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Biomedical subjects

A Pou

Publications and source records attributed to A Pou.

At least 37 records · Page 2Linked to original sources
PubMed1995

Motion of the cerebellar tonsils in Chiari type I malformation studied by cine phase-contrast MRI.

We studied the effects on CSF dynamics at the foramen magnum and the clinical significance of the abnormal tonsillar motion in 14 patients with Chiari type I malformation and 14 control subjects using cine phase-contrast MRI. Dynamic MRI consisted of axial and sagittal cine phase-contrast sequences. CSF and tonsillar motion were qualitatively and quantitatively evaluated, and the subarachnoid space at the foramen magnum measured. In Chiari patients, cine phase-contrast MRI detected the abnormal pulsatile motion of the cerebellar tonsils, which produced a selective obstruction of CSF flow from the cranial cavity to the spine. The amplitude of the tonsillar pulsation and the severity of the arachnoid space reduction were associated with the symptom of cough-strain headache, but not with the presence of syringomyelia. The finding of abnormal valve dynamics of the cerebellar hernia revealed by cine phase-contrast MRI conforms to the pathophysiologic mechanisms suggested in pressure register studies and opens a new possibility in the presurgical assessment of Chiari patients with exertional symptoms.

Adult↗
PubMed1992

[Neurologic syndromes associated with anti-Hu antibody. Study of 24 patients].

BACKGROUND: Twenty-four patients with neurologic involvement and anti-Hu antibodies were studied with the aim of defining the type of tumor associated, evaluating whether the clinico-pathologic picture agreed with the concept of paraneoplastic encephalomyelitis (PEM) and evaluating the treatments used. METHODS: The study was retrospective with the clinical histories being reviewed to define the neurologic syndromes, their evolution and response to the different treatments, time of appearance and type of tumor as well as the neuropathologic changes in the patients undergoing autopsy. RESULTS: In 18 patients a neoplasm was diagnosed as small cell pulmonary carcinoma (SCPC) in 89% of the cases. The neurologic picture preceded the tumor by an average of five months. The clinical pictures included: sensitive neuropathy (20 patients), cerebellous and truncus encephalicus involvement (8 patients), motor neuropathy (6 patients), cortical involvement (5 patients) and neurovegetative dysfunction (4 patients). In 55% of the patients more than one area was altered. Post mortem studies carried out on 5 patients demonstrated inflammatory infiltrates and neuronal loss in multiple areas of the nervous system. None of the patients improved with treatment. The 9 patients who only received immunodepressants evolved in a way similar to those who were not treated. In 7 of the 11 patients who received antitumoral therapy, the neurologic syndrome stabilized for at least 6 months. CONCLUSIONS: The clinicopathological picture and the associated tumor seen in patients with anti-Hu antibodies are identical to those seen in PEM. Antitumoral treatment seems to be more effective than immunodepressant treatment.

Adult↗
PubMed1991

Surface area-independent assessment of lung microvascular permeability with an amphipathic tracer.

A combination of an amphipathic-indicator-dilution (ID) diffusing tracer 1,4[14C]butanediol (B) and a hydrophilic tracer ([14C]urea) (U) was hypothesized to provide a capillary surface area- (S) independent assessment of lung microvascular permeability (P). We performed ID studies on isolated perfused dog lungs and administered randomly two interventions, increasing P by alloxan infusion and reduction in S by lobar ligation. The ratio of PS product of U (PSU) to that for butanediol (PSB) was sensitive to changes in P yet insensitive to changes in S. We performed ID studies in which the dependence of PSU and PSB on flow, hematocrit, and plasma protein binding were examined. Measurements of PSU and PSB after flow and hematocrit were changed suggested that these factors have no significant independent effects. From ID and in vitro studies we also found that no significant binding of B to plasma proteins (albumin) occurred. We concluded that ID techniques using B and U provide a consistent measure of P, despite changes in S, hematocrit, plasma protein concentration, and recruitment.

Animals↗
PubMed1990

Normal proprioceptive trigeminal afferents in patients with Sjögren's syndrome and sensory neuronopathy.

A pure sensory neuropathy due to neuronal damage in the gasserian and spinal ganglia has been described in patients with Sjögren's syndrome. Conventional electromyographic (EMG) studies can demonstrate the selective involvement of the sensory pathways but they do not provide definite evidence for the site of the lesion. Noting that the trigeminal sensory neurons carrying cutaneous and muscular afferents are differentially located in the gasserian and mesencephalic nuclei, respectively, we carried out an electrophysiological study of the trigeminofacial and trigeminotrigeminal reflexes in 5 patients with Sjögren's syndrome and pure sensory neuropathy, in 10 patients with sensory-motor neuropathies of other causes, and in 10 healthy subjects. Our results show that patients with Sjögren's syndrome and pure sensory neuropathy who exhibited abnormal blink reflexes and an abnormal, cutaneous-induced masseter silent period had normal jaw jerks, whereas patients with sensory-motor neuropathies who exhibited abnormal cutaneous responses had abnormal jaw jerks. These findings suggest that the lesion in pure sensory neuropathy involves damage to the neurons of the gasserian ganglia and not to the trigeminal axons, since an axonal lesion would be expected to involve the large axons from muscle spindle receptors.

Adult↗
PubMed1990

Pure sensory neuropathy in patients with primary Sjögren's syndrome: clinical, immunological, and electromyographic findings.

A pure sensory neuropathy caused by lymphocytic infiltration of the dorsal root ganglia has been reported in a few patients with Sjögren's syndrome. The clinical, immunological, and electromyographic findings of five patients with this type of neuropathy and primary Sjögren's syndrome were reviewed. Typical clinical indications were the presence of a chronic asymmetrical sensory deficit, initial disease in the hands with a predominant loss of the vibratory and joint position senses, and an association with Adie's pupil syndrome or trigeminal sensory neuropathy. The simultaneous impairment of the central and peripheral evoked cortical potentials suggested that there was a lesion of the neuronal cell body. The neuropathy preceded the diagnosis of Sjögren's syndrome in four patients. Four patients were positive for Ro antibodies, but systemic vasculitis or malignancy was not found after a mean follow up of six years. These findings indicate that in patients with a sensory neuropathy the diagnosis of Sjögren's syndrome has to be considered, even if the patient denies the presence of sicca symptoms, and that appropriate tests must be carried out.

Adie Syndrome↗
PubMed1990

Primary cerebral abscess due to nocardia presenting as 'ghost tumor'. Clinical and pathological study.

We report a case of a primary cerebral abscess due to Nocardia asteroides in a nonimmunocompromised patient with a particular clinical course. The first symptom (right subacute brachial palsy) and the lesion in a computed tomographic (CT) scan (left parietofrontal edema suggestive of brain tumor) disappeared after corticosteroid treatment and the patient was discharged with total recovery. After 2 months she complained of headache and visual disturbance. A new CT scan showed an annular lesion in the left occipital lobe. A cerebral biopsy was diagnosed of nocardia infection. The patient died 2 weeks after this biopsy. A postmortem study showed an occipital brain abscess but not structural abnormalities were seen in the left parietofrontal area. We believe that the first episode could be a local inflammatory response to cerebral implantation of nocardia which disappeared clinically in the CT scan and in the postmortem study after corticosteroid treatment. Then the nocardia could have displaced by the hematological route to the second and definitive cerebral lesion.

Aged↗
PubMed1990

[Multiple familial trichodiscoma].

Trichodiscomas are hamartomas of the pilar apparatus, and have been described alone or associated to other benign proliferations of the pilar complex. Two familial cases of trichodiscomas not associated to pilar alterations or systemic manifestations are described.

Adult↗
PubMed1989

[Non-infective neurologic complications associated to heroin use].

The spectrum of neurological complications associated with heroin addiction has changed in the past six years because of the progressive knowledge of the neurological complications related to HIV infection. We reviewed 48 heroin addicts with neurological complications and 452 heroin overdose who were seen in the Emergency Unit of our hospital during 1988 and the publications since 1967. Regarding the overdose we present the results of a prospective study leading to determine the causes. We emphasize the relationship with the level of total morphine in serum, instead of conjugate morphine, and with the presence of high levels of benzodiazepines found in the plasma rather than an hypothetic hypersensitivity phenomenon. We resume the neurological complications related with heroin addiction: spongiform leukoencephalopathy, epileptic seizures, stroke, transverse myelopathy and neuromuscular complications such mononeuropathy, plexopathy, acute inflammatory demyelinating polyradiculoneuropathy, rhabdomyolysis, fibrosing myopathy, musculoskeletal syndrome and acute bacterial myopathy. Some of such complications (i.e. transverse myelitis, polyradiculoneuropathy, leucoencephalopathy) must rise the suspicion of an HIV infection. Likewise, in patients assisted for overdosage we believe it's necessary rule out myoglobinuria by means of CPK serum levels and detection of urine hematic pigments without red blood cels in the urine sediment, in order to prevent and treat the renal failure. We report the results of muscular biopsy found in the musculoskeletal syndrome, which are similar to those found in alcoholic myopathy. Finally, we describe the clinical and diagnostic aspects in an unusually neuromuscular complication: the acute bacterial myopathy.

Cerebrovascular Disorders↗
PubMed1988

Comparison of two laser Doppler flowmetry systems for bone blood flow analysis.

The development of laser Doppler flowmetry (LDF) has provided a real-time, reliable method for monitoring capillary perfusion in multiple tissues. LDF has potential for the experimental and clinical assessment of bone blood flow. To compare the accuracy and ease of use of two commercially available laser Doppler flowmeters with different mechanisms for processing the Doppler-shifted component of light, estimates of bone blood flow were obtained in a sheep model using the two systems, and the values derived then compared with estimates of bone blood flow also obtained in a sheep using the technique of injection of labeled microspheres. The single-channel laser Doppler flowmeter, the LD 5000, processes the reference and Doppler-shifted beams on the surface of a single photodetector using optical heterodyning for measurement. The dual-channel flowmeter, the Periflux 2, uses two optical fibers to transmit reference and Doppler-shifted light to two separate photodetectors. The differential amplification and detection system improves the signal-to-noise ratio. Measurement of both metaphyseal (cancellous) and diaphyseal (cortical) blood flow using both LDF systems was compared with values obtained with an injection of 85Sr-labeled microspheres in three sheep. The LDF measurements were repeated after occlusion of the left femoral artery, and a 46Sc microsphere injection was performed prior to animal sacrifice. Two of the animals developed vasomotor instability, resulting in poor correlation between the measurements obtained with the Periflux 2, which is motion sensitive, and the values obtained with the microsphere method. High correlation was apparent in two of the three animals for the LD 5000 and the microsphere values.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Mononeuritis multiplex in Waldenström's macroglobulinemia.

We describe a patient with mononeuritis multiplex who had cranial nerve involvement in association with Waldenström's macroglobulinemia. Sural nerve biopsy showed abundant endoneurial granulofibrillary deposits related to microangiopathic changes. These changes were distributed in a multifocal pattern among the fascicles. Immunohistochemistry demonstrated the IgM nature of the deposit located in the endoneurial interstitium.

Biopsy↗
PubMed1987

Reduction of reperfusion injury in the canine preparation by intracoronary adenosine: importance of the endothelium and the no-reflow phenomenon.

We hypothesized that the endogenous coronary vasodilator adenosine may reduce infarct size by progressively increasing reflow in a preparation of coronary occlusion-reperfusion. After 90 min of proximal left anterior descending artery occlusion, 20 dogs were randomized to blood reperfusion with (n = 10) or without (n = 10) adenosine into the proximal left anterior descending vessel at 3.75 mg/min for 60 min after reperfusion. Regional myocardial blood flow was determined serially with microspheres and regional ventricular function was assessed by a computerized radial shortening method. At 24 hr, the area at risk was defined in vivo with monastral blue dye and area of necrosis was determined after incubation of left ventricular slices in triphenyltetrazolium chloride. Hemodynamic variables were similar in the two groups during the experimental protocol. Infarct size was significantly reduced in treated animals, both when expressed as a percentage of the area at risk (9.9 +/- 2.8% vs 40.9 +/- 6.6%, p less than .001) and as a percentage of the left ventricle (4.6 +/- 1.3% vs 18.0 +/- 3.4%, p = .002). This was associated with significant improvement in radial shortening in the ischemic zone 24 hr after reperfusion (10.1 +/- 2.5 vs -2.8 +/- 2.2%, p less than .01). Regional myocardial blood flow was significantly increased in endocardial and epicardial regions from the lateral ischemic zone 1 hr after reperfusion in adenosine-treated animals. Light microscopy demonstrated decreased neutrophil infiltration in the ischemic zone and electron microscopy showed relative preservation of endothelial structure in the subendocardium with reduced neutrophil and red cell stagnation of capillaries in the treated group. These findings suggest that intracoronary administration of adenosine after reperfusion significantly reduces infarct size and improves regional ventricular function in the ischemic zone in the canine preparation.

Adenosine↗
PubMed1987

Contralateral trigeminal neuralgia as a false localizing sign in intracranial tumors.

Three cases of contralateral trigeminal neuralgia as a false localizing sign in intracranial tumors are reported. In each patient (meningioma, 2 cases; cholesteatoma, 1 case) the tumor was asymptomatic, so that intracranial tumor had not been suspected preoperatively. In all cases, tumors were large and firm. The tumor was supratentorial in two cases. In one case, a cortically mediated mechanism may have caused the neuralgia, whereas in the remaining two cases distortion and displacement of the brain stem and compression of the contralateral Meckel's cave would explain the trigeminal nerve signs.

Adult↗