Olimpia Difruscolo

Università degli Studi di Bari Aldo Moro, Bari, Apulia, Italy

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Publications (20)45.3 Total impact

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    ABSTRACT: The aim of the present study was to evaluate pain perception and evoked responses by laser stimuli (LEPs) in mild not demented Huntington's Disease (HD) patients. Twenty-eight HD patients and 30 control subjects were selected. LEPs were obtained by four scalp electrodes, (Fz, Cz, referred to the nasion; T3, T4, referred to Fz), stimulating the dorsum of both hands. All patients were also evaluated by somatosensory evoked potentials (SEPs) by median nerve stimulation. Only 3 patients referred pain of arthralgic type. Laser pain perception was similar between HD patients and controls. An abnormal N2, P2 and N1 latency increase was evident in the majority of HD patients. LEPs features were similar between patients taking and not taking neuroleptics. The N2 and P2 latencies, showed a negative correlation with functional score and Mini Mental State Examination, and a positive correlation with the severity of hyperkinetic movements. A delay in nociceptive input processing emerged in HD, concurring with the main features of the disease, in absence of clinical evidence of abnormalities in pain perception. The dysfunction of pain signals transmission in HD may induce sub-clinical changes of sensory functions, which may probably interfere with sensory-motor integration and contribute to functional impairment.
    Acta neurologica Belgica 03/2011; 111(1):33-40. · 0.47 Impact Factor
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    ABSTRACT: The pathophysiological mechanism of the pain in ALS is still unclear. The aim of the study was to evaluate the laser evoked potentials (LEPs) in ALS patients in relation to their clinical features. Twenty-four ALS patients were selected. Pain features were assessed and their intensity was measured by a 0-10 VAS. LEPs were recorded in all patients and in 23 healthy subjects. The dorsum of both hands was stimulated, at laser stimuli intensity of 7.5 W, with 10s inter-stimulus interval and 25 ms duration. Four electrodes were placed at Cz, T3, T4 and Fz positions, with the reference electrode at the nasion; T3 and T4 electrodes were referred off-line to Fz, in order to detect the N1 component. Latencies of N2, P2 and N1 waves were significantly higher in ALS than in controls. N1 amplitude was significantly increased in ALS patients compared to controls, with a similar trend for the N2-P2 complex. No correlation was found between LEP abnormalities, pain intensity and clinical features. A degeneration of subcortical structures may subtend a delay in the afferent input to the nociceptive cortex in ALS. On the other hand, an increase of pain processing at the cortical level may derive from a potential sensory compensation to motor cortex dysfunction.
    Journal of the neurological sciences 10/2009; 288(1-2):106-11. · 2.32 Impact Factor
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    ABSTRACT: The aim of this study was to evaluate the function of Adelta fibers at the hand level in patients with clinical symptoms of Carpal Tunnel Syndrome (CTS) using CO(2) laser evoked potentials (LEPs), in light of the intensity and distribution of sensory symptoms and pain. Thirty-four CTS outpatients (62 hands) were compared to 23 sex- and age-matched control subjects (46 hands). The periungueal skin of the first, second, third and fifth fingers, and the dorsum of the hands were stimulated in random order. The latency and amplitude of the N2, P2 and N1 components were evaluated with respect to the Nerve Conduction Study (NCS) data, clinical scales, pain intensity and glove-like symptoms distribution. The amplitude of the N2-P2 complex was significantly reduced in CTS hands compared to normal hands after stimulation of the second and third fingers, even in patients with mild nerve conduction impairment. No significant fifth finger LEP abnormalities were found in patients with glove-like distribution symptoms. The N2-P2 amplitude at the second and third fingers was positively correlated with the severity of sensory symptoms. The involvement of median nerve Adelta fibers in CTS seems to be an early phenomenon, which concurs with the impairment of large motor and sensory afferents and is linked to the severity of the disease. The finding of reduced sensory symptoms in patients with severe thin afferents damage, may suggest a slight expression of central sensitisation phenomena in the advanced stage of CTS syndrome.
    Clinical neurophysiology: official journal of the International Federation of Clinical Neurophysiology 02/2009; 120(2):353-9. · 3.12 Impact Factor
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    ABSTRACT: To evaluate whether migraine patients exhibit less inhibition to painful stimuli when distracted from pain as compared to healthy subjects, testing the spatial discrimination of painful stimuli, the performance during the mental arithmetic task used to contrast the discrimination performance and the behavior of N1 and N2-P2 laser-evoked potentials (LEPs) amplitudes during spatial discrimination and during distraction. Eight migraine patients and 8 healthy controls were examined. During repetitive series of painful laser stimulation of the hand, they had to (1) perform a spatial discrimination task, contrasted by (2) a mental arithmetic task that served as distraction. Patients made 50% to 100% more mistakes than controls in the spatial discrimination task (P < .001) as well as during mental arithmetic (P < .05). Whereas healthy subjects showed a marked decrease of the LEP vertex potential amplitudes during distraction compared to the discrimination task, no such attenuation of LEPs was seen in migraine patients (group x task interaction, P < .05). N1 amplitude exhibited a left-hemisphere dominance in both groups, significantly smaller amplitude in migraine patients, but no significant task modulation. Migraine patients exhibited reduced inhibition by attentional modulation of pain processing, accompanied by impaired spatial discrimination of painful stimuli.
    Headache The Journal of Head and Face Pain 04/2008; 48(3):408-16. · 2.94 Impact Factor
  • Clinical Neurophysiology - CLIN NEUROPHYSIOL. 01/2008; 119.
  • Clinical Neurophysiology - CLIN NEUROPHYSIOL. 01/2008; 119.
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    ABSTRACT: The present study aimed to evaluate heat pain thresholds and evoked potentials following CO(2) laser thermal stimulation (laser-evoked potentials, LEPs), during remote application of capsaicin, in migraine patients vs. non-migraine healthy controls. Twelve outpatients suffering from migraine without aura were compared with 10 healthy controls. The LEPs were recorded by 6 scalp electrodes, stimulating the dorsum of the right hand and the right supraorbital zone in basal condition, during the application of 3% capsaicin on the dorsum of the left hand and after capsaicin removal. In normal subjects, the laser pain and the N2-P2 vertex complex obtained by the hand and face stimulation were significantly reduced during remote capsaicin application, with respect to pre-and post-capsaicin conditions, while in migraine LEPs and laser pain were not significantly modified during remote painful stimulation. In migraine a defective brainstem inhibiting control may coexist with cognitive factors of focalised attention to facial pain, less sensitive to distraction by a second pain.
    The Journal of Headache and Pain 07/2007; 8(3):167-74. · 2.78 Impact Factor
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    ABSTRACT: The contingent negative variation (CNV) is a neurophysiological pattern related to planning of external - paced, voluntary movements. The aim of the study, was to examine the CNV in a cohort of mild demented and non-medicated HD patients, evaluating the CNV amplitude modifications in the light of clinical features and performing Low Resolution Brain Electromagnetic Tomography (LORETA) analysis in order to show the CNV multiple generators. Fourteen HD patients and 25 sex and age-matched controls were studied. All subjects were evaluated by the motor section of UHDRS, MMSE and WAIS. The CNV was recorded by 19 scalp electrodes, with a red light flash as visual warning stimulus (S1), followed by a blue light flash (S2) after a fixed interval of 3 s. The amplitude of early CNV was significantly reduced in HD, compared to controls: the amplitude reduction was significantly correlated with the bradikinesia score. LORETA analysis of early CNV significantly discriminated patients from controls, for a prevalent activation of the posterior part of anterior cingulate cortex in HD. An abnormal activation of the associative cortex devoted to the processing of attention preceding voluntary movement may be supposed in HD, probably mediated by the altered basal ganglia modulation.
    Journal of the Neurological Sciences 04/2007; 254(1-2):84-9. · 2.24 Impact Factor
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    ABSTRACT: The MTHFR C677T genotype has been associated with increased risk of migraine, particularly of migraine with aura (MA) in selected clinical samples and with elevated homocysteine. The hyper-homocysteinemia may favor the vascular and neuronal mechanism underlying migraine, and the risk of stroke. The first aim of the present study was to examine the Contingent Negative Variation (CNV) amplitude and habituation pattern in a migraine sample versus non-migraine subjects, at the light of the MTHFR genotype, according to an unrelated and clinical based case-control panel. The second aim was to compare the frequency of Magnetic Resonance Imaging (MRI) subclinical brain lesions across the different C677 genotypes in the same migraine sample, selected for the young age and the absence of any cardiovascular risk factor. One hundred and five 18-45 year old out-patients, 90 affected by migraine without aura (MO) and 15 by MA, and 97 non-migraine healthy subjects, age and sex matched, were selected for the genetic analysis. All subjects had a common ethnic origin from Puglia. Sixty-four migraine subjects and 33 control subjects were submitted to the recording of the CNV. All migraine subjects underwent the MRI evaluation. The frequency of homozygosis was 14.33% in normal subjects, versus 25.7% in MA + MO group (chi2-test: 10.80 P= .001). The frequency of homozygosis in MO patients, was 25.5% (MA versus N: chi2-test: 9 P= .003), in MA group it was 26.6%. Considering the MTHFR genotype in migraine patients and controls, the C677TT subjects exhibited a reduced habituation index of the early CNV (iCNV), in respect with both C677TC and C677CC; in the migraine group, there was a significant decrease of CNV habituation in patients with homozygosis and a positive correlation between the habituation index values and the homocysteine levels. Nineteen migraine patients exhibited subclinical brain lesions (18.05%): patients with C677T homozygosis did not exhibit a higher risk for MRI abnormalities. This unrelated and clinical based case-control study showed that genetically induced hyper-homocysteinemia may favor the neuronal factors predisposing to migraine, while it does not influence the presence of subclinical vascular brain lesions probably linked with increased risk of stroke.
    Headache The Journal of Head and Face Pain 03/2007; 47(2):253-65. · 2.94 Impact Factor
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    ABSTRACT: In a previous short-term study, rivastigmine has shown a mild effect in ameliorating cognitive impairment and slowing motor deterioration in patients affected by Huntington disease (HD). The aim of the present study was to assess the long-term efficacy of rivastigmine on motor and cognitive impairment in HD patients. This was an open-label, controlled study with blinded rates: 11 HD patients were evaluated after 2 years under 6 mg rivastigmine treatment versus 6 patients sorted as controls. In basal conditions and after 2 years' follow-up, patients were submitted to the Mini-Mental State Examination, Marsden and Quinn Chorea Severity Scale, Total Functional Capacity score, Abnormal Involuntary Movement Scale, and the motor and functional section of the Unified Huntington Disease Rating Scale. Patients treated with rivastigmine showed a significant improvement of global motor performances and chorea in comparison with the control group, with a trend toward a reduction of functional disability and cognitive impairment. On the basis of the long-term follow-up of HD patients, rivastigmine exerted a significant improvement of motor performances with a positive trend on cognitive and functional scales. The results of this study suggest long-term efficacy of rivastigmine in HD, which needs to be confirmed in larger series.
    Clinical Neuropharmacology 01/2007; 30(1):43-6. · 1.82 Impact Factor
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    ABSTRACT: The aim of this study was to perform a topographic and dipolar analysis of nociceptive-evoked responses obtained by laser stimulus under basal conditions in a cohort of chronic migraine (CM) patients, compared with migraine without aura (MWA) patients and noncraniofacial pain controls. An increased activation of cortical areas devoted to the emotional and attentive components of pain was previously found during the course of the migraine attack; it was more pronounced in patients reporting higher frequency of migraine. Twenty-six outpatients were enrolled in the study; 16 fulfilled the criteria of CM, and 10 were affected by MWA. Fifteen noncraniofacial pain subjects were also selected. The pain stimulus was a CO2 laser pulses. The right-supraorbital zone was stimulated. Source localization analysis was performed on the most prominent laser-evoked potentials (LEPs) peak (P2) for each data set. The anatomical locations of the P2 sources were projected onto a standard normalized 3D MRI model. The CM group differed significantly from both MWA patients and controls for the x coordinate and from controls for the z coordinates. The P2 dipole localized in the rostral cingulate cortex in CM patients, lying in a more posterior location within the anterior cingulate cortex (ACC) in both controls and MWA patients. The x coordinate of the P2 dipole, expressing the postero-anterior location, was significantly correlated with frequency of headache. CM seems to be characterized by a distinctive pattern of cortical elaboration of pain, with a prevalent activation of the rostral portion of the ACC: our results suggest that this may be a predisposing factor to migraine chronicity.
    Headache The Journal of Head and Face Pain 11/2005; 45(9):1208-18. · 2.94 Impact Factor
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    ABSTRACT: To evaluate the efficacy of rivastigmine on motor and cognitive impairment in Huntington's disease (HD), we carried out a prospective, open-label, randomized, controlled study. Twenty-one HD patients were enrolled: 14 were randomly sorted into medication and 7 to no-treatment groups. Clinical and demographic features were similar between groups. After 8 months, an efficacy evaluation was carried out to compare the two groups. The improvement of cholinergic transmission in HD patients seemed to have a slight effect in ameliorating cognitive performance and slowing motor deterioration.
    Movement Disorders 01/2005; 19(12):1516-8. · 4.56 Impact Factor
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    ABSTRACT: The aim of this study was to compare the properties of the nociceptive system in eight migraine without aura patients in the pain-free phase with 10 healthy controls, by evaluating the topography and the source of the CO2 laser-evoked potentials (LEPs) obtained by the right supraorbital skin, during and after capsaicin topical application. In healthy subjects the acute cutaneous pain induced by capsaicin reduced the amplitude of the vertex LEPs and induced a posterior shifting of the P2 wave dipolar source within the anterior cingulate cortex. These functional changes seemed significantly reduced in migraine patients, for a disturbed pattern of pain modulation at the cortical level, which may subtend the onset and persistence of migraine.
    Neuroscience Letters 01/2005; 384(1-2):150-5. · 2.03 Impact Factor
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    ABSTRACT: The aim was to study mismatch negativity features and habituation during the interictal phase of migraine. In migraine patients, a strong negative correlation has been found between the initial amplitude of long latency auditory-evoked potentials and their amplitude increase during subsequent averaging. We studied 12 outpatients with a diagnosis of migraine without aura recorded in a headache-free interval and 10 gender- and age-matched healthy volunteers not suffering from any recurrent headache. The experiment consisted of two sequential blocks of 2000 stimulations, during which 1800 (90%) recordings for standard tones and 200 (10%) for target tones were selected for averaging. The latency of the N1 component was significantly increased in migraine patients in respect of controls in both the first and second repetitions; the MMN latency was increased in the second repetition. In the control group the MMN amplitude decreased on average by 3.2 +/- 1.4 microV in the second trial, whereas in migraine patients it showed a slight increase of 0.21 +/- 0.11 microV in the second repetition. The MMN latency relieved in the second trial was significantly correlated with the duration of illness in the migraine patients (Spearman correlation coefficient: 0.69; P < 0.05). The increases in N1 latency and MMN latency and amplitude, the latter correlated with duration of illness, seemed to be due to a reduced anticipatory effect of stimulus repetition in migraine patients. This suggests that such hypo-activity of automatic cortical processes, subtending the discrimination of acoustic stimuli, may be a basic abnormality in migraine, developing in the course of the disease.
    Cephalalgia 09/2004; 24(8):663-8. · 3.49 Impact Factor
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    ABSTRACT: In migraineurs nitroglycerin (NTG) induces severe delayed headache, resembling spontaneous migraine attacks. The aim of the present study was to evaluate NTG laser evoked potentials (LEP) features amplitude and pain sensation to laser stimuli during NTG-induced headache. Nine patients were selected. Headache was induced by oral administration of 0.6 mg of NTG; signals were recorded through disk electrodes placed at the vertex and referred to linked earlobes. CO(2)-LEPs delivered by stimulation of the dorsum of both hands and the right and left supraorbital zones were evaluated after the onset of moderate or severe headache resembling spontaneous migraine and at least 72 h after the end of the headache phase. Patients exhibited a significant heat pain threshold reduction and an LEPs amplitude increment during headache when both the supraorbital zones were stimulated. NTG appeared to support a reliable experimental model of migraine, based on the neuronal effects on the integrative-nociceptive structures. The LEPs facilitation during NTG-induced headache may be subtended by a hyperactivity of nociceptive cortex as well as by a failure of pain-inhibitory control.
    Neuroscience Letters 07/2004; 363(3):272-5. · 2.03 Impact Factor
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    ABSTRACT: The aim of this study was to perform further evaluation of laser-evoked potentials (LEPs) during migraine attacks using multichannel recording and topographic analysis. Specifically, this study aimed to confirm the pattern previously observed in acute migraine, while also defining the components of LEPs that are mainly modified during headache, as well as the correlation between features of LEPs and clinical variables. In addition, we aimed to conduct a dipolar source analysis of the main LEP waves in migraine patients to check the variability in the source location of LEPs during acute migraine. An amplitude enhancement of LEPs was previously detected during migraine attack using a single scalp derivation on the vertex; hyperalgesia to heat stimuli was also detected for both the face and hand. Eighteen patients suffering from migraine without aura were analyzed. The supraorbital zones and the dorsum of the hand were stimulated on both the symptomatic and nonsymptomatic sides in all patients. The LEPs were recorded via 25 scalp electrodes. Dipolar source analysis of the P2 components was performed using a spherical model in all patients and using a realistic Magnetic Resonance model in four patients. During attacks, the later waves, and particularly the P2 component, were significantly enhanced; the amplitude of the P2 component obtained during the attack by stimulation of the supraorbital zone on the side of the headache was significantly correlated with the intensity of pain and the frequency of headache. In our patients, the P2 wave was generated in the anterior cingulate cortex, with a shift toward its rostrocaudal portion, and was mainly devoted to elaboration of the emotive compound of pain during migraine attack. Cortical activation by laser stimuli during migraine attack was confirmed. This effect was more pronounced in patients with a higher frequency of migraine attacks. This may be due to a lack of inhibitory control over the transmission of pain to the cortex. The increased activation of cortical areas devoted to attention and emotion may be linked to headache.
    Headache The Journal of Head and Face Pain 01/2004; 44(10):947-60. · 2.94 Impact Factor
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    ABSTRACT: The P3 wave is one cognitive component of event-related potentials (ERP) used to investigate various types of dementia. The aim of this study was to use the odd-ball paradigm to evaluate the P3 in Huntington's Disease (HD) gene carriers who showed no symptoms of chorea, compared to a group of mildly affected HD patients. We selected 14 HD patients and six individuals who, despite testing positive for the HD gene, did not show any clinical evidence of the disease. Thirty-six normal subjects were also selected as controls. Statistical evaluation of N1, P2, N2 and P3 latencies and amplitudes was performed in each group. Both the N2 latency and the P3 latency corrected for age (cP3) were significantly correlated with the duration of illness in pooled symptomatic and presymptomatic gene carriers. However, these latencies did not correlate with any clinical scale or psychometric test, including WAIS subtests. As the individual P3 latency of the majority of HD patients and all presymptomatic gene carriers was distributed within normal confidence intervals, and no correlation existed between ERP parameters and the signs of illness progression, the data appear to provide preliminary evidence against the valence of P3 in detecting the early cognitive impairment of HD.
    Acta neurologica Belgica 01/2004; 103(4):192-8. · 0.47 Impact Factor
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    ABSTRACT: The aim of this study was to analyze EEG background activity in Huntington's disease (HD) patients and relatives at risk, in relation to CAG repeat size and clinical state, in order to detect an electrophysiological marker of early disease. We selected 13 patients and 7 subjects at risk. Thirteen normal subjects, sex- and age-matched, were also evaluated. Artifact-free epochs were selected and analyzed through Fast-Fourier Transform. EEG background activity was tested using both linear analysis and artificial neural network (ANN) classifier in order to evaluate whether EEG abnormalities were linked to functional changes preceding the onset of the disease. The most important EEG classification pattern was the absolute alpha power not correlated with cognitive decline. The ANN correctly classified 11/13 patients and 12/13 normals. Moreover, the neural scores for subjects at risk seemed to be correlated to the expected time before the onset of the disease. ANN is a very powerful method to discriminate between normals and patients. It could be used as an automatic diagnostic tool. EEG changes in positive gene-carriers for HD confirm an early functional impairment which should be taken into account in the genetic counseling and in the management of the early stages of the disease.
    Clinical Neurophysiology 08/2003; 114(7):1237-45. · 3.14 Impact Factor
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    ABSTRACT: The aim of the study was to correlate the features of the blink reflex (BR) with the genetic abnormalities and the clinical findings in patients with Huntington's disease (HD) and asymptomatic gene carriers. Twenty patients with HD and 20 relatives were studied. Mutation analysis was performed for the CAG expansion within the HD gene using HD 333-HD 447 as oligonucleotide primers. The BR was elicited transcutaneously by electrical stimulation of the right supraorbital nerve. The recovery curve of the R2 and R3 responses after a conditioning stimulus was evaluated. R2 latency and duration and R3 duration were significantly increased in HD patients and in presymptomatic carriers in comparison with controls; reduced R2 recovery was also clear in both HD and gene-carrier relatives. In HD patients, the R2 latency increase correlated significantly with the severity of facial chorea. The R2 abnormalities are probably caused by impaired suprasegmental control by the basal ganglia over brainstem interneurons, which may precede the onset of involuntary movements, probably conditioning the severity of facial chorea during development of the disease.
    Muscle & Nerve 12/2001; 24(11):1520-5. · 2.31 Impact Factor
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    ABSTRACT: Objective. To evaluate the blink reflex (BR) in chronic cluster headache (CH) patients. Design. The elecrophysiological data were collected in during the headache-free phase. Setting. Headache patients were recruited from outpatients seen for the first time at the First Neurologic Clinic of Bari University. Patients and participants. Ten CH patients, 19 migraine without aura patients with strictly unilateral headache (MwoA) and 18 normal controls were selected. Measurements and results. The BR procedure was applied. In CH, a significant R2 duration increase was found on the symptomatic side in comparison with MwoA and controls. In both patient groups an early appearance of the R3 component was bilaterally clear. Conclusions. The BR findings confirm the central genesis of CH. The R3 abnormalities suggest a basic dysfunction of the Central control on the trigeminal nociceptive circuits. The R2 involvement on the symptomatic side indicates a unilateral facilitation of the trigeminal-facial connections persisting after the CH bout.
    The Journal of Headache and Pain 11/2000; 1(2):97-104. · 2.78 Impact Factor