Femoral neuropathy

Does the L4 nerve root extend during femoral nerve stretch test? A cadaveric study of four cases analyzing the extension rates of the lumbar nerve root

BACKGROUND

Lumbar radicular pain is a common symptom of lumbar disc herniation and spinal canal stenosis, and L4 nerve root impingement is difficult to diagnose. This study aimed to elucidate the extension rate of L4 nerve roots in Thiel-embalmed specimens using both classic and new femoral nerve stretch test (FNST), as well as straight leg raising test (SLRT). Additionally, the extension rate of the L2 and L3 nerve roots and L5 and S1 roots were determined using FNST (both classic and new) and SLRT, respectively.

METHODS

Four Thiel-embalmed specimens were used. The extension rate data of the nerve root were obtained using a displacement sensor under the following conditions: knee joint flexed to 0°/45°/90°/135° with either the hip extension/flexion of 0° (classic FNST) or extension of 15° (new FNST); and hip joint flexed to 0°/30°/60°/90° with the knee flexion of 0° (SLRT).

RESULTS

Case A had almost no L4 nerve root lengthening at 45° and 90° knee joint flexion; however, at 135° of knee flexion, the nerve root was lengthened. In Case B, the L4 nerve root was hardly extended by the classic FNST, but it was extended at 135° of knee flexion and 15° of hip extension. In Case C, the L4 nerve root showed little change by classic FNST and it was shortened by new FNST, whereas, it was extended by SLRT. Case D showed a shortened L4 nerve root at 135° of knee flexion in classic FNST and at 0°/45°/90°/135° of knee flexion and 15° of hip extension. Further, no root shortening was observed for L2 and L3 nerve roots according to both classic and new FNST. In contrast, the extension of L2 and L3 nerve root with the new FNST was high. In all cases, nerve roots were lengthened by the SLRT. Further, as the hip flexion angle increased, the rate of nerve elongation also increased.

CONCLUSIONS

It was shown that in patients in whom L4 nerve root was extended by FNST, it was shortened by SLRT. The opposite pattern was also observed. Further, it is believed that FNST and SLRT are reliable tests for L2 and L3 radiculopathy and L5 and S1 radiculopathy, respectively, and that more tension on the femoral and sciatic nerves is better. Furthermore, we recommend that FNST should be performed with 15° hip extension and 135° knee flexion to improve the diagnostic accuracy.

Diabetic Mononeuropathies and Diabetic Amyotrophy

This brief review describes the etiology, pathophysiology, clinical features, therapy and prognosis of the diabetic mononeuropathies and diabetic amyotrophy and neuropathic cachexia. Mononeuropathies include cranial neuropathies, of which the oculomotor nerve is most commonly affected, and are thought to be due to microvascular occlusion. Peripherally, entrapment neuropathies occur in both the upper and lower limbs and are due to compression of an already damaged nerve in anatomically restricted channels. Diabetic radiculopathies occur in the dermatones of the thorax and abdomen, mimicking intraabdominal or intrathoracic pathology. I also describe the features of the rare but very distinctive diabetic amyotrophy and neuropathic cachexia. Overall, the prognosis from these conditions is excellent with residual pain or muscle weakness being rare with the exception of diabetic amyotrophy where the prognosis is dependent upon cooperation with intensive rehabilitation. Therapies include "watchful waiting," physical therapy and rarely surgical intervention, which may be urgently needed for nerve decompression and reversal of motor defects.

Lumbosacral radiculoplexus neuropathy: Incidence and the association with diabetes mellitus

OBJECTIVE

To determine the previously unknown incidence of lumbosacral radiculoplexus neuropathy (LRPN) and its association with diabetes mellitus (DM).

METHODS

LRPN defined by clinical and electrophysiologic criteria was identified among Olmsted County, Minnesota, residents during a 16-year period (2000-2015) using the unique facilities of the Rochester Epidemiology Project. DM was ascertained using American Diabetes Association criteria.

RESULTS

Of 1,892 medical records reviewed, 59 patients (33 men, 26 women) were identified as having LRPN. The median age was 70 years (range 24-88 years) and the median time of onset of symptoms to diagnosis was 2 months (range 1-72 months). DM was more frequent in patients with LRPN than in controls (39/59 vs 35/177, p < 0.001) but not in those with pre-DM (10/20 vs 55/142, p = 0.336). LRPN recurred in 3 patients with DM resulting in 62 LRPN episodes during the study period. The overall incidence of LRPN was 4.16/100,000/y (95% confidence interval [CI] 3.13-5.18). The incidences of LRPN among DM and non-DM groups were 2.79/100,000/y (95% CI 1.94-3.64) and 1.27/100,000/y (95% CI 0.71-1.83), respectively. The odds of LRPN among patients with DM and pre-DM was 7.91 (95% CI 4.11-15.21) and 1.006 (95% CI 1.004-1.012), respectively.

CONCLUSIONS

LRPN incidence in Olmsted County of 4.16/100,000/y makes LRPN a common inflammatory neuropathy and is higher than that of other immune-mediated neuropathies (acute or chronic inflammatory demyelinating polyradiculoneuropathy, brachial plexus neuropathy) assessed within the same population. DM is a major risk factor for LRPN and thus justifies the continued classification of LRPN into diabetic and nondiabetic forms.

Diabetic neuropathy part 2: proximal and asymmetric phenotypes

Diabetic neuropathies consist of a variety of syndromes resulting from different types of damage to peripheral or cranial nerves. Although distal symmetric polyneuropathy is the most common type of diabetic neuropathy, many other subtypes have been defined since the 1800s, including proximal diabetic, truncal, cranial, median, and ulnar neuropathies. Various theories have been proposed for the pathogenesis of these neuropathies. The treatment of most requires tight and stable glycemic control. Spontaneous recovery is seen in most of these conditions with diabetic control. Immunotherapies have been tried in some of these conditions however are controversial.

Diabetic neuropathy

Diabetes is the most common cause of peripheral neuropathy in the world. Both type 1 (insulin-dependent) and type 2 diabetes are commonly complicated by peripheral nerve disorders. Two main types of neuropathy are observed: the most common is a nerve fiber length-dependent, distal symmetrical sensory polyneuropathy with little motor involvement but frequent, and potentially life threatening, autonomic dysfunction. Alteration of temperature and pain sensations in the feet is an early manifestation of diabetic polyneuropathy. The second pattern is a focal neuropathy, which more commonly complicates or reveals type 2 diabetes. Poor diabetic control increases the risk of neuropathy with subsequent neuropathic pains and trophic changes in the feet, which can be prevented by education of patients.

Focal and multifocal diabetic neuropathies

Diabetic neuropathy is the most common neuropathy in industrialized countries, with a remarkable range of clinical manifestations. The vast majority of the patients with clinical diabetic neuropathy have a distal symmetrical form that progress following a fiber-length dependent pattern, with predominant sensory and autonomic manifestations. This pattern of neuropathy is associated with a progressive distal axonopathy. Patients are exposed to trophic changes in the feet, pains and autonomic disturbances. Less often, diabetic patients may develop focal and multifocal neuropathy that includes cranial nerve involvement, limb and truncal neuropathies. This neuropathic pattern tends to occur after 50 years of age, mostly in patients with longstanding diabetes mellitus. The LDDP does not show any trend to improvement and either relentlessly progresses or remain relatively stable over years. Conversely the focal diabetic neuropathies, which are often associated with inflammatory vasculopathy on nerve biopsies, remain self limited, sometimes after a relapsing course.

Diabetic Neuropathies

Diabetes mellitus is associated with a wide spectrum of neuropathy syndromes, ranging from a mild asymptomatic distal sensory neuropathy to a severe disabling radiculoplexus neuropathy. As the pathophysiology of these separate conditions is better understood, classification of the various phenotypes becomes important because of treatment implications. Here we provide a short summary of the history of the classification of diabetic neuropathies and try to describe the most common forms classified according to their presumed pathophysiology. We have tried to include epidemiological data where available, as well as histopathology of nerve in several diabetic neuropathies.

Changes in nerve root motion and intraradicular blood flow during intraoperative femoral nerve stretch test. Report of four cases

OBJECT

It is not known whether changes in intraradicular blood flow (IRBF) occur during the femoral nerve stretch test (FNST) in patients with lumbar disc herniation. An FNST was conducted in patients with lumbar disc herniation to observe the changes in IRBF, and results were then compared with clinical features.

METHODS

The study was composed of four patients with L3-4 disc herniation who underwent microdiscectomy. Patients were placed prone immediately before surgery, so that their knee flexed on the operating table with the hip joint kept in hyperextension, and the FNST was performed to confirm at which region pain developed in the anterolateral thigh. During the operation, the hernia-affected nerve roots were visualized under a microscope. The needle sensor of a laser Doppler flowmeter was then inserted into each nerve root immediately above the hernia, and the change in IRBF was measured during the intraoperative FNST. After removal of the herniated disc, a similar procedure was repeated and IRBF was measured again. The intraoperative FNST showed that the hernia compressed the nerve roots and there was marked disturbance of gliding, which was reduced to only a few millimeters. During the test, IRBF decreased by 92.8 to 100% (mean 96.9 +/- 3.7% [+/- standard error of the mean]) relative to the blood flow before the test. This study demonstrated that the blood flow in the nerve root is reduced when the nerve root is compressed in vivo.

CONCLUSIONS

The intraoperative FNST showed that the hernia compressd the nerve roots and there was marked disturbance of gliding, which was reduced to only a few millimeters. During the test, IRBF decreased by 92.8 to 100% (96.9 +/- 3.7% [mean +/- standard error of the mean]).

Diabetic and nondiabetic lumbosacral radiculoplexus neuropathies: new insights into pathophysiology and treatment

Diabetic lumbosacral radiculoplexus neuropathy (DLRPN) (also called diabetic amyotrophy) is a well-recognized subacute, painful, asymmetric lower-limb neuropathy that is associated with weight loss and type II diabetes mellitus. Nondiabetic lumbosacral radiculoplexus neuropathy (LRPN) has received less attention. Comparison of large cohorts with DLRPN and LRPN demonstrated that age at onset, course, type and distribution of symptoms and impairments, laboratory findings, and outcomes are similar. Both conditions are lumbosacral radiculoplexus neuropathies that are associated with weight loss and begin focally with pain but that evolve into widespread, bilateral paralytic disorders. Although both are monophasic illnesses, patients have prolonged morbidity from pain and weakness, and many patients become wheelchair-dependent. Although motor-predominant, there is unequivocal evidence that autonomic and sensory nerves are also involved. Cutaneous nerves from patients with DLRPN and LRPN show pathological evidence of ischemic injury (multifocal fiber loss, perineurial thickening and degeneration, neovascularization, microfasciculation, and swollen axons with accumulated organelles) and microvasculitis (mural and perivascular inflammation, separation and fragmentation of mural smooth muscle layers of microvessels and hemosiderin-laden macrophages). Controlled trials with immune-modulating therapies in DLRPN are in progress, and preliminary data suggest that such therapy may be beneficial in LRPN. It is likely that DLRPN and LRPN are immune-mediated neuropathies that should be separated from chronic inflammatory demyelinating polyneuropathy and from systemic necrotizing vasculitis.

A suspected case of proximal diabetic neuropathy predominantly presenting with scapulohumeral muscle weakness and deep aching pain

A 48-year-old man with a 14-year history of type 2 diabetes with proliferative diabetic retinopathy and distal symmetrical diabetic polyneuropathy visited our hospital. Eight months later, he subacutely developed difficulty in both shoulder movement and trouble standing up from a squatting position. This was accompanied by severe bilateral shoulder and thigh pain. Magnetic resonance imaging of the brain, cervical and lumbar spine, computed tomography of the shoulder and X-ray films of the cervical spine and shoulder revealed no abnormality. Cerebrospinal fluid showed a mild elevation of protein (0.93 g/l) without cell infiltration. Antiganglioside antibodies and point mutation of mitochondrial DNA at position 3243 were not found. Neuropathology of the sural nerve showed a moderate myelinated fiber loss, active axonal degeneration, but onion-bulb formation, endoneurial or epineurial vasculitis were not observed. Electromyography revealed neurogenic changes in the proximal upper limb muscles. Nerve conduction studies revealed mild bilateral slowing in nerve conduction velocity in both of the upper and lower limbs. The diagnosis of this patients was suspected to be a proximal diabetic neuropathy (diabetic amyotrophy). The pain and muscle weakness had persisted more severely in the shoulder than in the thigh throughout the clinical course. His unbearable symptoms could be partially alleviated by an administration of a selective serotonin reuptake inhibitor, fluvoxamine maleate. Proximal diabetic neuropathy is a rare disabling type of neuropathy, which is characterized with subacute bilateral muscle weakness and wasting in the proximal part of the lower limbs. The involvement of the scapulohumeral region observed in this case is very unusual in proximal diabetic neuropathy.

Subacute femoral compressive neuropathy from iliacus compartment hematoma

BACKGROUND

Traumatic retroperitoneal hematoma in the iliacus muscle is an unusual but potentially serious cause of femoral compression neuropathy.

CASE REPORT

We describe the clinical, imaging, and management features of a case of traumatic iliacus retroperitoneal hematoma with delayed manifestation of femoral neuropathy.

DISCUSSION

The anatomical substrate for hematoma formation with subacute compression of the femoral nerve is emphasized. A subacute compartment syndrome with progressive edema, swelling and ischemia of iliacus compartment is suggested as the underlying cause. Early fasciotomy with or without hematoma evacuation should be considered in order to provide rapid decompression and to minimize the chance of permanent nerve injury.

Postinjection vastus lateralis atrophy: 2 case reports

We report two cases of postsurgical intramuscular meperidine injection with injury to the femoral nerve and subsequent vastus lateralis atrophy. The first case is a patient who had arthroscopic anterior cruciate ligament reconstruction; the second, a patient with a C6-C7 anterior fusion. Photographs, radiography, and electrodiagnostic studies clearly depict the nature of the injuries, and their etiology is discussed. These case reports describe a unique neuropathic injection injury that, to our knowledge, has never before been described in the literature.

Microvasculitis in non-diabetic lumbosacral radiculoplexus neuropathy (LSRPN): similarity to the diabetic variety (DLSRPN)

Diabetic lumbosacral radiculoplexus neuropathy (DLSRPN) has been shown to be due to ischemic injury from microvasculitis. The present study tests whether ischemic injury and microvasculitis are the pathologic cause of non-diabetic lumbosacral radiculoplexus neuropathy (LSRPN), and whether the pathologic alterations are different between LSRPN and DLSRPN. We studied distal cutaneous nerve biopsies of 47 patients with LSRPN and compared findings with those of 14 age-matched healthy controls and 33 DLSRPN patients. In both disease conditions, we found evidence of ischemic injury (multifocal fiber degeneration and loss, perineurial degeneration and scarring, characteristic fiber alterations, neovascularization, and injury neuroma) that we attribute to microvasculitis (mural and perivascular mononuclear inflammation of microvessels, inflammatory separation, fragmentation and destruction of mural smooth muscle, and previous microscopic bleeding [hemosiderin]). Teased nerve fibers in LSRPN showed significantly increased frequencies of axonal degeneration, segmental demyelination, and empty nerve strands. The segmental demyelination appeared to be clustered on fibers with axonal dystrophy. The nerves with abnormal frequencies of demyelination were significantly associated with nerves showing multifocal fiber loss. We reached the following conclusions: 1) LSRPN is a serious condition with much morbidity that mirrors DLSRPN. 2) Ischemic injury from microvasculitis appears to be the cause of LSRPN. 3) Axonal degeneration and segmental demyelination appear to be linked and due to ischemia. 4) The pathologic alterations in LSRPN and DLSRPN are indistinguishable, raising the question whether these 2 conditions have a common underlying mechanism, and whether diabetes mellitus contributes to the pathology or is a risk factor in DLSRPN. 5) Both LSRPN and DLSRPN are potentially treatable conditions.

Femoral and obturator neuropathies

Femoral, saphenous, and obturator neuropathies have diverse causes, many of which are iatrogenic. They have overlapping, but distinct, clinical features. Electrodiagnostic testing can distinguish between these disorders and others in the differential diagnosis. Imaging studies may demonstrate the origin of the neuropathy in some cases. Conservative treatment is usually sufficient, but occasionally surgical exploration of the affected nerve is indicated.

Epineurial microvasculitis in proximal diabetic neuropathy

Amongst the focal and multifocal neuropathies that are associated with diabetes mellitus one of the most common is a proximal predominantly motor lower limb neuropathy. Recent evidence has indicated that, at least in a proportion of cases, this may have an inflammatory basis. We have examined a consecutive series of 15 cases of proximal diabetic neuropathy (diabetic amyotrophy). These were characterized by proximal pain and asymmetric proximal or generalized lower limb muscle weakness, associated in some cases with radicular sensory involvement. Two-thirds of the patients had an accompanying distal symmetric sensory polyneuropathy. Biopsy of the intermediate cutaneous nerve of the thigh, a sensory branch of the femoral nerve, showed epineurial microvasculitis in 3 patients and nonvasculitic epineurial inflammatory infiltrates in another case. In a further case, microvasculitis was found in both in the sural nerve and a quadriceps muscle biopsy specimen. The detection of inflammatory changes appeared to be correlated with the occurrence of sensory radicular involvement. Whether similar changes are present in muscle nerves in this predominantly motor syndrome requires further study. Nevertheless, the present observations confirm the view that secondary vasculitic or other inflammatory reactions may contribute to some forms of diabetic neuropathy.

Diabetic neuropathy

The most common form of diabetic neuropathy is chronic, distal symmetrical sensorimotor, or predominantly sensory neuropathy; the latter is invariably associated with some degree of autonomic dysfunction. There are, however, other neuropathic patterns in diabetes mellitus that are uncommon but are important to recognize, since they may mimic many other non-neurologic diseases. This article discusses a variety of forms of mononeuropathies and diabetic proximal motor neuropathy, commonly known as diabetic amyotropy.

Painful proximal diabetic neuropathy: inflammatory nerve lesions and spontaneous favorable outcome

Proximal diabetic neuropathy is a disabling neuropathy that occurs predominantly in non-insulin-dependent diabetic patients over the age of 50. Inflammatory lesions have been found in nerve biopsy specimens of diabetic patients with severe proximal neuropathy or with other patterns of multifocal neuropathy. Some of these patients respond dramatically to treatment with corticosteroids or with other immunomodulators. In this article we report on our findings in 4 additional patients with painful proximal diabetic neuropathy and different patterns of inflammatory nerve lesions whose condition improved spontaneously shortly after performance of a nerve biopsy, without additional treatment.

Crossed femoral stretching test. A case report

STUDY DESIGN

A case is reported of L3-L4 far lateral disc herniation, in which the femoral stretching and crossed femoral stretching tests were positive.

OBJECTIVES

To discuss the clinical usefulness and pathophysiologic mechanics of the femoral and crossed femoral nerve stretching tests.

SUMMARY OF BACKGROUND DATA

The femoral and crossed femoral stretching tests have received little clinical and research attention. The validity of these two nerve root tension signs to evaluate upper disc herniations remains unknown.

METHODS

A 73-year-old woman presented with progressive low back pain and left anterolateral thigh pain of 2 months duration. The diagnosis of far lateral disc herniation at L3-L4 was initially suspected from a positive crossed femoral nerve stretch. An open discectomy was performed without complications.

RESULTS

Eight months after surgery, the patient had recovered and the femoral and crossed femoral stretching tests were negative.

CONCLUSIONS

It is hypothesized that the crossed femoral stretching test may be a valid maneuver to help in the diagnosis of symptomatic disc herniation above L4.

Diabetic neuropathy: an update

Diabetic neuropathy is the most common neuropathy in industrialized countries, with a remarkable range of clinical manifestations. The usual pattern is a distal symmetrical sensory polyneuropathy, associated with autonomic disturbances. Less often, diabetes is responsible for a focal or multifocal neuropathy affecting cranial nerves, especially oculomotor nerves, and roots and nerves innervating proximal muscles of the lower limbs. Metabolic abnormalities due to hyperglycaemia, lack of insulin and their consequences and ischaemic phenomena secondary to diabetic microangiopathy account for nerve lesions.

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.

Femoral nerve damage after abdominal rectopexy

Iatrogenic femoral nerve damage has already been described after hysterectomy, but never after abdominal rectopexy. We report the occurrence of femoral nerve injury in six of twenty-four patients operated on for complete rectal prolapse (n = 21) or rectorectal intussusception (n = 3). Four patients had unilateral and two bilateral lesions. All six patients had clinical and electromyographic (EMG) assessment. EMG findings were given a score from 0 (complete denervation) to 5 (normal findings). During the immediate postoperative period all patients complained of reduced cutaneous sensation of the anterior surface of the thigh and knee, and quadriceps weakness. EMG showed complete denervation in one patient, marked denervation in three, and slight or moderate denervation in the remaining two. In five patients there was complete clinical resolution at 3 to 12 months postoperatively, while one showed an improvement only. EMG control performed in four patients showed a full recovery in three. Two patients refused this examination. We believe femoral nerve damage was caused by the large-bladed self-retaining retractors used, which directly or indirectly compressed the femoral nerve.

Neuropathies associated with diabetes

Diabetic neuropathy is the most frequent complication of diabetes and the leading cause of polyneuropathy in the Western world. A distal symmetric predominantly sensory polyneuropathy is the most common of the diverse neuropathies that occur secondary to diabetes. Pain is often the most bothersome and difficult to treat symptom of diabetic neuropathy. Autonomic neuropathy is a frequent feature of diabetic neuropathy and the source of many significant problems including postural hypotension, gastroparesis, diarrhea, constipation, neurogenic bladder, and male impotence. Physicians need to be familiar with the multiple, less common forms of diabetic neuropathy, as these often mimic other medical or neurologic conditions. The cause of diabetic neuropathy is not determined, but abundant evidence suggests that both metabolic and ischemic nerve injury are likely factors. These should not be considered mutually exclusive causes of diabetic neuropathy as both factors likely operate to different degrees to produce the clinical spectrum of neuropathies that are seen in diabetes. Although no effective treatment exists to cure diabetic neuropathy, improvement is possible with glycemic control and symptomatic therapy.

Proximal skeletal muscle alterations in streptozotocin-diabetic rats: a histochemical and morphometric analysis

The response of rat quadriceps muscle fibers to chronic streptozotocin (STZ) diabetes was studied. Transverse sections of rectus femoris muscle from diabetic and weight-matched control rats were assayed for myofibrilar adenosine triphosphatase (ATPase) and nicotinamide adenine dinucleotide-tetrazolium reductase (NADH-TR). A quantitative analysis was carried out by an automatic interactive analysis system focused on the fiber type size and distribution. STZ-induced diabetes caused important effects in this muscle, with changes in the distribution of oxidative enzyme reactions, type I fiber hypertrophy, and type II fiber atrophy, which was greater in type IIB than in type IIA. It is concluded that hypoinsulinism produces morphological alterations in proximal skeletal muscle fibers that are similar to those of neurogenic myopathy. Thus the pathological changes in these mammalian muscle fibers could explain the clinical syndrome seen in diabetic patients called "diabetic symmetrical proximal motor neuropathy," perhaps the least understood of the major neuropathic complications of diabetes.

Diabetic amyotrophy: reassessment of the clinical spectrum

Diabetic amyotrophy is a syndrome whose recognition may be difficult or delayed. We reviewed thirteen patients with this disorder, all of whom had significant proximal lower limb wasting and weakness as the predominant feature and eleven of whom had pain in the affected limbs. Significant weight loss was common. In nine patients the deficits were largely or totally reversible. Important variations from the classical features were observed. Only five patients displayed asymmetric proximal lower limb wasting, weakness and pain, motor deficits in the remainder being either unilateral or bilateral and symmetrical. The shoulder girdle and arms were also involved in two patients. Proximal limb pain was not invariable, a distal sensory peripheral neuropathy was common, and diabetic control at diagnosis was likely to be good. No prognostic factors were identified. Thus, not all patients with diabetic amyotrophy exhibit the classically-described features. Other than careful clinical examination, a thorough bilateral electromyographic and nerve conduction study remains the most helpful diagnostic test. Appreciation of the clinical spectrum and context of diabetic amyotrophy should facilitate its differentiation from other disorders, including other forms of diabetic neuropathy.

Complex repetitive discharges in the iliopsoas muscle

A prospective electromyographic investigation of lower limb muscles in patients with different neurogenic disorders showed that complex repetitive discharges (CRD) were observed predominantly and often only in the iliopsoas muscle. Analysis of the EMG findings in acute and chronic lesions shows that CRD are a feature of a chronic proximal motor axon lesion. Furthermore, the frequently focal occurrence of CRD in the iliopsoas muscle in clinically distal diabetic polyneuropathies suggests that this muscle and its nerves represent a locus minoris resistentiae.

Clinical aspects of diabetic neuropathies

Diabetic neuropathy is a common complication of diabetes that may be associated both with considerable morbidity (painful polyneuropathy, neuropathic ulceration) and mortality (autonomic neuropathy). The epidemiology and natural history of diabetic neuropathy is clouded with uncertainty, largely due to confusion in the definition and measurement of this disorder. We have reviewed a variety of the clinical manifestations associated with somatic and autonomic neuropathy and discussed current views related to the management of the different abnormalities. Although unproven, the best evidence suggests that near normal control of blood glucose in the early years following onset of diabetes may help delay the development of clinically significant nerve impairment. Intensive therapy to achieve normalization of blood glucose may also lead to reversibility of early diabetic neuropathy, but again this is unproven. Our ability to manage successfully the many different manifestations of diabetic neuropathy depends ultimately on our success in uncovering the pathogenic processes underlying this disorder. The recent resurgence of interest in the vascular hypothesis, for example, has opened up new avenues of investigation for therapeutic intervention. Paralleling our increased understanding of the pathogenesis of diabetic neuropathy, there must be refinements in our ability to measure quantitatively the different types of defects that occur in this disorder. These tests must be validated and standardized to allow comparability between studies and more meaningful interpretation of study results.

Femoral neuropathy after renal transplantation

We report 2 cases of cadaveric renal transplantation in which the grafts were placed in the right iliac fossa. Postoperatively, both patients complained of ipsilateral thigh weakness. Electromyography and nerve conduction studies indicated femoral nerve neuropathy. Muscle weakness gradually resolved. Difficulty was encountered in placing both grafts, and each kidney and limb were subjected to prolonged ischemia. We suggest that the femoral neuropathy was ischemic in origin.

Problems of etiology in femoral neuropathies

29 cases of femoral mononeuropathy are reported. While the clinical features of the femoral neuropathy are easily identified, the etiology is often hard to establish. The cases reported tend to fall into three general categories: 1) cases without major diagnostic difficulties (e.g. diabetic neuropathy); 2) those in which the definite diagnosis results from combined evidence of laboratory and instrumental data (degenerative changes in the lumbar spine, compressions, entrapments, etc.); 3) those in which the negative result of the investigations prevents a positive diagnosis and hence a presumptive etiology (spondylosis, inflammatory process, ischemia of the nerve) may be formulated. Attention is drawn to the favorable course of the condition in the patients of this group.

Diabetic neuropathy

Peripheral nerve disorders are important late complications of diabetes mellitus. Polyneuropathy, which may involve varying proportions of sensory, motor, and autonomic fibers, is considered the consequence of metabolic derangements that result from chronic hyperglycemia. Symmetrical proximal motor neuropathy ("diabetic amyotrophy") also may have a metabolic basis. Mononeuropathies in diabetes may have an ischemic or compressive cause. Advances have been made in understanding the biochemical basis for diabetic polyneuropathy. The treatment of symptomatic diabetic neuropathy should be directed toward long-term normalization of blood glucose until more specific therapies become available.

Treatment of severely painful diabetic neuropathy with an aldose reductase inhibitor: relief of pain and improved somatic and autonomic nerve function

11 patients with severely painful diabetic neuropathy previously unresponsive to numerous drugs were treated with an aldose reductase inhibitor ('Sorbinil'--Pfizer CP 45, 634); 8 also received a placebo. Response was assessed according to a 0-20 graphic rating scale for pain and by tests for motor and sensory nerve conduction velocities (NCV) and cardiac autonomic nerve function. 8 patients had moderate to marked relief of symptoms, generally beginning on the 3rd or 4th day of medication, 2 had equivocal responses, and 1 had no change. Each of 4 patients with diabetic amyotrophy reported striking improvement in pain and mild to moderate improvement in proximal leg muscle strength; 2 of these noticed improved sensory perception in their feet. Objective evidence of improved muscle strength was obtained in each of these 4 patients and of improved sensation in 3. On stopping medication, pain worsened in 7 of 8 responders, although generally with some delay, suggesting a carry over effect. During the course of treatment autonomic nerve function improved significantly in 6 of 7 patients tested and across the group, and NCV improved in 4 of 7 tested. Both of these variables deteriorated after withdrawal of the drug. A correlation between NCV response and clinical response was apparent. Very little toxicity was observed. These observations suggest that aldose reductase inhibitors may be important in the treatment of symptomatic somatic and autonomic neuropathies complicating diabetes.

Femoral neuropathy caused by iliacus hematoma

Two cases of femoral neuropathy caused by iliacus hematoma occurring during anticoagulant therapy are described. The pathogenesis and the clinical picture of this particular pathology are discussed and the necessity of early surgical decompression is emphasized.

Femoral neuropathy due to retroperitoneal bleeding. A red herring in medicine complicates anticoagulant therapy and influences the Russian Communist Revolution (Crown Prince Alexis, Rasputin)

Femoral neuropathy occurs when occult retroperitoneal bleeding impinges on the appropriate nerve roots. The syndrome involves the acute onset of groin and thigh pain with characteristic flexion and external rotation of the hip. It may mimic other conditions such as acute arterial occlusion. Thorough knowledge of the anatomy of the femoral nerve explains the clinical features and leads the clinician to suspect the occurrence of this syndrome. Three cases have been reviewed that exhibited this condition as a result of retroperitoneal bleeding, a complication of systemic heparin therapy. The hemophilia that afflicted Alexis, the Crown Prince of Russia and son of Tsar Nicholas and Tsarina Alexandra, resulted in this clinical syndrome. The consequences enabled the sinister starets, Gregory Rasputin, to become intimately involved with the royal family, influencing the response of the Tsar to the political events in Russia, thereby playing an important role in setting the stage for the 1917 Russian communist revolution.

The femoral stretching test. A valuable sign in diagnosing upper lumbar disc herniations

✓ The femoral stretching test is a valuable sign in diagnosing upper lumbar nerve root compression. We believe that it has the same significance for upper lumbar disc herniation as the sciatic stretching test has for the lower.

Diabetic proximal neuropathy. Clinical and electromyographic studies

Clinical and electromyographic findings in 27 diabetics with proximal lower extremity weakness were analyzed. Two groups could be distinguished: patients in whom electromyographic findings were restricted to the clinically involved parts of the lower extremity (group A) and those in whom an associated distal symmetric, peripheral neuropathy could be proved on clinical and electromyographic grounds (group B). Patients in group B had significantly greater incidence of the following features: gradual onset of symptoms, bilateral proximal lower extremity weakness, insulin dependency, recent weight loss, EMG evidence of bilateral disease and paraspinal fibrillations. These findings concur with recent reports describing heterogeneity in the syndrome of "diabetic proximal neuropathy".

Urologic manifestations of the iliacus hematoma syndrome

Anticoagulated patients may have a characteristic syndrome of femoral neuropathy from an iliacus muscle hematoma. They may present with urologic signs and symptoms, including groin, flank and thigh pain, groin tenderness, an iliac fossa mass and hematuria. Urography may reveal an enlarged psoas shadow and hydronephrosis from ureteral obstruction. Prompt diagnosis is essential so that early operative decompression of the femoral nerve can be done. The urologist has an important role in the diagnosis and treatment of this syndrome.

Mononeuropathy in diabetes mellitus: a phenomenon easily overlooked

In patients with diabetes, a carefully taken history and meticulously performed neurologic examination enable the clinician to separate superimposed mononeuropathy from more generalized symmetric polyneuropathy. Recognition of mononeuroparhy is important, since often it is reversible.

Lumbar plexus neuropathy resulting from retroperitoneal hemorrhage

A case of lumbar plexus neuropathy occurring in the setting of heparin therapy is reported. Documentation of the site of a retroperitoneal hematoma by CT scan was made prior to the full clinical evolution of lumbar plexus neuropathy resulting from a psoas-muscle hematoma. Two patterns of retroperitoneal bleeding and their respective clinical manifestations are discussed. Early diagnosis of these syndromes may allow for intervention before neurologic compromise is established.

Femoral neuropathy and ischemic colitis associated with amyloidosis in hemodialysis patients

Renal failure is often the presenting problem with amyloidosis and it portends a generally poor prognosis. Two of 121 patients in a home dialysis program were found to have amyloidosis after they developed unusual complications, ischemic colitis and femoral neuropathy. Both ultimately died as a result of their disease. From the limited experience that is reported, it appears that renal transplantation offers a better alternative for long term therapy than hemodialysis.