The course and prognostic factors of familial amyloid polyneuropathy after liver transplantation

Familial amyloid polyneuropathy (FAP) associated with mutations of the transthyretin (TTR) gene is the most common type of FAP, a devastating disease causing death within 10 years after the first symptoms. Because most of the amyloidogenic mutated TTR is secreted by the liver, transplantation is widely used to treat these patients, but long-term quantitative evaluation of the effects of liver transplantation on the progression of the neuropathy are not available. We have treated 45 patients with symptomatic TTR-FAP, including 43 with the Met30 TTR gene mutation, and report on the results of periodic evaluation of markers of neuropathy in 25 of them, who have been followed for more than 2 years after liver transplantation (mean follow-up 4 years). The overall survival rates at 1 and 5 years were 82 and 60%, respectively. Urinary incontinence and a low Norris score at liver transplantation were associated with poorer outcome. The motor score stabilized in seven of 11 patients (64%) with mild sensorimotor neuropathy (walking unaided) and in two of the eight patients (25%) with severe sensorimotor deficit (walking with aid) at liver transplantation. In five other patients, deterioration of motor deficit occurred only within the first year after liver transplantation, but was progressive after this interval in two patients. None of the six patients with pure sensory neuropathy developed motor loss and superficial sensory loss remained unchanged. Two years after liver transplantation, the rate of myelinated axon loss in nerve biopsy specimens was markedly lower in seven transplanted patients (0.9/mm(2) of endoneurial area/month) than in non-transplanted patients (70/mm(2) of endoneurial area/month). Symptoms of dysautonomia and quantitated cardiocirculatory autonomic tests remained unchanged. In all patients, serum mutated TTR decreased to 2.5% of pre-liver transplantation values and remained at this level during follow-up. We presently recommend liver transplantation in FAP patients at onset of first symptoms and exclusion of those with a Norris score below 55 and/or with urinary incontinence.

[Importance of neuromuscular "jitter" under stimulation in the diagnosis of myasthenia gravis]

Ninety five patients with global muscular weakness or purely extraocular weakness were included in a retrospective study. Electrical micro stimulation and single fiber electromyography were performed in all, for neuromuscular jitter evaluation in myasthenia gravis diagnosis. In our study, increased jitter was more often present (70% of generalised myasthenia gravis and 57% of ocular myasthenia gravis) than decrement after repetitive nerve stimulations (58% of generalised myasthenia gravis and 14% of ocular myasthenia gravis). Increased jitter was also found in non-myasthenic patients. With the aim of a better sensitivity and specificity of the electrophysiological diagnosis for myasthenia gravis a protocol is described.

Nerve biopsy findings in different patterns of proximal diabetic neuropathy

Besides distal symmetrical sensory polyneuropathy (DSSP), middle-aged diabetic patients may present with focal or multifocal neuropathies, including proximal neuropathy of the lower limbs, the pathophysiological features of which are uncertain. We studied 10 non-insulin-dependent diabetic patients, 45 to 72 years of age, who developed a painful proximal neuropathy of the lower limbs for which other causes of neuropathy were carefully excluded. The proximal neuropathy was asymmetrical in all patients, sensory in 4, motor and sensory in the others. Signs of DSSP were present in all. A sample of the intermediate cutaneous nerve of the thigh, a sensory branch of the femoral nerve, was taken by biopsy and examined by light and electron microscopy. Examination of the nerve specimens revealed ischemic nerve lesions in 3 patients. Nerve ischemia was associated with vasculitis and inflammatory infiltration in 2 of them. In the other patients the lesions of the cutaneous nerve of the thigh included a varying incidence of axonal and demyelinative lesions similar to those observed in DSSP, with mild inflammatory infiltration in 4 of them. The density of myelinated and of unmyelinated was variably decreased. This study shows that axonal and demyelinative lesions similar to those found in diabetic DSSP are present in proximal nerves in mild forms of proximal diabetic neuropathy; while nerve ischemia, inflammatory infiltration, and vasculitis are encountered in the most severe forms of proximal diabetic neuropathy.

Severe early-onset polyneuropathy in insulin-dependent diabetes mellitus. A clinical and pathological study

BACKGROUND AND METHODS

The pathophysiologic features of diabetic neuropathy, a common and disabling long-term complication of diabetes mellitus, are poorly understood. We studied five patients, 22 to 34 years old, in whom an uncommonly severe symmetric polyneuropathy developed soon after the onset of insulin-dependent diabetes. Their autonomic function and nerve conduction were studied, and sural-nerve biopsy specimens were examined by light and electron microscopy. Other causes of neuropathy were carefully excluded.

RESULTS

Four patients had autonomic dysfunction with postural hypotension, fainting, diarrhea, and Argyll Robertson pupils and peripheral neuropathy with loss of sensation of pain and changes in temperature that followed a pattern suggestive of a length-dependent degeneration of nerve fibers. In contrast, the fifth patient had muscle weakness and atrophy of limb extremities, with "glove and stocking" sensory loss, but little autonomic dysfunction. In the biopsy specimens of sural nerves, the mean (+/- SD) density of myelinated fibers was reduced to 20 +/- 14 percent of that measured in five control patients, and the density of unmyelinated fibers was reduced to 6 +/- 4 percent of that in the controls. Regenerating fibers accounted for 38 +/- 11 percent of the myelinated axons. Abnormalities of the myelin sheath affected 33 +/- 21 percent of the isolated fibers, and axonal degeneration 11 +/- 8 percent. Dying-back fibers, a characteristic of the centripetal degeneration of peripheral axons, were also identified. The dying-back process progressed at the rate of a few hundred micrometers per day.

CONCLUSIONS

Early-onset symptomatic polyneuropathy in patients with diabetes mellitus is characterized by the loss of both myelinated and unmyelinated nerve fibers. Spontaneous axonal regeneration is remarkably frequent, even when neuropathy is severe.

Cytomegalovirus neuropathy in acquired immunodeficiency syndrome: a clinical and pathological study

We have observed typical cytomegalovirus cytopathology associated with multifocal inflammatory and necrotic lesions of peripheral nerve in biopsy specimens from 4 patients who developed a rapidly progressive, multifocal neuropathy late in the course of human immunodeficiency virus infection. The inflammatory infiltrates, which contained numerous polymorphonuclear cells, were associated with mixed, axonal, and demyelinative lesions of nerve fibers. One of these patients improved on treatment with DHPG (9-[2-hydroxy-l(hydroxymethyl) ethoxymethyl] guanine) and remains stable after 18 months. The other 3 died soon after the onset of the neuropathy. In another patient with acquired immunodeficiency syndrome, who developed a severe, predominantly motor neuropathy of the lower limbs, the nerve biopsy did not reveal cytomegalovirus inclusions, but the neurological deficit improved on treatment with DHPG. The patient died from cachexia 2 months later; numerous cytomegalovirus lesions were found in the spinal cord at the time of postmortem examination. The multifocal necrotic endoneurial nerve lesions with polymorphonuclear cell infiltration we describe may help identify cytomegalovirus neuropathy when characteristic inclusions are not present in the biopsy specimen.

[Neurologic complications in hemodialysis patients]

Various neurological complications may occur in patients under haemodialysis for end-stage chronic renal failure. Their frequency has clearly been reduced by improvements in the modalities and techniques of dialysis. Some of these complications are related to uremia and/or to the accumulation of endogenous toxic substances the nature of which has not been elucidated (e.g. uraemic encephalopathy, polyneuropathy), while others are directly due to the haemodialysis itself (e.g. dialysis disequilibrium syndrome, aluminum encephalopathy).

[Coma and cerebral death]

The concept of cerebral death is universally accepted. It rests on a panel of signs which must all be present and constant, and provided this is the case no error is possible. No authentic case throwing doubt on this statement has ever been reported. It has been said that the term "coma dépassé" which we chose in 1959 could lead to confusion with the different degrees of coma and for this reason, be an obstacle to organ donation. I do not consider this a satisfactory explanation. In favour of the appellation "coma dépassé" are the originality of its first description and its use in the French medical language. It does not matter if "cerebral death" is preferred, both terms being synonymous. The individualization of "coma dépassé" and the possibility of grafting organs with success are acquisitions separated by only a few years. They have made it possible to obtain the remarkable successes known to every one, they have given medical thinking a new dimension and placed upon doctors an increased responsibility.

Inflammatory lesions of peripheral nerve in a patient with human T-lymphotropic virus type I--associated myelopathy

In a patient with tropical spastic paraparesis associated with a positive titer for human T-lymphotropic virus type I, electrophysiological study detected a mixed, axonal and demyelinating, multifocal neuropathy. Perineural and perivascular infiltrates, moderate axon loss, wallerian degeneration, and demyelinating lesions of isolated fibers were present in the nerve biopsy specimen. These inflammatory lesions resembled those found in the central nervous system of patients with tropical spastic paraparesis.