Phrenic nerve conduction in amyotrophic lateral sclerosis.

Respiratory failure accounts for the majority of deaths in amyotrophic lateral sclerosis (ALS). The main cause of respiratory failure is probably diaphragmatic weakness. In order to test the correlation between respiratory impairment and diaphragmatic function we studied the phrenic nerve conduction in 31 ALS patients. Our results showed that patients with respiratory symptoms, and decreased forced vital capacity with arterial PaO2/PaCO2 abnormalities, had more commonly increased phrenic nerve latencies or absent response due to severe diaphragm denervation than ALS patients without respiratory complaints. Diaphragmatic paresis commonly occurs during the course of ALS, and its presence and severity can be assessed by phrenic nerve studies. It is important to recognize the development of impairment in diaphragmatic function in order to prevent life-threatening complications.

[Acute polyradiculoneuritis associated with boutonneuse fever]. / Polirradiculonevrites agudas associadas à febre escaro-nodular.

We have recorded three cases of Mediterranean fever harboring peripheral nerve involvement. According to the time of occurrence of the neurological symptoms, the cerebrospinal fluid analysis and electromyographic features, we admit that the peripheral nervous system can be involved in two ways in this disease. One due to the direct action of the pathogenic agent, giving place to a vasculitis. The other by an immunological mechanism originating a Guillain-Barré syndrome.

Plasma catecholamines and postural hypotension in familial amyloidotic polyneuropathy of the Portuguese type.

Plasma adrenaline and noradrenaline levels were measured while supine and following head-up tilt to 45 degrees, in both normal controls and in patients with familial amyloidotic polyneuropathy of the Portuguese type. In nine patients systolic blood pressure fell by less than 15 mmHg, while in seven patients it fell by more than 15 mmHg. Plasma noradrenaline rose during tilt in the majority of patients, as in the controls. There was no correlation between levels of catecholamines and fall in blood pressure on head-up tilt. The data excludes widespread sympatho-neural failure as a cause for postural hypotension in familial amyloidotic polyneuropathy of the Portuguese type. The results are compatible with either segmental/patchy sympathetic denervation or dysfunction of the receptor/effector mechanisms in target organs such as the heart and blood vessels.

[Myocardiopathy caused by Portuguese-type familial amyloidotic polyneuropathy. Sequential morphologic and functional study of 60 patients]. / A miocardiopatia da polineuropatia amiloidótica familiar de tipo português. Estudo sequencial morfológico e funcional de 60 doentes.

AIM OF THE STUDY: To assess the cardiac involvement of familial amyloidotic polyneuropathy--Portuguese type (FAP) in a prospective study. INTRODUCTION: FAP is a sensitive, motor and autonomic familial polyneuropathy, due to amyloid deposits on nerve and vascular structures, related to abnormal transthyretin synthesis. FAP is a progressive systemic disease. The associated cardiomyopathy is well characterized in the Japanese form, but studies on FAP--Portuguese type cardiomyopathy remains controversial, regarding its occurrence and clinical and morphofunctional aspects. POPULATION: The Authors studied 60 Portuguese caucasoid patients, belonging to 55 different families: 23 women from 27 to 67 years old (m = 40.78 +/- 18.4) and 37 men, from 31 to 60 years old (m = 40.8 +/- 12.8). The diagnosis was established by characteristic clinical aspects, electromyograms and nerve or gut biopsies, positive for amyloid. Patients were classified in phases from I to VI according to the severity of neurological involvement and disability. METHODS: All the patients carried out clinical evaluation, thorax X-Ray, conventional EKG, Holter EKG (20-24 hours), M + 2D echocardiography and phonocardiography. Morphological and functional data were obtained from 85 echocardiographic recordings; special attention was paid to the evidence of structural abnormalities, evaluation of internal chamber dimension, left ventricular mass and systolic function indexes (left ventricular fractional shortening, left ventricular ejection fraction, left ventricular end-systolic stress index and Vcf). CONCLUSIONS: Suggestive aspects of pericardial and myocardial amyloid infiltration were found even in the earliest phases of the disease; all the records of patients in advanced phases (III to VI) were abnormal. The most frequent abnormalities founded were: a bright sparkling pericardial and myocardial echo pattern and increased ventricular wall thickness, with increased left ventricular mass index in 85% of patients in phases III to VI. Vcf was abnormally increased when plotted together with left ventricular end-systolic stress index, which was normal or decreased, probably reflecting "excessive" inotropism, in 1/3 of patients in phases III to VI. Systolic function was never depressed; no cardiac chamber enlarged. So, this study points out the presence of an infiltrative and/or hypertrophic cardiomyopathy in FAP--Portuguese type; suggestive aspects of diastolic dysfunction and decrease in systolic function were recorded. However, in the clinical setting of FAP, symptoms and signs like dyspnea, fatigue, oedema, may not be diagnosis of congestive heart disease.