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Biomedical subjects

G Polo

Publications and source records attributed to G Polo.

18 recordsLinked to original sources
PubMed2006

Subthalamic nucleus stimulation in Parkinson's disease : anatomical and electrophysiological localization of active contacts.

OBJECTIVES: 1 - To assess the anatomical localization of the active contacts of deep brain stimulation targeted to the subthalamic nucleus (STN) in Parkinson's disease patients. 2 - To analyze the stereotactic spatial distribution of the active contacts in relation to the dorsal and the ventral electrophysiologically-defined borders of the STN and the stereotactic theoretical target. METHODS: Twenty-eight patients underwent bilateral high-frequency stimulation of the STN (HFS-STN). An indirect anatomical method based on ventriculography coupled to electrophysiological techniques were used to localize the STN. Clinical improvement was evaluated by Unified Parkinson's Disease Rating Scale motor score (UPDRS III). The normalized stereotactic coordinates of the active contact centres, dorsal and ventral electrophysiologically-defined borders of the STN were obtained from intraoperative X-rays images. These coordinates were represented in a three-dimensional stereotactic space and in the digitalized atlas of the human basal ganglia. RESULTS: HFS-STN resulted in significant improvement of motor function (62.8%) in off-medication state and levodopa-equivalent dose reduction of 68.7% (p < 0.05). Most of the active contacts (78.6%) were situated close to (+/- 1.6 mm) the dorsal border of the STN (STN-DB), while 16% were dorsal and 5.4% were ventral to it. Similar distribution was observed in the atlas. The euclidean distance between the STN-DB distribution center and the active contacts distribution center was 0.31 mm, while the distance between the active contacts distribution center and the stereotactic theoretical target was 2.15 mm. Most of the space defined by the active contacts distribution (53%) was inside that defined by the STN-DB distribution. CONCLUSION: In our series, most of the active electrodes were situated near the STN-DB. This suggests that HFS-STN could influence not only STN but also the dorsal adjacent structures (zona incerta and/or Fields of Forel).

Action Potentials↗
PubMed2003

[Microsurgical vascular decompression for hemifacial spasm. Follow-up over one year, clinical results and prognostic factors. Study of a series of 100 cases].

BACKGROUND AND PURPOSE: The results of a series of 100 patients operated on for hemifacial spasm (HFS), using microsurgical vascular decompression (MVD), are reported. METHOD: MVD was performed through a retromastoid keyhole approach, under monitoring of brainstem auditory evoked potentials (BAEP) and facial EMG, and consisted in dissection of VII nerve from conflicting vessel(s), and interposition of Teflon fibers and/or screen(s). RESULTS: The offending vessels found were: the antero-inferior cerebellar artery in 57 cases, the postero-inferior cerebellar artery in 56 cases, the vertebrobasilar artery in 22 cases. A multiple conflict was found in 32 cases (32%). The result was considered excellent if there was no residual spasm, good if only "minimal twitching" remained with relief>80%, poor for spasm relief 20 to 80%, and as a failure if relief<20%. The effect of MVD was satisfying (excellent or good) in 75 patients (75%) at discharge (10th day) and in 85 (85%) after 1 to 18 years follow-up (mean: 5 years). Amongst the latter patients, 29 (34%) experienced a delayed (up to 3(1/2) years in one) cure. Spasm recurrence was noted in 9 cases after satisfying effect on discharge. We encountered following permanent neurological complications: 1 facial palsy, 7 cases of hearing deficit (5 of them complete), and 1 case of IX-X deficit. Neither death nor ischaemic complication at brainstem or cerebellum. Most of our hearing complications occurred before using intraoperative BAEP monitoring (3 cases of cophosis among our first 7 patients vs 2 out of our last 93). Local complications were: 1 meningitis, 8 cases of CSF leakage requiring either a series of lumbar punctures or a lumbar external drain, and 3 cases of wound infection and/or delayed woundhealing requiring surgical treatment. CONCLUSIONS: Our data are consistent with those of the literature, especially concerning high rate of long-term success and low complication rate of MVD for HFS. We do not recommend early re-operation in case of initial poor result. Again, the necessity of intraoperative BAEP monitoring to prevent hearing morbidity is highlighted.

Adult↗
PubMed2000

Double versus single renal allografts from aged donors.

BACKGROUND: The age limit of the cadaver kidney donors is increasing in response to the growing demand for renal transplantation. Simultaneous double kidney transplantation (SDKT) with kidneys obtained from elderly adults has been proposed to increase the transplantation number and improve its results. However, if SDKT is performed when there are no clear indications, a negative effect could be produced on the total number of transplanted patients as both kidneys would be used for only one recipient. MATERIAL AND METHODS: In December 1996 we designed a transplantation protocol to be able to extend the selection of cadaver kidney donors with normal serum creatinine levels without establishing any age limit. A pregraft renal biopsy was always performed to analyze the glomerulosclerosis (GE) percentage whenever the donors were 60 years of age or older. A SDKT was performed in a single recipient when the donor age was 75 years or older or when the donors between 60 and 74 years old had a GE rate of more than 15%. On the contrary, a single kidney transplantation was performed in two different recipients for kidneys from donors between 60 and 74 years of age with a GE rate of less than 15%. Kidneys having GE rates of more than 50% were discarded for transplantation. Donor kidneys from subjects younger than 60 years of age were always used for a single kidney transplantation. RESULTS: Based on the above mentioned protocol, from December 1996 to May 1998, 181 patients received a kidney transplantation in our hospital. These patients were divided into three groups: group I which included the SDKT recipients (n=21), group II or single kidney recipients from 60- to 74-year-old donors (n=40), and group III or recipients from <60-year-old donors (n=120). The mean follow-up time was 15+/-5 months (range 6-24). Mean donor age was 75+/-7 years in group I, this was significantly higher than in group II (67+/-4, P<0.001) and group III (37+/-15, P<0.001). The primary nonfunction rate was low in the three groups, there being no statistically significant differences (5, 5, and 4%, respectively). A significantly greater percentage of patients from group I (76%) presented immediate renal graft function as compared with group II (43%, P<0.01) and III (50%, P<0.05). The acute rejections rate was very low in all three groups (9.5, 7.5, and 22%, respectively) with significant differences between groups II and III (P<0.05). No significant differences between the different groups were observed for one year actuarial patient survival (100, 95, and 98%, respectively) or graft survival rates (95, 90, and 93%, respectively). The 6-month serum creatinine levels were excellent in the three groups, although there were significant differences between groups I and II (1.6+/-0.3 vs. 1.9+/-0.6 mg/dl, P<0.05), II and III (1.9+/-0.6 vs. 1.4+/-0.4 mg/dl, P<0.001), and I and III (P<0.05). CONCLUSIONS: Simultaneous double kidney transplantations make it possible to use kidneys from extremely elderly donors (>75 years) or those whose GE>15%. In addition, kidneys from donor 60-74 years old in which the GE<15% can be used for single kidney transplantations in two different recipients with excellent results.

Adult↗
PubMed2000

[Evidence of cerebral involvement in the chronic stage of Chagas disease obtained using the P300 potential and quantified electroencephalography].

It is already known the involvement of the peripheral nervous system in chronic stages of Chagas disease. Tomographic and neuropsychological evidence of brain compromise has been included recently. In order to evaluate the neurophysiological counterpart of cerebral involvement, we studied P300 evoked potential and quantified EEG (qEEG) of 35 patients (26-55 years), and compared to an equal number of control subjects (29-55 years). We have found increased P300 latency compared to the control group (331.24 +/- 24. 02 vs 318.86 +/- 23.18) (p=0.01716). qEEG showed lower relative Beta 1 power in the patients group (p=1.6E5), and the principal frequency 1 Hz slower in the same group (p=0.01077). Multivariate analysis showed three subpopulations: a normal one, pathological one with higher Alpha power and pathological with Alpha decrement and DeltaTheta increment. Pathological findings represented 20% for the qEEG and 11.43% for cognitive potentials. Cardiac and neurologic involvement were not correlated. We conclude that there is clear electrophysiological evidence of cerebral involvement in chronic Chagas disease, thus reinforcing findings obtained by other methods.

Adult↗
PubMed1990

[Intravesical echography. I. Anatomical correlation].

The scan images of the normal bladder were obtained by intravesical ultrasonography (IVU) and the ultrasonographic-anatomic correlation were defined based on 179 procedures. Except in bladder cancer, IVU did not prove to be useful in the evaluation of other bladder conditions or adjacent structures, including gynecological disorders.

Female↗
PubMed1981

The value of ultrasonic scanning in the differentiation of acute post-transplant renal failure.

In 43 renal transplant patients studied by ultrasonography there were 32 episodes of acute rejection and 17 of acute tubular necrosis. The size of the kidney increased in all cases. However, in 75 per cent of the patients with acute rejection the central echoes of the renal sinus increased conspicuously, while in 77 per cent of those with acute tubular necrosis the echogenicity of the central sinusal complex decreased. These findings may be expressions of different pathological lesions at the renal sinus level in patients with acute rejection and acute tubular necrosis, which would modify the acoustic interphase. Therefore, we have found panniculitis, vasculitis, thrombosis and inflammatory cellular infiltration of the urinary collecting systems to be significant in patients with acute rejection but not in those with acute tubular necrosis. Ultrasonography can be an adjuvant instrument for the sometimes difficult differential diagnosis between acute tubular necrosis and acute rejection immediately after transplantation, and also for the diagnosis of acute rejection whenever it appears.

Acute Kidney Injury↗
PubMed1976

Experimental study of synadelpho-ureterostomy (transuretero-ureterostomy).

An experimental study with synadelpho-ureterostomy (transuretero-ureterostomy) was performed in 25 dogs. The conclusions reached are: (1) side-to-side anastomosis is to be preferred to end-to-side suture; (2) risk of disruption is very slight even where an unexpected obstruction is encountered (test with induced cellophanic periureteritis), and (3) segmental replacement of the lumbo-iliac ureter may apparently be achieved by means of inverted synadelpho-ureterostomy (the damaged ureter is the recipient ureter). This replacement requires a double synadelphostomy, but in our study the normal transposed ureter suffered no harm despite the presence of previous infection and ureteral dilatation.

Animals↗
PubMedDate not supplied

[Paratesticular liposarcoma of the spermatic cord].

Funiculus liposarcoma is a very uncommon tumor. Most cases have a low degree of malignancy. Inguinal orchiectomy with a wide local excision is the appropriate treatment. Liposarcoma presurgical diagnosis is very infrequent and ultrasonography is the method that can provide some help to locate it. Currently, chemotherapy indication is unclear. Due to recurrence, specially of local foci, being a possibility a periodical follow-up is necessary in these patients. Nowadays, local recurrences are treated with repeated ample local excisions and radiotherapy. This work reviews the literature and presents a new case of round cells liposarcoma of the funiculus.

Genital Neoplasms, Male↗
PubMedDate not supplied

[Ectopic gas as a complication of surgical kidney biopsy].

Since the complications herewith presented as a consequence of surgical renal biopsy are really exceptional and references found in the existing literature rare, we have considered that the contribution of these two cases which developed a pneumomediastinum-pneumoperitoneum and pneumocele prespectively during the immediate post-surgical period would be of interest. Evolution was favourable in both cases, with spontaneous resolution of the process.

Adult↗
PubMedDate not supplied

[Renal emphysema].

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Adult↗