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Biomedical subjects

A Cruz Martínez

Publications and source records attributed to A Cruz Martínez.

At least 19 recordsLinked to original sources
PubMed1999

Central motor conduction in hereditary motor and sensory neuropathy and hereditary spastic paraplegia.

Conduction of the central motor pathways (CMCT) by magnetic stimulation of the motor cortex (TMS) was performed in 17 patients with hereditary motor sensory neuropathy (HMSN) and 2 siblings with hereditary spastic paraplegia (HSP). CMCT was prolonged in two patients with HMSN I with associated pyramidal features and in two subjects with HMSN II without clinical pyramidal signs. CMCT may be abnormal in HMSN due to central motor pathways involvement or altered spinal excitability with increased synaptic delay. CMCT was normal in the upper limbs in patients with HSP but increased in the legs. Diagnostic yield of TMS increased in less disabled cases with HSP when selective conduction at the spinal level (C7-S1) was calculated. Abnormal spinal conduction in HSP is consistent with degeneration of the crossed corticospinal tracts at the thoracic level found in neuropathologic observations.

Adolescent↗
PubMed1998

Carpal tunnel syndrome in childhood: study of 6 cases.

Six children, 4 girls and two boys, aged 5-14 years, with carpal tunnel syndrome (CTS) are reported. Median nerve entrapment had different aetiologies in each case. One patient developed unilateral CTS symptoms after intensive basketball training. He improved upon terminating this sporting activity. In 3 patients bilateral CTS was associated with Schwartz-Jampel syndrome, trigger finger and mucopolysaccharidosis I (MPS IS = Scheie syndrome), respectively. The latter subject, a boy aged 11 years who had severe bilateral muscle thenar weakness and atrophy, made a good recovery after surgery. Two cases with bilateral CTS had autosomal dominant disease. One of them showed familial CTS with thickening of the transverse carpal ligament. The other child (5 years old) presented early bilateral CTS as first manifestation of hereditary neuropathy with liability to pressure palsies (HNPP). His relatives were asymptomatic, but they showed electrophysiological and nerve biopsy changes consistent with HNPP. Nerve conduction studies (NCS) are diagnostic in paediatric CTS. Moreover, NCS is an objective method to evaluate the evolution of the nerve lesions after surgery. NCS must be performed in nerves of the propositus other than the median, as well as in first degree symptomatic and asymptomatic relatives in order to identify possible familial neuropathies.

Adolescent↗
PubMed1995

Transcranial magnetic stimulation in multiple system and late onset cerebellar atrophies.

Central motor conduction time (CMCT) after transcranial magnetic stimulation (TMS) of the cortex, electromyography and nerve conduction velocity were performed in 24 patients with multiple system (MSA) and late onset cerebellar atrophy (LOCA) (often olivopontocerebellar atrophy--OPCA -). CMCT was abnormal in 7 patients with OPCA and one with LOCA. CMCT abnormalities (43% of cases) and increased threshold (68%) were more often found within OPCA group than in another multisystem atrophy and LOCA. Reduction in amplitude of the response after TMS was significantly correlated with cerebral hemispheres's atrophy. Increased threshold was correlated with upper vermal hemisphere atrophy and enlargement of the fourth ventricle. Electrophysiologic signs of mixed peripheral neuropathy were found in 8 patients. TMS abnormalities were not related to peripheral nerve involvement. Marked variation in CMCT suggests heterogeneity in these diseases. However, the percentage of CMCT abnormalities in OPCA group suggests that TMS seems to play a role in the neurophysiological diagnosis of these heterogeneous disorders.

Adult↗
PubMed1995

Somatosensory evoked potentials and central motor pathways conduction after magnetic stimulation of the brain in diabetes.

Somatosensory evoked potentials (SEPs) on stimulating median and posterior tibial nerves, and central and spinal conduction time of the motor pathways calculated by means of magnetic stimulation of the cortex were valuated in diabetic patients. The latencies L1-Cortex and L1-C7 were significantly larger in 54 diabetics than in controls. An increment in L1-C7 interval was found in 17 patients, and the latency L1-Cortex was increased in 20. No patients showed increase in C7-Cortex interval. The increased latency L1-C7 reflects a delayed conduction along afferent spinal pathways in some patients with diabetes in contrast with the normal C7-Cortex supraspinal segment. The central and spinal conduction time after magnetic stimulation of the cortex were normal in 14 out of 15 tested diabetics suggesting that central motor pathways were spared. These results are consistent with the existence of a central-peripheral sensory axonopathy in some diabetics.

Adolescent↗
PubMed1994

[Clinical and investigative approaches in mitochondrial diseases. A review of 15 cases].

The results of laboratory investigations in concerning 15 patients suspected of mitochondrial disease (MD) are presented. Our purpose is to provide an outline of the investigative modalities that support the clinical suspicion and have been found to be useful in the diagnosis. Five clinical groups were studied including 5 exercise intolerances (2 with inflammatory myopathy), 3 with myopathies (1 with dilated cardiomyopathy), 2 with progressive external oftalmoplegia (1 associated with cerebellar ataxia+epilepsy+hypertrophic cardiomyopathy+pes cavus), 4 with encephalopathies (3 with myoclonic encephalopathies with ataxia and dementia and 1 with epilepsy and tremor), and 1 with metabolic acidosis and cardiomyopathy. We used the following categories of investigative procedures: clinical phenotype analysis including pedigree study, neurophysiological tests, bicycle ergometric evaluation, neuroimaging, microscopic study of skeletal muscle biopsy, post-mortem examination, biochemical assays and molecular genetic studies. EMG showed myopathic changes in 5 cases, features of neuropathy in 2, mixed myopathic and neuropathic pattern in 1 and nonspecific changes in 3. EMG was normal in 3 patients. The most common skeletal muscle abnormalities were variation in fiber size (60%), lipid inclusions (33.3%), oxidative subsarcolemmal aggregates (26.7%) and ragged-red fibers (26.7%). Electron microscopy revealed mitochondrial abnormalities in 8 out of 14 patients' muscle biopsies, and in myocardiac and hepatic tissues of another. Site of biochemical defect was located in 12 patients. Complex I defect in 6, complexes I+IV deficiencies in 3, complex II defect in 1, complex IV deficiency in 1, complexes II+IV deficiencies in 1, and complex III defect in 1. In 2 patients the biochemical defect was not located. Mitochondrial DNA alterations were not found in 7 investigated patients. The clinical spectrum of MD has become increasingly wider. After the clinica suspicion, the diagnosis depends up on the appropriate use of skeletal muscle biopsy, biochemical investigations and molecular genetic techniques. Conventional EMG and automatic measurement of the electromyogram are particularly helpful in confirming the clinical suspicion in patients with predominantly central nervous system disease or in cases in which clinical signs are few.

Adolescent↗
PubMed1992

Central motor conduction to upper and lower limbs after magnetic stimulation of the brain and peripheral nerve abnormalities in 20 patients with Friedreich's ataxia.

Central motor conduction time (CMCT) to thenar and soleus muscles was measured after magnetic stimulation of the cortex in 20 cases of Friedreich's ataxia (FA) and was abnormal in all. CMCT values were related to disease duration and disability. The amplitude of CMAP after cortex stimulation was severely reduced in the most disabled patients. Reduction in amplitude of the nerve evoked potentials was related neither to disease duration nor grade of disability. These results suggest that clinical worsening in FA is mainly due to progressive central motor pathway involvement. CMCT study is a better index of disease progression than peripheral nerve examination. Abnormalities in CMCT may be the third electrophysiological diagnostic criterion in FA, after reduced amplitude of nerve action potentials and absent H reflex.

Adult↗
PubMed1992

Peripheral nerve conduction and central motor conduction after magnetic stimulation of the brain in myotonic dystrophy.

Central motor conduction time was calculated after magnetic stimulation of the brain in 15 patients with myotonic dystrophy and in 38 healthy voluntaries of the same age. Conventional electromyography and motor and sensory conduction velocities were also performed. Central motor conduction time from vertex to C8 was within the normal range in all patients whereas motor conduction velocity of the peripheral nerve and amplitude of the nerve evoked potentials were slightly reduced in 3 and 2 cases respectively, supporting peripheral nerve involvement in some subjects. Our results suggest that the reported central nervous system involvement in myotonic dystrophy, including the nonspecific white matter lesions showed by magnetic resonance imaging, would not affect the conduction of the corticospinal tracts. Magnetic stimulation on the motor cortex is a painless method to study the central nervous system and apports a satisfactory approximation to central motor pathways conduction.

Adolescent↗
PubMed1991

Central motor pathways conduction after magnetic stimulation of the brain in Cockayne's syndrome.

Central motor pathways conduction abnormalities after magnetic stimulation of the brain are reported in two siblings with Cockayne's syndrome. Reduced amplitude of the responses with large central conduction time were the main changes. These results are consistent with signs of diffuse white matter hypomyelination found on MRI. Conversely, only mild changes in conduction velocity of the peripheral nerves were found. Central nervous system involvement can be more severe than peripheral neuropathy in Cockayne's syndrome.

Adolescent↗
PubMed1991

[Recurrent amyotrophic neuralgia with an unusual clinical expression. Clinical and electrophysiological study].

Neuralgic amyotrophy (NA) is an entity with great variability in its neurological expression. The patient reported here developed symptoms of NA one year before admission, with anterior interosseous nerve palsy. At the time of examination she reports pain in the left upper limb followed by sensory loss over lateral antebrachial cutaneous nerve. Electrophysiologic examination showed signs of chronic denervation in the right anterior interosseous nerve muscles, and reduced amplitude of the sensory nerve action potential of the left lateral antebrachial cutaneous nerve. This case confirms the variety of the nerve involvement in NA, and suggests axonal focal lesions of nerve fascicles or individual peripheral nerve affectation.

Adult↗
PubMed1991

[Trichinosis. A study of a large outbreak on the Iberian peninsula].

An epidemic outbreak of trichinosis after wild boar meat ingestion was analysed. The most frequent clinical manifestations were: muscular pain, fever, periorbitary edema and conjunctivitis. Laboratory tests showed eosinophilia and increased muscular enzymes. There was no mortality. 10 patients had electromyograms, which all showed an inflammatory myopathy pattern. The one fiber study showed similar signs as those found in cases of polymyositis. There was a significant statistical relationship between intensity and duration of symptoms in the intestinal phase and eosinophils levels in peripheral blood. There was also a statistically significant relationship between CPK levels and decrease of mean duration of motor unit potential. Treatment with thiabendazole and steroids was useful. The indirect immunofluorescence test (IIT) proved an excellent method for diagnosing trichinosis.

Adolescent↗
PubMed1990

[Evaluation of respiratory muscle function (maximal respiratory pressures) in myasthenia gravis].

In myasthenia gravis (MG) the status of respiratory function has a paramount importance and a careful evaluation is recommended. The weakness of respiratory muscles has been demonstrated in several studies. However, a reliable simple method for the evaluation of this muscular group was lacking until recently, when the usefulness of the maximum respiratory pressures, expiratory (MEP) and inspiratory (MIP), was demonstrated. We evaluated with this method a series of 23 patients with a diagnosis of MG (16 females and 7 males), with a mean age of 46 years (22-68 years), clinically stable and without symptomatic dyspnea. They were distributed in: grade I (5), grade II A (12), and grade II B (6). All of them were evaluated with flow-volume curves, pletysmography, gas transfer, MEP and MIP. The resulting values were then correlated with the expected ones, a reduction greater than one SD being considered as abnormal. The results showed that respiratory function was normal without a restrictive pattern. However, the force of respiratory muscles was reduced in the following proportions of patients in the different groups: grade I: MIP 40%, MEP 60%; in grades II A and II B both MEP and MIP were reduced in 84% of patients. When a statistical comparison with the expected values was carried out it was found that MEP and MIP, considered as a group, were reduced to 53% of the expected values (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Chronic inflammatory demyelinating polyneuropathy as first manifestation of human immunodeficiency virus infection.

We studied three patients who were admitted to the hospital because of progressive weakness without other systemic signs or symptoms. All three cases were young males who had been intravenous drug user for many years. Electrophysiologic study showed prolonged distal latencies and marked slowing of motor and sensory conduction velocities, consistent with primary demyelination. Nerve biopsy also showed signs of demyelination. Antibodies against HIV in CSF and blood were detected during the diagnostic evaluation. Clinical and electrophysiological studies improved in two cases after prednisone administration. Patients with predominant motor demyelinating neuropathies and risk factors should be screen for HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Conduction velocity along muscle fibers in situ in healthy infants.

The muscle fibers of the biceps brachii were stimulated distally with low voltages by means of two monopolar needles in twenty-two infants aged 2 to 14 years. The electrical activity was recorded proximally by means of a SFEMG electrode. Conduction velocity of the muscle fibers (MFCV) in situ calculated with this method had a bimodal distribution in the youngest individuals of less than 4 years, and a Gaussian distribution in children aged 5 to 14 years. Propagation velocity along muscle fibers increases with children's age and is significantly slower than in adults, in good correlation with the shorter limb perimeter and with the significantly smaller fiber diameter found in muscle biopsies in infancy. The latency of the evoked potentials was linearly related with the distance between stimulating and recording points, and muscle activity and propagation velocities were the same before and after curarization, that is consistent with the reliability of the method in infancy.

Action Potentials↗
PubMed1989

[Multifocal polyneuropathy with persistent conduction blockage. A new subset of chronic inflammatory polyneuropathies].

Recently a subset of chronic demyelinating inflammatory polyneuropathies with asymmetrical involvement limited to upper limbs, at least at the onset, resembling a multifocal mononeuropathy has been described. Electrodiagnostic testing disclosed multifocal CB outside the common entrapment sites has been described. We report a 55 years old man with a 4 years history of paresis, numbness, fasciculations, myokymia, cramps and mild amyotrophy. Electrophysiological evaluation showed proximal multifocal conduction block and abundant spontaneous activity as fasciculations, myokymia and scarce denervation activity. The importance of taking into account this entity in the differential diagnosis of patients with suspected mononeuritis multiplex or motoneuron disease is emphasized. The nosologic place of this entity is also discussed.

Arm↗