Biomedical subjects
Publications and source records attributed to R Leiguarda.
Bilateral intracerebral hydatid cysts developed in a 14-year-old patient after an infarct of presumed embolic origin in the left frontotemporoparietal region. The average rate of growth of these cysts was about 5 cm per year. This suggests that the growth rate is far from uniform and indeed, particularly in young patients, may be much faster than originally estimated.
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Reported are six cases of meningocerebral astrocytomas attached to dura, involving the superficial cortex, in infants under 1 year of age. They represent 1.25% of 483 intracranial tumors in infancy studied at the Children's Hospital in the last 12 years. Five were located in the frontal lobes, with variable extension to the parietal or the parietotemporal regions, and one was located in the parietal lobe. They were all composed of a solid portion and one or more cysts, and they measured approximately 6 to 12 cm in diameter. They had spindle cells, some more plump, arranged in areas in a storiform pattern. Tumors were very rich in reticulin fibers, mimicking a mesenchymal tumor. There was very slight pleomorphism. Bizarre giant cells were not observed and lipidization was not a prominent feature. Immunoperoxidase technique was performed in all of them and showed glial fibrillary acidic protein (GFAP) in most of the tumor cells. We believe their origin is from subpial astrocytes. They probably represent a separate entity whose diagnosis cannot be accurately established without immunohistochemical techniques.
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Neurological, psychopedagogic, and psychologic long-term sequelae were evaluated in two groups of ALL patients in continuous CR for more than 2 years treated with two different CNS prophylaxis schemes. Group A, 19 patients (protocol 10-LLA-72 GATLA) received cranial irradiation 2400 rads plus IT MTX-DMT, and group B, 23 patients (protocol 1-LLA-76-GATLA) IT MTX-DMT only during induction and maintenance. All the patients were evaluated by performing neurological examination, EEG, EMG with nerve conduction velocity, CT scans, CSF studies, psychometric and psychologic studies, and neuropsychological evaluation. The most important findings were: 11 patients from group A (58%) showed abnormal CT (low density areas in the periventricular white matter, widening of subarachnoid space, ventricular dilatation, intracerebral calcification) and only one patient from group B showed CT abnormalities (p less than 0.0005). The neuropsychologic evaluation (performed by L. Bender technique and Picq-Vayer scale) showed more severe impairment (grade 3-4) in eight patients from group A (42%) and none in group B (p less than 0.001). Higher incidence of abnormalities in group A suggests the existence of more severe sequelae in the patients treated with cranial irradiation plus IT MTX-DMT than with IT MTX-DMT alone.
Of 102 patients with bacterial meningitis admitted to the Children's Hospital of Buenos Aires, 25 were selected for computed tomographic (CT) scans on the basis of altered consciousness for more than 96 hours after admission, persistent or recurrent seizures after 72 hours of antibiotic therapy, development of focal neurologic signs, increased intracranial pressure or prolonged fever. Scan findings included hydrocephalus, cerebritis, vasculitis, subdural effusion, cerebral atrophy, abscess, and ependymitis. Serial CT scans demonstrated the progression or regression of some complications. The CT scan was very useful in indicating the need for neurosurgical procedures.
The incidence of phycomicosis has increased in the last decades. Its diagnosis is very difficult and usually not established ante morten. Early treatment is of crucial importance, because despite the antifungal drugs, the mortality rate remains around 80%. The present report describes a successfully treated diabetic patient with a rhino-orbital form of the disease and an unusual complication--a cerebral abscess--in whom the clinical diagnosis was supported by the CT findings.
The prognosis of patients with cerebral abscess depends on an early and accurate diagnosis and its delay carries a high mortality. The CT is at present the diagnostic method of choice for cerebral abscess, because it identifies and localizes precisely the lesion and it allows, based on its morphological characteristic, to select the appropriate time for surgery, and a correct follow up can be easily done. Our experience with 27 cases of cerebral abscess studied by CT is analized and discussed. The mortality rate in our experience was 15%. This is still too high, but we hope and believe it can be reduced with the regular use of CT, appropriate bacteriological studies, and accurate therapeutical management.
Two cases of alexia without agraphia, one due to a cerebrovascular accident which improved spontaneously and the other in a cerebral abscess partially recovered after surgical treatment are presented. Both were anatomically verified by computed tomography. The second was also verified at surgery. A small well localized lesion of the fusiform and lingual gyri in the dominant hemisphere can lead to alexia without agraphia. The lack of involvement of the optic radiation and calcarine fissure explain the abscence of visual field defects and hence the purest type of this syndrome as shown in our first case. The involvement of the splenium of the corpus calosus and related forceps majors seems essential for a long lasting reading defect. The integrity of the dorsal or superior splenium is responsible for the abscence of the color warning defect found on about 30% of the cases of pure word blindness. The severity and ultimate progression of the alexia will depend not only upon the extension of the dominant occipital lesion but of its association with the damage of other possible pathways. A slowly growing and potentially treatable expanding lesion, as in our second case, can also produce an almost pure form of the syndrome. It appears to us that the wider use of CT will allow on the near future will lead to a better knowledge of the anatomical lesions and a better understanding of this fascinating syndrome.
Five National Hunt jockeys have been found to have post-traumatic encephalopathy- three with epilepsy and two with significant intellectual and psychological deterioration. Closer supervision is needed.
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A patient with a right thalamic oligodendroglioma developed seizures characterized by circling behavior, speech arrest, and secondarily generalized seizures. Gyratory epilepsy is relatively uncommon and may either represent a benign form of primary generalized epilepsy or occur secondary to a focal cortical lesion. Thalamic stimulation has been shown experimentally to induce circling movements, but no other clinical cases with a thalamic lesion have been described.
Our aim was to evaluate the effect of Memantine (1-amino 3,5-dimethyl-adamantane hydrochloride) on cardinal symptoms of Parkinson's disease and on the latency, duration, and magnitude of the response to a single dose of L-Dopa and on drug-induced dyskinesias. Twelve Hoehn-Yahr III-IV patients with idiopathic Parkinson's disease with motor fluctuations and drug-induced dyskinesias were randomized to the NMDA antagonist memantine or placebo in a cross-over design. A single-dose L-Dopa challenge was performed after each medication arm. A significant drug effect on the Unified Parkinson's Disease Rating Scale motor score was observed in "off" and "on" states (F(1,11) = 13.5; p < 0.003). No significant effect on drug-induced dyskinesias was seen. The results suggest that memantine may improve parkinsonian symptoms independently of dopaminergic drugs and, in contrast to recent findings with amantadine, it has no effect on drug-induced dyskinesias.
The bulbocavernous reflex (BCR), cortical pudendal evoked responses (CPERs), non-invasive cardiovascular tests and nerve conduction studies were performed in 16 patients on chronic haemodialysis and in a group of normal subjects. BCR and CPERs were more severely affected in patients with impotence. There was a significant correlation between the Valsalva ratio and P1 latency of the CPERs. The BCR and CPERs are alternative techniques for the assessment of impotence in uremic patients.
To determine the effect of unilateral posteroventral pallidotomy (PVP) on latency and duration of response to L-dopa ipsilateral and contralateral to the side of the lesion, six severe fluctuating Hoehn-Yahr IV patients with Parkinson's disease were evaluated 2 days before and after unilateral PVP. After an overnight drug holiday in a fasting state, patients were challenged with a single dose of 200/50 mg of L-dopa/ carbidopa. Sequential tapping tests every 5 minutes in both hands were used to measure changes in motor status. Duration of L-dopa effect was significantly longer after PVP (p < 0.03). Mean latency of the effect improved by 50% without reaching statistical significance. Despite a clear, asymmetric improvement of cardinal Parkinson's disease symptoms after unilateral PVP, changes in the dose-response L-dopa profile occurred symmetrically, suggesting that mechanisms underlying the two effects are distinct.