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Biomedical subjects

F Sartucci

Publications and source records attributed to F Sartucci.

At least 19 recordsLinked to original sources
PubMed2006

Quantitative EEG analysis in post-traumatic anosmia.

Many objective and quantitative methods have been developed to create a procedure or a device to prove, describe and quantify olfactory deficit and anosmia, especially after a head trauma. Electrophysiological testing throughout olfactoelectroencephalography (olfactoEEG) is based on brain activity desynchronisation, and on the subsequent disappearance of alpha activity on the posterior regions after an olfactory stimulus. Yet traditional evaluation of EEG can be difficult, because of little or hardly detectable alpha activity on the posterior regions ('alpha rare'). The aim of this study was to evaluate the Olfactory Stop Reaction (OSR) by means of frequency band power calculation and subsequent topographical mapping in patients with post-traumatic anosmia, who presented 'alpha rare' EEG. Twenty-five consecutive patients, affected by anosmia caused by head trauma, were submitted to an EEG recording with olfactory stimulation. After signal processing and analysis, an Olfactory Stop Reaction was detected in 17 out of 25 patients; moreover, in these patients we detected a significant decrease in alpha band power in the occipital regions and an increase in theta band power on midline frontal and central regions after olfactory stimulation. In the remaining eight patients, no significant variation in band power was observed. In conclusion, an objective evaluation of the olfactory function with this method of automatic EEG signal analysis allows the limits given by psychophysical methods and traditional EEG to be overcome and attempts to fulfil the requirements for standardization of olfactory function evalution.

Adult↗
PubMed2006

Chromatic pattern-reversal electroretinograms (ChPERGs) are spared in multiple system atrophy compared with Parkinson's disease.

Idiopathic Parkinson's disease (IPD) patients have abnormal visual evoked potentials (VEPs) and pattern electroretinograms (PERGs), attributed to dopaminergic transmission deficiency in visual pathway, probably the retina. VEP abnormalities are not reported in multiple system atrophy (MSA). The aim of this study was to investigate and compare chromatic (Ch) red-green (R-G) and blue-yellow (B-Y), and luminance yellow-black (Y-Bk) PERGs in patients with MSA and IPD. We investigated 6 MSA patients (mean age: 62+/-7.4 years) not undergoing any pharmacological treatment, as well as 12 early IPD patients (mean age: 60.1+/-8.3 years) and 12 age-matched normal observers. ChPERGs were recorded monocularly in response to full-field equiluminant R-G, B-Y and Y-Bk horizontal gratings. In MSA only responses to R-G stimuli showed minimal insignificant changes (slight but not significant amplitude reduction without any significant latency delay); no significant abnormality was detected for B-Y and luminance Y-Bk stimuli. By contrast, in IPD all responses were reduced in amplitude and delayed in latency, above all for B-Y stimuli. Present data indicate that both chromatic and achromatic PERGs are virtually unaffected in MSA, whereas in early IPD they are clearly impaired, suggesting different pathogenic retinal mechanisms and a useful simple tool for distinguishing MSA from IPD.

Aged↗
PubMed2006

Visual-evoked potentials to onset of chromatic red-green and blue-yellow gratings in Parkinson's disease never treated with L-dopa.

The differential dysfunction of chromatic and achromatic visual pathways in early Parkinson's disease (PD) was evaluated by means of visual-evoked potentials (VEPs) recorded in 12 patients (mean age 60.1 +/- 8.3 years; range 46 to 74 years) in the early stages of PD and not yet undergoing treatment with L-dopa, and in 12 age-matched controls. Visual stimuli were full-field (14 deg) equiluminant red-green (R-G), blue-yellow (B-Y), and black-white (B-W) sinusoidal gratings of two cycles per degree, presented in onset (300 milliseconds)--offset (700 milliseconds) mode, at two contrast (K) levels (90% and 25%). The VEP mean latencies were significantly more delayed in PD patients than in controls for chromatic than for luminance stimuli, in particular for B-Y stimuli of low contrast (K90%: B-W = 6.6 milliseconds, R-G = 3.34 milliseconds, B-Y = 15.48 milliseconds; K25%: B-W = 7.8 milliseconds, R-G = 14.8 milliseconds, B-Y = 28.9). Latencies of chromatic VEPs were more variable that achromatic VEP latencies in both normal subjects and PD patients. Therefore, the frequency of latency abnormalities (within 30%) was not significantly different for the three visual stimuli. Our results show that, in addition to achromatic VEPs, chromatic VEPs are impaired in early PD patients not yet undergoing L-dopa therapy, indicating an acquired color deficiency in these patients. The greater delay for the B-Y VEPs suggests a higher vulnerability of visual blue-cone pathway in the early stages of the disease. However, the overall sensitivity of chromatic VEPs in detecting early visual impairment in PD is comparable with that of achromatic VEPs.

Aged↗
PubMed2005

Electrophysiological evidence by single fibre electromyography of neuromuscular transmission impairment in a case of Miller Fisher syndrome.

Miller Fisher syndrome is an autoimmune neuropathy characterised by ataxia, areflexia and ophthalmoplegia, with minimal if any limb weakness, and in the majority of cases by high titres of IgG anti-GQ1b ganglioside antibodies. In vitro electrophysiological experiments have demonstrated that these antibodies induce a transmission blockade at neuromuscular junction either pre- or post-synaptically. We report the case of a 63-year-old man with MFS that shows blood serum negative for anti-GQ1b but presents an impairment of neuromuscular transmission detected by single fibre electromyography. To the best of our knowledge, this represents the first case in the literature using jitter technique and suggests that other antibodies may be involved in the function of motor end plates by bindings to the synaptic membranes.

Electric Stimulation↗
PubMed2003

Electrophysiological evaluation of genito-sphincteric dysfunction in multiple system atrophy.

Thirteen patients with multiple system atrophy underwent multimodality neurophysiological evaluation, including sphincteric needle electromyography (EMG), sacral reflexes, pudendal nerve terminal latency, pudendal (PSEPs) and tibialis posterior nerve somatosensory evoked potentials (TPSEPs), and perineal motor evoked potentials (PMEPs). EMG revealed denervation or neurogenic changes, with reduction in spontaneous tonic activity at rest and abnormal pudendal nerve terminal latency in 10 patients (76.9%); anal reflex was delayed in 7 patients (53.8%). TPSEPs scalp responses were clearly abnormal in 4 patients (30.7%), whereas PSEPs exhibited changes in 9 (69.2%): in 6 patients responses were delayed at lumbar level (46.2%), and in 5 over the scalp (38.4%). PMEPs showed an increase in latency with a mild prolongation of central motor conduction time (CMCT) in 2 cases (15.3%); 1 patient had prolonged latencies following both cortical and sacral stimulation, but a normal CMCT. Even if diagnostic yield is not improved using these investigations they provide evidence of multiple lesion sites other than Onuf's nucleus.

Aged↗
PubMed2002

Vestibular-evoked myogenic potentials: a method to assess vestibulo-spinal conduction in multiple sclerosis patients.

Vestibular-evoked myogenic potentials (VEMPs), elicited by acoustic stimulation, have been proposed in the assessment of the vestibulo-cervical reflex pathways. The procedure has been previously validated in several otovestibular disorders. The aim of this study was to investigate patients affected by multiple sclerosis (MS) in the attempt to clarify the underlying physiopathogenetic mechanisms and the clinical utility of VEMPs in detecting vestibulospinal involvement in this disease. VEMPs were obtained according to the technique described by Colebatch and Halmagyi [Neurology 42 (1992) 1635]. We averaged the surface tonic electromyogram from right and left sternocleidomastoid muscle, after bilateral click stimulation (click duration 0.1 ms, repetition rate 3 Hz, intensity 140 dBSPL, 256 stimuli, repeated at least twice). In all cases, we obtained the biphasic, initially positive, p13-n23 wave pattern. P13 peak latency was bilaterally or unilaterally delayed in 8 out of 15 patients (mean delay: 2.2 ms; p < 0.01 on right and <0.05 on left side) and peak-to-peak amplitude significantly reduced (mean amplitude loss: 130 microV; p < 0.01 on right and <0.05 on left side). Their overall diagnostic yield resulted in 60%. In conclusion, the present findings prove that VEMPs are delayed in p13 component and altered in amplitude in MS patients. We hypothesise that these changes might be the result of a conduction impairment in vestibulo-spinal fibres, producing a morphologic alteration of the myogenic responses.

Acoustic Stimulation↗
PubMed2001

Characteristics of cerebral microembolism during carotid stenting and angioplasty alone.

BACKGROUND: Cerebral microembolism has often been documented by transcranial Doppler imaging during carotid angioplasty and stenting. However, few data are available about its characteristics during the 2 different kinds of procedure. OBJECTIVES: To compare the incidence of microemboli occurring during angioplasty alone with that during stenting in the different phases of the procedures and to relate it to periprocedural cerebrovascular complications. PATIENTS AND METHODS: Thirty-eight patients underwent 41 procedures (15 angioplasty alone and 26 stenting) for symptomatic carotid stenoses of 70% or more. Transcranial Doppler monitoring was performed to detect microemboli in the middle cerebral artery during 3 phases of the procedure: (1) guidewire crossing, (2) first dilatation in case of angioplasty alone or stent release with predilatation if performed, and (3) further dilatation. RESULTS: Microemboli occurred in all cases in phase 1 of the procedure but less frequently in the arteries treated with stenting when compared with those treated with angioplasty alone in phase 2 and particularly (P<.02) in phase 3. The mean number of microemboli was highest in phase 2, predominant (P<.05) during angioplasty alone, and particularly reduced (P<.02) in phase 3 during the stenting procedures. During 2 (5%) of the 41 procedures, cerebrovascular complications occurred in phase 1, with the number of microemboli being higher than mean values. CONCLUSIONS: Cerebral microembolism is a very common event, especially during guidewire crossing and angioplasty alone compared with stenting. Further studies concerning the prognostic significance of this are advisable.

Aged↗
PubMed2001

Early thrombolysis in stroke due to basilar artery occlusion.

Basilar artery occlusion is usually associated with a poor prognosis. Nevertheless, intra-arterial thrombolysis has been shown to improve clinical outcome in selected cases. We report the case of a 29-year-old patient who suffered a severe ischemic stroke due to basilar artery occlusion and who was treated with intra-arterial thrombolysis within 3 h of symptoms onset; treatment was followed by an almost full functional recovery. The young age of the patient, short segment occlusion in the middle tract of the artery, good collateral supply, and early recanalization may account for the favorable prognosis.

Adult↗
PubMed2001

Asymmetric scalp distribution of pattern visual evoked potentials during interictal phases in migraine.

The N70 and P100 components of transient pattern visual evoked potentials (P-VEPs) were measured in migraine patients, with and without aura, and in normal subjects in order to evaluate their latency, amplitude and occipital scalp distribution. The aim was to find any typical electrophysiological abnormalities in migraine. P-VEP N70 and P100 were analyzed in 59 patients without any known visual field defect. Mean latency and amplitude values were within normal ranges for either N70 and P100 all over the occipital scalp; the only significant abnormality we found was related to the absolute right-left amplitude ratio either for N70 and P100 waves, providing an asymmetry in P-VEP scalp distribution; this finding was detected in 78.9% of patients with aura and 72.5% without aura. Our results show that in migraine patients, both P-VEP waves N70 and P100, have an asymmetric topographic distribution, even during interictal phases, that can be explained by a cortical disturbance in agreement with the neural hypothesis of headache.

Adult↗
PubMed2001

Effects of grating spatial orientation on visual evoked potentials and contrast sensitivity in multiple sclerosis.

Previous studies suggest a delay of pattern visual evoked potentials (PVEPs) in multiple sclerosis (MS) depending on grating orientation. We examined a group of 14 patients with definite MS recording PVEPs to vertical and horizontal grating and analysing latency and amplitude of P60, N70 and P100 waves. We evaluated contrast sensitivity (CS) to dark and bright bars of several spatial frequencies (SF). The aim was to evaluate the diagnostic value of evoked responses and CS in revealing involvement of cortical structures. PVEPs to 1 degrees cycle/degree (c/d) vertical bars were abnormal in 25% for P60, in 32% for N70 and in 36%, for P100; in 25%, 36% and 42% respectively at 4 c/d; as regards horizontal bars at 1 c/d we found alterations of P60, N70 and P100 in 11%, 19% and 27% respectively; at 4 c/d in 19%, 27%) and 35%. CS resulted more abnormal for vertical grating, with a maximum impairment for 3.7 c/d SF. We may conclude that the use of vertical grating in clinical routine is more reliable both for PVEPs and CS testing; in addition CS can be abnormal even with normal PVEPs: this could mean an early impairment of CS and provide useful indications about a subclinical involvement of visual cortex.

Adult↗
PubMed2001

Equiluminant red-green and blue-yellow VEPs in multiple sclerosis.

The primate visual system is composed by two color-opponent pathways--red-green (R-G) and blue-yellow (B-Y)--subserved by the so-called parvo- and koniocellular streams respectively. The authors' aim was to compare the relative involvement of chromatic visual subsystems in multiple sclerosis (MS). In 30 MS patients with different forms of MS they recorded visual evoked potentials (VEPs) to onset (300 msec) and offset (700 msec) of equiluminant R-G and B-Y sinusoidal gratings of different contrast (90% and 25%). Equiluminance was established psychophysically by establishing the R-G and the B-Y color ratio at which chromatic gratings alternating at 15 and 10 Hz respectively had minimum visibility. The negative wave at stimulus onset with a peak latency of 120 to 160 msec was evaluated. Ordinary VEPs to luminance (LUM) contrast (black-white reversing checkerboards of 15' check size and 50% contrast) were also recorded for comparison. Latencies of R-G VEPs were abnormal in 53.3% and 58.3% of patients at 90% and 25% contrast respectively, whereas abnormal B-Y VEPs were 56.6% and 48.3%. Latencies of LUM VEPs were abnormal in 45% of patients. Interocular latency asymmetries were abnormal in 59.2% and 33.3% of patients for R-G, and 51.8% and 62.9% for B-Y. Latency asymmetries for LUM VEP were abnormal in 46.4% of patients. The higher rate of VEP abnormalities found with equiluminant chromatic stimuli compared with achromatic stimuli confirms the general vulnerability of color-opponent visual pathways in MS, even if the number of patients with abnormal findings was not significantly different when both test conditions were compared. VEPs to R-G and B-Y equiluminant stimuli appear to be involved approximately to the same extent.

Adolescent↗
PubMed1999

Cortical silent period in patients with amyotrophic lateral sclerosis.

Transcranial magnetic stimulation (TMS) during a muscle contraction induces a motor-evoked potential (MEP) in the skeletal muscle followed by a cessation of EMG activity, the cortical silent period (C-SP). The C-SP is a useful parameter to indicate the activation of the motor system. Accurate determination of the C-SP can be important in amyotrophic lateral sclerosis (ALS), a progressive disorder of unknown etiology characterised by degeneration of upper and lower motor neurons. The aim of this study was to evaluate the sensitivity of C-SP as an index of motor system involvement, in ten patients affected by ALS, with a mean duration of the disease: 5. 5+/-3.4 months, by means of an objective computer-aided method to measure C-SP and its relationship to stimulation intensity. C-SP duration was significantly reduced in ALS patients compared to controls at low stimulation intensity corresponding to an MEP threshold increased by 15%. While in less severely affected patients C-SP duration approached control values at higher stimulation intensities (25 and 50% upper MEP threshold), in more severe ALS subjects it showed a further reduction, allowing them to be discriminated.

Aged↗
PubMed1999

Amplitude loss of electrically and magnetically evoked sympathetic skin responses in early stages of type 1 (insulin-dependent) diabetes mellitus without signs of dysautonomia.

The sympathetic skin responses following both electrical nerve (eSSRs) and magnetic (mSSRs) brain stimulations have been investigated in 19 insulin-dependent diabetic patients with no evidence of a peripheral neuropathy or dysautonomia and compared to those obtained in 10 age-matched healthy subjects. SSR was recorded from the right hand and foot, controlateral to the stimulated side. The main findings were amplitude loss and disappearance of the eSSR in 12/19 (63.2%) and 11/19 (57.9%) patients, occurring more frequently than the mSSR; 7/19 (36.8%) and 5/19 (26.3%) were recorded from the hand and foot, respectively. The SSR to electrical stimulation was significantly reduced in the upper and lower extremities (p < 0.0001) compared to control results, whereas latencies were normal to both stimulation modalities. Only in two cases the responses were absent from the foot, one following electrical stimulation and the other after magnetic stimulation. No correlation was found between the SSR and metabolic indexes of diabetes mellitus or conduction velocity studies. On the basis of these data an early impairment of afferent pathways may be postulated.

Adult↗
PubMed1999

Is lithium able to reverse neurological damage induced by vinca alkaloids? (Short communication).

Lithium (Li) actively antagonises the inhibiting action of vinca alkaloids on human leukocyte chemotaxis; it proved to be related to the activation of microtubular system, possibly mediated by its inhibiting effect on cyclic AMP. Vinca alkaloids induce peripheral neuropathy and muscle damage. The molecular basis of this neurotoxicity has not been fully explained, but a possible role of neurofibrillary degeneration has been reported. We studied both in animals and in humans, whether Li is able to antagonise vinca alkaloid neurotoxicity.

Adult↗
PubMed1999

Plaque surface and microembolic signals in moderate carotid stenosis.

We performed Transcranial Doppler Monitoring to detect microembolic signals (MES) in 47 patients with moderate (30%-69%) carotid stenosis proven by selective angiography. We compared the occurrence of MES with the clinical characteristics of stenosis (symptomatic or asymptomatic) and the angiographic plaque features (nonulcerated, deep ulceration, superficial ulceration, ulceration with flap, or ulceration without flap). For these cases there was no indication for endarterectomy, nevertheless we thought it would be useful to identify risk subgroups that might benefit from surgical treatment. MES were detected in 17.9% of the stenoses with a prevalence (p <. 01) in symptomatic cases (25%) compared to asymptomatic cases (14. 3%). There was a significant correlation of MES with plaque ulceration (p <.01) and particularly with ulceration without flap (p <.01). No difference between deep and superficial ulceration was observed. The availability of prospective data on this topic might be useful to select subgroups of patients with moderate carotid stenosis at risk for embolism.

Aged↗