Oculomotor abnormalities in motor neuron disease

To determine whether there are oculomotor abnormalities in motor neuron disease (MND), electrooculographic recordings were performed prospectively in 16 MND patients and the results compared with age-matched healthy controls. Parameters analysed included random and fixed saccades (latency, velocity and accuracy), smooth pursuit (gain, total harmonic distortion and number of saccadic intrusions) and optokinetic nystagmus (maximal and mean slow component velocity). Increased saccadic latencies and decreased smooth pursuit gain were the main alterations in the MND group. Correlation with clinical variables showed a positive relationship between smooth pursuit saccadic intrusions and the bulbar clinical score and the rate of progression and a lower optokinetic nystagmus maximal velocity in patients with pseudobulbar syndrome. Our results demonstrate the presence of subclinical supranuclear abnormalities in MND, and support the notion that MND is not merely a degeneration of the motor system.     

连枷臂综合征:表现为上肢无力和萎缩的良性运动神经元病

目的回顾总结3例连枷臂综合征患者的临床、电生理和骨骼肌病理改变的特点,并分析此类患者的护理策略。方法与结果3例患者均为男性,发病年龄分别为54岁、71岁和64岁,病程2～4年。主要表现为缓慢、进行性发展的双上肢肌无力和肌肉萎缩,例1和例3均于病程发展后期出现双下肢轻度无力;例2以认知功能障碍发病;例3于疾病后期出现认知功能障碍。3例神经系统检查均呈现双上肢明显肌无力,近端和远端广泛分布的肌肉萎缩,伴随肌张力下降和腱反射减退。例2和例3还同时合并下肢上运动神经元损害及认知功能障碍。对3例患者进行电生理学及病理检查显示:(1)肌电图呈静息状态下的肌纤维颤动和肌束颤动电位,胸锁乳突肌、上肢和下肢肌肉轻收缩时运动单位电位时限增宽、波幅增高或为宽大运动单位电位,重收缩时呈单纯相或混合相。例1双侧尺神经运动神经传导未发现传导阻滞现象。3例感觉和运动神经传导速度于正常值范围,诱发电位波幅有不同程度下降。(2)骨骼肌病理检查可见小角状萎缩肌纤维呈簇分布并累及Ⅰ型和Ⅱ型,伴随明显的肌纤维肥大;有肌纤维核内移现象,还原型辅酶Ⅰ四氮唑还原酶染色偶见靶样纤维,非特异性酯酶染色显示部分萎缩的肌纤维深染。结论3例患者的临床症状、体征及病变分布均符合连枷臂综合征的诊断,以双上肢的局限性损害为突出表现,同时可合并下肢的轻微损害或亚临床改变,与其他运动神经元病一样可合并认知功能障碍。由于上肢严重病残,应当注意采取相应的保护措施,避免发生意外伤害。     

The cutaneous silent period in motor neuron disease

ObjectiveTo investigate the cutaneous silent period (CSP) by measuring its onset latency, duration and amount signal suppression in patients with motor neuron disease (MND) grouped according to the intensity of upper motor neuron involvement (UMN), and to test the effect of contralateral hand contraction.MethodsPainful stimulation was applied at the V finger, and contraction recorded from the abductor digiti minimi (ADM) muscle (baseline condition). Afterwards, CSP was studied during strong contralateral ADM contraction (test condition). 10–15 consecutive traces were recorded for each condition, signals were rectified, averaged, and analyzed offline.Results46 patients were investigated, 15 with progressive muscular atrophy (PMA), 16 with typical amyotrophic lateral sclerosis (ALS), 15 with primary lateral sclerosis/predominant UMN-ALS (PLS+UMN-ALS), and 28 controls. In the baseline condition, all MND groups showed delayed onset latencies (p = 0.001). There was no significant difference in the CSP duration. Suppression was lower in the PLS + UMN-ALS group (p = 0.004). In the control group, contralateral contraction did not change CSP, but onset latency shortened significantly in the PMA group.ConclusionsCSP onset latency is delayed in all investigated groups of MND, including in PMA, indicating subclinical UMN involvement. Changes in CSP can indicate UMN lesion in MND.SignificanceCSP should be explored to identify UMN involvement in MND.     

Unusual association of sporadic olivopontocerebellar atrophy and motor neuron disease

Sporadic olivopontocerebellar atrophy (OPCA) is a neurodegenerative disorder that presents a wide clinical spectrum. Motor neuron disease (MND) is characterized by a selective degeneration of motor neurons. A 60-year-old man developed slurred speech and unsteadiness of gait. He had also noticed difficulty in holding his head upright and shoulder weakness. The disease had a rapid progression. At the age of 63 years, magnetic resonance imaging supported a diagnosis of OPCA, and a diagnosis of MND was suggested by clinical and electrophysiological findings. He also had upward gaze palsy. A muscular biopsy showed sporadic ragged red and Cox deficient fibers. The present case could define a unique disorder, as the occasional occurrence of two degenerative disorders appears unlikely. Received: 12 February 2002 / Accepted in revised form: 26 August 2002     

Cyanide metabolism in motor neuron disease

Cyanide concentrations in whole blood, saliva and urine were measured in 83 patients with motor neuron disease (MND) and age-, sex-matched control subjects consisting of 62 patients with and 49 without neurological disorders. Cyanide levels in whole blood and urine of MND patients were significantly higher than the non-neurological control groups in smokers and non-smokers. Cyanide levels in whole blood of MND patients were also higher than the neurologic control group in smokers, but not in non-smokers. There was no significant difference between the cyanide level and either the clinical types or degree of disability of MND. The results suggest that MND patients possess a disorder in cyanide metabolism.     

Ubiquitin-positive intraneuronal inclusions in the extramotor cortices of presenile dementia patients with motor neuron disease

Summary Ubiquitin-positive intraneuronal inclusions were found in the extramotor cortices of ten presenile dementia patients with motor neuron disease. There were inclusions in the hippocampal granular cells and in the small neurons of the superficial layers of the temporal and frontal cortices. Bunina bodies were present in the anterior horn cells in all cases. These results suggest that ubiquitin-related cytoskeletal abnormalities are common in cerebral non-motor small neurons in these patients.     

Mice with a mutation in the dynein heavy chain 1 gene display sensory neuropathy but lack motor neuron disease

In neurons, cytoplasmic dynein functions as a molecular motor responsible for retrograde axonal transport. An impairment of axonal transport is thought to play a key role in the pathogenesis of neurodegenerative diseases such as amyotrophic lateral sclerosis, the most frequent motor neuron disease in the elderly. In this regard, previous studies described two heterozygous mouse strains bearing missense point mutations in the dynein heavy chain 1 gene that were reported to display late-onset progressive motor neuron degeneration. Here we show, however, that one of these mutant strains, the so-called Cra mice does not suffer from motor neuron loss, even in aged animals. Consistently, we did not observe electrophysiological or biochemical signs of muscle denervation, indicative of motor neuron disease. The «hindlimb clasping» phenotype of Cra mice could rather be due to the prominent degeneration of sensory neurons associated with a loss of muscle spindles. Altogether, these findings show that dynein heavy chain mutation triggers sensory neuropathy rather than motor neuron disease.     

Immunocytochemical and ultrastructural studies of hyaline inclusions in sporadic motor neuron disease

Summary We investigated hyaline inclusion bodies (HI) immunocytochemically and ultrastructurally in six cases of sporadic motor neuron disease (MND). All HI contained large amounts of ubiquitin and some HI were stained at the core or the center with anti-neurofilament antibody, with the surrounding halo unstained. No HI were stained with antibodies raised against cytoskeletal proteins such as high-molecular weight microtubule-associated proteins and phosphorylated tau. Ultrastructurally, HI were chiefly composed of filaments measuring about 20 nm in diameter thicker than neurofilaments, and contained fine granules and frequently one or more of four characteristic profiles, i.e., small electron-dense materials resembling Bunina bodies, bundles of tubular filaments measuring approximately 20 nm in diameter, large electron-dense cores, and focal accumulations of randomly arranged neurofilaments. Hyaline inclusions can be regarded as one of the characteristic markers for sporadic MND as well as familial amyotrophic lateral sclerosis. Hyaline inclusions have a markedly heterogeneous ultrastructure and, therefore, differences in immunoreactivity with antineurofilament antibodies are not unexpected.     

Decreased synaptophysin immunoreactivity of the anterior horns in motor neuron disease

This study concerns the synaptophysin expression in anterior horn neurons of 15 patients with amyotrophic lateral sclerosis and of 4 patients with lower motor neuron disease, who had no upper motor neuron and corticospinal tract involvement. Immunohistochemical procedures were employed and specimens from 13 patients without neurological disease served as controls. A decrease in synaptophysin expression was observed in the anterior horn neuropil of all motor neuron disease patients and this reduction was correlated with the degree of degeneration or neuronal loss of anterior horn cells. Synaptophysin immunoreactivity was preserved in the proximal dendrites and around the somata of the remaining normal-appearing neurons, but it was reduced around the somata and dendrite, especially the distal portion of the proximal dendrites of small degenerated neurons with central chromatolysis, pigmentary atrophy, or simple neuronal atrophy. These observations suggest that presynaptic terminal loss is not secondary to motor cortical neuronal loss, but that the synaptic alterations in anterior horns occur in the wake of motor neuron degeneration.Supported by a Grant-in-Aid for General Scientific Research (C) from the Japanese Ministry of Education, Science and Culture, and a research grant for New Drug Development in ALS from the Ministry of Health and Welfare in Japan     

ALS功能评分和CMAP波幅对MND患者预后评估的研究

目的探讨MND患者ALSFRS与运动传导改变的相关性及其对预后评估的价值。方法2007年8月～2008年7月间符合Escorial诊断标准不同确定性水平的MND患者40例,健康志愿者102名为对照组。对所有患者均进行ALSFRS,并分别测量尺神经（腕部）-小指展肌以及胫神经（踝部）-[足母]展肌的复合肌肉动作电位（CMAP）波幅和末端运动潜伏期（DML）,分析ALSFRS与运动传导参数的关系。结果（1）肯定型ALS20例,拟诊型ALS10例,可能型ALS4例,进行性脊肌萎缩6例;（2）与对照组比较,患者组小指展肌和[足母]展肌CMAP波幅（mV）减低,尺神经DML延长（P〈0．01）;（3）ALSFRS与小指展肌和[足母]展肌CMAP波幅以及尺神经DML均呈显著相关（r分别为0．653,0．446和-0．592;P分别为0．000、0．004和0．000）;ALSFRS％30分的9例（100％）患者CMAP波幅均异常减低,31例ALSFRS≥30分的患者有17例（54．8％）的CMAP波幅异常减低（Х^2=6．25,P=0．012）;（4）随访的8例患者中6例ALSFRS在30分以下;与首次就诊相比,随访的8例患者其ALSFRS以及小指展肌CMAP波幅均减低（P〈0．05）。随访者的ALSFRS与小指展肌及[足母]展肌CMAP波幅均呈正相关（r分别为0．836和0．822;P分别为0．01和0．012）,与DML无相关（P〉0．05）。结论MND患者可出现CMAP波幅减低及DML延长;ALSFRS与CMAP波幅显著相关,二者同时减低提示预后差,可作为客观反映MND患者严重程度的可靠指标。     

Sporadic motor neuron disease with severe sensory neuronopathy

We report a 62-year-old man with sporadic motor neuron disease (MND) of 52 months’ duration with progressive sensory disturbance and high cerebrospinal fluid protein content. Neuropathologically, both the upper and lower motor neuron systems were severely affected, and light and electron microscopy revealed Bunina bodies and skein-like inclusions, which are characteristic of amyotrophic lateral sclerosis, in the remaining anterior horn cells. Moreover, there was severe degeneration without inflammatory infiltrates in the spinal posterior columns, spinal ganglia, and peripheral sensory nerves. These findings suggest that this case may be an unusual variant of sporadic MND with severe somatic sensory system involvement. Received: 27 July 1997 / Accepted: 29 October 1997     

The prognosis of adult-onset motor neuron disease: a prospective study based on the Scottish Motor Neuron Disease Register

The Scottish Motor Neuron Disease Register (SMNDR) is a prospective, collaborative, population-based project which has been collecting data on incident patients since 1989. In this report we present the clinical features of 229 patients with motor neuron disease (218 sporadic and 11 familial) diagnosed in 1989 and 1990 and compare their prognosis with previous studies of survival. The overall 50% survival from symptom onset was 2.5 years (95% CI, 2.2–3.0) and 5-year survival 28% (95% Cl, 20–36%). The presence of progressive bulbar palsy (PBP), either at presentation or developing during the course of the illness, significantly reduced survival and was the most important prognostic indicator. Patients who survived longer than 5 years from symptom onset did not have BP as part of their presenting illness. The prognosis was worse for women, and this was in part related to the higher frequency of PBP in older women, but age was also an independent adverse risk factor. Differences in survival between this and previous series can probably be explained on the basis of variation in case definition and ascertainment methods.     

Motor nerve biopsy studies in motor neuropathy and motor neuron disease

The clinical presentation of motor neuropathy often resembles that of motor neuron disease, sometimes leading to an erroneous diagnosis. Moreover, the underlying pathological process in motor neuropathy has been rarely investigated and there are no systematic studies of the affected motor nerves. We describe a new motor nerve biopsy procedure, performed in 15 patients: 6 with motor neuropathy and 9 with motor neuron disease. The motor branch from the anterior division of the obturator nerve to the gracilis muscle in the thigh was biopsied. In both groups of patients the motor nerves exhibited depletion of myelinated nerve fibers. In motor neuropathy there was a significantly higher density of regenerative clusters of small myelinated fibers in comparison to motor nerves from patients with motor neuron disease. In addition, in 3 patients with motor neuropathy there was evidence for demyelination with thinly myelinated axons and small onion bulb formations. These pathological studies of motor nerve biopsies can help to differentiate motor neuropathy from motor neuron disease. © 1997 John Wiley & Sons, Inc.     

Extrapyramidal features in patients with motor neuron disease and dementia; a clinicopathological correlative study

Motor neuron disease (MND) may be complicated by frontotemporal dementia and/or an extrapyramidal movement disorder. Several studies have identified the pathological substrate for dementia in MND as being ubiquitin-immunoreactive inclusions and dystrophic neurites in the extramotor neocortex and hippocampus. Although degenerative changes have previously been noted in the basal ganglia and substantia nigra in MND, detailed pathological studies with clinical correlation are lacking. We examined postmortem material from eight patients with a history of MND and dementia, four of whom also had prominent extrapyramidal features. All cases showed the expected degenerative changes in the pyramidal motor system and ubiquitin-positive inclusions in the extramotor cortex. In addition, the cases with a history of extrapyramidal features had striking pathology in the basal ganglia and substantia nigra; neuronal loss and gliosis ranged from moderate to severe and immunohistochemistry demonstrated numerous neuronal inclusions and dystrophic neurites, which were reactive for ubiquitin, but not tau or -synuclein. Similar pathology was either absent or much milder in cases without extrapyramidal features. This study illustrates the utility of ubiquitin immunohistochemistry in demonstrating the range of pathology in MND and provides a neuropathological correlate for the extrapyramidal features which may occur in MND with dementia.     

Chronic multifocal demyelinating neuropathy simulating motor neuron disease

We describe a patient with a chronic acquired predominantly motor polyneuropathy. His clinical picture initially led to a diagnosis of lower motor neuron form of amyotrophic lateral sclerosis. However electrophysiological examination revealed multifocal, prevalently proximal, conduction blocks at sites not prone to compression. Distinguishing this unusual polyneuropathy from motor neuron diseases is critical, since the former is a potentially, treatable disorder.

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Sommario Viene descritto un paziente con polineuropatia cronica acquisita prevalentemente motoria, inizialmente diagnosticata come sclerosi laterale amiotrofica. L'esame elettrofisiologico ha evidenziato blocchi di conduzione prevalentemente prossimali in segmenti nervosi solitamente non soggetti a compressione. Distinguere questa inusuale polineuropatia dalle malattie del motoneurone è di fondamentale importanza sia per quanto riguarda la prognosi che la terapia.

     

Infantile motor neuron disease with autonomic dysfunction and bunina bodies

A 2-month-old girl developed motor neuron disease (MND) with autonomic disturbances and died at the age of 5 months. Neuropathological examination revealed Bunina bodies (BBs) in the lower motor neurons of the lumbar spinal cord. The significance of the presence of BBs and the classification of the MND in this child are discussed. Received: 28 April 1997 / Accepted: 8 July 1997     

Synaptic loss in the proximal axon of anterior horn neurons in motor neuron disease

This report deals with an ultrastructural investigation of the synapses of the proximal axons of normal-appearing anterior horn neurons of 7 patients with amyotrophic lateral sclerosis (ALS) and 4 patients with motor neuron disease who had no upper motor neuron and corticospinal tract involvement (lower motor neuron disease, LMND). Specimens from 12 age-matched individuals who died of non-neurological diseases served as controls. Proximal axons directly emanating from the normal-appearing neurons were examined: 42 axons were from ALS patients, 43 from LMND patients and 87 from controls. Our results show that the number of synapses on axon hillocks, as well as the lengths of the synaptic contact and of the active zone were reduced in both groups of patients (P<0.0001), but no significant differences were seen between patients and controls with respect to the synaptic parameters of initial axon segments. There was no overall difference between ALS and LMND patients. These findings suggest that the electrophysiological functions pertaining to integration of electrical inputs into the axon and information transduction on the axon may be greatly impaired in the early stages of motor neuron diseases, and that the observed synaptic alterations may be pathological events, likely to be due to anterior horn neuron degeneration.     

Motor neuron disease with neurofibrillary tangles in a non-Guamanian patient

Neurofibrillary tangles are described in Guamanian and post-encephalitic forms of motor neuron discase (MND) but not in sporadic MND. We report the neuropathological findings in a 79-year-old man who died after a 1-year history of MND without extrapyramidal features or dementia. There was no family history of neurological disease and he had not visited Guam. The spinal cord showed loss of anterior horn cells, and skeletal muscle typical changes of denervation. The brain appeared macroscopically normal but histology revealed many neurofibrillary tangles, particularly in medial temporal lobe structures, insula, nucleus basalis, hippocampus, oculomotor nucleus, raphe nuclei and locus ceruleus. Neurofibrillary tangles were not seen in the primary motor cortex, which appeared histologically unremarkable. Occasional tangles were present in the substantia nigra and pontine nuclei. None were seen in the cerebellum, medulla or spinal cord. The tangles were argyrophilic, and, in sections stained with thioflavin-S, both the intracellular and the extracellular tangles fluoresced strongly under ultraviolet light. The intracellular neurofibrillary tangles reacted strongly with an antibody to tau protein, and only occasional tangles showed weak ubiquitin immunoreactivity. Scattered neuropil threads were present in the cortex in the areas of neurofibrillary tangle formation. No plaques were present in any part of the brain and no A4/ protein immunoreactivity was detected. Ultrastructural examination revealed Alzheimer-type neurofibrillary tangles composed of paired helical filaments. The present findings further extend the spectrum of diverse neurological disorders associated with neurofibrillary tangles.     

Decremental responses to repetitive nerve stimulation (RNS) in motor neuron disease

Objective

To clarify the features of decremental responses following repetitive nerve stimulation in patients with motor neuron diseases (MNDs), in comparison with myasthenia gravis (MG).

Methods

The subjects consisted of 48 MND, 39 generalized MG and 19 ocular MG patients. Six muscles, both proximal and distal muscles, were tested.

Results

Significant decrements (>5%) in at least one muscle were observed in 83% of the MND patients, and 74% and 47% of the generalized MG and ocular MG patients, respectively. Decrements were more frequently observed in the proximal muscles both in MND and MG patients (deltoid 76% and 62%, and trapezius 71% and 51% for MND and generalized MG, respectively), suggesting lower safety factors in neuromuscular transmission in those muscles. Decrements in the nasalis were rare in MND (8%) in comparison with generalized MG (54%).

Conclusions

Decremental responses were frequently observed in MND patients. There were small differences between MND and MG regarding the distribution and other features of decrements, such as the degree of the U-shape or the responses to different stimulus frequencies and to brief exercise.

Significance

These results imply that the underlying mechanism regulating the decrements is common to MND and MG.     

Motor neuron disease with multi-system involvement presenting as tetraparesis,ophthalmoplegia and sensori-autonomic dysfunction

We carried out a postmortem examination on two Japanese patients, 64- and 80-year-old men whose survival was prolonged with an artificial respirator. They had no family history of neuropsychiatric disorders and were suspected, clinically, as having a motor neuron disease that differed from amyotrophic lateral sclerosis (ALS). As well as upper and lower motor neuron impairment, they showed a variety of symptoms, such as sensory disturbances, hypohidrosis, impotence, ophthalmoparesis and/or atonic neurogenic bladder, and their protein content in cerebrospinal fluid was elevated markedly. Pathological examination revealed the following extensive nervous system involvement: (1) the upper and lower voluntary motor systems, including the IIIrd, IVth and VIth cranial nerve nuclei: (2) the reticular formation and its major afferent pathways; (3) the vestibulospinal and tectospinal systems; (4) the spinocerebellar system and the exteroceptive somatic afferent pathways; (5) the dentatorubral and pallidoluysian system; and (6) the substantia nigra, locus ceruleus and intermediolateral and Onufrowicz's nuclei. Neither Bunina bodies, Lewy body-like hyaline inclusions nor ubiquitin immunoreactive skein-like structures were observed. The distribution of the lesions was quite different from that in patients with ALS and the other known related diseases. Recently, seven autopsied cases with clinical and histopathological similarities to our patients have been reported in Japan. Our conclusion is that our two and these seven patients should be classified as having a new motor neuron disease entity, which can be is differentiated from ALS.