舞蹈病-棘状红细胞增多症(附二例报告)

目的了解舞蹈病-棘状红细胞增多症（chorea-aeanthocytosis，ChAc）的临床表现及辅助检查特点，以便早期做出诊断。方法回顾分析2例ChAc患者的诊断过程，总结其临床表现、实验室检查、肌电图、头颅MRI及红细胞形态变化的特点。结果ChAc以舞蹈样不自主运动为主要临床表现，伴有肌酶增高，肌电图检查结果示失神经电位，MRI检查示脑萎缩，外周血可见棘状红细胞。结论ChAc是一种罕见的进展型、致命性神经系统运动障碍性疾病，目前治疗以对症支持为主，早期诊断有助于延长患者生命。     

神经棘红细胞增多症(附1例报告)

目的通过舞蹈-棘红细胞增多症(ChAc)的临床资料分析,提高对ChAc的认识。方法对收治的1例ChAc病例的诊断过程进行分析,结合文献复习对神经棘红细胞增多症(NA)的遗传方式、影像学和实验室检查等特点进行总结。结果NA临床症状复杂多样,其发病特点与广泛的非特异性神经系统病变、棘红细胞增多密切相关。NA治疗以对症支持为主。结论NA是一种罕见的神经退行性疾病,预后差;早发现、早诊断、早治疗可改善预后。     

Sensory action potentials and biopsy of the sural nerve in neuropathy.

In 167 consecutive patients with various types of neuropathy, the amplitude of the sensory potential and the maximum conduction velocity along the sural nerve were compared with conduction in other sensory nerves, and were related to structural changes revealed by nerve biopsy. Electrophysiological findings in the sural nerve were similar to those in the superficial peroneal and the median nerve, though the distal segment of the median nerve was normal in 20 per cent of the patients when it was abnormal in the sural nerve. Quantitation of histological findings was a more sensitive method than the electrophysiological study in that two-thirds of 33 patients with normal electrophysiology in the sural nerve showed mild loss of fibres or signs of remyelination in teased fibres. The amplitude of the sensory potential was grossly related to the number of large myelinated fibres (more than 7 micrometer in diameter). Considering the 95 nerves from which teased fibres were obtained, maximum conduction velocity was abnormal in half. In 18 of these nerves, slowing in conduction was due to axonal degeneration: the velocity was as to be expected from the diameter of the largest fibres in the biopsy ("proportionate slowing"). In 9 nerves slowing was severe and more marked than to be expected from loss of the largest fibres ("disproportionate slowing"); these nerves showed paranodal or segmental demyelination in more than 30 per cent of the fibres. In 16 nerves from patients with neuropathy of different aetiology neither loss of fibres nor demyelination could explain the moderate slowing. The cause of slowing in these nerves is unknown; other conditions are referred to in which slowing in conduction cannot be attributed to morphological changes. Finally, electrophysiological and histological findings are reported in some patients with neuropathy associated with malignant neoplasm, with rheumatoid arthritis, with polyarteritis nodosa, with acute intermittent porphyria and with cirrhosis of the liver.     

Huntington's disease--like 2 can present as chorea-acanthocytosis

Three patients from a previously described family with autosomal dominant chorea-acanthocytosis were found to have the CTG trinucleotide repeat expansion mutation of the junctophilin-3 gene associated with Huntington's disease-like 2 (HDL2). One of six previously identified patients with HDL2 had acanthocytosis on peripheral blood smear, suggesting that HDL2 should be considered in the differential of chorea-acanthocytosis.     

Late changes in human sural nerves in minamata disease and in nerves of rats with experimental organic mercury poisoning

Summary The sural nerves of 2 human cases with Minamata disease and poisoned rats were examined histopathologically. Both showed similar findings: the myelinated nerve fibres were decreased in number, but small myelinated nerve fibres were increased: The latter were irregular in shape and their Schwann cells showed regressive changes, with high electron density of the cytoplasms and many glycogen granules. Onion, bulb formation was not found. According to fibre diameter histograms, the ratio of small myelinated nerve fibres of 2–5 m showed a high percentage. A large number of the small myelinated nerve fibres were presumed to be regenerated nerve fibres. These findings are different from other peripheral neuropathies and may be characteristics of the late changes of the sural nerve induced by organic mercury compound.     

Peripheral neuropathy in amyotrophic chorea-acanthocytosis

We investigated involvement of the peripheral nervous system in 6 patients with amyotrophic chorea-acanthocytosis. Electromyographic and neurographic findings, and pathological changes as demonstrated by examination of biopsy specimens of muscle and sural nerve indicate that most patients had an axonal sensorimotor polyneuropathy with more pronounced involvement of the distal portion of the nerves. Results obtained in one patient raised the question of an anterior horn cell disorder.     

The syndrome of continuous muscle fibre activity: light and electron microscopic studies in muscle and nerve biopsies

Summary Histological and ultrastructural studies were performed on nerve and muscle biopsy specimens from two patients with the syndrome of continuous muscle fibre activity. The characteristics of muscle biopsies were as follows. By light microscopy, internal nuclei were present in many of the fibres. By electron microscopy many fibres contained filamentous bodies and subsarcolemmal aggregates of mitochondria embedded in the peripheral zone of cytoplasm, and occasional mitochondria with disorganized or branched cristae were larger than normal. Biopsies of sural nerves revealed a decreased number of myelinated fibres, clusters of small myelinated fibres, and evidence of active axonal degeneration such as disintegrated myelin segments and degenerated axon components, as well as loss of axonal contents. With the present biopsy findings, it is suggested that the pathological process of this syndrome affects peripheral nerves as well as muscles.     

Fine structural changes in the sural nerve of patients with acanthocytosis

Summary The fine structure of sural nerve biopsies is described in two brothers with normo-lipoproteinaemic acanthocytosis and an associated neurological syndrome. There was a severe reduction of myelinated fibres. The Schwann cells had an increased population of lysosomes and contained remnants of myelin. The myelin lamellae were often split at the intraperiod lines. Centrioles were found in Schwann cells, fibroblasts and endothelial cells. The significance of these findings is discussed.     

Alcoholic neuropathy. An electron-microscopic study.

The sural nerves of 6 patients with different signs of alcoholic neuropathy were studied qualitatively and quantitatively by electron microscopy. Myelinated and unmyelinated fibres showed degenerative changes of the Wallerian type. Concomitant involvement of the myelin appears to be secondary to axonal lesions. Regenerative processes, although frequently observed, did not balance the destruction of fibres in the degenerative phase. Quantitative studies indicated a reduced number of myelinated fibres and decreased percentage of the area covered in cross-section by myelinated and unmyelinated axons. The histograms of myelinated fibres showed a shift to the left of the peak of large and small fibres and an increased number of small-sized fibres. Similarly the histograms of unmyelinated fibres showed a shift to the left and a bimodal distribution with an increased number of small-sized fibres. Imbalance in degenerative and regenerative processes seems to be the basis of the chronic partial denervation observed in the nerves of alcoholic patients in this study.     

TULLIDORA (KARWINSKIA HUMBOLDTIANA) TOXIN MAINLY AFFECTS FAST CONDUCTING AXONS

Cats were given a single oral dose of ether extracts from tullidora ( Karwinskia hunboldtiana ) fruit which contains an identified neurotoxin. Acute experiments were performed 4–7 weeks after toxin administration when flaccid limb paralysis was evident. Normal cats were used as controls. The medial gastrocnemius, the soleus and the sural nerves were electrically stimulated and the unitary potentials evoked by the stimuli were extracellularly recorded from spinal root filaments to measure the conduction velocity of single fibres. In control cats, the average conduction velocity (CV) was greater in medial gastrocnemius motor fibres than in the afferent ones of the same nerve and the soleus motor axons, whereas in the sural nerve CV was less than in the aforementioned cases. The CV values and the proportion of fast conducting fibres (> 80 m/s) in each nerve were directly related ( r = 0.99). In treated cats, CV diminished in all the nerves studied, but the conduction velocity was further reduced in the faster fibres. Consequently, the motor division of the medial gastrocnemius nerve, normally composed of a high proportion (57%) of fast fibres, was more affected by tullidora and the sural nerve, which has the lowest proportion (0.7%) of these type of fibres, was the less affected. Our findings suggest that the preferential involvement of motor nerves in the experimental tullidora (buckthorn) neuropathy, as well as the preservation of somatic sensation in quadriplegic children accidentally poisoned with tullidora, are related to the distribution of axonal diameters in peripheral nerves.     

Familial mitochondrial myopathy associated with peripheral neuropathy: partial deficiencies of complex I and complex IV

Two brothers, 46 and 48 years old, presented with optic atrophy and blepharoptosis since childhood, and later developed muscle wasting and weakness of the extremities, and glove and stocking type sensory impairment. Biopsies of muscles and sural nerves clearly showed mitochondrial myopathy with many ragged-red fibers and peripheral neuropathy with onion-bulb formation. Biochemical studies of muscles disclosed partial deficiencies of complexes I and IV of the mitochondrial respiratory chain in both cases. Since the parents were first cousins, this mitochondrial disorder seemed to be transmitted as an autosomal recessive trait.     

"Myopathic" changes in chorea-acanthocytosis. Clinical and histopathological studies

Four cases of chorea-acanthocytosis were studied with special reference to muscular changes. All the cases showed the clinical stigmata of oro-linguo-facial dyskinesia with tongue biting, mild neurogenic muscular involvement and acanthocytosis. Serum creatine kinase (CK) was persistently elevated, showing MM type isozyme predominance. Histopathological studies of the peroneus brevis muscle showed prominent small group atrophy, increase of small fibers on diameter analysis, frequent angulated fibers, and angulated fibers with increased acid phosphatase activity. These findings are compatible with chronic denervation. However, central nucleation (approximately 10%) and fiber splitting (2-8%) were also found in all cases. These are compatible with myopathic changes. No correlation of these "myopathic" changes and serum CK levels was found. The "myopathic" findings are probably secondary to chronic denervation.     

Substance P in subdivisions of the sciatic nerve, and in red and white skeletal muscles

Substance P (SP) has been determined by radioimmunoassay in the sciatic nerve and its fibular, tibial and sural branches; and in a red, slow-twitch and a white, fast-twitch muscle supplied by the sciatic nerve. The mixed sciatic nerve contained 25 ng SP per g tissue wet wt., while the sural branch, which is supplying mainly skin, and thus is rich in sensory fibres, had a significantly higher content (49 ng/g). The mixed fibular and tibial branches contained approximately the same amount as the sciatic nerve proper. SP was also found in the skeletal muscles. The red m. soleus had a significantly higher content (0.61 ng/g) than the white m. extensor digitorum longus (0.22 ng/g). A dorsal root lesion which leads to degeneration of sensory fibres, reduced the SP level more than 90% both in nerves and muscles. Ventral root section, which leads to degeneration of somato-motor fibres and terminals, had, on the other hand, no effect. We conclude that sensory neurons are the only source of importance for SP in the sciatic nerve and in skeletal muscles. Based on the above findings, the possibility that SP may function as a mediator of an axon reflex in skeletal muscle is discussed.     

Arthrogryposis multiplex congenita: Part 2: Muscle pathology and pathogenesis

Pathological findings are reported on 34 specimens from 16 cases of arthrogryposis multiplex congenita (AMC), including initial observations on paraffin sections from 28 muscles, and subsequent observations on six additional specimens from three of these cases studied both histologically and histochemically. Thirteen of the 34 specimens (from 11 cases) were histologically normal, probably on account of an unaffected muscle being sampled. The most constant pathological feature in the remaining specimens was a disorganization of the muscle fibres and fascicles by severe fibrosis; only three specimens (from two cases) did not show this. Very thin faintly striated muscle fibres embedded in this matrix were encountered in 10 specimens from nine cases. An attempt at grouping of these atrophic or ill-developed fibres was noticed in four specimens; but this may not be denervation atrophy. Two specimens (from two cases) showed `myopathic' features. Repeat biopsy after two to three years was carried out on two affected muscles each from three patients. Case 3 showed well preserved but uniformly small fibres. Case 4 showed extremely few and scattered small rounded fibres. Case 14 showed pronounced variation of fibre size in both, with both atrophic and hypertrophied fibres. Normal nerves and spindles were seen in all these six specimens irrespective of the state of the muscle, and excessive fibro-fatty tissue in cases 4 and 14. Histochemical examination for oxidative enzymes, ATPase, and phosphorylase in these six specimens revealed a normal checkerboard pattern and ratio of type I and type II fibres, in case 3 only. The muscles of case 4 showed a preponderance of type I fibres. One specimen from case 14, showed the same fibres reacting for both oxidative enzymes and phosphorylase, suggesting a lack of development of fibres. The intrafusal fibres were mainly of type I in all. Two possible pathogenetic mechanisms operating in early embryonic life, which may lead to the characteristic changes of AMC, are discussed: (1) a defect in the development of the muscle whereby the full recruitment of myoblasts from the mesenchyme of the limb-bud does not take place and muscles do not form adequately; (2) a lack of innervation of the muscles on account of arrested growth of anterior horn cells. The combined operation of both these mechanisms is also considered. Fibrous tissue replaces the muscle tissue that is lacking, and contractures and deformities ensue. The evidence gathered on our material, such as the very thin smooth muscle fibres, the large numbers of well-formed nerves and spindles especially in the repeat biopsies, and the above-mentioned histochemical feature, would appear to favour the hypothesis of ill-developed muscles in the production of AMC in the majority; in the rest denervation playing either a major or concurrent role.     

Insecticide poisoning. Microdissection of nerves and muscle histochemistry in 10 cases]

A sural nerve and a muscle biopsy study of patients with chronic insecticides poisoning, with teased fiber preparations, routine pathologic studies of nerves and histochemistry of muscle is reported. The sural nerves of ten patients were studied and a teased fiber preparation was done in nine. The tenth patient had only fibrosis and no myelin was found. The sural nerves were abnormal in all patients and the teased fiber preparation resulted in preponderance of type C, D and large amount of G type fibers, according to Dyck's classification. These fibers had enlargement of the axon and myelin sheath, also seen in routine sections. The muscle biopsy with routine and histochemistry methods was done in 8 cases; in 6 there was found signs of denervation; the remaining cases were normal, but these were proximal muscles. The authors conclude that the process primarily interfere with the functions of the axons, with distal axonal degeneration and a dying back phenomen.     

Accuracy of sampling methods in morphometric studies of human sural nerves.

The aim of this study was to ascertain the minimum sample required to accurately measure the total number of myelinated fibres, mean myelinated fibre density (MFD), myelinated fibre diameter (Ds) and axonal diameter (Da) in morphometric studies of sural nerve biopsies. Measurements were obtained by sampling a single fascicle or systematic sampling of up to 50% of the total transverse fascicular area of two control and eighteen pathological sural nerves showing varying degrees of demyelination and axonal degeneration. MFD and fibre size were heterogeneous between fascicles in both control and pathological sural nerves, and morphometric results from one fascicle and systematic sampling of up to 50% of the total transverse fascicular area did not accurately represent the whole myelinated fibre population in the sural nerve. For accurate morphometric data it is necessary to quantitate all the myelinated fibres in the sural nerve.     

A biopsy case of Wilson's disease pathological changes in peripheral nerves

Summary The sural nerve from a patient with'Wilson's hepato-lenticular degeneration was examined by electron microscopy. The myelin sheaths showed remarkable changes and the axons secondary changes, while the unmyelinated nerve fibres were intact. These findings demonstrate that pathological changes of peripheral nerves occur in Wilson's disease. The changes are considered to be primary degeneration of the myelin sheaths.     

Hereditary sensory neuropathy with spastic paraplegia.

Five cases of spastic paraplegia with a progressive symmetrical sensory neuropathy producing ulceration and osteomyelitis of the hands and feet are reported. The pathology in one patient, who died of secondary amyloidosis, was similar to that found by Denny-Brown in hereditary sensory radicular neuropathy with severe loss of posterior root ganglion cells and loss of myelinated fibres in both peripheral nerves and posterior columns of the spinal cord. A sural nerve biopsy in another case showed a striking loss of both myelinated and unmyelinated fibres, with some evidence of degeneration and regeneration. The inheritance is probably by an autosomal recessive gene. The prognosis in the more severe form of the disorder is poor.     

Ultrastructural changes of skeletal muscles in polyarteritis nodosa and in arteritis associated with rheumatoid arthritis

Summary Muscle biopsies from two cases of polyarteritis nodosa (PN) and one of arteritis in association with rheumatoid arthritis (RA) were examined by electron microscopy.The histological changes were similar in all three cases. The endothelial cells of the small blood vessels were often hypertrophied. Inflammatory reaction was present mainly in the vicinity of the blood vessels. Individual muscle fibres showed mostly nonspecific degenerative changes. In a case of PN, however, annulate lamellae were present in a small number of the muscle fibres. The annulate lamellae have been reported, to our knowledge, in the human skeletal muscles only in a few cases of polymyositis. In addition, two cases, one of PN and one of arteritis with RA, showed fine filamentous inclusions in the muscle fibres. Changes were also noted in the motor end-plate.A sural nerve biopsy in a case of arteritis with RA showed changes both in axons and myelin sheaths, in addition to the changes in the blood vessels similar to those in the muscle.     

The effects of axotomy on the conduction of action potentials in peripheral sensory and motor nerve fibres.

Medial gastrocnemius and sural nerves in one hindlimb of the cat were transected and prevented from regenerating. After periods ranging from 29-273 days, compound action potentials were recorded from axotomised and contralateral control nerves. The amplitude and integrated area of action potentials decreased and conduction velocity slowed following axotomy. The area under compound action potentials generated by stimulating sensory fibres declined significantly faster than that generated by stimulating motor fibres. Analysis of changes in whole nerve conduction velocity distributions showed that the velocities of fast conducting sensory fibres decreased at the most rapid rate. The conduction velocities of motor fibres and slow sensory fibres declined at significantly slower rates. The loss of electrical activity in the largest sensory nerve fibres following axotomy, may play a role in determining the faster rate at which their action potentials deteriorate.