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Biomedical subjects

A K Afifi

Publications and source records attributed to A K Afifi.

8 recordsLinked to original sources
PubMed1992

Predictive value of electromyography in diagnosis and prognosis of the hypotonic infant.

To investigate the diagnostic validity of electromyography in the hypotonic infant, 79 children aged 0 to 12 months, seen over a 20-year period, were studied retrospectively. The diagnoses using clinical, muscle biopsy, and laboratory characteristics were: 25 central hypotonia, 20 spinal muscular atrophy, 20 myopathy, four myotonic dystrophy, four benign congenital hypotonia, two congenital muscular dystrophy, two myasthenia gravis, one infantile inflammatory myopathy, and one arthrogryposis multiplex congenita. Using strict criteria, electromyography accurately predicted the final diagnosis in 65% of infants with spinal muscular atrophy and was consistent with the diagnosis in another 25%. In contrast, electromyography accurately predicted the final diagnosis in only 10% of infants with myopathy and was normal in 88% of infants with central hypotonia. In infants with spinal muscular atrophy, there was no difference in the predictive value of electromyography when performed in the newborn compared to older infants. Normal distal nerve conduction velocities in infants with spinal muscular atrophy may predict prognosis, since these infants had a longer survival. Electromyography thus has a high predictive value for infantile spinal muscular atrophy but not for myopathy.

Biopsy↗
PubMed1979

Clofibrate-induced muscular syndrome. Report of a case with clinical, electromyographic and pathologic observations.

In this report the clinical features of a case of clofibrate-induced muscular syndrome, as well as the electromyographic, histochemical, light- and electron-microscopic findings are described. The clinical features are similar to those of previously reported cases. Electromyography was consistent with a myopathy. Histochemical profile was normal. The myopathology included breakdown of contractile material, deranged mitochondria, dilated sarcoplasmic reticulum profiles, accumulation of membrane bound dense bodies, discontinuities in sarcolemma and thickening of capillary basement membrane. Macrophages invaded severely affected fibers.

Adult↗
PubMed1979

Efferent connexions of the pars lateralis of the substantia nigra (SNL).

Unilateral lesions were made in the lateral nucleus of the substantia nigra in eight cats and in the zona compacta and reticularis in two cats. After a 10 days survival period, brains were perfused and stored in 10% formalin. Frozen sections were stained with the De Olmos-Ingram and Fink-Heimer silver methods for degenerating axons and terminals. Efferents from the lateral nucleus of the substantia nigra projected to the dorsolateral third of the head of the caudate nucleus, putamen, medial reticular formation, central tegmental tract, amygdala, zona compacta and reticularis of the substantia nigra, ventral anterior and ventral ateral thalamic nuclei. Projections to the amygdala, medial reticular formation and central tegmental tract were seen only in animals with lesions in the lateral nucleus of the substantia nigra. Projections to the caudate and putamen were more abundant when compared to those in the thalamus. Within the thalamus, projections to the ventral lateral nucleus were scanty compared to those in the ventral anterior nucleus. The present study compares for the first time efferent connexions of the lateral nucleus of the substantia nigra and those of the pars compacta and reticularis. The findings suggest a specialization of the different zones of the substantia nigra with regard to their projection sites.

Amygdala↗
PubMed1977

Nigro-amygdaloid fiber connections in the cat.

Relatively discrete unilateral lesions were made in the lateral portion of the substantia nigra of eight cats and in the medial substantia nigra of two. After a 10-day survival period the animals were killed, brains were stored in buffered 10% formalin, and frozen sections were stained for degenerating axons and terminals, or by Weil and cresyl violet methods. Electordes passed through the midial suprasylvian gyrus, pulvinar and/or posterolateral thalamic nucleus and the medial geniculate body. The stria terminalis and hippocampus were undamaged. Degeneration from the lesion followed two paths. One projected through the reticular nucleus into the internal capsule and then ventrolaterally below the putamen to enter the lateral and central amygdaloid nuclei, with degenerated terminals. The second path ran dorsolaterally in the internal capsule to enter the external capsule where some of the fibers spread into the lateral amygdaloid nucleus. It appears that some of the terminals in the lateral amygdaloid nucleus are from the external capsule. Perhaps these connections link the extrapyramidal system to the amygdaloid body.

Amygdala↗
PubMed1977

Postganglionic cholinergic dysautonomia.

A 9-year-old boy presented with symptoms and signs of marked postganglionic cholinergic autonomic dysfunction manifested by bilateral internal ophthalmoplegia, impaired secretion of tears and saliva, lack of gastrointestinal motility, atony of the bladder, generalized absence of sweating, and hypertension. Clinical and pharmacological studies confirmed that the abnormalities were restricted mainly to the postganglionic cholinergic autonomic system and showed evidence of postdenervation supersensitivity to parasympathomimetic drugs. The patient was treated in the early phase of his illness by the administration of carbachol, and eventually he made a slow and partial spontaneous recovery. Histoimmunofluorescent studies on a skin biopsy specimen suggested an autoimmune origin for his disease, with IgG antibodies being produced against postganglionic cholinergic autonomic fibers.

Autoimmune Diseases↗
PubMed1976

The myopahtology of congenital generalized lipodystrophy light and electron microscopic observations.

The light and electron microscopic myopathology in five patients with congenital generalized lipodystrophy consist of variation in fiber size, ringbenden, various degrees of fiber degeneration and fragmentation, accumulation of glycogen, aggregation of mitochondria. streaming of Z line, myofilamentous inclusions and dilatation of sarcoplasmic reticulum profiles. The light microscopic myopathology in the five patients is compared with the few available observations in the literature. No reports of electron microscopy of muscle in this syndrome are available in the literature. No reports of electron microscopy of muscle in this syndrome are available in the literature. It is concluded that the myopathologic features are nonspecific in nature and may be secondary to the diencephalic disturbance which is known to occur in this syndrome.

Adolescent↗
PubMed1976

Autonomous peripheral nerve activity causing generalized muscle stiffness and fasciculations: report of a case with physiological, pharmacological, and morphological observations.

A 14-year-old boy with generalized muscle weakness, stiffness and fasciculations associated with profuse and continuous electromyographic (EMG) activity is described. The spontaneous mechanical and electrical muscle activity was unaffected by sleep, general anesthesia, or spinal anesthesia but was abolished by small doses of curare, succinyl-choline, and gallamine. Proximal and distal peripheral nerve block caused moderate and marked reduction of EMG activity, respectively, thus indicating that the disorder is due to autonomous peripheral nerve activity. The delayed motor nerve conduction velocities and the structural abnormalities seen in some of the myelin sheaths by light and electron microscopic studies on sural nerve biopsy preparations constitute further evidence that the peripheral nerve is the site of abnormality in this disorder. Diphenyl hydantoin and carbamazepine maintenance therapy produced adequate clinical relief.

Adolescent↗