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Biomedical subjects

M Abbruzzese

Publications and source records attributed to M Abbruzzese.

At least 55 records · Page 3Linked to original sources
PubMed1993

Motor evoked potentials following cervical electrical stimulation in brachial plexus lesions.

The diagnostic relevance of recording motor evoked potentials (MEPs) after electrical stimulation of the cervical region, as compared with conventional needle electromyography (EMG), was evaluated in 26 patients with brachial plexus (BP) damage of different aetiology, severity and topography. MEP abnormalities (absence or latency increase) were observed in at least one muscle of all the patients, with a global incidence of 61.5% of the muscles examined. Neurogenic EMG signs were present in all but one patient with an incidence of 62.2% of the muscles examined. Combining the two methods, the global incidence of abnormalities rose to 69.9%. MEP abnormalities were consistent with the clinical topography and severity of BP lesions and were fairly parallel with EMG findings. Recording MEPs after percutaneous electrical stimulation of the cervical region may be regarded as a rapid, non-invasive method for quantitative electrophysiological assessment of BP damage.

Adolescent↗
PubMed1993

Smooth pursuit and saccadic eye movements and Wisconsin Card Sorting Test performance in obsessive-compulsive disorder.

Smooth pursuit eye movements (SPEMs), voluntary saccadic eye movements (VSEMs), and neuropsychological test (Touluse-Pieron Test and Wisconsin Card Sorting Test) performance were studied in 23 patients with obsessive-compulsive disorder and 27 age-matched normal control subjects. The patients performed more poorly than the control subjects on the SPEM and, to a lesser degree, VSEM measures. They also showed impairment on some aspects of the neuropsychological tests. No relationship was found between eye movement performance and neuropsychological impairment.

Adult↗
PubMed1993

Impairment of central motor conduction in diabetic patients.

In 70 patients with diabetes mellitus (DM) we recorded the motor evoked potentials (MEPs) following magnetic stimulation of the motor cortex and spinal roots. Central motor conduction time (CMCT) was determined as the difference between MEP latencies after cortical and spinal stimulation. The mean CMCTs for the biceps, thenar and tibialis anterior muscles were prolonged in the DM group, as compared to normal controls, and 21 patients exceeded the CMCT upper confidence limit for at least one muscle. CMCT changes and peripheral conduction velocity abnormalities occurred independently and were related to different clinical parameters. We conclude that a subclinical impairment of central motor conduction is present in 30% of DM patients, independently from the occurrence of a diabetic peripheral neuropathy and possibly reflecting different pathophysiological mechanisms.

Adult↗
PubMed1993

Memory and attention dysfunctions in story recall in schizophrenia: evidence of a possible frontal malfunctioning.

Story recall deficits in schizophrenia have been related to some deficit in interhemispheric transfer of information, suggestive of a collosal pathology or, alternatively, to malfunctioning in attention and mnesic systems. The present investigation, performed on 61 DSM-IIIR schizophrenic inpatients and 40 age-and education-matched, normal controls demonstrates that story recall deficit is dependent on the length and complexity of the stories. This finding might implicate a critical role for the attention and mnesic functions in determining story recall performances. Both functions have an anatomo-functional substrate in neural circuits involving the frontal lobe, which also plays a critical role in determining the level of the conceptualization and abstraction capacities.

Adolescent↗
PubMed1993

Size of the corpus callosum and auditory comprehension in schizophrenics and normal controls.

19 schizophrenic patients and 15 normal controls, matched for sex and age, were evaluated by magnetic resonance imaging for corpus callosal size and had neuropsychological functioning assessed using an auditory comprehension test. Although the MRI data did not reveal any significant differences between groups, the degree of laterality to the left versus right ear response was significantly correlated with the size of the posterior part of the corpus callosum in male schizophrenics.

Adult↗
PubMed1993

The Wisconsin Card Sorting Test discriminates schizophrenic patients and their siblings.

The following report is an evaluation of the performances of 35 schizophrenic patients and 35 of their siblings on the Wisconsin Card Sorting Test (WCST), a neuropsychological test considered sensitive to frontal lobe functioning. Thirty five normal subjects matched for age and education were the comparison group. The purpose of this study was to examine the relationship of the neurofunctional basis for schizophrenia to its familiar occurrence. Non-schizophrenic siblings of schizophrenic patients did not perform significantly different from normal subjects on the WCST; however, schizophrenic patients performed significantly worse than both their siblings and normal subjects. These results indicate that WCST dysfunction seems to be a characteristic related to the presence of the disease and that non-genetic factors could contribute to the WCST pathological profile.

Adult↗
PubMed1993

Memory functions and temporal-limbic morphology in schizophrenia.

Several psychopathological and morphological studies support the hypothesis of temporal-limbic involvement in the pathophysiology of schizophrenia. In the present study, magnetic resonance imaging was used to evaluate the areas of the temporal lobes and related structures in 18 schizophrenic patients and 18 normal control subjects who were homogeneous for sex and age. The Wechsler Memory Scale was used to assess the memory functions of all subjects. Although the MRI data did not reveal any significant differences between the two groups, the Wechsler Memory Scale indices of memory functions showed significant differences between the schizophrenic patients and the control subjects.

Adult↗
PubMed1992

Interindividual variability of central delay changes in the soleus H reflex pathway.

Central delay (CD) changes in the soleus H reflex pathway, as demonstrated by variations in the time interval between afferent (P1) and efferent (P2) neurographic volleys underlying the reflex response, were assessed in a group of normal subjects, both during the steady state and after homosynaptic spatial summation of afferent impulses. The maximal range of CD changes, regardless of whether "spontaneous" or provoked, showed significant interindividual differences whose size was positively related to the Hmax/Mmax ratio, provided that the extension of the subliminal fringe was suitably normalized. Comparatively similar variations in amplitude of the reflex motoneuronal discharge under different experimental conditions can be associated with different CD changes. Indeed, "spontaneous" CD fluctuations occurring during the steady state were consistently greater than CD reductions provoked by spatial summation, the gap size being negatively related to the Hmax/Mmax ratio.

Adolescent↗
PubMed1992

Hereditary motor and sensory neuropathy with deafness, mental retardation and absence of large myelinated fibers.

Two brothers with a presumably hereditary motor and sensory polyneuropathy (HMSN), sensory-neural hearing loss and mental retardation had clinical features and neuropathological changes in the sural nerve which may set the disorder apart from previously described types of HMSN. Consecutive sural nerve biopsies from one case showed absence of large myelinated fibers and a normal complement of small fibers. We infer from our findings that a developmental abnormality with faulty growth and subsequent axonal atrophy may be responsible.

Adolescent↗
PubMed1992

Increased right caudate nucleus size in obsessive-compulsive disorder: detection with magnetic resonance imaging.

Magnetic resonance images were used to measure the volume of the head of the caudate nucleus in 20 patients with obsessive-compulsive disorder and 16 normal control subjects. The obsessive-compulsive patients showed a significant increase in the volume of the right side of the head of the caudate nucleus compared with that of control subjects. This finding was not correlated with demographic, psychopathological, or clinical characteristics.

Adult↗
PubMed1991

Motor evoked potentials (MEPs) in lacunar syndromes.

Motor evoked potentials (MEPs) evoked in the biceps, thenar and tibialis anterior muscles by electrical stimulation of the scalp and of the spinal regions were recorded in 32 patients with focal deficits due to minor cerebral ischemia of the lacunar type and in a control group. Somatosensory evoked potentials (SEPs) to median nerve stimulation were also recorded. The central motor conduction times (CMCTs) and the threshold intensities for eliciting MEPs in the relaxed muscles were significantly increased on the affected side. Central motor conduction, for at least one muscle, was altered in 18 patients. MEP abnormalities were related to pyramidal signs (though they could be observed also in a patient without any motor impairment) and occurred independently of a specific clinical picture or a radiologically confirmed lacunar lesion. SEPs were less frequently altered than MEPs.

Aged↗
PubMed1991

Frontal and callosal neuropsychological performances in schizophrenia. Further evidence of possible attention and mnesic dysfunctions.

Some level of frontal and callosal dysfunction has been reported in patients with schizophrenia. In the present study 68 normal controls and 117 schizophrenic patients were administered the Wisconsin Card Sorting Test (WCST), which involves the function of the frontal areas, and the Auditory Comprehension Test (ACT) which involves the corpus callosum and to a lesser degree attention and mnesic mechanisms. WCST correctly discriminated 69.8% of schizophrenics and 74.2% of controls, ACT 86.7% of schizophrenics and 90.2% of controls. Moreover, schizophrenics correctly classified by the WCST performed more poorly than schizophrenics incorrectly classified by the WCST on the related ACT indices for the attention and mnesic mechanisms. There were no differences in present age, age at onset, duration of the illness, diagnostic subtype and course of the disease between correctly and incorrectly classified schizophrenics by the WCST and the ACT. These data indicate a prevalent malfunctioning of attention and mnesic mechanisms in schizophrenia. Finally there seems to be no relationship between these neurofunctional abnormalities and demographic and clinical characteristics of the disease.

Adult↗
PubMed1991

Changes in central delay of soleus H reflex after facilitatory or inhibitory conditioning in humans.

1. Central delay (CD) changes after facilitatory or inhibitory conditioning of the soleus H reflex have been investigated in a group of normal subjects as a function of the conditioning and test stimulus intensities and also as a function of the Hmax/Mmax ratio. Both facilitation and inhibition of the reflex response have been obtained by conditioning stimulation of the ipsilateral tibial nerve at suitable conditioning-test stimulus intervals. CD changes have been extrapolated from the variations of the time interval between afferent and efferent neural volleys underlying the H reflex, directly recorded from the sciatic nerve. 2. The CD was significantly decreased by facilitatory and increased by inhibitory conditioning. Facilitatory CD changes were positively related to test stimulus strength (at a given conditioning stimulus intensity) and negatively related to conditioning stimulus strength (at a given test stimulus intensity). Both trends were reversed after inhibitory conditioning. The effectiveness of facilitatory conditioning was positively related to the individual Hmax/Mmax ratio whereas a negative relationship could be observed after inhibitory conditioning. 3. Also, the "conditioning threshold" (the minimal conditioning stimulus strength affecting the reflex size) and the "maximal conditioning effect" (the conditioning stimulus intensities leading to either the saturation of the facilitatory effect or the suppression of the reflex response) were significantly related to the Hmax/Mmax ratio. 4. We suggest that temporal changes in the H reflex pathway after facilitatory or inhibitory conditioning stimuli depend both on the size of the motoneuronal pool underlying the reflex response, as determined by the test stimulus intensity, and on the individual excitability of the motoneuronal pool, as defined by the Hmax/Mmax ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Do muscle afferents contribute to the cervical response evoked by electrical stimulation of the median nerve in man?

The possible contribution of low threshold muscle afferents to the postsynaptic component (N13) of the cervical response evoked by electrical stimulation of the median nerve (MN) was investigated in normal subjects. Electroneurographic (ENG) and electromyographic (EMG) correlates of the reflex motoneuronal discharge (RMND) were recorded simultaneously. A. No reflex activity could be elicited by stimulation of the MN at the wrist, at least in the resting subjects, while well developed ENG (P2 efferent volley) and EMG (H reflex) monosynaptic responses occurred following stimulation of the MN at the elbow at suitable strengths. In neither case could a surface correlate of interneuronal activity evoked by muscle afferents be demonstrated. B. Recruitment curves showed that at stimulus intensities above maximal for the H reflex both P2 and H responses started to decrease until they completely disappeared, while N13 showed further enhancement. C. Subthreshold conditioning stimulation of the MN enhanced both P2 and H responses, while vibratory muscle stimuli provoked a clearcut suppression of these two responses. In contrast, N13 was completely unaffected by either manoeuvre. D. No cervical evoked activity could be detected following tendon tapping of the anterior forearm muscles in spite of the appearance of well developed cortical responses and the ENG and EMG correlates of the T reflex. E. Conditioning volleys elicited by tendon taps of the anterior forearm muscles suppressed both P2 and H responses following stimulation of the MN at the elbow without affecting the related N13 component. Conditioning supramaximal stimulation of the MN at the wrist suppressed the N13 component of the cervical response evoked by stimulation of the MN at the elbow without affecting the related reflex responses. No component chronologically related to the RMND could be recorded at the posterior neck region during suppression of N13, thus ruling out the possibility that failure to detect the RMND (as well as its interneuronal concomitants) with cervical electrodes is due to a masking effect of the N13 component. G. Conditioning tendon taps of anterior forearm muscles provoked a clearcut reduction of the primary cortical response to finger stimulation without affecting the postsynaptic component of the related cervical response. It is concluded that neither segmental (motoneuronal or interneuronal in origin) nor ascending postsynaptic impulses generated in the spinal cord by stimulation of low threshold muscle afferents contribute to N13, the latter being probably due to activation of both short and long axoned spinal neurons by cutaneous afferents.

Adult↗
PubMed1988

Corneal astigmatism after cataract extraction.

We studied all cataract surgery done at the ophthalmologic clinic of the University of Bari, Italy in the last 20 years (1966-85). We considered three methods of anterior-chamber incision (blade, Worsth's knife, Graefe's bistoury) and their effect on the dioptric values obtained from ophthalmometry a year after surgery. The larger corneal astigmatism occurred after opening the anterior chamber with Graefe's method; the best results were obtained using Worsth's knife. In this evaluation, the surgeon was not considered. Because postsurgical astigmatism is important for visual acuity after cataract extraction, it is desirable to keep astigmatism as minor as possible.

Astigmatism↗
PubMed1987

Parietal and prerolandic somatosensory evoked responses in carotid artery reversible ischemic attacks (RIA).

Somatosensory potentials evoked by median nerve stimulation were recorded bilaterally from the prerolandic and parietal scalp in 36 patients with reversible ischemic attacks in one carotid artery distribution. Responses recorded from the affected and unaffected hemisphere were compared. SEP abnormalities were observed over the affected hemisphere in 22 subjects (61.1%), irrespective of number and/or duration of episodes, and appeared selectively correlated to their clinical features. SEP studies proved to be more sensitive than conventional EEG recordings and are suitable for evaluation of the functional impairment of specific cerebral areas following transient cerebral ischemia. The occurrence of SEP abnormalities in RIA may represent an unfavourable sign, being more frequent in patients with evidence of internal carotid artery disease.

Adult↗