[Polyneuropathy in the course of Hodgkin's disease: case report]

Polyneuropathy in neoplastic process practically may occur in every stage, before clinical signs, together with clinical signs and in the last period. In some percent of patients polyneuropathy may outstrip manifestation of neoplastic process even for many years. We present a 61-year-old patient in whom signs of polyneuropathy appeared before the signs of essential disease - Hodgkin's disease. Our case confirms the necessity of very careful and precise diagnostics of polyneuropathy with unclear aetiology.

Cerebrospinal fluid norepinephrine and acetylcholine concentrations during acute pain

Painful stimulation increases spinal cord norepinephrine (NE) in animals, and spinally released NE induces acetylcholine (ACh) release to cause analgesia. The purpose of this study was to determine the relationship between NE and ACh in cerebrospinal fluid (CSF) in sheep and humans during painful stimulation. CSF was sampled in anesthetized sheep before and during electrical nerve stimulation at an intensity sufficient to increase mean arterial pressure 15%-20%. To determine whether spinally released NE caused ACh release by stimulation of alpha(2)-adrenoceptors, seven sheep received intrathecal (IT) idazoxan whereas seven sheep received IT saline before stimulation. To examine the effect of pain on CSF NE and ACh in humans, CSF was sampled in 33 women after at least 4 h of painful labor and in 22 pregnant women without pain. Painful stimulation in sheep increased CSF NE and ACh. IT idazoxan blocked the increase in both NE and ACh. Although mean concentrations of CSF NE and ACh did not differ between parturients with and without pain, there was a significant correlation between NE and ACh concentrations only in those with pain. These data provide evidence in animals for activation of spinal cord noradrenergic-cholinergic systems in response to pain. There is only weak evidence for such activation, however, in women with painful labor.

Mononeuropathia multiplex and idiopathic intracranial hypertension

A young obese woman with menstrual irregularities presented with bilateral papilledema, abducens nerve paresis, visual obscurations and severe headache. Neuroimaging studies were normal but CSF opening pressure was elevated. The diagnosis of idiopathic intracranial hypertension was made. Insertion of a shunt quickly alleviated the symptoms. A few weeks later the patient developed a left femoral nerve paresis and an ulnar nerve paresis on the right. Electrodiagnostic tests confirmed the diagnosis of mononeuropathia multiplex. Bone marrow histology showed a vasculitis. We hypothesize that the vasculitis is underlying both, idiopathic intracranial hypertension and mononeuropathia multiplex.

Surgical outcome for intra- and extrapelvic femoral nerve lesions

Seventy-eight traumatic neuropathies were seen in 94 patients with femoral nerve lesions; 54 of these were operated on because of persistent complete functional loss and/or pain. The most common mechanism of injury to the femoral nerve was iatrogenic due to inguinal herniorrhaphy, total hip replacement, intraabdominal vascular or gynecological operation, and, less commonly, appendectomy, lumbar sympathectomy, and laparoscopic procedures. Femoral nerve injuries also resulted from penetrating gunshot and stab wounds, laceration by glass, and stretch/contusive injuries associated with pelvic fractures. There were no signs of clinical or electrical recovery in 45 of 78 patients with traumatic nerve injuries. These and other partial injuries associated with pain were explored and evaluated by intraoperative nerve stimulation and recording of nerve action potentials (NAPs). Despite complete loss of nerve function preoperatively, 13 patients had recordable NAPs and underwent neurolysis; each recovered function to at least a Grade 3 level. Twenty-seven patients had sural graft repairs performed with graft lengths varying from 2.5 to 14 cm. Most patients had some nerve regeneration and regained function to Grade 3 to 4 levels by 2 years postoperatively. Four of five patients with suture repairs recovered to Grade 3 or better within 2 years postoperatively. Despite a proximal pelvic level for most of these injuries and, as a result, lengthy graft repairs, recovery of some useful function was the rule rather than the exception. Tumors involved the femoral nerve in 16 patients and included eight neurofibromas, four schwannomas, one neurogenic sarcoma, two ganglion cysts, and one leiomyosarcoma. All tumors were treated surgically and most were removed successfully.

Changes in transmission across synapses of Ia afferents in spastic patients

The transmission across synapses of Ia afferents on spinal motor neurons was investigated in 30 healthy subjects and 25 spastic multiple sclerosis patients. Slow passive stretch (17 degrees/s of the soleus muscle evoked a pronounced depression of the soleus Hoffmann reflex (H-reflex) lasting for more than 10 s in the healthy subjects. This depression was less pronounced and had a shorter duration in the spastic patients. A tap applied to the biceps femoris tendon also produced an inhibition of the soleus H-reflex, which was larger in the healthy subjects than in the spastic patients. This inhibition only lasted for 300-400 ms. Finally, stimulation of the femoral nerve (FN) produced a facilitation of the soleus H-reflex, which was larger in the spastic patients than in the healthy subjects. The inhibition of the H-reflex evoked by the biceps femoris tendon tap is known to be caused by presynaptic inhibition of the Ia afferents, which mediate the reflex. The facilitation of the soleus H-reflex produced by FN stimulation has also been shown to be influenced by changes in presynaptic inhibition. The increased facilitation from the FN and the decreased inhibition from the biceps femoris tendon tap onto the soleus H-reflex in spastic patients are thus both compatible with a deficient presynaptic inhibition in these subjects. The long lasting depression of the reflex evoked by a previous slow stretch of the soleus muscle is most likely caused by a decrease of the probability of transmitter release from the Ia afferents. The decrease of this depression in spastic patients suggests that mechanisms other than presynaptic inhibition may contribute to changes in the efficiency of transmission across the synapses of Ia afferents in spastic patients and thus contribute to the exaggeration of stretch reflexes seen in these patients.

[Meralgia paraesthetica and its surgical treatment]

Compression neuropathy of the lateral femoral cutaneous nerve (meralgia paresthetica) leads to pain and dysesthesia in the anterolateral thigh. Over a period of 23 1/2 years, 29 patients (33 procedures) were operated on after failure of conservative treatment: 18 patients (20 procedures) underwent neurolysis of the nerve, and in 11 the nerve was transected. The 33 procedures were necessary because 1 patient had bilateral meralgia paresthetica and there were 3 recurrences with persisting pain. The average follow-up was 32 months after neurolysis and 87 months after transection. Complete or partial pain relief was found in 72% after decompression and in 82% after transection of the nerve.

A noninvasive method of neurography in meralgia paraesthetica

The lateral femoral cutaneous nerve (LFCN) becomes superficial 10 cm distal to the anterior superior iliac spine, where it can be located and stimulated by superficial electrodes. This is not the case in the inguinal region. In the present study the LFCN compound nerve action potential (NAP) was recorded with a pair of 8-cm-long strip electrodes placed on the anterolateral aspect of the thigh 25 cm distal to the stimulating electrodes. Normative values were obtained in 58 healthy nerves. The conduction velocity (CV) was 62.3 +/- 5.5 m/s for NAP onset and 55.3 +/- 4.1 m/s for the negative NAP peak. The CV variability was comparable to that obtained with needle recordings despite a relatively low NAP amplitude (2.0 +/- 1.0 muV). This method provided definite neurophysiological evidence of the disorder in 12 of 13 patients with meralgia paraesthetica. According to our results, a slowing of CV is a more reliable sign of the condition than a decrease of NAP amplitude alone.

Isolated femoral mononeuropathy to the vastus lateralis: EMG and MRI findings

A 16-year-old female track athlete experienced sudden onset of right anterolateral thigh pain, initially thought to be cramping. After 2 months of continued postexercise pain she sought medical evaluation. A 3-cm thigh circumference discrepancy was noted on physical exam. She was referred for electromyography (EMG) and magnetic resonance imaging (MRI) studies. Femoral and screening nerve conduction studies were normal. Needle EMG revealed acute neuropathic changes confined to the right vastus lateralis only. These findings were confirmed by MRI, including short T1 inversion recovery (STIR) sequences. All other medical work-up was normal, including lumbar and pelvic MRI, and complete serologic studies. This case represents a unique presentation of an idiopathic femoral mononeuropathy isolated to the vastus lateralis only, which has not been previously reported. The highly unusual anatomical presentation of this case illustrates the emerging complementary usefulness of EMG and MRI in delineating neuromuscular pathology.

A quantitative assessment of presynaptic inhibition of Ia afferents in spastics. Differences in hemiplegics and paraplegics

Soleus H-reflex facilitation evoked by a supramaximal conditioning stimulation to the femoral nerve was investigated in 28 healthy control subjects and 35 spastic patients of whom 17 were paraplegics with bilateral spinal cord lesion and 18 were hemiplegics with unilateral cerebral lesion. Heteronymous facilitation from quadriceps to soleus was measured 0.4 ms after onset, while the monosynaptic Ia excitation is still uncontaminated by any non-monosynaptic effect and can be used to assess ongoing presynaptic inhibition on Ia terminals to soleus motor neurons. In paralegics, this heteronymous Ia facilitation was significantly larger than in control subjects (all individual results in these patients being above the mean observed in controls). This must reflect a decrease in presynaptic inhibition of Ia terminals in the paraplegics explored here. There was no correlation between this decreased presynaptic inhibition of Ia terminals and the degree of spasticity measured by Ashworth's scale. Surprisingly, the amount of heteronymous Ia facilitation in hemiplegics was the same as in normal subjects. This indicates that presynaptic inhibition of Ia terminals is unchanged in these patients and disagrees with the usual interpretation of reduced vibratory inhibition of the soleus H-reflex in hemiplegics. It is argued that this disagreement is due to the fact that vibratory inhibition of the reflex also depends on post-activation depression following repetitive synaptic transmission.

Extra-territorial pain in rats with a peripheral mononeuropathy: mechano-hyperalgesia and mechano-allodynia in the territory of an uninjured nerve

The abnormal pain sensations that accompany peripheral neuropathies are sometimes found in a distribution that does not coincide with the territories of nerves or posterior roots. This 'extra-territorial' pain is one of the lines of evidence that has been advanced to support the proposal that these patients suffer from a psychogenic disorder. In the present experiments, rats were prepared with a unilateral chronic constriction injury (CCI) to the sciatic nerve. Beginning on the first postoperative day and continuing for at least 18 days, exaggerated withdrawal reflexes to pinprick stimulation, indicative of mechano-hyperalgesia, were seen on the side of nerve injury in the hindpaw territories of both the injured sciatic nerve and the uninjured saphenous nerve. Beginning on postoperative day 4 and continuing for at least the next 3 weeks, the withdrawal responses to von Frey hair stimulation on the nerve-injured side occurred at a significantly lower threshold, indicating the presence of mechano-allodynia. The severity and time course of the mechano-allodynia were similar in both nerve territories. When tested 18 days after the CCI, mechano-allodynia in the saphenous territory was abolished by an acute saphenous transection, but unaffected by sciatic transection. Conversely, mechano-allodynia evoked from the mid-plantar sciatic territory was abolished by acute sciatic transection, but unaffected by saphenous transection. These results show that rats with an experimental painful peripheral mononeuropathy have extra-territorial pain like that seen in man. Extra-territorial pain may be partly or entirely due to a peripheral nerve injury-evoked dysfunction of pain processing neurons in the central nervous system.

[Unilateral, sensorimotor femoral nerve paralysis following abdominal gynecological operation]

Unilateral or bilateral femoral nerve functional deficiency deficit occurs as a rare iatrogenic complication of gynaecological abdominal or vaginal surgery. Self-retaining abdominal retractors, that exert a constant pressure on the femoral nerve during the operation, are the most frequent cause. This situation occurs especially, if retractors of unsuitable size are used on very slender patients with thin abdominal walls. The favourable prognosis of the femoral nerve sensory and motor deficiencies can be complicated by damage to the knee joint resulting from leg muscle paresis. A personal observation and a literary review on sensomotor paresis after gynaecological abdominal surgery are discussed.

[Neurogenic intermittent claudication of the femoral nerve caused by occlusion of the common iliac artery]

A 52 year old heavy smoker complained of paresthesiae and pain at the ventral side of the right thigh and the antero-medial side of the right lower leg as well as weakness of the right quadriceps femoris during exercise. Clinical examination revealed a paresis of the right quadriceps, hypesthesia and hypalgesia in the area of the femoral nerve and a reduced right patellar reflex after 10 min walking. An occlusion of the right common iliac artery was diagnosed by angiography. Following transluminal angioplasty and implantation of an intravascular stent, the patient was free of symptoms. On the basis of the clinical observations following recanalisation of the common iliac artery, the symptoms can best be explained by a reduced perfusion of the iliolumbar artery supplying the upper part of the femoral nerve, causing ischemia of the femoral nerve during exercise. In conclusion, stenosis/occlusion of the common iliac artery should be considered as a differential diagnosis of quadriceps weakness and paresthesia in the area of the femoral nerve associated with exercise.

Combined effects of compression and hypotension on nerve root function. A clinical case

Previous animal experiments suggest that mild compression may increase susceptibility of nerve roots to the effects of hypotension. The authors report the case of a patient with an unstable L2 burst fracture whose motor skills and senses were intact. During fracture reduction and spinal distraction, sensory-evoked potentials were recorded from the epidural space after right and left femoral and tibial nerve stimulation. Induced hypotension was used during the surgery. All responses were normal at the outset of the surgery. With hypotension, a marked drop in the amplitude of the right femoral evoked potential amplitude occurred; left femoral and both tibial responses remained unchanged. Evoked potential changes were reversible with reversal of hypotension. Postoperatively, the patient was neurologically intact. Further analysis revealed a significant correlation between the right femoral evoked potential amplitude and systolic blood pressure (r = 0.63, P < 0.005), whereas amplitudes of the other responses were not significantly correlated with systolic blood pressure. This report provides clinical evidence to support the hypothesis that hypotension and local compression exert additive adverse effects on nerve root function.

Idiopathic, progressive mononeuropathy in young people

We describe six young patients with insidiously progressive, painless weakness in the distribution of a single major lower extremity nerve. No cause could be found despite extensive evaluation, including surgical exploration. At the time of diagnosis, all patients had weakness and three patients had sensory loss. In all cases, electromyography revealed a chronic axonal mononeuropathy without conduction block or focal conduction slowing. Magnetic resonance, computed tomographic, and ultrasound imaging studies did not identify a region of nerve swelling, mass, or compression. At surgical exploration, the nerve appeared atrophic in two patients, indurated in one patient, and normal in two patients. Biopsy specimens obtained from two abnormal nerves revealed either wallerian degeneration or endoneurial fibrosis. The clinical features of these patients comprise an unusual clinical entity with no known cause or treatment.

The electrophysiologic and histologic effects of the Argon Beam Coagulator on peripheral nerves

The electrophysiologic and histologic effects of the Bard Argon Beam Coagulator (ABC) were investigated in the New Zealand White rabbit. Thirty-four rabbits were divided into three groups. Controls underwent simple femoral exploration and closure. The remaining rabbits' femoral nerves were spot coagulated with either the ABC or standard electrosurgical unit (ESU). Stimulus thresholds were recorded before treatment and again prior to sacrifice at 0, 30, 60, or 120 days. Thresholds were significantly elevated for the ABC and ESU compared to controls (P = .0077 and .0351, respectively). Changes in threshold were greater for the ABC than for the ESU, but were not significant. All ABC- and ESU-treated nerves had significant histologic injury when compared to controls (P < .0002). Although the ABC may be clinically safe, significant injury to rabbit femoral nerves occurs when they are exposed to energy emitted by this instrument.

The H-reflex to magnetic stimulation of lower-limb nerves

We elicited H-reflexes by magnetic and electrical stimulation of several different nerves in 10 healthy subjects and two patients with S-1 radiculopathy. The posterior tibial nerve at the popliteal fossa and the femoral nerve at the inguinal ligament were tested with both electrical and magnetic stimulation; the proximal sciatic nerve was tested only with magnetic stimulation. Muscle activity was recorded from the soleus muscle for posterior tibial and sciatic nerve stimulation and from the vastus medialis muscle for femoral nerve stimulation. No significant difference was found between the latency of H-reflexes evoked by magnetic or electrical stimulation. With magnetic stimulation, the mean (+/- SD) Ia sensory fiber conduction velocity in the proximal segment of the sciatic nerve was 72.4 +/- 3.3 m/s, while the motor nerve fiber conduction velocity in the same portion of the nerve was significantly slower, at 60.6 +/- 2.0 m/s. In two patients with unilateral S-1 radiculopathy, the latency of the H-reflex from the soleus muscle to both magnetic and electrical stimulation of the posterior tibial nerve was absent or prolonged on the affected side. Magnetic stimulation can be used to study the H-reflex and Ia fiber conduction velocity and is particularly advantageous when testing deeply located nerve trunks.

[Femoral neuropathy, diabetes mellitus, reduced glucose tolerance. Possible correlations]

44 cases are reported of definite femoral mononeuropathy, by clinical and neurophysiological criteria. In 11 patients there was diabetes mellitus, in 10 compressions, in 23 no determined etiology was identified. Among these 23 patients, 15 showed glucose intolerance. The value of diabetes mellitus and the glucose intolerance in the etiology of femoral mononeuropathy is discussed.

Neurapraxia of the femoral nerve in a modern dancer

We have presented a case of an acute onset femoral nerve neurapraxia in a pure modern dancer. Repeated mild stretching of the femoral nerve during an established dance routine over a period of several months is implicated as the etiology. The thigh muscles quickly weakened, but regained strength within 3 months. Electromyographic evidence of specific femoral nerve injury initially was negative, but was evident 6 weeks following injury. Overuse syndrome in dancers can cause rapid loss of strength. Other conditions such as herniated intervertebral disc, acute hemorrhage, trauma, iliopsoas rupture, and acute stretching must be ruled out. Complete recovery was the natural outcome.

The role of the saphenous nerve in insomnia: a proposed etiology of restless legs syndrome

Entrapment of the saphenous nerve after emergence from its lumbar roots and before its distribution to the medial surface of the leg is suggested as a cause of Restless Legs Syndrome (other anomalies of the saphenous nerve, especially those where the nerve is part of a general neuropathy, are not considered here). This finding is supported by evidence which: 1) identifies Restless Legs Syndrome as a nerve entrapment syndrome from: the dysesthesia in Meralgia Paresthetica, the paraesthesiae of Carpal Tunnel Syndrome and the poorly localized pain in pronator syndrome and suprascapular nerve entrapment; 2) isolates the saphenous nerve as the entrapped nerve from the patient's difficulty in identifying the precise area of sensation in saphenous nerve entrapment at Hunter's Canal; 3) localizes the pelvic region as the site of entrapment from rates of Restless Legs Syndrome of 11 and 19% in pregnant women, a correlation between chronic nonspecific prostatitis and Restless Legs Syndrome.

Anterior femoral cutaneous nerve injury following femoral artery reconstructive surgery

Two cases are presented exhibiting symptoms and signs of bilateral anterior femoral cutaneous nerve injury, clinically sparing femoral nerve branches to the saphenous nerve and quadriceps muscles. This occurred following surgical dissection in the femoral triangles associated with femoral artery reconstructive surgery. Anterior femoral cutaneous nerve injury should be considered when anterior medial thigh pain and numbness occur following aortofemoral bypass graft surgery and other types of femoral artery reconstructive surgery.