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Biomedical subjects

C Colosimo

Publications and source records attributed to C Colosimo.

At least 91 records · Page 5Linked to original sources
PubMed1996

Motor response to acute dopaminergic challenge with apomorphine and levodopa in Parkinson's disease: implications for the pathogenesis of the on-off phenomenon.

OBJECTIVES: To evaluate the contribution of postsynaptic changes to motor fluctuations, three groups of parkinsonian patients with differing responses to treatment were acutely challenged with two dopaminergic drugs-apomorphine and levodopa-having different mechanisms of action. METHODS: Forty two patients with Parkinson's disease (14 untreated, eight with a stable response to levodopa, and 20 with levodopa induced motor fluctuations) were challenged on two consecutive days with apomorphine and levodopa. The latency, duration, and magnitude of motor response was measured. RESULTS: A progressive shortening of mean latency after levodopa challenge was found passing from the untreated to the stable and fluctuating groups; the difference between untreated and fluctuating patients was statistically significant (P < 0.01). Response duration after levodopa challenge was similar in untreated and stable patients, whereas it showed a significant shortening in patients with motor fluctuations (P < 0.05 v both untreated and stable patients). When subcutaneous apomorphine was given, untreated patients had a longer response duration than those who had developed motor fluctuations (P < 0.05). Although baseline disability was significantly greater in the fluctuating patients than in the untreated and stable patients, the severity of residual parkinsonian signs after both apomorphine and levodopa challenge was similar for all three groups; as a result, the degree of improvement in parkinsonian signs after dopaminergic stimulation was substantially greater in more advanced than in early cases. Linear regression analysis also indicated that latency and duration after apomorphine challenge did not significantly correlate with those after levodopa challenge, whereas magnitude of response to apomorphine showed a strong positive correlation with that after levodopa challenge (r = 0.9, P < 0.001). CONCLUSION: The progressive shortening of motor response after both apomorphine and levodopa suggests that pharmacodynamic factors play an important part in determining the duration of motor response and argue against altered central pharmacokinetics of levodopa being principally responsible for the on-off effect. The widening response amplitude and increasing off phase disability occurring during disease progression are also critical factors in determining the appearance of motor fluctuations.

Aged↗
PubMed1996

Spinal responses to median and tibial nerve stimulation and magnetic resonance imaging in intramedullary cord lesions.

We recorded median and tibial nerve somatosensory evoked potentials (SEPs) in 18 patients with intramedullary lesions of the cord (intramedullary tumors in 14 patients and syringomyelia cavitations in 4). Patients were divided into four groups on the basis of the longitudinal extension of the lesions as revealed by magnetic resonance imaging. The lesions involved the cervical cord in nine patients (group 1), both cervical and lumbar cord ("holocord" lesion) in two (group 2), the dorsal cord in one (group 3), and the lumbar cord in six (group 4). The recording technique enabled us to analyze clearly the spinal SEPs, labeled for the median nerve as N13, and for the tibial nerve as N24. Both spinal responses are probably generated by the activation of dorsal horn cells and proved useful in revealing focal lesions of the cervical or lumbar cords. Median nerve N13 was abnormal in all group 1 and group 2 patients; in three patients, this was the only median SEP abnormality, suggesting that the dysfunction was limited to the cervical grey matter. Tibial nerve N24 was abnormal in all group 2 and group 4 patients. The abnormality of both cervical and lumbar segmental responses in patients with holocord lesions strongly suggested that both the cervical and lumbar cords were involved. The SEP study was often more effective than the clinical examination in revealing cord involvement and the actual extension of damage. The recording of the spinal SEPs is thus highly sensitive in assessing cord dysfunction in intramedullary lesions, providing that specific recording techniques are used.

Adult↗
PubMed1995

Some specific clinical features differentiate multiple system atrophy (striatonigral variety) from Parkinson's disease.

OBJECTIVE: The clinical recognition of multiple system atrophy (MSA) in patients presenting with parkinsonian signs is difficult. We attempted to verify the predictive value of some pointers that are used in clinical practice. DESIGN: Sixteen consecutive patients with pathologically confirmed MSA who presented with a parkinsonian syndrome over an 8-year period were studied retrospectively, and their clinical features were analyzed in detail. SETTING: Parkinson's Disease Society, Brain Tissue Bank, Institute of Neurology, London, England. PATIENTS: Sixteen patients with pathologically proven MSA who presented with parkinsonian syndrome in the first 3 years since disease onset. METHODS: Clinical features that were analyzed included the rapidity of disease progression, the relative symmetry of symptom onset, the presence or absence of tremor at initial presentation, the therapeutic response to levodopa and the associated presence of autonomic dysfunction. Fourteen of the 16 patients also had a computed tomographic scan of the brain performed. The frequency of selected items in MSA was compared with that found in 20 pathologically confirmed cases of Parkinson's disease and 16 pathologically confirmed cases of progressive supranuclear palsy (Steele-Richardson-Olszewski disease). RESULTS: It was found that a probability scale based on five selected items discriminated MSA with a pure parkinsonian presentation from Parkinson's disease, but not from progressive supranuclear palsy. Patients affected by the latter disorder, however, commonly presented with additional clinical features (supranuclear vertical down-gaze palsy, axial dystonia, and cognitive impairment), which helped to differentiate it from MSA.

Autonomic Nervous System Diseases↗
PubMed1995

Carboplatin in childhood medulloblastoma/PNET: feasibility of an in vivo sensitivity test in an "up-front" study.

Sixteen patients with high risk MB/PNET at diagnosis were included in a pilot study employing carboplatin (CBDCA) as a single drug prior to conventional therapy. The main goal of the study was to identify in a short-term trial a significant response that would predict further response to CBDCA in the single patient. Exploration of CBDCA activity was focused on response after the first course as compared to the response following the second course. A course consisted of CBDCA 600 mg/m2 on days 1 and 2 administered in a 1 h infusion to be repeated 3-4 weeks later. After two cycles we observed 1 CR and 9 PR, that is a 62% response rate. The first course resulted in 5 PR, 5 MR, 5 SD, and 1 PD; after the subsequent course in all responding patients, response persisted or improved whereas in no patient with SD any improvement was observed. The correlation of response to the first course with response to the second course was statistically significant (P = 0.0009). The main toxicity of the single course was hematologic and consisted of rapidly reversible grade 3-4 neutropenia and thrombocytopenia in 94% of patients. Pharmacokinetic studies showed a very limited interpatient variability of both Cmax 57.6 +/- 9.9 micrograms/ml) and AUC (15.3 +/- 1.5 mg/ml.min) of free CBDCA, which eliminates an important variable in the evaluation of response. In conclusion, this "in vivo test" appears effective, reasonably safe, and reproducible in identifying patients likely to benefit from CBCDA: after a period of time as short as 3-4 weeks following the first course, multidrug chemotherapy including CBDCA may be employed in the responding patients, whereas an alternative regimen would be indicated in the non-responding patients.

Adolescent↗
PubMed1995

Hypothesis on the nature of comprehension deficit in a patient with transcortical mixed aphasia with preserved naming.

Patients with poor comprehension and preserved naming have been occasionally described. Such patients, who are affected by transcortical aphasia, have been taken as evidence of the possibility of naming an object while bypassing the semantic system. We describe a patient affected with mixed transcortical aphasia who presented a clear dissociation between ability in naming and difficulties in performing word-picture matching tasks. The pattern is explained by the existence of covert compulsory automatic naming that interferes with less automatic procedures involved in word-picture matching. In fact, when we tried to oppose automatic naming by using, in word-picture matching tasks, pictures difficult to name, the comprehension improved. This finding excludes a semantic deficit at the basis of poor comprehension of our patient. We suggest that the dissociation between naming and comprehension could be an expression of a computational limitation within the processes involved in word-picture matching, due to the competition for limited processing resources by automatically activated hyperactive naming.

Aphasia↗
PubMed1995

Callosotomy for intractable epilepsy from bihemispheric cortical dysplasias.

Four patients suffering for severe drug-resistant epilepsy from bihemispheric cortical dysplasias underwent anterior callosotomy. One of these patients also presented mental retardation of mild degree associated with the epileptic syndrome. There were no operative complications in this series. Clinical signs of interhemispheric disconnection were not detectable postoperatively. Twenty-eight to 53 months after surgery, the generalized seizures were completely suppressed in 2 cases, and were reduced by 89-97% in frequency in the other 2 cases. Partial seizures were less affected by callosotomy being reduced by 14-87%. In an additional fifth case of intractable epilepsy from bihemispheric cortical dysplasias with associated severe mental retardation operated upon elsewhere for callosotomy and followed at our institution, the outcome for seizures was completely unsatisfactory. Neurophysiological studies revealed that the interhemispheric transfer (IHT) of visuo-motor responses was functionally impaired after callosotomy only in one patient who harboured bilateral cortical dysplasias in the occipital lobes. This malformation might affect the pattern of axonal projection to the posterior portion of the corpus callosum which is considered of crucial importance for the integration of crossed visuo-motor responses. From this paper the following conclusions can be drawn: a) epileptic patients with severe drug-resistant epilepsy due to bihemispheric cortical dysplasias are good candidates for callosotomy, b) one-stage extensive anterior callosotomy sparing the splenium is the procedure of choice, c) associated severe mental retardation seems to contra-indicate callosotomy, d) the neurophysiological study of the IHT can yield information on the functional status of the corpus callosum.

Adult↗
PubMed1995

Surgical treatment of late neurological deterioration in children with myelodysplasia.

Late deterioration of the neurological condition in patients operated on for myelomeningocele repair has been repeatedly reported in the literature. At the present time magnetic resonance imaging (MRI) allows one to recognize various pathological conditions which can be amenable to surgical correction in these patients, such as Chiari type II malformation, hydro/syringomyelia, decompensated hydrocephalus, and tethered spinal cord. The authors report their experience with 26 myelodysplastic children operated on for myelomeningocele repair in the early neonatal period, who exhibited late deterioration at variable time intervals from the first operation. The children were examined pre-operatively by means of MRI; the results were compared with those provided by MRI in 46 myelodysplastic children who underwent the investigation as a routine follow-up control. The MRI findings were subdivided into 4 main groups of increasing severity from 1 to 4; in some subjects, associated pathological conditions (Chiari II malformation, hydromyelia, etc.) were detected as well. Twenty-two out of the 26 patients with late neurological deterioration were operated on. Eleven of them (grades 2 to 4) underwent detethering of the fixed conus, with an improvement of their clinical picture from mild to good. On the other hand the remaining 11 subjects (grades 1 to 2) improved their condition following the correction of the associated abnormalities (malfunctioning CSF shunt: 5 cases; hydromyelia: 4 cases; symptomatic Chiari II malformation: 2 cases).

Child↗
PubMed1995

Fatigue in MS is associated with specific clinical features.

INTRODUCTION: fatigue is a common and disabling symptom in multiple sclerosis (MS). In this study we evaluated if fatigue is associated with different demographic and clinical features of MS. MATERIAL: A survey was performed on 507 consecutive patients affected by clinically definite MS referred to our centre between January 1 and December 31, 1993. During the examination patients were asked to answer a brief fatigue questionnaire. To evaluate the probability of the occurrence of fatigue in association with several covariant factors (age, sex, duration, disease form, disease severity, month of examination, functional sub-systems on the expanded disability status scale (EDSS), a logistic regression analysis was performed. RESULTS: we confirmed that fatigue is common in MS, recorded in 53% of patients. Patients affected by a more severe disability, by progressive MS, both primary and secondary, with an older age at examination, and assessed during spring, had a significantly higher risk of fatigue. Sex was not associated with the occurrence of fatigue. When the single items of EDSS were considered, we found that fatigue is also associated with the occurrence of cerebellar, sphincteric, pyramidal and sensitive signs, but not with brain stem, visual and cognitive impairment. CONCLUSION: fatigue in MS is more frequent in association with specific clinical features.

Adolescent↗
PubMed1995

Multiple system atrophy presenting as parkinsonism: clinical features and diagnostic criteria.

To evaluate the possibility that parkinsonian signs may be the only presenting feature of multiple system atrophy (MSA), parkinsonian patients were studied who had no atypical clinical signs and had no symptoms of autonomic dysfunction, but who reported that they had not experienced the anticipated good response to dopaminergic treatment. These stringent criteria identified 20 patients from a series of 298 consecutive parkinsonian outpatients. The following clinical pointers were analysed: (a) rate of disease progression; (b) symmetry of parkinsonian symptoms and signs; (c) occurrence of resting tremor during the first three years from onset. In addition, all patients underwent (d) acute and chronic challenge with dopaminergic drugs; (e) cardiovascular reflex autonomic function tests; (f) high field MRI. Rapid progression of disease was seen in 45% of patients, onset was symmetric in 25%, tremor was absent at onset in 70%, response to dopaminergic drug challenges was inadequate in 40%, abnormal cardiovascular reflexes occurred in 50%, and some abnormal MRI finding occurred in 35% of cases. Each of these features was equally weighted by giving to each patient a 0 to 6 point score corresponding to the number of abnormal findings. Fifteen patients scoring higher than 1 were considered at risk for having MSA: five of them were classified as clinically possible (score 2), six as clinically probable (score 3-4), and four patients were classified as clinically definite multiple system atrophy (score 5). The six pointers considered were variably combined in each patient, none of them being universally abnormal in patients with high scores. The patients were followed up for a mean 2.1 (SEM 0.65) years. All but one of the 10 patients prospectively classified as probable or definite MSA developed unequivocal clinical signs of fully symptomatic MSA. A receiver operator characteristic cure was plotted for the prospective score based on follow up diagnosis. The best compromise for trade off between sensitivity and specificity was a cut off value at a score of 3. The sensitivity and specificity of the individual pointers considered to predict fully symptomatic MSA varied considerably, and no single item could predict whether patients presenting with just parkinsonian signs went on during the two year follow up period to develop fully symptomatic MSA. Instead, the number of abnormalities offered a predictive value for the clinical prognosis of these parkinsonian patients.

Adult↗
PubMed1995

Surgical treatment of craniopharyngiomas: an evaluation of the transsphenoidal and pterional approaches.

Fifty-seven patients with craniopharyngiomas underwent a total of 64 operations. Their clinical follow-up ranged from 2.5 to 15.5 years, with a mean follow-up of 6.5 years. A transsphenoidal approach was used in 35 patients (61%), whereas 22 (39%) were operated on using a pterional approach (in 16 patients, the tumor was found in the suprasellar cisterns, and in 6, the tumor was found in the third ventricle and was removed passing through the lamina terminalis). Total removal of the tumor was achieved in 43 patients (75%). In six patients (11%), fragments of the capsule remained attached to the hypothalamus (subtotal removal), and, in eight patients (14%), the tumor was partially removed. No recurrence occurred in those patients in whom removal was total. Regrowth was observed in two patients (33%) in whom removal was subtotal and in two (25%) in whom removal was partial. Three of them underwent subsequent operations, and a total removal with good clinical outcome was achieved. All patients except two had good postoperative recovery. Twenty patients (35%) required hormonal replacement therapy. When transsphenoidal surgery was used, a total removal of the tumors was achieved in 23 (66%) of the patients. Good clinical outcome was seen in all 35 patients. Six patients (17%) required hormonal replacement therapy. When the pterional approach was used for tumors in the suprasellar cisterns, we achieved total removal of tumors in 15 patients (94%). Good clinical outcome was seen in 20 patients (91%). Eleven patients (50%) required hormonal replacement therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

[Magnetic resonance and computerized tomography of posterior cranial fossa tumors in childhood. Differential diagnosis and assessment of lesion extent].

In the last thirty years much progress has been made in the treatment of brain tumors in children, thanks to modern diagnostic imaging techniques, together with neurosurgery and radiotherapy, for the diagnosis and follow-up of these lesions. MRI and paramagnetic contrast agents have revolutionized the imaging of intracranial conditions, especially in the posterior cranial fossa. The superiority of MRI over CT is well known and reported in the literature, but the adequacy of the two methods has rarely been compared. Therefore, this study was aimed at assessing and quantitating the accuracy of MRI and CT relative to two essential parameters: preoperative "histologic" diagnosis and local and distant intracranial tumor extent. In 52 selected patients the final histologic diagnosis was cerebellar medulloblastoma in 20 cases, cerebellar astrocytoma in 12 cases, brain stem glioma in 12 cases and ependymoma in 8 cases. CT allowed the correct diagnosis to be made in 25 patients (48%), with questionable findings in 21 patients (40%) and 6 misdiagnoses (12%). MRI allowed the correct diagnosis to be made in 43 patients (83%), with questionable findings in 9 patients (17%) and no misdiagnoses. MRI depicted local and distant tumor spread in 34 patients while CT showed it in 22 patients only. The analysis of the results confirmed the superiority of MRI over CT, relative to the parameters considered, i.e. histology and the assessment of tumor spread. In the clinical suspicion of brain tumors of the posterior cranial fossa in children, MRI--if available--should be the examination of choice if the patient's clinical status does not prevent its use. CT should be used only in emergency cases (acute intracranial hypertension) to identify hydrocephalus and intratumoral hemorrhages. Unenhanced CT also yields useful pieces of information for lesion "histology" and may be used to integrate MR findings in selected cases.

Adolescent↗
PubMed1994

Evidence for a possible neuroanatomical basis for lexical processing of nouns and verbs.

Neuropsychological studies have revealed that brain-damaged patients may show impairments of specific word categories. This study reports the performance of three patients with impairments of the categories noun and verb. The first and second patients, with left frontal lobe atrophy, were impaired in naming and comprehension of verbs. The third patient, with striking atrophy of the left temporal lobe, was disproportionately impaired in naming and comprehension of nouns. These findings suggest that anatomically distinct neural systems in the temporal and frontal lobes of the dominant hemisphere might play a critical role in lexical processing of nouns and verbs, respectively.

Aged↗
PubMed1994

Clinical usefulness of apomorphine in movement disorders.

Apomorphine, the first dopamine agonist to be synthesized, has received a renewed interest in the last few years. This compound acts powerfully on D1 and D2 dopamine receptors and has the most complete pharmacological profile of all clinically available dopamine agonists. When given subcutaneously, apomorphine consistently reverses levodopa-resistant "off" periods in parkinsonian subjects: thus, it is used in cases with severe motor fluctuations, either by continuous infusion with a portable pump or by multiple injections. Studies based on this approach have been highly encouraging, as they have shown a significant reduction in off time and a good drug tolerability. The main side effect has been the occurrence of nodular skin lesions, especially when continuous infusions were used. At variance with other dopamine agonists, a low incidence of psychiatric morbidity has been reported with apomorphine. The few available comparative reports have shown that this compound is more potent and better tolerated than lisuride. Parenteral apomorphine has been used in Parkinson's disease (PD) to replace levodopa after surgery or to treat the malignant syndrome brought about by sudden levodopa withdrawal. Acute challenge with apomorphine has been used to test dopaminergic responsiveness in parkinsonian syndromes and in dystonia. The clinical response to apomorphine may predict the effect of a chronic therapy with levodopa in approximately 90% of PD cases. Further studies are still necessary to evaluate the exact relationship between the acute response to apomorphine and a chronic therapy. In addition, apomorphine has been used to conduct clinical pharmacological studies in PD, for it is particularly well suited for research on the pharmacodynamics of central dopamine receptors. In summary, apomorphine appears to be an efficacious and safe drug for the treatment of advanced PD. It must still be considered under clinical evaluation as a test drug for acute challenge in PD and dystonia. Finally, in our opinion, the available data suggest apomorphine (in conjunction with domperidone) as a first-choice treatment for the neuroleptic malignant syndrome and the temporary replacement of levodopa (e.g., after gastrointestinal surgery).

Antiparkinson Agents↗