Task-specific dystonia in a horn player.
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Aged↗
Biomedical subjects
P Bergonzi
Publications and source records attributed to P Bergonzi.
Relationship between Delta, Sigma, Beta, and Gamma EEG bands at REM sleep onset and REM sleep end.
OBJECTIVE: The aim of the present study was to analyze in detail the relationship of two newly introduced measures, related to the Beta and Gamma EEG bands during REM sleep, with Delta and Sigma activity at REM sleep onset and REM sleep end, in order to understand their eventual role in the sleep modulation mechanism. METHODS: For this purpose, power spectra of 1 EEG channel (C4, referred to A1) were obtained by means of the fast Fourier transform and the power of the bands ranging 0.75-4.50 Hz (Delta), 4.75-7.75 (Theta), 8.00-12.25 (Alpha), 12.50-15.00 (Sigma), 15.25-24.75 (Beta), 25.00-34.75 (Gamma 1), and 35.00-44.75 (Gamma 2) was calculated for the whole period of analysis (7 h), in 10 healthy subjects. Additionally, two other time series were calculated: the ratio between Beta and Gamma2, and between Gamma1 and Gamma2 (Beta and Gamma ratios). For each subject, we extracted 3 epochs of 30 min corresponding to the 15 min preceding and the 15 min following the onset of the first 3 REM episodes. Data were then averaged in order to obtain group mean values and standard deviation. The same process was applied to the 30-min epochs around REM sleep end. RESULTS: The course of the Delta band around REM sleep onset was found to be characterized by a first phase of slow decline lasting from the beginning of our window up to a few seconds before REM onset; this phase was followed by a sudden, short decrease centered around REM onset, lasting for approximately 1.5-2 min. At the end of this phase, the Delta band reached its lowest values and remained stable up to the end of the time window. The Sigma band showed a similar course with stable values before and after REM sleep onset. The Beta and Gamma ratios also showed a 3-phase course; the first phase, in this case, was characterized by stable low values, from the beginning of our window up to approximately 5 min before REM onset. The following second phase was characterized by an increase which reached its maximum shortly after REM sleep onset (approximately 1 min). In the last phase, both Beta and Gamma ratios showed stable high values, up to the end of our time window. At REM sleep end, the Delta band only showed a very small gradual increase, the Sigma band presented a more evident gradual increase; on the contrary, both Beta and Gamma ratios showed a small gradual decrease. CONCLUSIONS: The results of the present study show a different time synchronization of the changes in the Delta band and in Beta and Gamma ratios, at around REM sleep onset, and seem to suggest that the oscillations of these parameters might be modulated by mechanisms more complex than a simple reciprocity. All these considerations point to the fact that REM sleep can be considered as a complex phenomenon and the analysis of high-frequency EEG bands and of our Beta and Gamma ratios represent an additional important element to include in the study of this sleep stage.
Adult↗
Sleep and sleep deprivation as EEG activating methods.
OBJECTIVES: We examined retrospectively 19 patients with a history of clinical seizures, but normal activity or unclear epileptiform abnormalities in wake EEG recordings and obtained preliminary data for a controlled cohort study to evaluate the effects of sleep deprivation (SD) on interictal epileptic activity. METHODS: Nineteen patients referred to our EEG department for diagnostic or follow-up purposes were divided in two groups on the basis of the different EEG protocols applied. The first group (n=5) underwent two laboratory polysomnographies during afternoon naps, after SD, but the patients failed to fall asleep in one of the two occasions. The second group (n=14) was submitted to two polysomnographies, the first without SD and the second after SD. RESULTS: The first group of patients demonstrated focal epileptic discharges in 4 patients in which wake after SD appeared to be less activated that sleep after SD. In the second group the results obtained from the waking part of the recordings suggest a lack of activating effect due to SD. CONCLUSIONS: SD does not seem to offer greater activation than sleep alone. However, a mild SD may be a convenient activating method for inducing sleep and drowsiness without using any drug.
Brain↗
Correlations between individual clinical manifestations and CTG repeat amplification in myotonic dystrophy.
Myotonic dystrophy (DM) is a multisystemic disease caused by the expansion of a CTG repeat, located in the 3'-untranslated region of the DMPK gene. The number of CTG repeats broadly correlates with the overall severity of the disease. However, correlations between CTG repeat number and presence/absence or severity of individual clinical manifestations in the same patients are yet scarce. In this study the number of CTG repeats detected in blood cells of 24 DM subjects was correlated with the severity of single clinical manifestations. The presence/absence of muscular atrophy, respiratory insufficiency, cardiac abnormalities, diabetes, cataract, sleep disorders, sterility or hypogonadism is not related to the number of CTG repeats. Muscular atrophy and respiratory insufficiency are present with the highest frequency, occurring in 96 and 92% of the cases, respectively. A significant correlation was found with age of onset (r = -0.57, p<0.01), muscular disability (r = 0.46, p<0.05), intellective quotient (r = -0.58, p<0.01) and short-term memory (r= -0.59, p<0.01). Therefore, the CTG repeat number has a predictive value only in the case of some clinical manifestations, this suggesting that pathogenetic mechanisms of DM may differ depending on the tissue.
Adolescent↗
Sclerosteosis: report of a case in a black African man.
Sclerosteosis is a rare genetic disorder of bone modelling, similar to, but distinct from, van Buchem disease; it has been described almost exclusively in Afrikaners of South Africa, a white population of Dutch ancestry. Isolated cases have been reported in a girl in Japan, a boy in Spain, and in multiracial families in Brazil and USA. Here we report a case of sclerosteosis in a black man born in Senegal. He presented with the full features of the disease: tall stature; syndactyly: nail dysplasia; massive sclerosis of the long tubular bones, the ribs, the pelvis and the skull; multiple cranial nerve involvement: optic atrophy, facial palsy and trigeminal neuralgia. Radiologic examination, visual and brainstem auditory evoked potentials, computerized tomography and magnetic resonance imaging of the skull were performed. This seems to be the first case of the disease in a black African individual, with no known relationship with Dutch ancestry.
Abnormalities, Multiple↗
Median nerve F-wave study derived by flexor carpi radialis.
F-responses are produced by the antidromic activation of a limited number of motoneurones and its study can be used as a diagnostic criteria in cervical radiculopathies. Usually ulnar nerve stimulation (hypothenar derivation) and median nerve stimulation (thenar derivation) is used, so providing information mainly about 8th cervical root and 1st thoracic root. The authors describe a method for studying F-wave by median nerve stimulation and flexor carpi radialis derivation to evaluate C6-C7 roots. F-waves were clearly individuated in 47 normal subjects (94 nerves) aged from 21 to 59. Latency range was 18.0-24.0 msec, mean 21.4 +/- 1.48 (2 SD). The results of the test applied on 6 paradigmatic cases of C6-C7 radiculopathy are reported.
Adult↗
Long-term administration of butoctamide hydrogen succinate on nocturnal sleep of mentally retarded subjects: a polygraphic study versus placebo.
Butoctamide hydrogen succinate (BAHS) has been proved to increase REM sleep in patients with reduced REM sleep. Following previous experiments on the effects of BAHS on nocturnal sleep of mentally retarded (MR) subjects, a polygraphic study was conducted on 20 MR subjects (age 8-14 years) to verify the effects of BAHS, 1) after long-term administration and 2) in different etiologies of MR. Subjects were divided into two balanced groups receiving placebo or 400 mg BAHS before sleep for a 6-month period. Basal sleep did not differ substantially in the two groups, both presenting reduced REM sleep. Low amounts of REM sleep were partially reversed by BAHS administration, which caused a significant increase in the REM sleep stage. Post-treatment sleep modifications found in the experimental group were not observed in the control group. BAHS produced its effects on REM sleep immediately after the first administration of the drug, but they became more apparent after long-term treatment. Our findings indicate that long-term administration of BAHS at low dosage maintains its effects on REM sleep of mentally retarded children, causing modifications similar to those previously obtained with single administration at higher dosages in cats, in healthy young and elderly volunteers and in Down's syndrome children. In addition, our observations demonstrate the effectiveness of BAHS on REM sleep, when utilized in mental retardation of etiologies other than Down's syndrome.
Adolescent↗
Clinical and neurophysiological aspects of epilepsy in subjects with autism and mental retardation.
Clinical and neurophysiological findings for 28 patients with mental retardation, autism, and epilepsy were described. Correct classification of seizure type and epileptic syndrome (when possible), etiology, severity of autism and epilepsy, EEG findings, and neuroimaging findings were given. No particular epileptic syndrome was found to be more frequently correlated to autism, severity of autism was not correlated with a more pronounced tendency to develop seizures, and females with autism were more frequently affected by seizures than were males. In conclusion, the risk for epilepsy does not seem to be correlated to autism itself, but the same noxious event induces autism and epilepsy. The severity of epilepsy is strictly correlated with its etiopathogenetic mechanisms.
Adolescent↗
BIT-mapped somatosensory evoked potentials in the fragile X syndrome.
Middle-latency somatosensory evoked potentials (MLSEPs) were recorded from 19 scalp electrodes in ten male patients with the fragile X (fraX) syndrome and nine normal controls. One fraX patient was found presenting the so-called "giant" MLSEPs with an amplitude of N60 of about 60 microV and of 40 microV after stimulation of the right and left median nerves, respectively. Tapping of the right hand, in the same patient, induced the appearance of left parietal evoked EEG spikes. These findings further support the already suggested similarity between the epileptic picture of several fraX patients with that of the benign childhood epilepsy with centrotemporal spikes. Color mapping of the MLSEPs recorded in the remaining nine patients, when compared with the control group, showed an abnormally large N30 over the frontal regions, together with an increase in amplitude of P27, over the parietal areas, and of N60 and P100 which also presented abnormal field distributions, being represented preferentially over the frontal regions. These data could suggest the existence of a cortical dysfunction mostly involving the frontal lobes (supplementary motor area, in particular) in the fraX syndrome which could support many behavioral changes usually observed in these patients.
Adolescent↗
Bit-mapped somatosensory evoked potentials in Down's syndrome individuals.
Middle-latency somatosensory evoked potentials (MLSEPs) were recorded from 19 scalp electrodes in 19 patients with Down's syndrome (DS), in 13 age-matched normal controls and in 11 aged normal individuals. DS patients showed an increase in amplitude of P22, N30, P45, and N60. P100 latency was significantly shortened. After this potential, DS subjects showed the occurrence of a high voltage negative potential at around 100-110 msec followed by another high-voltage positive deflection; both these components showed a frontal-central distribution and were not observed in the two control groups. MLSEPs of DS subjects show peculiar alterations which could be supported by particular neurometabolic and/or neuropathologic changes.
Adolescent↗
Giant somatosensory evoked potentials and pathophysiology of hyperekplexia. Neurophysiological study of one patient.
EEG during wakefulness and sleep and somatosensory evoked potentials from the median nerve were recorded in a 3 year-old boy with hyperekplexia and his close relatives (parents and two sisters). Centro-temporal spikes during sleep were found in the patient and in the older sister, while somatosensory evoked potentials, in the patient, showed abnormally high amplitude over the centroparietal regions. Pathophysiological mechanisms of hyperekplexia are discussed and the existence of symptomatic forms is suggested.
Child↗
Brainstem auditory evoked potentials in tuberous sclerosis.
Brainstem auditory evoked potentials were recorded in 4 subjects and pattern reversal evoked potentials in 1 subject, all with tuberous sclerosis. Alterations were found (absence or delay of components and prolonged interpeak intervals) which may suggest impaired nervous conduction also at brainstem level in patients with tuberous sclerosis.
Adolescent↗
Tuberous sclerosis and Down syndrome: a casual association?
This paper reports on the clinical, neurophysiological and neuroradiological characteristics of a patient with Down syndrome unusually associated with tuberous sclerosis. In particular, epilepsy is investigated in detail and its polygraphic study and etiopathological factors are discussed. The most interesting findings are those related to the presence of a structural abnormality of the rolandic-parietal cortex, bilaterally, in the form of pachygyria.
Adult↗
Unsuspected, surreptitious drug-induced parkinsonism.
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Adult↗
Modulation of the interictal epileptiform EEG activity during sleep: from oscillations to complex dynamics.
Polygraphic sleep recordings (EEG, EMG, and EOG) were performed in two groups of epileptic subjects, six with fragile-X syndrome and six with symptomatic epilepsy. Recordings were visually scored for sleep stages and number of spikes/min. Subjects with fragile-X syndrome showed a well defined pattern of production of interictal epileptiform activity with the lowest values during REM sleep; symptomatic epileptic subjects showed less defined and more variable spike/min diagrams. The spectral analysis of the outline of such diagrams confirmed these differences showing shorter periodicities (80-100 min) in the fragile-X group compared to those of the symptomatic group (160-220 min). Finally, a model with multiple feedback circuits is proposed in order to explain the different patterns observed.
Activity Cycles↗
Seizures in patients with trisomy 21.
We report on the incidence of seizures in 113 patients with Down Syndrome (DS), 43 coming from the OASI Institute for Research on Mental Retardation and Brain Aging, Troina, and 70 from the outpatient clinic of the Department of Pediatrics, University of Catania. We obtained the following results: 15 (13.2%) patients had seizures; 6 (5.3%) febrile seizures (FS) and 9 (7.9%) afebrile seizures (aFS). Among the latter group 2 patients had generalized tonic-clonic seizures, 3 partial complex seizures, and 4 infantile spasms. The seizures appeared early in life. Only 2 adult patients had seizures. These results suggest that patients with DS show a higher incidence of FS and of aFS than non-DS individuals. Seizures in DS may be an epiphenomenon of the neurological abnormalities, both anatomical and functional, usually observed in these patients.
Adult↗
The specificity of the characteristic sleep EEG pattern in the fragile-X syndrome.
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Electroencephalography↗
A simple electronic and computer system for automatic spindle detection.
The authors present a new system for the automatic detection of sleep spindles. The electronic and computer analysis are described and a comparison between automatic and visual analysis, performed by two independent readers, was carried out with the aim of evaluating the reliability of the system. Results are discussed and compared with those of different systems already described.
Electroencephalography↗