Trophic functions of the neuron. V. Familial dysautonomis. Current concepts of dysautonomia: neuropathological defects

Optic atrophy in familial dysautonomia

We examined three patients with classic findings of familial dysautonomia (Riley-Day syndrome) whose visual impairment was associated with optic atrophy. The presence of an optic atrophy in familial dysautonomia is indicative of central nervous system involvement, at least in these cases. Each of these patients was first noted to have visual impairment after the first decade. The late onset of optic atrophy may partly explain its apparent rarity. Since the life span of patients with familial dysautonomia is increasing, optic atrophy may be more commonly recognized in the future.

Reduced neuronotrophic activity of fibroblasts from individuals with dysautonomia in cultures of newborn mouse sensory ganglion cells

The neuronotrophic activity of human skin fibroblast cell lines from two normal individuals and 3 individuals with Familial Dysautonomia (FD) was compared in terms of their ability to support neuron survival and neurite regeneration in cultures of newborn mouse sensory neurons. Neuronotrophic activity was assayed by culturing dissociated sensory neurons from newborn mice: (1) on fibroblast 'cell beds' consisting of monolayer cultures of living fibroblasts, (2) with medium that had been conditioned by monolayer fibroblast cultures and (3) with extracts of the cultured fibroblasts. Neurite regeneration was compared by determining the percentage of neurons that had regenerated neurites after 24 or 48 h in culture. Neuron survival was determined by counts at 48 h, 7 days and 14 days after culture initiation. Neurite regeneration and neuron survival was found to be significantly less on FD cell beds or with FD-conditioned medium than in replicate cultures with normal fibroblasts or their conditioned medium. The reduced neuronotrophic activity of FD fibroblasts or conditioned medium was still observed in the presence of antibody sufficient to block the neuronotrophic effects of purified nerve growth factor (NGF). Thus, fibroblasts from individuals with FD exhibit reduced neuronotrophic activity for newborn mouse sensory neurons that appears to be due to factor(s) other than NGF.

Ultrastructural aspects of nerves, bones, and vessels in hereditary sensory neuropathy

This study concerns two children, from the same otherwise normal family, presenting progressive spontaneous amputations of the limbs, suggesting peripheral hereditary sensory neuropathy. Samples from the distal nerves and vessels and the distal tibial epiphyses were examined ultrastructurally. The nerves showed signs of degeneration, and a typical bone necrosis, without osteoclasts, was observed in the 2 cm margin of the samples. Simultaneous modifications of the vessels suggest a neurally initiated vascular reflex resulting in bone destruction. Theories that might explain the observations are discussed.

Structural gene for beta-nerve growth factor not defective in familial dysautonomia

The developmental loss of neurons in sympathetic, sensory, and some parasympathetic ganglia in familial dysautonomia suggests an inherited defect in the action of beta-nerve growth factor (beta-NGF). The role of this growth factor in dysautonomia has been difficult to resolve as there is no known source of authentic human beta-NGF. The availability of a cloned DNA probe for the human beta-NGF gene has allowed identification of some copies of the gene (alleles) in six affected families. Alleles differ in the length of restriction endonuclease fragments that hybridize to DNA probes for the gene. In two families, affected children did not inherit the same two alleles at the beta-NGF locus. Since this disease is transmitted in an autosomal recessive manner, affected children must share the same alleles at the locus causing the disease. This analysis excludes the beta-NGF gene region as the cause of this neurologic disease but does not eliminate other genes involved in beta-NGF action, such as those coding for processing enzymes, receptors, or other subunits of the NGF complex.

Congenital megacolon associated with familial dysautonomia

A 4-year-old child suffering from both familial dysautonomia (FD) and congenital megacolon (CM) is described. The possibility of a single etiology of the two conditions is discussed.

Reduced substance P-like immunoreactivity in hereditary sensory neuropathy of pointer dogs

Two unrelated Pointer dogs, each from a breeding of normal parents which produced three affected pups in a litter of nine, began to bite their paws at 3 and 5 months of age. Insensitivity to painful stimuli was marked in the distal parts of the limbs and receded proximally. The affected dogs were euthanatized at 5 and 20 months because of acral mutilation and infection. Changes affecting the primary sensory neurons included: small spinal ganglia with reduced numbers of cell bodies, degeneration of unmyelinated and myelinated fibers in dorsal roots and peripheral nerves, and reduced fiber density in the dorsolateral fasciculus (dlf). Since nociceptive loss was the salient deficit in a neuropathy affecting primary sensory neurons, immunohistochemical studies focused on substance P, the undecapeptide imputed to mediate nociception at the first synapse in the spinal cord and brain. The localization and density of substance P-like (SPL) immunoreactivity was studied in three control dogs and the two Pointers by the indirect antibody peroxidase-antiperoxidase method. The spinal intumescences of the control dogs contained dense SPL-immunoreactivity in fibers of the dlf and the superficial laminae of the dorsal horn (i.e., laminae I, II, and the dorsal part of III). Immunoreactive fascicles on the lateral aspect of the dorsal horn and in the reticular process sent contributions medially to a plexiform fiber arrangement in lamina V. Medially, SPL-immunoreactive fibers were more loosely arranged in the internal third of laminae VI and VII and in lamina X.(ABSTRACT TRUNCATED AT 250 WORDS)

Studies of cellular radiosensitivity in hereditary disorders of nervous system and muscle

Skin fibroblasts from patients with familial dysautonomia, Duchenne muscular dystrophy and Charcot-Marie-Tooth disease show normal sensitivity to ionising radiation, as measured by post-irradiation clonal growth. Previous reports of cellular hypersensitivity to ionising radiation and other DNA-damaging agents in familial dysautonomia and Duchenne muscular dystrophy have not been confirmed.

Congenital autonomic dysfunction with universal pain loss

Three patients who appear to have a previously undescribed congenital neuropathy are described. None is of Ashkenazi Jewish extraction, but each seems to fulfill the clinical diagnostic criteria for familial dysautonomia. All lack overflow tears, fungiform papillae, and deep-tendon reflexes; intradermal administration of histamine did not produce an axon flare. Intraocular instillation of dilute mecholyl produced miosis in the one patient tested. In contrast to patients with familial dysautonomia, the three patients had universal loss of pain sensation, profound hypotonia, and unusual facies. Pathologic examination of the sural nerve in one patient was not consistent with the usual findings in familial dysautonomia. These patients are believed to have a previously undescribed congenital neuropathy.

Sleep structure and nocturnal disordered breathing in familial dysautonomia

In 13 patients with familial dysautonomia sleep recordings were obtained to investigate the possibility that autonomic nervous system dysfunction plays a role in disordered breathing during sleep. Sleep structure in some of our patients was abnormal, showing decreased amount of REM sleep and increased REM latencies. All patients showed breathing disorders in sleep. The average number of apneic spells was 73.4 per night; 77% of the patients had more than 50 apneic spells per night. Abnormal breathing patterns were not uniform and were independent of patient's primary complaints. Typically, even severe respiratory irregularities were not associated with the usual cardiac response, indicating that our patients had "cardiac dysautonomia".

Neuropeptides in sensory neurons

Substance P, somatostatin, VIP, CCK, angiotensin II, and bombesin have all been localized by immunohistochemical or radioimmunological means in neurons of sensory ganglia or in the dorsal horn of the spinal cord. Most of these neuropeptides have electrophysiological effects on spinal neurons and for substance P and somatostatin, these effects have been associated with particular sensory modalities. Newer investigations using the compound capsaicin are consistent with the hypothesis that substance P is an important neurochemical mediator of certain kinds of noxious peripheral stimuli. The newly described substance P antagonists promise to be important pharmacological tools for investigation of the long-neglected neurochemical bases of sensory neuron function. Elaboration of the roles of these sensory neuropeptides will no doubt shed light on many disease states in which there seems to be sensory neuron involvement.

Gastroesophageal fundoplication and gastrostomy in familial dysautonomia

Gastric and esophageal dysfunction are components of familial dysautonomia. The limited success of various medical management programs, has led to two types of surgical intervention. Experience with nine patients who had gastrostomy alone and 12 patients who had gastroesophageal fundoplication is reviewed. Both surgical procedures decreased frequency of vomiting and pneumonias and had positive effects on weight gain. Although "dysautonomic crises" are not eliminated, sufficient modification in character occurs so that associated risks are lessened. It is suggested that if medical management cannot control recurrent pneumonia, postprandial vomiting, esophageal bleeding, and/or inadequate weight gain, then the patient should be evaluated for fundoplication and/or gastrostomy.

Behavioral effects of early deprivation of nerve growth factor: some similarities with familial dysautonomia

Female rats immunized with mouse nerve growth factor develop an antibody (anti-NGF) which reaches offspring through the placenta and via the milk. Pups exposed to maternal anti-NGF have fewer dorsal root and sympathetic neurons. When the offspring are examined on a wide variety of behavioral tests, they exhibit severe deficits in response to stress (ulceration, corticosterone levels), and mild deficits on some sensory and cognitive tasks. Exploratory and motor functions, however, are relatively normal. The pathologic and behavioral profiles of the animals closely mimic the sensory and sympathetic aspects of familial dysautonomia.

Sleep apnea and hypoventilation syndrome associated with acquired nonprogressive dysautonomia: clinical and pathological studies in a child

A 6-year-old girl had subacute onset of hypoventilation and apnea during sleep. Diffuse dysautonomic changes were identified, including dilated, nonreactive pupils, decreased tearing and sweating, and abnormal temperature and cardiovascular control. All-night polysomnographic studies revealed frequent obstructive and central sleep apnea episodes. Her serum contained cytotoxic antineuroblastoma immunoglobulins. She died two years later during sleep. The general pathological examination revealed a ganglioneuroma originating in the sympathetic ganglia. Abnormalities in the brain were confined to the brainstem and consisted of complete loss of neurons with severe fibrillary gliosis in the region of the Edinger-Westphal nuclei as well as loss of neurons with gliosis in the locus ceruleus and in the reticular formation bilaterally.

Abnormal innervation of lower limb epineurial arterioles in human diabetes

A quantitative ultrastructural analysis was made of the terminal innervation of epineurial arterioles in the sural nerve of 6 diabetic and 6 non-diabetic patients of comparable age (mean +/- SD: 68 +/- 9 non-diabetic, 65 +/- 16 diabetic) with end stage peripheral vascular disease. The results demonstrated specific differences, identifiable morphometrically, in the pattern of innervation of epineurial vessels of diabetics compared with non-diabetics. The differences were: 1) in the diabetic group the proportion of perivascular axons found less than 7 microns from the nearest smooth muscle cell was significantly less than in the non-diabetic group (p less than 0.001); 2) the mean distance of the axons from their effector sites, the vascular smooth muscle cells, was nearly twice as far in the diabetic group compared with the non-diabetic group (p less than 0.05); and 3) the mean absolute number of axons less than 7 microns from the arteriole in the diabetic group was significantly less than in the non-diabetic group (p less than 0.01). These results demonstrate that the neuropathy associated with diabetes mellitus also involves the autonomic terminal innervation of some blood vessels. In addition, this neuropathy selectively affects the vasomotor nerves closer than 7 microns to the media.

Altered nerve growth factor in fibroblasts from patients with familial dysautonomia

Nerve growth factor was measured in cultured human skin fibroblasts from controls and from patients with familial dysautonomia and dystonia musculoram deformans. Cells from these sources grown over a range of cell densities contained similar levels of beta-nerve growth factor as measured by radioimmunoassay. Results of bioassay demonstrated that the nerve growth factor from dysautonomic cells was only approximately 10% as active per ng of immunoreactive protein as that from control and dystonic cells. Treatment of fibroblasts with the beta-adrenergic agonist isoproterenol resulted in a 17- to 170-fold rise in the cyclic AMP content of both control and dysautonomic cells in 10 min. The content of immunoreactive beta-nerve growth factor in control fibroblasts increased 50--300% after 3--4 hr of exposure to isoproterenol. At no time, throughout a 7.5 hr period, was there a change in the amount of immunoreactive beta-nerve growth factor in the dysautonomic cells. These studies suggest that the molecular basis of the genetic defect in familial dysautonomia may lie in processing of the precursor or in the structure of the biologically active beta subunit of nerve growth factor.

Corneal transplantation in familial dysautonomia

A 15-year-old girl with familial dysautonomia had acute corneal ulcerations while on a respiratory during a dysautonomic crisis. Within 18 days she developed irritating corneal ring calcifications. Subsequent corneal perforation in the left eye was treated successfully with a lamellar graft, followed later by a penetrating graft in the right eye under local anesthesia. Four days postoperatively, the patient died during a vomiting crisis. Neuropathologic studies showed marked cell reduction in the superior cervical and trigeminal ganglia, but slight in the ciliary. The foveas appeared immature and macular ganglion cells were mildly reduced. The corneal button and lamellar grafted cornea had severe thinning and superficial calcification. Keratoplasty in familial dysautonomia is considered hazardous because of the continual threat of vomiting crises, but with sufficient care may be worthwhile for corneal perforation or advanced corneal scarring.

Quantitative studies of sympathetic ganglia and spinal cord intermedio-lateral gray columns in familial dysautonomia

In adult patients with familial dysautonomia the mean volume of superior cervical sympathetic ganglia is reduced to 34% of the normal of 222 mm3. Packing density of neurons is reduced to 37% of normal. The mean total number of ganglionic neurons is 120,000 as compared to 1,060,000 in controls. The mean totals of preganglionic neurons in the first three thoracic cord segments are 13,600 in patients and 25,150 in controls. Deficits in sympathetic neurons account for many of the clinical, pharmacological and biochemical manifestations of familial dysautonomia.

Pregnancy in familial dysautonomia

This report describes the first two known instances of viable pregnancies in two patients with familial dysautonomia (Riley-Day syndrome). The offspring were apparently normal. Several conditions, specifically related to autonomic and sensory dysfunction in pregnancy, are discussed.

Quantitative studies of ciliary and sphenopalatine ganglia in familial dysautonomia

In 3 patients with familial dysautonomia (FD) sphenopalatine ganglia were less than one fifth normal in volume and their total neuronal content was reduced to a mean of 1,510 (control mean 56,500). Parasympathetic denervation accounts for absence of overflow tears in FD. Ciliary ganglia were not reduced in volume and in 4 patients the mean neuron total was only slightly diminished to 2,900 (control 3,670, P less than or equal to 0.05). This does not appear sufficient to account for pupillary supersensitivity to methacholine in FD on the basis of denervation. Temporal differences in the embryogenesis of sphenopalatine and ciliary ganglia may underlie the observed differences in neuronal populations and suggest that the developmental anomaly in FD does not occur early in gestation.

Quantitative studies of dorsal root ganglia and neuropathologic observations on spinal cords in familial dysautonomia

Intrauterine development and postnatal maintenance of dorsal root ganglion neurons are abnormal in familial dysautonomia, an autosomal recessive disorder associated with autonomic, motor and sensory deficits. Normally, dorsal root ganglion weight increases with age. This does not occur in the cervical plexus ganglia of dysautonomic patients. Neurons in dorsal root ganglia are found to be markedly diminished in the youngest patients and slow degeneration causes further depletion with age. Quantitative studies on C8 dorsal root ganglia show the normal neuron content to be between 42,500 and 53,600. In 3 patients with familial dysautonomia the range was 4,090-8,590 with the smallest number being in the oldest patient. Lateral root entry zones and Lissauer's tracts are severely depleted of axons. In older patients loss of dorsal column myelinated axons becomes evident and is first seen in lumbar fasciculus gracilis, cervical fasciculus cuneatus and interfascicular fasciculus. Temperature sensation is markedly impaired from infancy in familial dysautonomia. Loss of pain sensation is prominent and worsens with age. Vibration sense diminishes in adolescence and coordination of limb movements becomes poor in older patients. Neuron depletion in dorsal root ganglia and the progressive pattern of cord changes correlate well with these clinical observations.

Myocardial infarction association with the Riley-Day syndrome

The "sudden death" of a 23-year-old Ashkenazy Jew, suffering from "familial dysautonomia" was probably caused by an arrhythmia accompanying a myocardial infarction. Such a report is unique. Diffuse coronary atherosclerosis and direct myocardial "catecholamine cardiomyopathy" seem responsible for the myocardial damage. However, diversion of the endocardial blood flow toward dpicardium and a "coronary steal" phenomenon, both the result of a sudden catecholamine discharge, could aggravate the ischemic injury.

Increased nerve-growth-factor beta-chain cross-reacting material in familial dysautonomia

To determine whether dysautonomia arises from alteration in nerve-growth factor (NGF), we measured serum levels of NGF subunits in normal and dysautonomic subjects using a biologic assay based on neurite outgrowth from chick ganglions, a binding assay based on displacement of radiolabeled betaNGF from rabbit-ganglion microsomes, and radioimmunoassays of chi, gamma and betaNGF subunits via antiserum to mouse NGF polypeptides. A threefold increase (P less than 0.001) in serum antigen levels of the biologically active subunit (betaNGF) was found for dysautonomic as compared with normal subjects. By all other assays, the groups were alike. The marked discrepancy in betaNGF levels between antigenic and functional (biologic and binding) measurements suggests a qualitative abnormaltiy of betaNGF in dysautonomia. Alternatively, elevation of betaNGF antigen can be regarded as secondary to disease. This alternative seems less likely since we must then suppose that the normalcy of functional assays in spurious.

Deficient sympathetic nervous response in familial dysautonomia

Norepinephrine concentration and dopamine-beta-hydroxylase activity were measured in the plasma of 10 dysautonomic patients and 10 normal subjects while they were reclining, standing and exercising. While reclining, dysautonomic patients had normal norepinephrine concentrations and blood pressure, but after standing they did not have a normal increase in their levels of norepinephrine (P less than 0.005), dopamine-beta-hydroxylase (P less than 0.05) or plasma protein concentration (P less than 0.01); they became hypotensive. In reclining dysautonomic patients there appeared to be a correlation between blood pressure and plasma norepinephrine concentration. These data support the view that hypertension and hypotension in dysautonomia are related to the rate of norepinephrine release.