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Biomedical subjects

G A Merli

Publications and source records attributed to G A Merli.

At least 19 recordsLinked to original sources
PubMed2001

Chordoid glioma of the third ventricle: an ultrastructural study of three cases with a histogenetic hypothesis.

Chordoid glioma is a rare neoplasm occurring in the third ventricle and, as the name implies, having a chordoid appearance. It is currently considered a glial neoplasm of uncertain histogenesis with distinct clinicopathologic features. We report three cases of chordoid glioma with a focus on the ultrastructural appearance. The patients were two men and one woman aged, respectively, 34, 40, and 43 years. Immunohistochemically, all tumors showed strong and diffuse reactivity for glial fibrillary acidic protein and vimentin, whereas immunoreactivity for epithelial membrane antigen and cytokeratin was focal. Ultrastructurally, they showed features of ependymal differentiation for the presence of an apical pole with microvilli and a basal pole characterized, as in normal ependyma, by many hemidesmosomelike structures connecting cell membranes to the underlying basal lamina. Constant features were a submicroscopic cell body zonation (i.e., perinuclear, intermediate, subapical, and apical regions) and the presence of secretory granules. These findings were similar to those described for the secretory ependymal cells of the subcommissural organ, a small structure located in a dorsocaudal region of the third ventricle that undergoes regression after birth in humans. Our observations suggest that chordoid glioma may represent a subtype of ependymoma whose cells resemble the highly specialized ependyma of the subcommissural organ.

Adult↗
PubMed2000

Intracranial spread of a giant frontal mucocele: case report.

A giant mucocele eroded both the anterior and posterior wall of the frontal sinus and infiltrated the dura mater. Its extracranial growth caused a frontal bony prominence. The tumour and part of the dura were resected. A 12 x 6cm defect in the dura was repaired with a freeze-dried patch. A split-thickness bone graft from the right parietal region was used to repair the anterior frontal bony defect. The result one year later was satisfactory. Spiral computed tomography with thr ee-dimensional reconstructions excluded any recurrence of the tumour and showed good integration of bone grafts.

Aged↗
PubMed1991

Monosialoganglioside in subarachnoid hemorrhage.

We studied 119 patients with disturbance of consciousness following subarachnoid hemorrhage, due mostly to verified aneurysm rupture, admitted to five Italian neurosurgical departments over 18 months. Level of consciousness as assessed by score on the Glasgow coma Scale ranged from 8 to 14 before the beginning of treatment; level of consciousness was assessed again 7, 14, and 21 days later. Patients were randomly allocated to treatment with monosialoganglioside or placebo according to a double-blind experimental design. The two treatment groups were homogeneous at entry with regard to the main clinical parameters. Both groups improved, but the rate and degree of improvement were greater in the monosialoganglioside-treated group. The difference was significant on days 14 (p = 0.04) and 21 (p = 0.02). Our results seem to confirm the hypothesis that monosialoganglioside reduces brain edema and provides nonspecific neuronal membrane protection.

G(M1) Ganglioside↗
PubMed1989

[Monitoring of intracranial pressure].

A very small fiberoptic catheter initially developed as an intravascular pressure sensor was incorporated into a system to be used as an intracranial pressure (ICP) monitor. 13 patients with intracranial hypertension have been studied with this probe. The clinical experience confirmed the safety, accuracy and reliability of the device. The monitor has functioned very well, and there have been no complications except for two breakages of optic fiber as a result of nursing manoeuvres. This new device can be placed into the ventricular, subdural and epidural space. Camino System appears to offer advantages over other monitors presently in use.

Adult↗
PubMed1988

Investigation on cerebrospinal fluid opioids and neurotransmitters related to spinal cord stimulation.

The purpose of this study was to assess the biochemical mechanisms underlying spinal cord stimulation (SCS). Seventeen patients with chronic pain were investigated by measuring cerebrospinal fluid concentrations of endogenous opioids and biogenic amines before and during dorsal column stimulation. Basal cerebrospinal fluid beta-endorphin levels were below the normal range. No significant change of norepinephrine, epinephrine, dopamine, beta-endorphin, beta-lipotropin, or adrenocorticotropic hormone levels were found after SCS. A 50% increase of cerebrospinal beta-endorphin and beta-lipotropin levels occurred in 6 out of 16 patients, namely those where SCS gave the major pain relief. These data confirm the derangement of the endogenous opioid system in chronic pain conditions and suggest that the beta-endorphin response to SCS could have clinical value in predicting the success of treatment.

Adult↗
PubMed1985

Neuropsychological evaluation of mild head injury.

Neuropsychological deficits following mild head injury have been reported recently in the literature. The purpose of this study was to investigate this issue with a strict methodological approach. The neuropsychological performance of 50 mildly head injured patients was compared with that of 50 normal controls chosen with the case-control approach. No conclusive evidence was found that mild head injury causes cognitive impairment one month after the trauma.

Adult↗
PubMed1984

Aphasia and right hemiplegia after cervical myelography with metrizamide. A case report.

We report a case of aphasia and right hemiplegia, developing after myelography with metrizamide and lasting for an unusually long time. The neurological disorders, manifested 1 h after the examination was completed, were due to accidental passage of contrast medium into the basal cisterns. In the light of analogous case reports in the literature, as well as experimental data concerning the biochemical activity of metrizamide, possible aetiopathogenetic mechanisms responsible for such disturbances are indicated. The authors underline the lack of effective therapeutic measures after the onset of the disorders, and thus the importance of preventing such complications that behave functionally as true ictuses although with no anatomic substratum.

Aphasia↗
PubMed1984

[Value of neurophysiologic methods in the follow-up of Cloward's multiple cervical vertebral fusion].

In 11 patients suffering from radicular and in some cases also medullary symptoms anterior spinal fusion at 2 or 3 cervical levels was performed. At follow-up radicular pain had disappeared, and no clinical deficits were found with the exception of one previously tetraparetic patient. Neurophysiological studies including needle electromyography, conduction velocity studies and somatosensory evoked potentials showed, however, that denervation potentials persisted frequently in the C7-C8-T1 innervated muscles, while those innervated by the upper cervical roots were normal in all patients. Somatosensory evoked potentials could not detect medullary compression due to "angulation deformity", a frequent complication of multiple spinal body fusion.

Adult↗
PubMed1984

Metrizamide-enhanced computed tomography of intracranial arachnoid cysts.

Between July 1981 and August 1983 the authors studied 21 patients with intracranial arachnoid cysts using metrizamide-enhanced CT. With this method we are able to determine the degree of communication between the cysts and the surrounding subarachnoid space as well as to assess the evolving character of some of these lesions. This information will allow a more rational choice of surgical treatment.

Adolescent↗