PubMed Health⌕ Search

Biomedical subjects

M L Luís

Publications and source records attributed to M L Luís.

18 recordsLinked to original sources
PubMed2000

[Diastolic dysfunction and left ventricular hypertrophy in familial amyloidotic polyneuropathy: a cause-effect relationship?].

UNLABELLED: TTR Met30 Familial Amyloidotic Polyneuropathy of the Portuguese type (FAP) is an incapacitating and lethal hereditary disorder that affects predominantly young adults of both genders. Portuguese type FAP patients have sensory, motor and autonomic polyneuropathy. The generalised systemic amyloid infiltration involves the heart, leading to the characteristic granular bright sparkling echocardiographic pattern. LV wall thickening occurs in the late phases of the disease. LV diastolic dysfunction has been reported in the absence of systolic dysfunction; an abnormal diastolic transmitral flow pattern assessed by pulsed wave Doppler (PW) was described. PW is very much dependent on load conditions. Tissue Doppler imaging (TDI) has been used as a more reliable method to assess long axis diastolic function. OBJECTIVE: 1--To identify the incremental value of TDI in the assessment of diastolic function in FAP. 2--To correlate diastolic pattern abnormalities and left ventricular mass index (LVMI) in FAP patients. METHODS: We performed a prospective evaluation of 24 consecutive FAP patients and selected 14 (sinus rhythm, age < 45 years). Diastolic function was assessed by PW and classified as normal (GI-E/A > 1) or abnormal (GII-E/A < 1). TDI was performed in 4 sites of the mitral annulus (septum, lateral, inferior, anterior). Velocities of the rapid filling wave (E') and atrial contraction wave (A') were measured and E'/A' calculated. In each site we considered the TDI as normal (E'/A' > 1) or abnormal (E'/A' < 1). The LVMI was calculated by Devereux's formula. RESULTS: Age, gender and heart rate were similar in both groups. TDI at the septal mitral annulus was normal in all of the GI patients (E'/A': 1.29 +/- 0.19) and suggestive of abnormal LV relaxation in all of the GII patients (E'/A': 0.82 +/- 0.11, p < 0.0001). TDI revealed abnormal diastolic pattern when a restricted number of sites of the mitral annulus were assessed, even in GI patients and before PW abnormalities occurred. Fractional shortening (FS) and LVMI were similar in GI and GII (FS-GI: 45.5 +/- 5.3, GII 43.5 +/- 8.1%, p: NS; LVMI--GI: 66 +/- 9.3, GII: 67 +/- 3.0 g/m2 p: NS). CONCLUSION: The assessment of mitral annulus motion has introduced new data in the study of diastolic function of FAP patients. An abnormal LV relaxation pattern occurred early in the evolution of the disease in patients with normal LVMI and systolic function.

Adult↗
PubMed1999

Cortical muscle representation in amyotrophic lateral sclerosis patients: changes with disease evolution.

Transcranial magnetic stimulation (TMS) mapping was performed regularly on 11 patients with amyotrophic lateral sclerosis (ALS). Map area decreased by 25% (P = 0.03) and normalized volume decreased by 47% (P = 0.01) in those patients who were mapped four times over a period of 11.6 months. The center of gravity (CoG) position moved randomly along the interaural line by distances larger than could be explained by experimental error (P = 0.002). Central conduction time, threshold, and motor evoked potential:compound muscle action potential (MEP:CMAP) amplitude ratio did not change significantly with time (P > 0.05). There were significant linear correlations between strength and CMAP amplitude and between map area and volume. No correlation was found between strength or CMAP amplitude and area or volume. The changes in map parameters were attributed primarily to loss of cortical cells. These results indicate that map parameters may be more sensitive to cortical neuronal loss than other TMS parameters.

Adult↗
PubMed1999

Fibrillation and sharp-waves: do we need them to diagnose ALS?

BACKGROUND: Fibrillation/sharp-waves (fibs-sw) are considered an essential neurophysiological marker in Amyotrophic Lateral Sclerosis (ALS). We investigated how frequently an initial electrophysiological (EMG) evaluation, performed in ALS patients, revealed no fibs-sw. METHODS: The initial EMG studies from 68 ALS patients were analysed. The presence of fibs-sw in at least two muscles of each limb and two cranial-innervated muscles was assessed. RESULTS: We observed no fibs-sw in cranial-innervated muscles, and 7/15 bulbar-onset patients had no fibs-sw in limb muscles. Two of 28 upper-limb-onset patients, who had a short history before EMG, showed no fibs-sw. All lower-limb-onset patients had fibs-sw. Generally patients with no fibs-sw had diffuse abundant fasciculations. CONCLUSIONS: The absence of fibs-sw should not necessarily preclude the neurophysiological diagnosis of ALS in bulbar-onset patients. Early affected upper-limb-onset patients might show no fibs-sw, but profuse fasciculations associated with mild to moderate denervation-reinnervation in weak muscles are found.

Adult↗
PubMed1997

Magnetic stimulation in Alzheimer's disease.

Alzheimer's disease (AD) is a common cause of dementia in which some clinical motor abnormalities have been described. We used transcranial magnetic stimulation in order to test the hypothesis that the change in the motor cortex might cause modifications in motor excitability. Fourteen mildly to moderately affected AD patients were compared with 11 controls matched for age, height and sex. The motor evoked potential threshold value for the relaxed abductor digiti minimi was lower in the AD patients than in the control group for both left and right hemispheres (P < 0.05). No statistically significant difference was found comparing the left and the right hemispheres thresholds in each population. The mean interside threshold differences were small and not significantly different between patients and controls. The spinal motor neuron excitability, as evaluated by F/M and H/M waves amplitude ratios, showed no difference between the groups, reinforcing the motor cortex increased excitability hypothesis to explain this difference. Degeneration of inhibitory gabaergic terminals might be the basis for the increased cortical excitability in the motor cortex of the Alzheimer patients; postsynaptic changes in the GABAA receptors might also affect inhibitory gabaergic transmission. The increased excitability found by transcranial magnetic stimulation in the motor cortex is important for understanding the emergence of seizures and myoclonus in this disease.

Aged↗
PubMed1997

Relapsing chronic low-dose corticosteroid-responsive multifocal motor neuropathy with conduction block.

Multifocal Motor Neuropathy (MMN) is a newly described disorder that might mimics the Motor Neuron Disease (MND). MMN is considered by some authors to be an entity distinct from Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP), nevertheless because a pure-motor variant of CIDP is well recognized and CIDP can present Partial Motor Conduction Block (PMCB), several authors believe that MMN can be a variant of CIDP. We describe a 27-year old male with a relapsing chronic low-dose corticosteroid-responsive MMN with conduction block. Our case stresses that MMN includes a wide range of motor neuropathies with different immunological profiles conditioning distinct treatment strategies.

Adrenal Cortex Hormones↗
PubMed1996

Motor neuron disease presenting with respiratory failure.

Respiratory failure accounts for the majority of deaths in amyotrophic lateral sclerosis (ALS) but only rarely is ALS diagnosed on the basis of respiratory insufficiency. We report four ALS patients presenting with acute respiratory failure. In three patients we have performed EMG needle examination of both hemidiaphragms which showed severe denervation. We reviewed 25 patients previously described presenting with respiratory failure. Almost all patients showed upper limbs weakness and diaphragm involvement; few patients had bulbar dysfunction. The prognosis of these patients is not always in permanent ventilator dependence. Rapidly progressive ventilatory failure may be a striking initial sign of ALS; the main reason is a weakened diaphragm. There are possibilities of significant improvement after a period of rest with ventilatory assistance. In the initial phase of the disease, bulbar dysfunction is not the more common reason of acute respiratory failure.

Aged↗
PubMed1996

Motor neuropathies mimicking amyotrophic lateral sclerosis/motor neuron disease.

We report three patients in whom the initial diagnosis was of possible A myotrophic lateral sclerosis (ALS/MND) according to the 'El Escorial Criteria'. All of them presented with monomelic paresis, atrophy of the paretic muscles and generalised brisk reflexes. The initial electromyograms showed a neurogenic pattern in the limbs with normal sensory and motor conduction velocities. Laboratory evaluation and imagiological investigations were normal in all of them. The previous diagnosis was changed in to demyelinating motor neuropathy with conduction block in 2 patients and tomaculous neuropathy in one after clinical and electromyographic follow-up and nerve biopsy. Patients 1 and 2 were given intravenous immunoglobulin treatment and showed moderate improvement.

Amyotrophic Lateral Sclerosis↗
PubMed1995

Somatosensory evoked potentials in the differential diagnosis between spinal cord compression and amyotrophic lateral sclerosis.

Spinal cord compression (SCC) often presents a similar clinical picture to amyotrophic lateral sclerosis (ALS). An early differential diagnosis is important because SCC is a potentially treatable clinical disorder. We carried out a longitudinal study of 43 patients with an initial diagnosis of ALS, in order to ascertain the percentage of patients with SCC, and to evaluate the usefulness of somatosensory evoked potentials (SEPs) in early diagnosis. Thirty-three patients had a final diagnosis of ALS and 8 of SCC. SEPs central conduction was abnormal in 3 ALS and 7 SCC patients, respectively (Fisher exact test, p < 0.05). We concluded that SEPs investigation is useful in the differential diagnosis between ALS and SCC patients with pure motor signs.

Adult↗
PubMed1995

[Lumbar spinal stenosis. Significance of neurophysiologic tests].

The authors review Lumbar Spinal Stenosis discussing the diagnostic criteria, the etiopathogenesis, and clinical manifestations. Imaging and neurophysiological investigations are also discussed. EMG, Sensory Evoked Potencials and Motor Stimulation are described stressing their role in differential diagnosis. The therapeutic approach is briefly commented.

Diagnosis, Differential↗
PubMed1993

[Familial amyloidotic polyneuropathy --Portuguese type-- clinical and neurophysiologic course].

Sixteen (16) patients with Familial Amyloidotic Polyneuropathy-Portuguese Type (FAP) were evaluated longitudinally, using the EMG and Clinical protocols with the aim of establishing the clinical and neurophysiological evolution rate of FAP. We conclude that spontaneous evolution of FAP patients shows a linear progression. Clinical and neurophysiological evolution times are parallel, with the EMG scores being higher than Clinical ones. We propose that Clinical and EMG scores should be used in the evaluation of future therapeutic trials, namely immunodepuration and liver transplantation.

Adult↗
PubMed1990

Magnetic resonance imaging in motor neuron disease.

Magnetic resonance imaging (MRI) of the brain was evaluated in 20 patients with motor neuron disease (MND) and in a control group of 11 healthy people. Bilateral increased signal areas of various sizes in the centrum semiovale, corona radiata, internal capsule, pedunculi of midbrain, pons, medulla and even in the frontal lobe, topographically related with the corticospinal tract, were found in 8 out of 20 patients. Three out of 4 patients with progressive bulbar paralysis and 5 out of 11 cases of amyotrophic lateral sclerosis had abnormal MRI. Such MRI abnormalities have neither been found in patients with progressive muscular atrophy nor in controls, suggesting that they may be the hallmark of pyramidal tract degeneration in motor neuron disease.

Adult↗
PubMed1978

Electroneurophysiological studies in familial amyloid polyneuropathy--Portuguese type.

Electroneurophysiological studies were performed in 15 patients with familial amyloid neuropathy (ages 29 to 67 years) and in 16 symptom-free members of affected families (ages 9 to 64 years). These studies included needle EMG, motor conduction velocities of deep peroneal and median nerves, sensory conduction velocities, sensory potentials, and nerve potentials of the sural and medium nerves. Results support the view that familial amyloid neuropathy is a peripheral neuropathy with predominantly axonal damage, which affects first the distal segments of the sensory fibres and then the motor fibres. It is suggested that, in some respects, this condition is akin to the dying-back neuropathies. Results also show that it is possible to detect the disease before it becomes obvious clinically, and this has important implications for genetic counseling.

Adolescent↗
PubMedDate not supplied

Chronic steadily progressive central and peripheral predominantly motor demyelination, involving the cranial nerves, responsive to immunoglobulins.

The association of central and peripheral demyelination was reported previously. Most of the cases refer to central chronic relapsing demyelination with clinical criteria for multiple sclerosis associated with later signs of peripheral nerve involvement. Other authors, described central lesions in patients with chronic inflammatory demyelinating polyneuropathy and in Guillain-Barré syndrome, as a seldom occurrence. We report a patient in which a chronic steadily progressive central and peripheral predominantly motor nervous system demyelination, involving the cranial nerves, was identified. The patient improved after intravenous immunoglobulin suggesting an immune-mediated mechanism. To our knowledge this presentation was not described before.

Adult↗
PubMedDate not supplied

[Myopathy caused by hypothyroidism].

The authors report a case of primary hypothyroidism where the main symptoms were caused by muscular lesions and disappeared after treatment with L-thyroxine. Based on this case study the authors then review both the clinical aspects and the diagnostical methods of hypothyroidism myopathy, noting its frequency, be it in terms of isolated laboratory changes or in terms of functional changes.

Adult↗