Quantitative analysis of edema in the dorsal nerve roots induced by acute mechanical compression

STUDY DESIGN: Edema in the dorsal nerve roots caused by acute compression was assessed quantitatively in the lumbar spine of the adult dog. OBJECTIVE: To establish quantitative evaluation of edema in the dorsal nerve roots and to observe changes after acute compression with time. SUMMARY OF BACKGROUND DATA: Mechanical compression induces an increase in microvascular permeability of the endoneurial capillaries and results in intraneural edema. However, there are no quantitative studies on edema in the nerve roots. METHODS: The seventh lumbar nerve root was compressed with a 60-g force clip for 10 minutes. The nerve roots were removed immediately and at 24 hours, 1 week, and 3 weeks after compression. Nerve roots from the control and the sham groups were also obtained. Before removing the nerve roots, Evans blue albumin was injected intravenously. Changes in edema were examined using fluorescence microscopy. Evans blue albumin emits a bright red fluorescence. The relative red fluorescent area was calculated using computer image analysis, and the data were used to indicate the degree of edema. RESULTS: In the compressed segment, edema was most pronounced just after decompression and reduced in nerves removed at 24 hours. In nerves removed at 1 week, edema was pronounced but was reduced at 3 weeks. In the segments closest to the spinal cord, edema was seen after 1 week and was significant after 3 weeks. In the segments closest to the dorsal root ganglion, edema was not detected at any time. CONCLUSION: In the dorsal nerve roots the degree and the area of edema changed with time elapsed after acute compression. The degree of edema 24 hours after decompression was one third the degree immediately after decompression. These results show that edema induced by mechanical compression can recover after decompression.     

Age dependent possibilities for healing in cartilage injuries (experimental investigations with animals) (author's transl)

Regenerative and degenerative changes of cartilage were studied in animals by micromorphological methods and autoradiography. Cartilage lesions of defined size were set in the femoral condyle of rabbits of variing age by means of an electrical drill developed by us. We used juvenile animals, 3 months old, and senile animals 4 years old. The lesions were studied by lightmicroscopy, electronmicroscopy and scanning electron microscopy. In young animals we were able to demonstrate prevailing reparative changes after injury and the potency for genuine regeneration originating from cartilage. Isolated chondral lesions develop reactive tissue originating mainly from superficial parts of the cartilage. When subchondral bone is exposed we see granulation tissue filling up the defect and change by metaplasia. The replacing tissue originating from superficial cartilage as well as from subchondral bone is able to fill the defect within 3 months. In the replacing tissue originating from cartilage we find fibroblasts and fibrocytes with many mitoses. Consecutively the cells are rounding increasingly. Finally chondrocytes are developing. At the same time as these reparative changes occur we see degenerative changes with decreased mucopolysaccharide synthesis, cell necroses with consecutive decrease in number of cells and singular small cluster. In old animals we could not demonstrate any reparative or regenerative changes after injuries; the artificial defect in cartilage persists. Instead, degenerative changes with signs of arthrosis are developing rapidly: chondroitin sulfate synthesis is decreased, there is ample cluster formation, cell necrosis, decrease in number of cells, and incorporation of paraplasmatic substances in cartilage. We could not demonstrate any mitoses. The causes for the inability of cartilage of aged individuals for reparative changes are discussed.     

Clinical analysis of two-level compression of the cauda equina and the nerve roots in lumbar spinal canal stenosis

STUDY DESIGN: This study is a prospective, clinical study assessing the efficacy of selective decompression of the responsible level in two-level stenosis in accordance with neurologic findings defined by the gait load test, and functional diagnosis based on selective nerve root block. OBJECTIVE: To clarify the clinical features of two-level stenosis regarding the neurologic level responsible for the symptoms, neurogenic intermittent claudication, and the outcome of selective decompression. SUMMARY OF BACKGROUND DATA: Experimental studies have indicated that double-level compression of the cauda equina induces a more severe impairment of nerve function than does single-level compression. However, few studies have focused on the clinical importance of two-level stenosis. The clinical effects of two-level stenosis on the cauda equina and nerve roots are unknown. METHODS: A total of 81 patients with lumbar spinal canal stenosis due to spondylosis and degenerative spondylolisthesis were divided into two groups, two-level stenosis at L3-L4 and L4-L5, and one-level stenosis at L4-L5, based on myelography. The types of neurogenic intermittent claudication, the level responsible for neurologic findings, and the postsurgical outcome were compared between both groups. The level responsible for the symptoms in two-level stenosis was determined in accordance with neurologic findings on the gait load test and functional diagnosis based on a selective nerve root block. All patients underwent a prospective, selective decompression at the neurologically responsible level only. The average follow-up period was 4.6 years (range, 1-8 years). RESULTS: The patients with two-level stenosis more frequently had cauda equina symptoms than those with one-level stenosis, except patients with degenerative spondylolisthesis. It was therefore assumed that two-level stenosis was associated with cauda equina impairment, Changes in neurologic condition before and after the gait test were observed in four patients with two-level stenosis. Finally, for 28 patients with two-level stenosis, the levels responsible for the neurologic symptoms were the caudal level (L4-L5) in 22 patients, the cranial level (L3-L4) in 1 patient, and both cranial and caudal levels (L3-L4 and L4-L5) in 5 patients. All stenotic levels on the myelogram were not always symptomatic in two-level stenosis. However, in one-level stenosis, all of the responsible levels completely corresponded to the myelogram. Selective decompression only at the neurologically responsible level improved neurogenic intermittent claudication in all patients. The asymptomatic levels at which the stenotic condition was left unchanged at surgery did not become symptomatic at follow-up; in addition, there was no significant difference in the postoperative outcome between two-level stenosis and one-level stenosis. CONCLUSIONS: Two-level stenosis in patients with lumbar spondylosis is associated with production of cauda equina lesions. The gait load test provides information regarding changes in symptoms and neurologic condition during exercise. The responsible levels should be determined based on neurologic findings after the gait load test and a selective nerve root block. It is uncommon for both stenotic levels to be symptomatic in patients with two-level stenosis. Less invasive surgery such as selective decompression for the responsible level in patients with two-level stenosis is a useful technique with a good potential for long-term success.     

Computed tomography of sternoclavicular joint lesions in spondylarthropathies

To evaluate the computed tomography (CT) findings of inflammatory lesions of the sternoclavicular joints (SCJ) in spondylarthropathies. DESIGN AND PATIENTS: CT scans of the SCJs were obtained in 23 patients (group 1) with inflammatory SCJ lesions in spondylarthropathies. These scans were reviewed by four readers and compared with the CT scans of 23 matched controls (group 2). Each reader had to complete a 27-item grid. RESULTS AND CONCLUSION: In the 23 patients of group 1, the mean number of observed signs was 5.3 +/- 4.2 higher (P < 0.01) than in the group of 23 matched controls (2.4 +/- 1.6). Four signs were more frequently observed (P < 0.05) in group 1: surrounded subchondral clavicular erosions and cysts, surrounded subchondral sternal cysts and sternal bone sclerosis. A cyst and/or an erosion was associated with hyperostosis and/or bone sclerosis in 9 of 23 patients in group 1. This association was not observed in group 2; the difference was significant (P < 0.001). A cyst and/or an erosive lesion was observed 18 times in group 1 versus 11 times in group 2; the difference was significant (P < 0.05). Conversely, signs of degenerative lesions (osteophytes, subchondral sclerosis, unevenness of joint surface) were no more frequently observed in controls than in group 1. This study emphasizes the diagnostic value of CT, in particular in the identification of inflammatory lesions, even when pre-existing degenerative disease is present.     

Effect of amniotic fluid in corneal sensitivity and nerve regeneration after excimer laser ablation

To examine the effect of topical application amniotic fluids on the recovery of corneal sensitivity and nerve regeneration after excimer laser photokeratectomy, excimer laser was applied to 18 rabbits (VISX 20/20, 5 Hz, 7 microns depth: nine rabbits; 100 microns depth: nine rabbits). Human amniotic fluid (AF) was topically applied to the right eyes (AF group), and a balanced salt solution (BSS) was applied to the left eyes (BSS group). Corneal sensitivity was measured by using a Cochet-Bonnet aesthesiometer after weeks 1, 2, 4, 5, 8, and 12. Nerve-regeneration status was evaluated after weeks 2, 4, 5, 8, and 12 by gold chloride staining. Corneal sensitivity was initially subnormal and recovered close to the normal level at week 8. The sensitivity was higher in the AF group than in the BSS control group, except at week 2. Subepithelial nerve regeneration at the laser site was detected both at week 4 in the AF group and at week 5 in the BSS group. There was no significant correlation between the nerve-regeneration state and sensitivity changes. Long striated nerve regeneration from the deep stromal nerve was remarkable at the third month, especially in the BSS group. The BSS group showed more marked scarring of the superficial stroma, compared with the AF group. The nerve regeneration at the scar site was discontinued and delayed. Subepithelial leash nerves in the AF group were more abundant than those in the BSS group. The recovery of sensitivity and nerve regeneration were faster in the AF cornea than in the BSS cornea. These results suggest that the factors in AF helped the recovery of corneal sensitivity, nerve regeneration, and reduced scar formation.     

Acute sensory neuronopathy: identified with electrodiagnosis and magnetic resonance imaging

We report on a 13-year-old female with idiopathic acute sensory neuronopathy mimicking a sensory form of Guillain-Barré syndrome, which was identified by using electrodiagnosis and spine magnetic resonance imaging. Motor conduction results were normal, but no sensory nerve action potentials were seen in the four limbs. On magnetic resonance imaging of the whole spine, the diffuse gadolinium enhancement of the dorsal roots in the spinal canal was detected, without evidence of intramedullary lesions. The clinical symptoms and electrodiagnostic findings had persisted for more than 18 months of follow-up.     

The effect of prolonged spinal cord compression on the extent of morphological changes in experimental spinal cord injury in rabbits

The analysis of early spinal cord decompression influence on the extent of morphological and microvascular changes after traumatic cord injury was the subject of this study, carried out on Polish-breed rabbits divided into two groups. Microvascular changes were evaluated in the first group of 20 animals and morphological changes in the second group of 36 rabbits. The injury causing paraplegia was performed at D9-D10 level by Allen method modified. Every group was subdivided into 4 subgroups depending on the duration of cord compression 2, 4, 6 and 12 hours. Fragments of cord were taken for examination 12 hours after decompression, from sites 0.5, 1.0 and 1.5 cm distant from the injury level. Histopathological analysis was performed by light and electron microscopy and for the analysis of microcirculation with microangiography the Górkiewicz method was used. Great changes were found in nerve fibres, vascular endothelium and microcirculation. The most pronounced lesions were found in the subgroup with 6-hour compression, in the form of haemorrhage, central necrosis and oedema within and around axona as well as destruction of myelin sheaths. Early decompression (within 6 hours) can reduce the extent of morphological and vascular changes.     

Collagen fibres and mechanoreceptors in regenerated menisci of rabbits

Total medial meniscectomy was carried out on 30 mature rabbits; subsequent regeneration of the meniscus and degenerative joint changes were observed. Out of 30 knees, 22 had regenerated menisci and 10 of these had not developed gross degenerative changes after 6 months. Collagen fibres were arranged irregularly in the regenerated menisci, although in some areas they occurred in parallel. Every type of mechanoreceptor was found in the outer third of the normal menisci, and in the middle and outer third of the regenerated menisci with no statistical difference in numbers. Mechanoreceptors can regenerate in regenerated menisci and may protect the join from degeneration.     

Magnetic resonance volumetry of the cerebellum in epileptic patients after phenytoin overdosages

BACKGROUND/AIMS: Cystic lesions of the orbit constitute a group of lesions with diverse clinical findings, histopathologic features and pathogenesis. METHODS: We reviewed the histopathologic and clinical records on 128 orbital cystic lesions diagnosed during a 32-year period from 1963 to 1995. RESULTS: Of the 128 orbital cystic lesions, dermoid cysts were the most frequent (38 cases, 29.7%). The other lesions, in decreasing order of frequency, were hydatid cysts (33 cases, 25.8%), mucoceles (31 cases, 24.2%), pyoceles (10 cases, 7.8%), meningoencephaloceles (9 cases, 7.0%), epidermal inclusion cysts (4 cases, 3.1%), hematoceles (2 cases, 1.6%) and teratoma (one case, 0.8%). CONCLUSIONS: Our review showed that 64.1% of patients with cystic lesions were aged 18 years or less. With the exception of mucopyoceles, all the other cystic lesions were more frequent in pediatric patients. Cystic lesions behaved clinically as benign lesions. At a mean follow-up of 6.7 years we did not observe development of malignancy in any of the cystic tumor cases though variable degrees of vision loss developed due to factors such as optic nerve compression, ocular damage and amblyopia.     

Pathophysiology and treatment of cardioembolic stroke

To elucidate the pathophysiologic mechanism of cardioembolic stroke in elderly people and to devise therapeutic strategies for it, was analyzed 120 consecutive patients (77 men and 43 women aged 65 +/- 13 years) with acute cardioembolic stroke who were admitted within 7 days of the stroke onset. We compared underlying heart diseases. NIH stroke scale on admission, lesion size on computed tomography (CT), the relation between anticoagulant therapy and recurrence, complications during admission. ADL at discharge, recurrence, and death during the follow up period in three groups: patients aged less than 65 years (the young group), those aged from 65 to 74 years (the "non-old" group), and those aged more than 75 years (the "old old" group). In the "old old" group, non valvular atrial fibrillation (75.8%) was the most common underlying heart disease and so was rheumatic heart disease (33.3%) in the "non-old" group. NIH stroke scale score (median, 11) and the proportion of patients with a large lesion (> 3 cm) of CT were higher in the "old old" group than in the other two groups. Immediate anticoagulation (A/C) within 14 days of onset was performed in more than 70% of the "non-old" and the "young old" groups but in only 57.6% of the "old old" group. Stroke recurred more often in 34 patients who did not receive immediate A/C than in the 86 who did (11.8% v.s. 2.3%. Chi square test, p = 0.053). Hemorrhage during immediate A/C and other complications (infection and pulmonary embolism) were seen in 2 and 14 patients, respectively, in both the "young old" groups, but not in the "non-old" group. Good outcomes (able to walk with or without cane) were more common in the "non-old" group (78.9%) than the other groups (57.1%, Chi square test, p < (0.01). A/C after the acute stage was done in more than 80% of those in the "non-old" and the "young old" groups, but in less than 30% of those in the "old old" group (Chi square test, p = 0.0514). Survival without recurrence during the observation period (605 +/- 550 days) was significantly lower in the "old old" group than in the other two groups (log-rank test, p = 0.0091). Cardioembolic stroke in the elderly may be characterized as follows: (1) non valvular atrial fibrillation is the most common, (2) severe neurologic deficits on admission and large lesions on CT are noted, (3) complications (infection and pulmonary embolism) often occur, (4) A/C in both acute and chronic stages are done infrequently. Therefore, the indication and intensity of A/C for primary and secondary prevention and prevention of complications are important in management of cardioembolic stroke in the elderly.     

Effect of macrophage colony stimulating factor on the advanced atherosclerosis in Watanabe heritable hyperlipidemic rabbits

We have reported that macrophage colony-stimulating factor (M-CSF) prevents atherosclerosis in young WHHL rabbits (Atherosclerosis 93:245, 1993). In the present study, we injected recombinant human M-CSF (250 micrograms/day) into WHHL rabbits aged 11 months 3 times a week after advanced atherosclerosis was established. After 8 months of treatment, we did not find any significant difference in plasma lipid levels, cholesterol ester content in the aorta or macroscopic atherosclerosis lesion area between M-CSF treated and non-treated rabbits. There was, however, a significant difference in the ratio of intimal to medial thickness (1.08 vs 1.7, p < 0.01). Thus, M-CSF may influence vascular smooth muscle cell function and modify the process of atherosclerosis in advance lesions.     

The function of sensory nerve fibers in lumbar radiculopathy. Use of quantitative sensory testing in the exploration of different populations of nerve fibers and dermatomes

STUDY DESIGN: The function of sensory nerve fibers in patients with lumbar radiculopathy and in control individuals was evaluated using quantitative sensory testing. OBJECTIVES: To investigate the effect of lumbar nerve root compression on different populations of nerve fibers and to explore the function of sensory nerve fibers in neighboring nerve roots not involved in the mechanical compression. BACKGROUND DATA: Results from experimental and clinical studies indicate that chronic compression of lumbar nerve roots affects the large myelinated nerve fibers. The majority of nerve fibers involved in the sensation of pain, however, are small afferent nerve fibers. It is therefore of interest to study the effect of compression on large and small sensory afferent channels. Several authors have elucidated the biochemical interaction between disc tissue and nerve roots. Chemical substances in the epidural space can reach the nerve fibers in nerve roots at the same or neighboring lumbar segments. In this way, fibers not involved in the mechanical compression may be affected. METHODS: The small nerve fibers were studied using tests for thermal thresholds (thermotest), and the large myelinated fibers were studied by vibrametry. Forty-two patients were investigated in the symptomatic and the asymptomatic leg, and the results were compared with those of 21 healthy individuals. RESULTS: The thresholds of cold, warmth, and vibration were significantly increased in the dermatome of the compressed nerve root, indicating that large and small sensory nerve fibers were affected. Further, the thresholds were significantly increased in the neighboring dermatomes in the symptomatic and the asymptomatic leg. CONCLUSION: Large and small sensory afferent nerve fibers are affected in lumbar radiculopathy. The increase in sensation thresholds in the ipsilateral neighboring dermatome and in the dermatomes in the asymptomatic leg indicates that adjacent nerve roots are involved in the pathophysiology of sciatica in patients with lumbar disc herniation.     

Chronic double-level cauda equina compression. An experimental study on the dog cauda equina with analyses of nerve conduction velocity

STUDY DESIGN: Nerve conduction velocity was studied in the dog cauda equina subjected to chronic double-level compression. OBJECTIVES: To analyze the effects of chronic double-level cauda equina compression. SUMMARY OF BACKGROUND DATA: Double-level cauda equina compression produces more symptoms in patients and more changes in acute experimental set-ups than does single-level compression. However, there have been no controlled, experimental studies on chronic double-level compression. METHODS: A total of 20 dogs were anesthetized. Two balloons were placed under the lamina of the seventh lumbar vertebra and the first sacral vertebra, respectively. One week (10 mm Hg, n = 5; 0 mm Hg, n = 5) and 1 month (10 mm Hg, n = 5; 0 mm Hg, n = 5) after inflation with a viscous substance, nerve conduction velocity was studied by local electrical stimulation and recording of muscle action potentials in the tail muscles. RESULTS: Nerve conduction velocity was determined over the cranial balloon, the caudal balloon, and both balloons. The data were similar for all three recordings. After 1 week there was a significant reduction in nerve conduction velocity induced by 10 mm Hg, compared with that induced by 0 mm Hg, which showed normal conditions. However, after 1 month this initial reduction in nerve conduction velocity had recovered partially. The reduction was similar to that described for single-level compression in a previous study in which the same compression model was used. CONCLUSIONS: Unlike the acute situation, chronic double-level compression does not induce more changes than single-level compression after 1 week, although the recovery after 1 month of compression is less complete after double-level compression. This less complete recovery may be a result of an adaptation of the nerve tissue and the vascularization of the cauda equina nerve roots to the applied pressure.     

Cervical radiculopathy as a form of presentation of non-Hodgkin's lymphoma

INTRODUCTION: Neurological involvement in no-Hodgkin lymphoma is usually a serious problem leading to subacute compression of the spinal cord secondary to invasion of the spinal extradural space. This condition may be the presenting form of the illness, although relatively infrequently. Onset with involvement of the cauda equina or as an isolated radiculopathy is even rarer and has mainly been described at lumbar level. CLINICAL CASE: We present the case of a 27 year old man with no significant previous clinical history who had progressive, insidious onset of moderate-serious senso-motor radiculopathy at C8. On MR there was an infiltrating mass affecting the nerve root and reaching the spinal extradural space. Following decompression laminectomy the patient's leg recovered and on histology there was a large cell B lymphoma. The other complementary tests showed disseminated disease, although analysis of the cerebro-spinal fluid (including cytology) was normal. HIV seriology was also normal. CONCLUSION: Although isolated nerve root involvement is unusual in the presentation of lymphoma it should be considered to be part of the differential diagnosis of nerve root syndromes in young patients with no history of trauma or degenerative lesions.     

Peripheral nerve allograft preservation improves regeneration and decreases systemic cyclosporin A requirements

Peripheral nerve allografting is limited by the need for long-term systemic immunosuppression. The purpose of this study was to determine if nerve allograft preservation reduced the requirements for systemic Cyclosporin A (CsA) immunosuppression. One hundred twenty Lewis rats were randomized to one of seven experimental groups. Group 1 received a 2-cm Lewis posterior tibial nerve autograft. Groups 2-7 received 2-cm ACI posterior tibial nerve allografts. The allograft group was then further subdivided into three groups of two receiving daily subcutaneous injections of 0, 2.5, or 5.0 mg/kg of CsA for 12 weeks. Within each CsA dose, one group received a fresh while the other received a preserved allograft. Preserved grafts were stored in University of Wisconsin solution for 7 days at 5 degrees C prior to implantation. Animals from each group were sacrificed at 6, 12, and 20 weeks postoperatively. Evaluations included histomorphometry, electrophysiology, and serial walking track analysis. Histology revealed varying degrees of nerve regeneration in all groups at 6, 12, and 20 weeks. For a given CsA dose, the group receiving the preserved graft revealed evidence of better nerve regeneration by all histomorphometric parameters including fiber width and density, percentage neural tissue, and total fiber number. There was no statistical difference in walking track analysis between groups at 4 weeks. By 20 weeks, functional recovery statistically poorer than autograft was seen only in the fresh allograft groups receiving 0 or 2.5 mg/kg of CsA. Identical electrophysiologic findings were seen at 20 weeks. These results suggest that nerve graft preservation may decrease systemic immunosuppression requirements while improving functional recovery. As well, storage of nerve grafts is feasible and would facilitate elective surgery and less costly reconstructive repair.     

Spatial organization of cortical and subcortical afferent projections of the neostriatum in dogs

Injury to the facial nerve in the temporal bone presents a challenge to the recovery of nerve function, in that the fallopian canal in which it lies is poorly vascularized. This study was designed to determine if wrapping an intratemporal facial nerve defect repaired with a cable graft with a well-vascularized temporoparietal fascial (TPF) flap would improve facial nerve regeneration. To evaluate this question, a defect was created in the intratemporal left facial nerve of 10 rabbits. All nerves were repaired using cable grafts. In 5 animals, the nerve graft was wrapped with temporoparietal fascia, whereas in the other 5 rabbits it was not. Three additional animals underwent exposure only. The contralateral nerve served as a control in all animals. Quantitative analysis of the nerve graft 12 weeks after repair revealed greater recovery of original fiber diameter and myelin sheath thickness in TPF flap-wrapped repairs. Histological evidence of improved neural regeneration and functional nerve recovery was also seen in the repairs where the TPF flap was utilized. Nerve conduction and electromyographic studies of the cable-grafted nerve at 6 and 12 weeks were equivocal, however.     

A new model of experimental arthrosis: contusion of the cartilage. Experimental and clinical study

The effects of a single contusion without surface disruption and without fracture of the patella were studied in 40 rabbits. Macroscopic observation as well as light and electromicroscopy revealed lesions comparable to those observed in patients with chondromalacia of the patella and arthrosis. Three successive stages can be distinguished: a degeneration of the chondrocytes, a temporary proliferative reaction and an extension of the degenerative lesions resulting in an arthrosis. This is therefore a new model of chondromalacia and experimental arthrosis which is comparable in every respect to what is observed in human traumatology.     

Cyst of the ligamentum flavum of the lumbar spine: description of 6 cases

Cysts of the ligamentum flavum of the lumbar spine have seldom been described. They are clearly visible in computed tomography as well as nuclear magnetic resonance, but are frequently wrongly diagnosed as ganglion or synovial cysts. The correct diagnosis is not feasible until after surgery. Such space occupying lesions can most often lead to uniradicular pain due to compression of a root. These cysts should be viewed as part of the degenerative process of the spine but not as tumor lesions. They need to be removed only in case of root entrapment. On the basis of six of our cases treated by surgery we describe the symptoms, imaging findings, operative techniques and pathological investigations.     

Spinal pathology in spinal muscular atrophy in comparison with amyotrophic lateral sclerosis

We analyze neuronal cytopathology and secondary reactions in spinal-muscular atrophy (SMA) in comparison with amyotrophic lateral sclerosis (ALS). In a series of SMA and ALS cases, immunohistochemistry was performed on spinal cord sections for neuronal, astroglial and microglial antigens, ubiquitin and tau proteins. Swollen motoneurons staining for phosphorylated neurofilament proteins are seen in most SMA but few ALS cases. Ubiquitinated inclusions are found only in ALS. In SMA, glial bundles are prominent in anterior roots, to lesser extent in posterior roots. In ALS, glial bundles are seen only in some cases. While basic histopathologies are similar in both types of motor neurone diseases, neuronal cytoskeletal pathology is more prominent in SMA, possibly reflecting a more acute degenerative process. The presence of axon spheroids and glial bundles also in posterior horns/roots of both types of motor neurone disease suggests spread of degenerative pathology beyond the motor system.