Bisphosphonate therapy of reflex sympathetic dystrophy syndrome

Four cases of post-operative ulnar nerve mononeuropathy are reported. In all the cases a severe sensory and motor loss was strictly limited to ulnar nerve territory. The electrophysiological examination: needle examination, motor and sensory nerve conduction studies and even more somatosensory potential evoked from ulnar nerve after stimulation above elbow allowed to eliminate a lesion at the elbow and to asses the lesion at wrist, arm, axilla or plexus. Full recovery occurred once and partial recovery twice. We considered that these ulnar lesions are neuralgic amyotrophies of Parsonage and Turner according to the epidemiological, clinical, evolutive and electrophysiological data.     

Subacute multifocal painful neuropathy with spontaneous remission

We present the cases of two patients with subacute onset of multifocal painful neuropathy with spontaneous remission and no relapse. The distribution of pain in patient 1 was hands (median > ulnar nerve region) and feet (peroneal and terminal tibial nerve regions), and in patient 2, hands (ulnar nerve region) and feet, left worse than in right. Both patients experienced facial numbness. Deep tendon reflexes were intact except for absent ankle jerks in patient 2. Motor nerve conduction studies demonstrated a marked prolongation of the distal motor latencies with normal proximal segment conduction velocities, suggesting distal demyelination. Cerebrospinal fluid protein concentration was elevated in patient 2, but no definite abnormality was found on sural nerve biopsy. A demyelinating neuropathy with a monophasic self-limited course may be consistent with Guillain-Barre syndrome (GBS). However, the multifocal painful sensory symptoms with facial numbness and the marked distal nerve conduction slowing in our cases are not consistent with GBS.     

Abnormal sensory nerve conduction in multifocal demyelinating neuropathy with persistent conduction block

Two patients exhibited chronic, slightly asymmetric weakness and wasting with fasciculations of the upper limb and hand muscles. Motor nerve conduction studies showed features of multifocal conduction block in nerve segments other than those usually involved in entrapment syndromes. The F wave was markedly delayed in the median and ulnar nerves. Transcranial cortical and cervical root magnetic stimulation showed bilaterally delayed thenar responses with normal central conduction time. Needle electromyography demonstrated a chronic denervation pattern with large polyphasic motor units in several muscles of the upper limbs. Sensory symptoms were mild and limited to paresthesias in the fingertips. Sensory nerve conduction velocity and sensory nerve action potential amplitudes were normal in elbow-to-wrist and wrist-to-finger segments of the median and ulnar nerves, but there was a delayed cortical response and unrecognizable Erb's point and cervical responses in the somatosensory evoked potentials to median nerve electrical stimulation. Electrophysiologic examination was normal in most nerves of the lower limbs. These two patients, meeting clinical and electrophysiologic criteria of multifocal neuropathy with conduction block, demonstrate that sensory fibers may also be involved in this syndrome.     

Body mass index effect on common nerve conduction study measurements

This study was performed to determine whether there is a difference in nerve conduction study (NCS) measures based on body fat (body mass index; BMI). Two hundred fifty-three subjects had the following NCS tests performed on them: median, ulnar, peroneal, and tibial motor studies; median, ulnar, radial, and sural sensory studies; median and ulnar mixed nerve studies; and H-reflex studies. BMI was calculated as weight (kg) divided by height (m) squared. A repeated measures analysis of variance was run adjusting for age, sex, and height and using BMI as both a continuous variable and by dividing BMI into upper, middle, and lower thirds. The sensory and mixed nerve amplitudes correlated significantly (P < or = 0.01) with BMI for all nerves tested, with means being approximately 20-40% lower in the obese than in the thin subjects. No correlation was noted between BMI and nerve conduction velocity, H-reflex latency, or most of the other motor/sensory/mixed measures. The correlation between increased BMI and lower sensory/mixed nerve amplitudes should be taken into account in clinical practice.     

Lipoteichoic acid as a target for antimicrobial action

Fifteen patients with unilateral functioning arteriovenous fistula were assessed clinically and electromyographically to identify local neurologic changes. Ten of the patients were symptomatic (motor and/or sensory) and 5 were asymptomatic. Clinically, 11 patients had signs of a mild polyneuropathy, 2 patients of ulnar neuropathy, and 1 patient had signs of median neuropathy. A decrease of the above-elbow ulnar conduction velocity was noted in the study group on the side of the functional fistula, and in the symptomatic patients only on the side of the nonfunctional/nonexisting fistula. We suggest that ulnar nerve vulnerability should be taken into consideration during construction of the fistula, as well as during dialysis.     

Peripheral nerve repair in the hand with and without motor sensory differentiation

To investigate the value of motor sensory differentiated nerve repair, we examined a group of 9 patients with motor sensory differentiated nerve repair and a group of 13 patients without motor sensory differentiated nerve repair. The clinical and electroneurographic findings were compared. For the clinical examination, Millesi's scoring system was used. The hand function after motor sensory differentiated median nerve repair was 72% +/- 16% compared with 57% +/- 14% without motor sensory differentiation. The hand function after motor sensory differentiated median and ulnar nerve repair was 53% +/- 12% compared with 43% +/- 24% without motor sensory differentiation. After ulnar nerve repair the achieved values for hand function were high even without motor sensory differentiation. Our results indicate that intraoperative motor sensory differentiation of injured nerves is helpful to reestablish particularly the sensory function in median nerve injuries.     

Granulomatous orchitis. A case report and review of the literature

We developed a method for determination of motor conduction along the mandibular and sensory conduction along the lingual and inferior alveolar nerves in 10 controls and 6 patients with lingual neuropathy following lower wisdom tooth extraction. Patients with lingual neuropathy had reduced/absent or delayed compound sensory action potentials and normal conduction along the fibers of the inferior alveolar nerve and mandibular nerve. The method provides a useful electrophysiological means of evaluating lingual nerve lesions.     

The sword of Damocles: the psychosocial impact of familial spinocerebellar ataxia in South Africa

It has been recently recognized that increased titers of serum anti-GM1 antibodies may be associated with motoneurone diseases or with multiple motor neuropathy with or without conduction block and also with chronic sensorimotor neuropathy and Guillain-Barré syndrome. Santoro et al. were the first to note that anti-GM1 antibodies were able to bind to the nodes of Ranvier of the sural nerve of a patient with clinical signs and symptoms mostly resembling amyotrophic lateral sclerosis who also showed, in nerve conduction studies, multifocal motor nerve fibers conduction block and serum IGM anti-GM1 antibodies. The two patients presented in this report had asymetrical motor neurone disease with signs and symptoms of lower motoneurone involvement, and other signs, in the first patient, which suggested the existence of upper motoneurone damage. Besides, the second patient also had clinical sensory impairment in the lower limbs. Electrophysiologically, none of them had nerve conduction block but both showed inexcitable median and sural nerve sensory fibers. Both had high titers of anti-GM1. A sural biopsy of both patients showed immunoglobulins into the sensory fibers. However, we do not know whether the anti-GM1 antibodies bind to a cross-reactive glycolipid other than the GM1 itself. In any case, it seems that the presence of anti-GM1 antibodies might be a marker signalling a potentially treatable immune disorder which may have signs of lower and upper motor neurone disease and, also, clinical and electrophysiological evidences of peripheral sensory involvement.     

Langerhans cell density in normal human oral mucosa and skin: relationship to age, smoking and alcohol consumption

Hyperthyroidism is a common endocrinologic disorder affecting many organ systems. Musculoskeletal and neurological involvement present themselves as fatigue, muscle weakness and paralysis. Electromyography (EMG) is essential for differential diagnosis of muscle weakness. Well defined neuropathy and myopathy have been described in these patients. In the present study 17 hyperthyroid patients were evaluated with electrophysiological tests in addition to physical and neurological examinations and biochemical laboratory studies. Needle EMG, motor and sensory conduction velocities, median and tibial somatosensory evoked potentials (SEP) were studied. For assessment of the activity of disease clinical status, neurological symptom and disability scores and serum T3, T4 and TSH levels were examined. Statistical analysis of neuroelectrophysiological findings of the patient and the control groups yielded meaningful difference in the needle EMG, sensory conduction velocity and evoked potential findings. Abnormalities were observed in 80% of the proximal muscles besides polyphasic potentials that were seen in 20% of the extensor digitorum brevis muscle. Median, ulnar and sural nerve sensory action potential amplitudes were found to be lower than that of the control group. Sural sensory nerve conduction velocity of patients was decreased in 35.5%, prolongation of median SEP latencies and increase in the amplitudes were not however statistically significant. Prolongation of Tibial SEP N1, P2 latencies were seen in 47%, amplitudes of N1 were increased in 88.2%, P2 in 58.8%, N2 in 47%. The thyroid clinical status score was correlated with Tibial SEPs amplitude. These findings suggest the presence of an initial axonal type of mild polyneuropathy. As a conclusion electrophysiological studies can be useful in the diagnosis of asymptomatic polyneuropathy in hyperthyroid patients.     

Insulin-like growth factor-I prevents development of a vincristine neuropathy in mice

Vincristine is a commonly used antitumor agent whose major dose-limiting side-effect is a mixed sensorimotor neuropathy. To assess whether insulin-like growth factor-I (IGF-I), a neurotrophic agent that supports the survival of motoneurons and enhances regeneration of motor and sensory neurons, could prevent the peripheral neuropathy produced by vincristine, mice were treated with both vincristine (1.7 mg/kg, i.p., 2 x /week) and/or IGF-I (0.3 or 1 mg/kg, s.c. daily) for 10 weeks. In mice treated with vincristine alone, there was evidence of a mixed sensorimotor neuropathy as indicated by changes in behavior, nerve conduction and histology. Caudal nerve conduction velocity was significantly slower in mice treated with vincristine alone as compared with vehicle-treated mice. Vincristine treatment alone also significantly increased hot-plate latencies and reduced gait support and stride length, but not toe spread distances. The effects of vincristine were accompanied by degeneration of sciatic nerve fibers and demyelination, indicating a peripheral neuropathy. IGF-I (1 mg/kg, s.c.) administered to vincristine-treated mice prevented the neurotoxic effects of vincristine as measured by nerve conduction, gait, response to noxious stimuli and nerve histology. At a lower dose of 0.3 mg/kg administered s.c., IGF-I partially ameliorated the neuropathy induced by vincristine as this dose only prevented the change in nerve conduction and hot-plate latencies. IGF-I administered alone had no effect on any of these parameters. These results suggest that IGF-I prevents both motor and sensory components of vincristine neuropathy and may be useful clinically in preventing the neuropathy induced by vincristine treatment.     

Effects of birch pollen-specific immunotherapy on apple allergy in birch pollen-hypersensitive patients

Electrophysiological testing remains an important efficacy parameter in clinical neuropathy trials. The quality of nerve conduction studies in reported trials varies greatly, and may be responsible for negative results. We report the utilization of an expert core lab for electrophysiological testing. With the core lab, the variability of repeat testing is comparable to that of a single, excellent laboratory. Motor conduction velocities demonstrated a coefficient of variation of 3% and sensory conduction velocities 4% across 60 study sites. The distal motor evoked potential amplitudes varied by 13% at the ankle, and 10% at the wrist. The sensory potential amplitudes varied by 16% at the ankle, and 11% at the wrist in 60 sites. The overall monitoring rate in all submitted nerve conduction tracings was 36.6%. Our results show that an expert core lab can improve the electrophysiological quality of clinical trial data with the potential to show small changes in nerve conduction velocities and in both motor and sensory potential amplitudes.     

The fate of T cells in the brain: veni, vidi, vici and veni, mori

Perioperative ulnar neuropathy is a complication that occurs even in patients who seem to be appropriately padded and positioned. The disproportionately high incidence of postoperative ulnar nerve injury compared with the median and radial nerves has largely been attributed to its vulnerability to compression or stretch at the cubital tunnel. Some clinical and laboratory evidence suggests that compromise of perfusion to the upper extremity may also play a role in this complication. To determine whether the ulnar nerve is more sensitive to ischemia of the upper extremity, we studied 10 men during general anesthesia. Somatosensory evoked potentials of the radial, median, and ulnar nerves were simultaneously recorded during general anesthesia with the brachial artery occluded proximal to the cubital fossa. All three nerves showed rapid changes in signal amplitude in response to occlusion of the brachial artery, but the amplitude of the ulnar nerve was affected earlier and to a greater degree. Compared with the median nerve, the change in ulnar nerve signal amplitude during ischemia was significantly greater after 4 min (P = 0.002). This trend persisted at 6 and 8 min (P = 0.008). At 4, 6, and 8 min of ischemia, the ulnar nerve likewise showed a greater decrease in amplitude compared with the radial nerve, with corresponding P values of 0.015, 0.008, and 0.008. We conclude that the ulnar nerve is more sensitive to ischemia of the upper extremity compared with the radial and median nerves. In addition to its increased vulnerability at the elbow, compromise of arterial flow may contribute to some cases of postoperative ulnar neuropathy. IMPLICATIONS: Postoperative ulnar neuropathy is thought to result from compression or stretch of the ulnar nerve at the elbow. However, patients may sustain this complication despite careful padding and positioning. This study suggests that the ulnar nerve may also be unusually sensitive to decreases in blood supply to the arm. Care should not only to properly position and pad the elbows, but also to ensure adequate perfusion of the upper extremities.     

A comparison of traditional electrodiagnostic studies, electroneurometry, and vibrometry in the diagnosis of carpal tunnel syndrome

In 49 patients (98 hands), referred to an electrodiagnostic laboratory, assessments were made by conventional nerve conduction studies on the upper extremity and by two more portable modalities, namely electroneurometry (skin surface electrical stimulation of the motor nerve) and single-frequency (120 Hz) vibrometry. Tests were performed on median and ulnar nerves. Correlations with motor nerve conduction studies for each screening test on the median nerve were r = .81 for the electroneurometer and r = .48 for the vibrometer. When carpal tunnel syndrome was diagnosed either by clinical criteria only or by nerve conduction abnormality, the association with electroneurometry was characterized by high sensitivity and low specificity, while the opposite relationship prevailed with vibrometry. These associations were highly dependent on the methods used to select normal values from a reference population. While the manufacturer's recommended normal values offered good predictability, with thresholds that corresponded to nerve conduction studies, normal values generated in a more standard way produced much weaker and less useful associations. The selection of an appropriate electrical screening test for peripheral nerve injury, such as entrapment neuropathy, depends on the prevalence and seriousness of the target disease and the relative consequences of over- and underdiagnosis.     

Root stimulation studies in the evaluation of patients with motor neuron disease

Nerve root stimulation may be employed in patients with motor neuron disease (MND) to rule out motor neuropathy with conduction block. The diagnostic utility of these studies is unknown, in part because the range of amplitude changes across nerve root segments in patients with active neuronal degeneration has not been well studied. We reviewed root stimulation studies in 32 patients (59 nerves) with MND and found segmental amplitude reduction from 0 to 45%, a range similar to values reported for normal subjects; there was no suggestion of conduction block based on our usual criteria.     

Prolonged muscle weakness after neuromuscular blockade in the intensive care unit

As noted, quadriparesis with reduced reflexes and difficulty with ventilator weaning may be seen as a result of a number of neuromuscular disorders. The clinical approach relies on exclusion of a central cause first, followed by careful examination of peripheral nerve and muscle function. Persistent neuromuscular blockade should be excluded initially because it is a readily reversible condition. Use of a train of four stimulation with a peripheral twitch monitor can quickly establish integrity of conduction across the neuromuscular junction. If necessary, further electrophysiologic studies allow differentiation among the relevant diagnostic possibilities. CIP is characterized by nerve conduction and EMG findings consistent with axonal degeneration of sensory and motor fibers. GBS is distinguished by evidence of demyelination on nerve conduction studies, in addition to elevated spinal fluid protein. Persistent neuromuscular blockade is identified by a decremental response on repetitive stimulation studies of neuromuscular transmission. The acute myopathy following neuromuscular blockage does not involve sensory responses. Needle EMG examination reflects a myopathic pattern, rather than a neurogenic one as seen in CIP or GBS. In myopathic patients who are unable to move their limbs at all (precluding a full EMG examination), a muscle biopsy identifies muscle as the site of involvement.     

Cubital tunnel syndrome pathophysiology

Cubital tunnel syndrome is the second most common peripheral compression neuropathy. The unique anatomic relationships of the ulnar nerve at the elbow place it at risk for injury. Normally with elbow range of motion, the ulnar nerve is subjected to compression, traction, and frictional forces. As the elbow is flexed the arcuate ligament elongates producing a decrease in canal volume of 55%. Intraneural and extraneural pressures increase and have been shown to exceed 200 mm Hg with elbow flexion and flexor carpi ulnaris contraction. Because the ulnar nerve courses behind the elbow axis of rotation, elbow flexion produces excursion of the nerve proximal and distal to the medial epicondyle. The ulnar nerve also elongates 4.7 to 8 mm with elbow flexion. Cubital tunnel syndrome may develop because of various factors including repetitive elbow motion, prolonged elbow flexion, or direct compression. An understanding of the anatomy and pathophysiology associated with cubital tunnel syndrome will aid in patient evaluation and determination of the appropriate treatment.     

Acute progressive polyneuropathy in a patient with Waldenstr?m macroglobulinemia

A case of Waldenstr?m's macroglobulinemia (WM) (IgM-kappa type) associated with acute-onset demyelinating peripheral neuropathy is reported. A 49-year-old woman was admitted to our hospital because of general fatigue and recurrent syncope attacks. She was treated with vincristine, cyclophosphamide, epirubicin and prednisolone. By 10th hospital day, her clinical condition improved and serum viscosity was reduced. However, on the 21st hospital day, she suffered from rapidly progressive writing and gait disturbance. Neurological examination showed muscular atrophy and weakness in the distal part of four extremities. Deep tendon reflexes were diminished. There was no sensory deficit. Cerebrospinal fluid was normal. Anti-myelin associated glycoprotein activity of her serum was negative. Both motor and sensory nerve conduction velocities were markedly decreased. Biopsy of sural nerve revealed marked demyelination and onion bulb formation. There was IgM deposition on myelin sheath. Minimal axonal changes excluded the possibility of vincristine neuropathy. Plasmapheresis improved her symptoms, but nerve conduction velocities remained unchanged. Polyneuropathy associated with WM is usually gradual onset and sensory dominant. In this case, associated neuropathy was acute onset, progressive and motor dominant. This type of neuropathy in patients with WM is very rare.     

Abdominal wall metastases in incidental gallbladder carcinoma--different incidence after laparoscopic and open surgery?

We investigated 303 diabetic patients in order to clarify the relationship between progression of diabetic polyneuropathy and conduction delay across the carpal tunnel. Distal latency ratio (DLR) was determined by comparison of distal motor latency of the median nerve with that of the ulnar nerve. Lower extremity polyneuropathy index (LPNI), expressed as a mean percentage of the normal for six indices over two nerves obtained by motor nerve conduction studies, was 82.9% on the average in the patients. Their DLR (1.44 +/- 0.24) was larger than the normal value (1.29 +/- 0.10). About 30% of the diabetics had abnormal DLR, especially in women its incidence was as high as 39%. The lower the LPNI level, the larger the incidence of abnormal DLR. In diabetic polyneuropathy patients peripheral nerves will become fragile, which might increase the incidence of conduction delay across the carpal tunnel. This phenomenon might also be called as 'double crush syndrome'.     

Lower extremity sensory nerve conduction studies

The need for routine recording of sensory potentials in the lower extremity was developed in efforts to better investigate peripheral neuropathy. Sensory nerve conduction studies (NCS) are more sensitive to many abnormalities in the peripheral nervous system than the motor NCS responses. This article provides a thorough review of sensory nerve conduction studies of the lower extremity, with special emphasis on electrodiagnostic issues.     

Nortropane-3beta-acetic acid, tropaquinuclidine and dehydrotropaquinuclidine (author''s transl)]

The greater decrease of conduction velocity in sensory than in motor fibres of the peroneal, median and ulnar nerves (particularly in the digital segments) found in patients with chronic carbon disulphide poisoning, permitted the diagnosis of polyneuropathy to be made in the subclinical stage, even while the conduction in motor fibres was still within normal limits. A process of axonal degeneration is presumed to underlie occurrence of neuropathy consequent to carbon disulphide poisoning.