PubMed Health⌕ Search

Biomedical subjects

F Pierelli

Publications and source records attributed to F Pierelli.

At least 37 records · Page 2Linked to original sources
PubMed2002

L-Dopa decreases cutaneous nociceptive inhibition of motor activity in Parkinson's disease.

OBJECTIVES: To estimate changes in motor inhibitory mechanisms at the spinal level in Parkinson's disease (PD) patients by measuring cutaneous silent responses to nociceptive stimuli in the course of L-Dopa therapy. MATERIALS AND METHODS: Fourteen patients with idiopathic PD (Group 1) and 13 patients with other forms of parkinsonism (Group 2) participated in the study. The cutaneous silent period (CSP) from the hand and clinical scores (UPDRS, part III) were measured "off" therapy (T0), after a single dose of L-Dopa (T1) and 3 months after the beginning of L-Dopa daily therapy (T2). RESULTS: At T0 the duration of the CSP was significantly prolonged in Group 1 and Group 2. At T1 and T2 the mean duration of the CSP significantly decreased in Group 1 (P < 0.05) and a significant correlation was found between the shortening of the CSP and the improvement of rigidity and bradikynesia in the upper limb. CONCLUSIONS: Our findings show that L-Dopa decreases the cutaneous nociceptive inhibition of motor activity in PD patients. CSP may be useful to assess L-Dopa responsiveness during the clinical course of PD.

Administration, Oral↗
PubMed2001

Mitochondrial myopathy, parkinsonism, and multiple mtDNA deletions in a Sephardic Jewish family.

The authors describe a family of Sephardic Jews with progressive external ophthalmoparesis, skeletal muscle weakness, and parkinsonism. Autosomal recessive inheritance was suggested by many consanguineous marriages, although a dominant disorder could not be excluded. No linkage to known progressive external ophthalmoparesis locus was found. The presence of cytochrome c oxidase-negative ragged-red fibers, biochemically reduced respiratory chain complexes, and multiple mitochondrial DNA deletions in muscle biopsies from four patients suggested a new mitochondrial disorder of intergenomic communication.

Adult↗
PubMed2001

Presymptomatic tests in Huntington's disease and dominant ataxias.

Huntington's disease (HD) and dominant ataxias (SCA) represent neurodegenerative hereditary diseases dominantly transmitted for which a direct and accurate genetic test is now available for molecular confirmation and presymptomatic test. Predictive testing programs, according to published international guidelines, are available worldwide. A large number of subjects (n=165) required a predictive HD diagnosis, although only 36% completed the program flow-chart and received the final genetic result (26 had a positive, 34 negative result for mutation). In 4 cases, an allele of intermediate range (33-34 CAGs) was found. Two of these shared the intermediate allele with an expanded repeat. In this case, we estimated the patient's risk to have affected children over the usually reported 50%. In 4 cases, the presymptomatic diagnosis was requested by persons at-risk for SCA1 and SCA3/Machado-Joseph disease. There were no adverse events to results of both HD and SCA presymptomatic diagnoses.

Age of Onset↗
PubMed2001

Morphological and functional retinal impairment in Alzheimer's disease patients.

OBJECTIVE: Our study aims to assess the optic nerve fiber layer thickness in vivo, the function of the innermost retinal layer and whether a correlation exists between morphological and functional parameters in patients affected by Alzheimer's Disease (AD). METHODS: Seventeen AD patients (mean age 70.37+/-6.1 years, best corrected visual acuity >8/10 with refractive error between +/-3 sf, intra-ocular pressure (IOP)<18 mmHg) were enrolled. They were compared to 14 age-matched controls. Nerve fiber layer (NFL) thickness was measured by optical coherence tomography (OCT). Three different measurements in each quadrant (superior, inferior, nasal, and temporal) were taken and averaged. The data in all quadrants (12 values averaged) were identified as NFL Overall. Retinal function was assessed by pattern electroretinogram (PERG) recordings using high-contrast (80%) checkerboard stimuli subtending 15 min of the visual arc and reversed at the rate of two reversals/s. RESULTS: In AD eyes, there was a significant (P<0.01) reduction in NFL thickness in each quadrant and in the NFL Overall evaluation compared with the values observed in control eyes. PERGs showed a significant (P<0.01) delay in N35, P50 and N95 implicit times, and reduction in N35-P50 and P50-N95 amplitudes. NFL Overall values were significantly correlated (P<0.01) to the PERG P50 and N95 implicit times and P50-N95 amplitude. No correlations (P>0.01) between NFL values and other PERG parameters (N35 implicit time, N35-P50 amplitude) were found. CONCLUSIONS: Our results suggest that in AD patients, there is a reduction of NFL thickness evaluated in vivo by OCT and this morphological abnormality is related to a retinal dysfunction as revealed by abnormal PERG responses.

Aged↗
PubMed2001

Cutaneous afferents mediating the cutaneous silent period in the upper limbs: evidences for a role of low-threshold sensory fibres.

OBJECTIVES: To evaluate the contribution of the low-threshold afferents to the production of the cutaneous silent period (CSP) in the upper limbs. METHODS: The CSP was studied in 10 healthy adults and 4 patients with Friedreich's ataxia. The following neurophysiological aspects were studied: (a) relationship between sensory threshold (ST), sensory action potential (SAP) amplitude and CSP parameters; (b) habituation and recovery cycle of the CSP at different stimulus intensities (2xST and 8xST); (c) pattern of responses in distal and proximal muscles at different stimulus intensities (2xST and 8xST). RESULTS: (a) The CSP occurred at low intensities (1xST and 2xST) and increased abruptly between 3.5xST and 4xST (corresponding to the pain threshold). The SAP amplitude was saturated before CSP saturation. In the patients with Friedreich's ataxia, the CSP appeared only at higher stimulus intensities (6xST-8xST). (b) The CSP evoked at 2xST showed a fast habituation and slow recovery cycle whereas the opposite behaviour was found at 8xST. (c) Low-threshold stimuli induced an inhibitory response restricted to the distal muscles. High-intensity stimulation produced an electromyographic suppression, significantly increasing from proximal to distal muscles. CONCLUSIONS: Our findings support the notion that low-threshold afferents participate in the production of the CSP in the upper limbs. The different afferents may activate different central neural networks with separate functional significance.

Action Potentials↗
PubMed2000

Preprogramming and control activity of bimanual self-paced motor task in Parkinson's disease.

OBJECTIVE: The authors investigated programming (Bereitschaftspotential or BP) and control activity (Skilled Performance Positivity or SPP) of a bimanual, sequential, skilled motor act in off-therapy Parkinson's disease (PD) patients. METHODS: We recorded Movement Related Potentials (MRPs) in 12, non-demented, off-therapy parkinsonian patients and in 17 control subjects who were performing a skilled, time-locked motor act, which was not routine in their everyday life but had to be learned: the Skilled Performance Task (SPT). BP, SPP and correct performances were evaluated in grand average waveforms and in sequential blocks. RESULTS: The analysis of correct performances showed that accuracy in PD patients was significantly lower than in the control group and this accuracy did not improve throughout the blocks. A significantly low level of performances was associated with an increased BP amplitude (P<0.05) and decreased SPP amplitude (P<0.05) in PD patients. CONCLUSION: Our findings suggest that skill motor learning is impaired in non-demented unmedicated PD patients. We discuss the view that PD patients may allocate more attentional resources, as suggested by the increased BP amplitude, the decreased SPP amplitude and the low correct performances, in order to perform a new skilled motor act.

Aged↗
PubMed2000

Visual electrophysiological responses in subjects with cerebral autosomal arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL).

OBJECTIVES: To evaluate visual electrophysiological responses in subjects with cerebral autosomal arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). METHODS: Three subjects (one male and two females, mean age 55.3+/-2.9 years) belonging to an Italian family already diagnosed with CADASIL through clinicopathological and genetic studies and 14 control subjects (6 males and 8 females, mean age 52.7+/-3.6 years) were enrolled in the study. Flash electroretinogram (ERG), oscillatory potentials (OPs) and simultaneous recordings of pattern electroretinogram (PERG) and visual evoked potentials (VEPs) were assessed in all 3 subjects with CADASIL and age-matched controls. RESULTS: Subjects with CADASIL showed: reduced ERG, OP and PERG (N35-P50, P50-N95) amplitudes with respect to our normal limits; delayed PERG (N35, P50) and VEP (P100) implicit times when compared with our normal limits; and VEP (N75-P100) amplitudes and retinocortical times within our normal limits. CONCLUSIONS: Subjects with CADASIL present a dysfunction in the outer, middle and innermost retinal layers when the index of neural conduction in the postretinal visual pathways is normal. The delay in visual cortical responses observed in subjects with CADASIL may be ascribable to retinal impairment with a possible functional sparing of the postretinal visual structures.

Dementia, Multi-Infarct↗
PubMed2000

A simple method for estimating conduction velocity of the spinothalamic tract in healthy humans.

OBJECTIVES: The object of this study was to establish a method for estimating the conduction velocity (CV) of the spinothalamic tract (STT) in relation to clinical application. METHODS: The CV of the STT was estimated by an indirect method based on that reported by Kakigi and Shibasaki in 1991 (Kakigi R, Shibasaki H. Electroenceph clin Neurophysiol 80 (1991) 39). Laser-evoked potentials (LEP) were measured in 8 subjects following hand (LEPH) and foot (LEPF) laser stimulation. The conduction times recorded at the scalp (P340, P400 and N150 potentials) were considered as the summation of peripheral and central components. The peripheral conduction times were calculated by measuring the latency of the electrical cutaneous silent period (from the same stimulus site of LEPs), corrected for F- and M-wave latency values. RESULTS: The CV of the STT ranged between 8.3 and 11.01 m/s and its mean value was found to be approximately 9.87+/-1.24 m/s. The CV of the STT obtained by the N150 latencies overlapped that obtained by the P340/P400 latencies. CONCLUSIONS: Our data suggest that our method appears appropriate and useful for practical clinical purposes, furnishing an additional tool for investigating the physiological function of small-fiber pathways.

Brain↗
PubMed2000

Multiple mtDNA deletions: clinical and molecular correlations.

We studied six Italian patients harbouring multiple mitochondrial DNA (mtDNA) deletions in order to correlate clinical and molecular features. Earlier age at onset (17 vs 36 years), fewer ragged-red fibres (none vs 35%), and lower proportions of deleted mtDNAs (9 vs 33%) were found in one patient with autosomal recessive inheritance as compared to five with dominant transmission. Our findings add to the features associated with multiple deletions of mtDNA.

Adult↗
PubMed2000

Afterdischarge activity in neuropathic patients with frequent muscle cramps.

OBJECTIVES: To evaluate the presence of the afterdischarge activity following M- and F-waves in patients with peripheral neuropathies with or without muscle cramps. MATERIAL AND METHODS: Ten patients with peripheral neuropathies complaining of frequent muscle leg cramps (Group 1) and 14 patients with peripheral neuropathies without muscle cramps (Group 2) participated in our study. The afterdischarge was evaluated through a repetitive stimulation of the peroneal and tibial nerves. RESULTS: An abnormal afterdischarge activity following F-wave was identified below 5 Hz only in Group 1. On high frequency of stimulation (> 5 Hz), this activity was present in every patient in Group 1. Moreover, it was particularly present in the muscle affected by cramps. CONCLUSION: Since the afterdischarges following F-waves have been considered to be the result of a hyperactive "bistable" state of alfa-motor neurons, our findings are indicative of an impairment of motor neuron excitability. Thus, it is hypothesizable that either peripheral and central mechanisms may together contribute in producing muscle cramps.

Aged↗
PubMed1999

Molecular and clinical examination of an Italian DEFECT11 family.

The DEFECT11 syndrome is a contiguous gene syndrome associated with deletions in the proximal part of chromosome 11p. In this study, we describe in an Italian family the co-existence of multiple exostoses (EXT) and enlarged parietal foramina (FPP), the two major symptoms of this syndrome, with abnormalities of the central nervous system. The latter may be a yet undescribed feature of DEFECT11 syndrome. FISH and molecular analysis allowed us to identify a small deletion on 11p11-p12, further refining the localisation of the FPP gene involved in the DEFECT11 syndrome.

Adult↗
PubMed1999

Transcranial Doppler evaluation of cerebral hemodynamics in migraineurs during prophylactic treatment with flunarizine.

Transcranial Doppler (TCD) recording was used to evaluate the mean flow velocity (MFV) and cerebrovascular reactivity to CO2 in 21 migraineurs during the interictal phase. Nine were affected by migraine with aura (MwA) and 12 by migraine without aura (MwoA). During each session the middle cerebral artery (MCA) flow velocity was examined in basal conditions, in hypocapnia after a 3-min period of hyperventilation, in basal conditions a second time, and in hypercapnia after breath-holding. The same procedure was followed in a group of 21 age- and sex-matched volunteers. Recordings were performed before (T1), during (T2), and after (T3) prophylactic treatment with flunarizine (10 mg/day for 2 months) to assess the possible effect of this drug on cerebral hemodynamics. In basal condition, increased MFV values were found in both MwA and MwoA patients. In MwA patients the reactivity index (RI) to hypocapnia was significantly increased in T1 (p < 0.05). This abnormal cerebrovascular reactivity disappeared during flunarizine treatment (T2) and in the post-therapy period (T3).

Adult↗
PubMed1999

Correlation between morphological and functional retinal impairment in multiple sclerosis patients.

PURPOSE: To assess whether a correlation exists between optic nerve fiber layer (NFL) thickness and the retinal or visual pathway function in multiple sclerosis (MS) patients previously affected by optic neuritis. METHODS: Fourteen patients with a diagnosis of definite MS were examined. All had been affected by optic neuritis (MSON) with complete recovery of visual acuity (14 eyes included in study). These were compared with 14 eyes from 14 age-matched control subjects. NFL thickness was measured by optical coherence tomography (OCT). Three different measurements in each quadrant (superior, inferior, nasal, and temporal) were taken and averaged. The data in all quadrants (12 values averaged) were identified as NFL Overall, whereas the data obtained in the temporal quadrant only (3 values averaged) were identified as NFL Temporal. Retinal and visual pathway function was assessed by simultaneously recording pattern electroretinograms (PERGs) and visual evoked potentials (VEPs) using high-contrast (80%) checkerboard stimuli subtending 15 minutes and 60 minutes of the visual arc (min arc) and reversed at the rate of two reversals per second. RESULTS: In MSON eyes there was a significant (P < 0.01) reduction in NFL thickness in both NFL Overall and NFL Temporal evaluations compared with the values observed in control eyes. PERG, (15-min arc checks) and VEP (15-min arc and 60-min arc checks), showed a significant (P < 0.01) delay in latency and reduction in amplitude. NFL Overall and NFL Temporal values were significantly correlated (P < 0.01) to the PERG P50 latency and P50 to N95 amplitude recorded with 15-min arc checks. No correlations (P > 0.01) between NFL values and the other electrophysiological data (PERG recorded with 60-min arc checks and VEP recorded with 15-min arc and 60-min arc checks) were found. CONCLUSIONS: There is a correlation between PERG changes and NFL thickness in MS patients previously affected by optic neuritis, but there is no correlation between VEP changes and NFL thickness.

Adult↗
PubMed1998

Impaired VEP after photostress response in multiple sclerosis patients previously affected by optic neuritis.

The aim of our work was to evaluate if an optic nerve involvement (multiple sclerosis patients previously affected by optic neuritis) may induce any change in visual evoked potential (VEP) after photostress response. VEP in basal conditions and after photostress were assessed in 10 patients with defined multiple sclerosis without a history of optic neuritis (MSWO); in 14 patients with defined multiple sclerosis previously affected by optic neuritis but with complete recovery of the visual acuity (MSON) and in 14 age-matched controls. In order to complete the investigation of the retinal function, Transient Pattern electroretinogram (PERG) and steady-state focal-ERG (counterphased gratings presented at 8 Hz in the macular region) were performed in MSON patients only. In MSWO eyes VEP parameters in basal condition and after photostress did not undergo significant changes compared to controls (ANOVA; P > 0.05). In MSON eyes we observed basal VEP with delayed P100 peak latency and reduced N75-P100 amplitude when compared with the control ones (P < 0.01). In MSON eyes the parameters of VEP after photostress underwent large changes and longer recovery time (RT) than in control and MSWO eyes (P < 0.01). In addition; in MSON eyes we found increased transient PERG P50 latency (P < 0.01) and reduced P50-N95 amplitude (P < 0.01); Focal-ERG (that displays a major component at 16 Hz; 2nd harmonic:2P) with reduced 2P amplitudes and delayed 2P phases (P < 0.01). Our results indicate that patients previously affected by optic neuritis present an abnormal VEP after photostress response and this may be ascribed predominantly to an involvement of the inner retinal layers as indicated by the concomitant impairment of PERG and focal-ERG responses.

Adult↗
PubMed1998

Low dosage clozapine effects on L-dopa induced dyskinesias in parkinsonian patients.

OBJECTIVES: The aim of this study was to investigate the clinical efficacy of clozapine, an atypical neuroleptic, on L-dopa induced dyskinesias of Parkinson's disease. MATERIAL AND METHODS: In an open study, a group of 10 PD patients was treated with low dosage clozapine (mean 30 mg/day) for a 4-month period and L-dopa dyskinesias were evaluated in basal conditions and during clozapine treatment after the usual morning dose of clozapine. We utilized the AIMS for evaluation of dyskinesias and UPDRS for the assessment of motor performances. RESULTS: Clozapine produced a significant (P<0.05) reduction of dyskinesias 1 week after the therapy onset. This effect was more pronounced at the end of the 2nd week and remained stable through the following months. We did not observe significant variations of motor performances. CONCLUSION: A low dose of clozapine appears to be beneficial for patients with L-dopa induced dyskinesias that do not respond to other drugs and therapeutic measures.

Aged↗
PubMed1998

A case of myokymia-cramp syndrome successfully treated with gabapentin.

We report a case of "myokymia-cramp syndrome", a rare and benign disease consisting of muscular cramps in the upper and lower limbs associated with generalized myokymias. In our patient, cramps had been present since adolescence and had increased in frequency and duration during the last 3 years, occurring about 8 or 9 times a day. Cramps were mainly nocturnal and also precipitated by walking; a previous treatment with carbamazepine did not improve the symptoms. Gabapentin therapy proved to be very satisfactory in relieving muscular cramps with a relatively low dosage (600 mg/day) and without any remarkable side effects. The possible interpretation of the mechanism involved in gabapentin induced relief of cramps is discussed. Gabapentin should be considered as a safe alternative treatment for muscular cramps.

Acetates↗
PubMed1997

Episodic ataxia type 2 (EA2) and spinocerebellar ataxia type 6 (SCA6) due to CAG repeat expansion in the CACNA1A gene on chromosome 19p.

Point mutations of the CACNA1A gene coding for the alpha 1A voltage-dependent calcium channel subunit are responsible for familial hemiplegic migraine (FHM) and episodic ataxia type 2 (EA2). In addition, expansions of the CAG repeat motif at the 3' end of the gene, smaller than those responsible for dynamic mutation disorders, were found in patients with a progressive spinocerebellar ataxia, named SCA6. In the present work, the analysis of two new families with small CAG expansions of the CACNA1A gene is presented. In one family, with a clinical diagnosis of EA2, a CAG23 repeat allele segregated in patients showing different interictal symptoms, ranging from nystagmus only to severe progressive cerebellar ataxia. No additional mutations in coding and intron-exon junction sequences in disequilibrium with the CAG expansion were found. In the second family, initially classified as autosomal dominant cerebellar ataxia of unknown type, an inter-generational allele size change showed that a CAG20 allele was associated with an EA2 phenotype and a CAG25 allele with progressive cerebellar ataxia. These results show that EA2 and SCA6 are the same disorder with a high phenotypic variability, at least partly related to the number of repeats, and suggest that the small expansions may not be as stable as previously reported. A refinement of the coding and intron-exon junction sequences of the CACNA1A gene is also provided.

Adolescent↗