had cerebellar haemorrhage, possibly due to increased transmural venous pressure. In our patients with temporal neocortical and extratemporal ganglioglioma, lesionectomy allowed good seizure control. The unsatisfactory outcome for mesiotemporal gangliogliomas might indicate the need for extensive neurophysiological presurgical evaluation in order to perform tailored surgery. To avoid cerebellar haemorrhage, attention should be paid to those factors involved in transmural venous pressure increases.

Adolescent↗
PubMed2006

Transthyretin RNA profiling in livers from transplanted patients affected by familial amyloidotic polyneuropathy, and identification of a dual transcription start point.

Mutations in the transthyretin (TTR) gene cause familial amyloidotic polyneuropathy (FAP), an autosomal dominant peripheral neuropathy, often associated with cardiomyopathy. Liver transplant currently represents a powerful therapeutic approach for FAP patients, although its efficacy is heavily dependent both on the disease severity and on the cardiac functionality. We have investigated the TTR gene expression searching for tissue-specific additional messengers in human adult and foetal tissues as well as in eight livers from FAP transplanted patients carrying different TTR mutations (Met30, Pro36, Ala47, Arg50, and Gln89). We identified a novel transcript, recognising a different transcription start site. The additional 5'-UTR sequence of this novel transcript contains regulatory boxes possibly highlighting an additional transcription start point. RNA analysis revealed that this region is represented in all foetal/adult tissues analysed. We discussed the implications of this finding which might provide perspectives for better understanding the TTR gene expression.

Amyloid Neuropathies, Familial↗
PubMed2006

Suppressive efficacy by a commercially available blue lens on PPR in 610 photosensitive epilepsy patients.

PURPOSE: Photosensitivity can represent a serious problem in epilepsy patients, also because pharmacologic treatment is often ineffective. Nonpharmacologic treatment using blue sunglasses is effective and safe in controlling photosensitivity, but large series of patients have never been studied. METHODS: This multicenter study was conducted in 12 epilepsy centers in northern, central, southern, and insular Italy. A commercially available lens, named Z1, obtained in a previous trial, was used to test consecutively enrolled pediatric and adult epilepsy patients with photosensitivity. Only type 4 photosensitivity (photoparoxysmal response, PPR) was considered in the study. A standardized method was used for photostimulation. RESULTS: Six hundred ten epilepsy patients were tested. Four hundred (66%) were female patients; 396 (65%) were younger than 14 years. Three hundred eighty-one (62%) subjects were pharmacologically treated at the time of investigation. Z1 lenses made PPR disappear in 463 (75.9%) patients, and PPR was considerably reduced in an additional 109 (17.9%) of them. PPR remained unchanged only in the remaining 38 (6.2%) patients. The response of PPR to Z1 lenses was not significantly influenced by the patients' age, sex, or type of epilepsy. No difference was found between pharmacologically treated and untreated patients. CONCLUSIONS: The Z1 lens is highly effective in controlling PPR in a very large number of photosensitive epilepsy patients irrespective of their epilepsy or antiepileptic drug treatment. The lens might become a valid resource in the daily activity of any clinician who cares for patients with epilepsy.

Adolescent↗
PubMed2006

Cognition and paroxysmal EEG activities: from a single spike to electrical status epilepticus during sleep.

Epileptic EEG paroxysms can interfere with cognitive processes producing transitory effects, such as those related to a single spike, as well as long-lasting effects, such as in electrical status epilepticus during slow-wave sleep (ESES). Focal spike-related disruption of cortical functions can produce transitory cognitive impairment, with neuroanatomical specificity between the site of the epileptic focus and the impaired cognitive tasks. ESES represents a model of the long-lasting effects of continuous spike-wave activity on higher cortical functions. The duration of ESES and the localization of interictal foci seem to play a major role in influencing the degree and type of cognitive dysfunction, suggesting that the ESES clinical picture results from a localized disruption of EEG activity caused by focal epileptic activity during sleep. Recently, Giulio Tononi's group reported that a local increase of slow-wave activity (SWA) during sleep after learning is associated with improved performance of the learned task after sleep (Huber et al., Nature 2004;430:78-81). On the basis of these findings, we can speculate that prolonged focal epileptic activity during sleep (as occurring in ESES) interferes with local SWA at the site of the epileptic focus, impairing the neural processes and, possibly, the local plastic changes associated with learning and other cognitive functions.

Brain↗
PubMed2006

Video-EEG analysis of ictal repetitive grasping in "frontal-hyperkinetic" seizures.

The aim of this study was to obtain a qualitative and quantitative description of the phenomenon of forced prehension during epileptic seizures (ictal grasping- IG) with hyperkinetic semiology. We analysed retrospectively the presurgical, video-EEG recordings of 35 "frontal hyperkinetic" seizures (FHS) in 14 patients (age range: 9-48 years) evaluating the features of ictal grasping by means of off-line, frame-by-frame video-analysis. Ictal grasping was observed in 97.1% of the frontal hyperkinetic seizures in 100% of the patients, with a mean latency of 3.2 seconds with respect to seizure-onset; a mean number of 7.7 IG per seizure were detected. During the same FHS, both arms could perform IG in an alternating fashion. Grasping was usually preceded by a reaching movement and followed by holding or pulling. The sites of prehension were restricted to relatively few sectors, either on the patient's body (45.5%) or the peri-personal space (54.5%). In some cases, the grasping was elicited by hand touching. We did not find a consistent relationship between side of hand grasping and side of ictal EEG discharge or MRI lesion. In conclusion, ictal grasping is an extremely frequent clinical manifestation during FHS. It was an early, forced and repetitive motor behavior, without a clear lateralizing value. Ictal grasping appeared with consistent semiological features, similar to voluntary prehension, suggesting a probable ictal release of physiological grasping behavior. [Published with video sequences].

Adolescent↗
PubMed2005

Negative myoclonus induced by cortical electrical stimulation in epileptic patients.

Negative myoclonus (NM) is a motor disorder characterized by a sudden and abrupt interruption of muscular activity. The EMG correlate of NM is a brief (<500 ms) silent period (SP) not preceded by any enhancement of EMG activity (i.e. myoclonus). This study investigated the role of premotor cortex (PMC), primary motor cortex (MI), primary somatosensory area (SI) and supplementary motor area (SMA) in the pathophysiology of cortical NM by means of intracerebral low frequency (1 Hz) electrical stimulation. In three drug-resistant epileptic patients undergoing presurgical evaluation, we delivered single electric pulses (stimulus duration: 3 ms; stimulus intensity ranging from 0.4 to 3 mA) to PMC (2 patients), MI (1 patient), SI and SMA through stereo-EEG electrodes; surface EMG was collected from both deltoids. The results showed that (i) the stimulation of PMC or MI could evoke a motor evoked potential (MEP) either at rest or during contraction, in this latter case followed by an SP; however, in two patients, at the lowest stimulus intensities (0.4 mA), 50% of stimuli could induce a pure SP, i.e. not preceded by an MEP; raising the intensity of stimulation (0.6 mA), the SPs showed an antecedent MEP in >80% of stimuli; (ii) the stimulation of SI at low stimulus intensities (from 0.4 to 0.8 mA) induced in two patients only SPs, never associated with an antecedent MEP, whereas in the third subject the SPs could be inconstantly preceded by an MEP; by incrementing the stimulus intensity (up to 3 mA), in all three patients the SPs tended to be preceded, although not constantly, by an MEP; stimulus intensity affected SP duration (i.e. the higher the intensity, the longer the SP), without influencing the latency of onset of the SPs; (iii) the stimulation of SMA induced only pure SPs, at all stimulus intensities up to 3 mA; as for SI, increment of stimulus intensity was paralleled by an increase in SP duration, without influencing the onset latency of SPs. We conclude that single electric pulse stimulation of PMC, MI, SI and SMA through stereo-EEG electrodes can induce pure SPs, not preceded by an MEP, which clinically appear as NM, suggesting therefore that these cortical areas may be involved in the genesis of this motor phenomenon. However, it must be pointed out that SMA stimulation induced only pure SPs, regardless of the stimulus intensity, whereas occurrence of pure SPs following stimulation of PMC, MI, and SI depended mainly on the intensity of stimulation.

Adolescent↗
PubMed2005

Epilepsy with myoclonic absences.

Epilepsy with myoclonic absences is characterized clinically by absences accompanied by marked, diffuse, rhythmical myoclonias, often associated with a progressive tonic contraction. The ictal EEG shows bilateral, synchronous and symmetrical spike and wave discharges repeated at 3 Hz (similar to that observed in typical absences of childhood absence epilepsy) in strict relation with myoclonias recorded on EMG. These seizures occur many times a day. Associated seizures are present in 2/3 of the cases, the most frequent association being GTCS in 45%. The age at onset is about 7 years. There is a male preponderance. The evolution is variable and seems to depend on the existence or not of GTCS. Classical cotherapy with valproate and ethosuximide with appropriate plasma levels is more efficient if myoclonic absences are non-associated with GTCS. In cases where GTCS are associated, there is often an unfavourable outcome, with persistence of myoclonic absences or with modification of the epilepsy with a possible evolution towards a generalized cryptogenic or symptomatic form.

Anticonvulsants↗
PubMed2005

Biting behavior, aggression, and seizures.

PURPOSE: To describe the semiologic features of aggressive behaviors observed in human epileptic seizures with particular reference to the act of biting a conspecific. METHODS: We analyzed the biting behavior (BB) and other aggressive gestures occurring in a group of 11 patients retrospectively selected from >1,000 patients subjected to video-EEG/SEEG monitoring for presurgical evaluation of drug-resistant seizures. RESULTS: Patients displaying BB showed (a) a male sex predominance, (b) heterogeneous etiologies and lesion locations, and (c) seizures involving the frontotemporal regions of both hemispheres. The act of biting was a rapid motor action, lasting approximately 600 ms, occurring in the context of strong emotional arousal, fear, and anger, with various bodily gestures with aggressive connotation. BB was mainly a "reflexive" behavior, in that biting acts were evoked (both during and after seizures) by actions of people in close contact with the patient. The sole intrusion of the examiner's hand in the space near the patient's face was effective in triggering BB. Rarely, self-directed or object-directed biting acts were not triggered by external stimuli. Intracranial data (SEEG) obtained in one subject showed that the amygdala/hippocampal region plus the orbitomedial prefrontal cortex had to be involved by ictal activity to observe BB. CONCLUSIONS: Anatomic and electrophysiologic data in our patients suggest that a model of dual--temporal and frontal--dysfunction could account for the occurrence of ictal/postictal BB. Behavioral data suggest also that BB and related aggressive gestures can be considered as the emergence of instinctive behaviors with an adaptative significance of defense of the peripersonal space.

Adult↗
PubMed2004

Impaired fear processing in right mesial temporal sclerosis: a fMRI study.

Lesion and neuroimaging studies have demonstrated that the mesial temporal lobe is crucial for recognizing emotions from facial expressions. In humans, bilateral amygdala damage is followed by impaired recognition of facial expressions of fear. To evaluate the influence of unilateral mesial temporal lobe damage we examined recognition of facial expressions and functional magnetic resonance (fMRI) brain activation associated with incidental processing of fearful faces in thirteen mesial temporal lobe epilepsy (MTLE) patients (eight with right MTLE, five with left MTLE). We also examined the effect of early versus later damage, comparing subjects with hippocampal-amygdalar sclerosis (MTS) and seizures occurring before five years of age to epilepsy patients with late onset seizures. Fourteen healthy volunteers participated as controls. Neuropsychological testing demonstrated that the ability of right MTLE patients to recognize fearful facial expressions is impaired. Patients with early onset of seizures were the most severely impaired. This deficit was associated with defective activation of a neural network involved in the processing of fearful expressions, which in controls and left MTLE included the left inferior frontal cortex and several occipito-temporal structures of both hemispheres.

Adult↗
PubMed2004

Telephone-induced seizures: a new type of reflex epilepsy.

PURPOSE: To report a new form of reflex epilepsy in which the seizures are repeatedly and exclusively triggered by answering the telephone. METHODS: Three patients with a history of telephone-induced seizures were studied in detail by means of clinical, EEG, and neuroradiologic investigations. Intensive video-EEG monitoring to record the reflex seizures also was performed in all cases. RESULTS: The patients (two men, one woman, aged 21 to 30 years) had the onset during early adulthood of complex partial and secondarily generalized seizures exclusively triggered by answering the telephone. The seizures were stereotyped, with subjective auditory or vertiginous auras and inability to speak or understand the spoken voices. In one patient, a telephone-induced seizure arising from the dominant temporal lobe was recorded by means of video-EEG technique. In the interictal EEGs, temporal abnormalities were detected in all cases. The patients had a normal neurologic examination and normal magnetic resonance imaging or computed tomography scans. CONCLUSIONS: We suggest that telephone epilepsy is a previously unrecognized form of reflex epilepsy induced by a complex auditory stimulus involving the lateral temporal areas.

Adult↗
PubMed2003

The expression of interictal, preictal, and postictal facial-wiping behavior in temporal lobe epilepsy: a neuro-ethological analysis and interpretation.

By videotape recordings analysis we investigated the frequencies of interictal, preictal, and postictal wiping or rubbing movements targeting the face region (face wiping, FW) in 17 right and 13 left mesial temporal lobe epilepsy (MTLE) patients. Patients' data were compared with FW frequencies obtained in 22 healthy controls listening to a presentation. Results showed that: (1) FW movements were present in both controls and patients; however, the patient groups showed lower interictal and preictal FW rates relative than controls; (2) right and left temporal lobe seizures were followed by a marked increase in the expression of wiping activities directed to the nose as well as to other face regions with respect to the interictal-preictal period; (3) during the first 5min postictal FW was performed preferentially with the hand ipsilateral to the seizure focus; (4) postictal examination of the patient by an observer, especially if of the opposite sex, resulted in a higher incidence of FW acts. After temporal lobe seizures there is an exaggerated expression of movements targeting the face region, and not exclusively directed to the nose. According to an ethological interpretation of the FW behavior as a motor behavior present throughout the phylogenetic scale, from rodents to primates, we suggest the postictal emergence of an innate action pattern modulated by external emotional-cognitive stimuli.

Adolescent↗
PubMed2003

Transcranial magnetic stimulation and epilepsy.

Epileptic conditions are characterized by an altered balance between excitatory and inhibitory influences at the cortical level. Transcranial magnetic stimulation (TMS) provides a noninvasive evaluation of separate excitatory and inhibitory functions of the cerebral cortex. In addition, repetitive TMS (rTMS) can modulate the excitability of cortical networks. We review the different ways that TMS has been used to investigate pathophysiological mechanisms and effects of antiepileptic drugs in patients with epilepsy and epileptic myoclonus. The safety of different TMS techniques is discussed too. Finally, we discuss the therapeutic prospects of rTMS in this field.

Anticonvulsants↗
PubMed2003

Autosomal dominant lateral temporal epilepsy: clinical spectrum, new epitempin mutations, and genetic heterogeneity in seven European families.

PURPOSE: [corrected] To describe the clinical and genetic findings of seven additional pedigrees with autosomal dominant lateral temporal epilepsy (ADLTE). METHODS: A personal and family history was obtained from each affected and unaffected member, along with a physical and neurologic examination. Routine and sleep EEGs, computed tomography (CT), or magnetic resonance imaging (MRI) were performed in almost all the patients. DNAs from family members were typed with several microsatellite markers localized on either side of LGI1 at 10q24 and screened for LGI1 mutations. RESULTS: The seven families included a total of 34 affected individuals (10 deceased). The age at onset ranged between 8 and 50 years (average, 22 years). Twenty-six patients had clear-cut focal (elementary, complex, or secondarily generalized) seizures, characterized by prominent auditory auras in 68% of the cases. Less frequent ictal symptoms were visual, psychic, or aphasic seizures, the latter occurring in isolation in one family. The attacks were rare and well controlled by antiepileptic drug treatment but recurred after drug discontinuation. Interictal EEGs were usually unrevealing. MRI or CT scans were negative. Analysis of LGI1/Epitempin exons failed to show mutations in three pedigrees. Linkage analysis strongly suggested exclusion of linkage in one of these families. We found two novel missense mutations, a T-->C substitution in exon 6 at position 598, and a T-->A transition in exon 8 at position 1295, the latter being detected in a family with aphasic seizures. CONCLUSIONS: Our data confirm the inclusion of aphasic seizures within the ADLTE clinical spectrum, suggest the existence of locus heterogeneity in ADLTE, and provide new familial cases with LGI1 missense mutations associated with the disease.

Adolescent↗
PubMed2002

Ictal pattern of EEG and muscular activation in symptomatic infantile spasms: a videopolygraphic and computer analysis.

PURPOSE: To investigate ictal muscular phenomena characterizing symptomatic infantile spasms (ISs) and their relation to ictal EEG. METHODS: Four children with severe encephalopathy, neurologic impairment, and refractory ISs related to different dysplastic lesions, underwent videopolygraphic recordings collecting surface electromyogram (EMG) activity from several cranial and limb muscles to evaluate the pattern of muscular recruitment, duration, and side-to-side asymmetry of ISs. Acquired data were stored for off-line analysis by a computerized polygraphic system. RESULTS: Spasms were characterized by a complex pattern of muscular activation. A constant or rostrocaudal propagation pattern was lacking in all patients. Intervals between the onset of EMG activity in different muscles in each spasm were very long: </=100-200 ms. Two patients, with hemispheric cortical dysplasia and agenesis of the corpus callosum, had asymmetric and asynchronous spasms in which the EMG onset of the muscles contralateral to the affected hemisphere constantly anticipated that of the ipsilateral ones. Backaveraging of EEG activity disclosed a high-amplitude EEG complex on the same side as the dysplastic lesion, preceding or succeeding the contralateral muscle activity onset. In the other two patients with diffuse cortical dysplasia, no EEG transient was related to EMG activity onset. CONCLUSIONS: Despite clinical similarity between spasms in the same patient, our data demonstrate the complexity and heterogeneity of these motor phenomena. Our findings cannot be explained simply in terms of cortical or reticular generators like other motor phenomena such as cortical myoclonus or startle reflex.

Brain Damage, Chronic↗