Disintegration of the motor unit in post-polio syndrome. Part I. Electrophysiological findings in patients after poliomyelitis

CN EMG and SF EMG were performed in 12 patients many years after acute poliomyelitis, without symptoms of post-polio syndrome. In 19 muscles with clinical symptoms and in 11 clinically normal muscles chronic neurogenic changes of a similar degree were observed. Fibre density was increased in both groups of muscles. In muscles with clinical symptoms complexes of single fibres with increased jitter and blocking were more frequent than in muscles without clinical manifestations. It seems that the reinnervation after acute polio is a continuing process and thus complete stabilization and integration of the motor unit cannot be achieved.     

Dysphagia in patients with the post-polio syndrome

BACKGROUND AND METHODS. Dysphagia may develop in some patients many years after an attack of acute paralytic poliomyelitis. To identify clinical or subclinical signs of oropharyngeal dysfunction, we examined 32 patients (mean age, 48.9 years) with the post-polio syndrome (defined by new weakness in the limbs). Of the 32 patients, 14 had symptoms of new swallowing difficulties, and 18 were asymptomatic in this respect; 12 had a history of bulbar involvement during acute poliomyelitis. Swallowing function was assessed objectively by ultrasonography, videofluoroscopy, and an oral motor index score for 10 components of oral function. RESULTS. All but 1 of the 32 patients, regardless of whether they had new symptoms or previous bulbar involvement, had some abnormality on detailed testing of oropharyngeal function; only 2 patients had any signs of aspiration. The mean oral motor index score (a quantitative measure of oral sensorimotor function) in the patients was higher than that in age-matched normal subjects (P less than 0.001). Videofluoroscopy showed abnormalities of varying severity, including unilateral bolus transport through the pharynx, pooling in the valleculae or pyriform sinuses, delayed pharyngeal constriction, and impaired tongue movements. On ultrasonography, the mean (+/- SD) duration of wet swallows was significantly longer in the symptomatic patients than in the asymptomatic patients (2.67 +/- 0.70 vs. 1.65 +/- 0.42 seconds). The four patients who were reexamined two years later had objective signs of worsening oropharyngeal function and corresponding new symptoms. CONCLUSIONS. In patients with the post-polio syndrome, the bulbar muscles often have clinical or subclinical signs of dysfunction. These abnormalities suggest that in bulbar neurons there is a slowly progressive deterioration similar to that in the muscles of the limbs.     

Intrathecal immune response in patients with the post-polio syndrome.

BACKGROUND. The syndrome of progressive muscular atrophy decades after acute paralytic poliomyelitis (post-polio syndrome) is not well understood. The theory that physiologic changes and aging cause the new weakness does not explain the immunologic abnormalities reported in some patients. An alternative explanation is persistent or recurrent poliovirus infection. METHODS. We assessed the intrathecal antibody response to poliovirus and intrathecal production of interleukin-2 and soluble interleukin-2 receptors in 36 patients with the post-polio syndrome and 67 controls (including 13 who had had poliomyelitis but had no new symptoms and 18 with amyotrophic lateral sclerosis). Intrathecal antibody responses to measles, mumps, herpes simplex, and varicella zoster viruses were also determined. RESULTS. Oligoclonal IgM bands specific to poliovirus were detected in the cerebrospinal fluid of 21 of the 36 patients with the post-polio syndrome (58 percent) but in none of the control group (P less than 0.0001). In quantitative studies there was evidence of increased intrathecal synthesis of IgM antibodies to poliovirus only among the patients with the post-polio syndrome; there was no increased synthesis of IgM to measles, mumps, herpes simplex, or varicella zoster viruses. The patients with post-polio syndrome had significantly higher mean (+/- SD) (cerebrospinal fluid levels of interleukin-2 and soluble interleukin-2 receptors than the controls (8.1 +/- 5.3 vs. 1.4 +/- 0.8 U per milliliter and 159.6 +/- 102.9 vs. 10.7 +/- 6.2 U per milliliter, respectively). The intrathecal synthesis of IgM antibodies to poliovirus correlated with the cerebrospinal fluid concentrations of interleukin-2 (P less than 0.0005) and soluble interleukin-2 receptors (P less than 0.001). CONCLUSIONS. An intrathecal immune response against poliovirus is present in many patients with the post-polio syndrome. In some of these patients the recrudescence of muscle weakness may be caused by persistent or recurrent infection of neural cells with the poliovirus.     

Electrophysiological findings in poliomyelitis patients at the subacute phase.

Electrodiagnostic tests-needle EMG, nerve conduction and somatosentory evoked potential (SEP) studies of the upper and the lower limbs were performed in three patients during the subacute phase of poliomyelitis. Although poliomyelitis is traditionally considered a "pure motor" disease, involvement of the sensory system was demonstrated by prolonged sensory nerve conduction and by delayed latencies and amplitude asymmetries of SEPs obtained from the lower limbs. Sensory deficit in poliomyelitis is well known to exist during the acute phase of illness. The present report describes the electrophysiological findings in patients during the subacute phase, several months after onset of illness. Sensory nerve action potentials and sensory evoked potentials were abnormal, especially those elicited by lower limb stimulation although the patients had no overt signs of sensory loss at that time. The associated EMG findings are described, and the probable pathologic changes of the motor unit are discussed.     

Sensory and motor evoked potentials findings in patients with thoracic outlet syndrome

OBJECTIVE: Diagnostic utility of somatosensory and motor evoked potentials in two patients with neurogenic and vascular thoracic outlet syndrome (TOS) were investigated. MATERIALS AND METHODS: In two female patients with progressive weakness and sensory disturbance of the arms, mixed nerve somatosensory evoked potentials (SSEP), and motor evoked potentials (MEP) were tested before and after dynamic position of the affected arm. RESULTS: The cortical and cervical (C7) ulnar SSEPs demonstrated no change in latency of major peaks at rest and after abduction of the shoulder. A slight diminishment of cortical amplitude was noted in the first patient after the dynamic position of the arm. The MEPs demonstrated significant drop in amplitude after dynamic position of the arm in both cases signifying neurovascular compression during elevation of the affected arm. No change in MEP latency was noted. The MEP amplitude completely returned to normal after repositioning the arm. CONCLUSIONS: Evoked potential studies are helpful in the diagnosis of neurogenic or vascular TOS. Reduced amplitude of MEP occurs after elevation of the arm above the head which improves after normal position of the arm.     

Neurological manifestations of the post-polio syndrome

Patients with late effects of poliomyelitis, i.e., PPS, are being seen at an ever increasing frequency by general physicians, neurologists, and orthopedists. An appropriate time interval for the onset of late manifestations has elapsed since the major epidemics of poliomyelitis in the 1940s and 1950s. Post-polio neurological manifestations primarily include new weakness, atrophy, muscle pain, and fasciculations. Fortunately, the weakness is of a very slow, progressive nature. Abnormal laboratory studies include routine EMG, demonstrating chronic denervation; SFEMG, demonstrating increased fiber density, increased jitter, and blocking; and muscle biopsy most often revealing fiber-type grouping of chronic denervation and small isolated angular (or angulated) fibers and group atrophy in some series, both suggestive of active denervation. Unfortunately, both EMG and muscle biopsy studies suffer from a lack of specificity as they do not appear to distinguish asymptomatic from symptomatic (new weakness, PPMA) patients with prior poliomyelitis. Although the cause of PPMA is unknown, electrophysiological (SFEMG) and muscle biopsy studies suggest that the process involves a loss or dropout of axon terminals of reinnervated motor units. The axons terminal dropout could be due to dysfunction in the cell soma, the axon, or the terminals themselves. Whether motor neuron exhaustion, a persistent viral infection, or immune-mediated mechanisms play a role in the pathogenesis of the late weakness is unclear at present and will require further investigation. Treatment at this time is of a supportive nature. A major controversy involves the role of strengthening exercises in these patients since experimental animal studies suggest that excessive exercise of denervated muscles leads to increased weakness. Clearly, a better understanding of PPS and PPMA will allow more effective management of these patients' problems and might also provide insight into other motor neuron and neuromuscular junction diseases.     

Heart-hand syndrome II. A report of Tabatznik syndrome with new findings

The association of upper limb malformations and congenital cardiac anomalies was established as a definite clinical and genetic entity by Holt & Oram in 1960. Significant variability of malformations in both the upper limbs and the cardiovascular system has been well documented. In 1978, Temtamy & McKusick reported a family studied by Tabatznik, in which upper limb deformities, including type D brachydactyly, occurred in association with cardiac arrhythmias as a dominant, either autosomal or X-linked trait. They called this apparently new entity "Heart-Hand syndrome II" to distinguish it from the Holt-Oram syndrome. No other similar cases have subsequently been reported. We describe here the second family affected with the Tabatznik syndrome and add some new findings to the clinical spectrum of this condition.     

Abdominal visceral findings in patients with Marfan syndrome.

PURPOSE: Marfan syndrome is an autosomal dominant disorder historically defined by well-characterized features in the cardiovascular, ocular, and skeletal systems. To date, there have been no reports concerning abdominal visceral findings in this disorder. The purpose of this study was to determine the prevalence of abdominal visceral findings in patients with Marfan syndrome. METHODS: Computed tomography or magnetic resonance studies of 69 patients with Marfan syndrome and an age- and sex-matched cohort of control subjects were reviewed. The presence of abdominal visceral findings was noted. Chi-square and Student t tests were used to determine significance of differences between the patient and control groups. This retrospective study was approved by the local institutional review board and determined to be exempt from Health Insurance Portability and Accountability Act reporting requirements. RESULTS: Renal cysts were present in 41 Marfan patients (59.4%) versus 21 control subjects (30.4%), P=0.001. The average number of renal cysts was greater in Marfan patients than controls (2.4 vs. 0.9, P=0.005). Hepatic cysts were present in 24 Marfan patients (34.8%) versus 12 control patients (17.3%), P=0.02. The average number of hepatic cysts was also greater in Marfan patients than controls (0.9 vs. 0.3, P=0.027). Cholelithiasis was present in 12 Marfan patients (18.1%) versus one control patient (1.5%), P<0.001. CONCLUSIONS: Marfan syndrome patients have liver and renal cysts more often, in increased number, and at an earlier age than controls, in addition to an increased prevalence of cholelithiasis. Further study will be needed to relate these findings to recent developments concerning the underlying molecular genetics of this disorder.     

Cytogenetic and molecular findings in patients with Turner''s syndrome stigmata.

Cytogenetic and DNA analysis in 12 people with stigmata of Turner's syndrome was carried out. Cytogenetic analysis of these patients showed two subjects with 46,X, i(Xq) karyotypes, one with 45,X/46,X, i(Xq), one with 46,X,t(X;Y), and eight with 45,X/46,X,mar. Molecular analysis of DNA samples was performed in nine out of 12 patients with marker chromosomes. PCR analysis with oligoprimers specific for SRY, DYZ1, or DYZ3 loci identified Y chromosome material in five patients in the latter group. The X chromosome origin of the marker chromosome was proved by FISH technique with biotin labelled pericentromeric X chromosome specific probe in four other patients. These results show that patients with a number of Turner's syndrome stigmata usually do not have a typical XO karyotype but have some structural chromosomal aberrations involving the X or Y chromosomes. Combined application of cytogenetic, molecular cytogenetic (FISH), and PCR techniques significantly improves the precision of marker chromosome identification and thus might be of practical importance for the proper management and treatment of affected patients. Peculiarities of pathological manifestations of different karyotypes bearing structural abnormalities of the X or Y chromosomes in patients with Turner's syndrome stigmata, as well as feasible genetic mechanisms of sex determination and differentiation abnormalities in these subjects, are briefly discussed.     

Autopsy findings in patients with acquired immunodeficiency syndrome

We have evaluated the autopsies of 11 patients with HTLV III/LAV-infection. The clinical diagnosis was AIDS in 10 cases and AIDS related complex (ARC) in one case. The most common infectious disease was pneumocystis carinii pneumonia, occurring in 5 cases. 3 patients showed evidence of mycobacterial infections and another three showed cytomegalovirus infections. Kaposi's sarcoma was found in 4 and other malignancies in 3 cases. Our results are in agreement with the findings of other authors.     

Clinical significance of immunopathological findings in patients with post-pericardiotomy syndrome. II. The significance of serum inhibition and rosette inhibitory factors.

Serum inhibition factors (SIF) that suppress phytohaemagglutinin-induced blast transformation of normal lymphocytes, and lymphocyte E-rosette inhibitory factors (RIF) that inhibit the T cell-specific property of E-rosette formation were determined in sixty-five patients before and after cardiac surgery. SIF was found in the first post-operative week in almost all patients; patients with complete post-pericardiotomy syndrome (PPS) still had these factors in the fourth postoperative week. The appearance of SIF correlated well with the intensity of the PPS. Persistence of SIF in eleven out of eighteen patients with clinically incomplete PPS reaffirms the probability that they had an 'immunologically' positive PPS. RIF was to be found in one third of the patients with complete or incomplete PPS and may be of prognostic value. The two factors were not identical.     

Pathological findings in three non-japanese patients with the POEMS syndrome

Summary The pathological features of three European patients with plasma cell dyscrasia, osteosclerosis and a multisystem disorder, most frequent in Japan, that includes polyneuropathy, organomegaly, endocrinopathy, M-protein anti skin changes (POEMS syndrome), are reported. The material was obtained from biopsies (peroneal nerve, lymph node) and general autopsy, including hypophysis, in one case. The most salient findings were: peripheral nerve lesions, including both segmental demyelination and axonal degeneration, with socalled uncompacted myelin lamellae (UML); angiofollicular lymph node hyperplasia (AFLNH); and non inflammatory vascular changes. Though not specific, it appears that UML and AFLNH may be contributive findings in atypical cases of POEMS syndrome (incomplete forms, lack of underlying malignant plasma cell dyscrasia or circulating monoclonal immunoglobulin). Among the various autopsy findings we emphasize the skin thickening which was secondary to a hyaline sclerosis of the papillary dermis, and the presence in adenohypophysis of numerous cells showing positive reactions with the anti-alpha MSH antibody. Though immunological, vascular and hormonal disturbancies have been implicated at the origin of several manifestations of the disorder, the pathogenesis of the POEMS syndrome remains obsecure.     

Motor unit remodelling in Duchenne muscular dystrophy. Electrophysiological assessment.

Conventional EMG, motor and sensory conduction velocities, averaging analysis of MUPs, SFEMG, and muscle fiber conduction velocity in situ were performed in 14 boys with Duchenne muscular dystrophy (DD) aged 5 to 11 years. MUPs parameters study showed a striking increment of long duration MUPs followed by satellites and increase of polyphasic potentials of variable duration. The main findings in SFEMG examination were increment in fiber density of the motor unit, large MISI and presence of complex potentials of long duration in all patients. Muscle fiber conduction velocity in situ was significantly slower than in controls, with significant decrease in minimum conduction and increased variability (large SD) in propagation velocity values. Low conduction velocity of muscle fibers, long duration of polyphasics and MUPs followed by satellites, and large MISI were significantly related. These findings support the hypotheses which have suggested that the motor unit remodelling in DD is mainly myogenic. The abnormalities in muscle fiber conduction velocity in situ reflect an increased diameter variation of muscle fibers consistent with splitting fibers, small groups of regenerating and necrotic fibers, and fiber diameter variation found in histological studies. Thus, increased variability in fiber diameter may be the cause of complex and long duration MUPs in DD.     

Electrophysiological findings of acute peripheral facial palsy in diabetic and non-diabetic patients

The aim of this study is to investigate the role of diabetes mellitus on the clinical and electrophysiological findings of peripheral facial palsy (PFP), the effect of the diabetes duration and polyneuropathy on the electrophysiological parameters. A total of 32 diabetic and 40 non-diabetic patients with peripheral facial palsy were included. All patients were divided into two subgroups based on the time of electrophysiological examinations: within the first 15 days versus within 16–30 days. Neuropathy symptoms and the results of neurological examinations and electrophysiological findings were recorded. The findings of electroneurography (EnoG), blink reflex (BR) evaluation, and needle electromyography (EMG) indicated statistically significant blink reflex abnormalities in diabetic patients compared to non-diabetics. Delay in the latency was more remarkable in the R2 component than in the R1 (p < 0.001). The delay in the R1 latency was also observed in the non-affected side for diabetic patients. The longer duration of the diabetes caused significant delay on the blink reflex latency on both the affected and non-affected sides for R1 component (p = 0.019, p = 0.041, respectively). In contrary, neither the diabetes duration nor the age of the patients correlated with the clinical severity of facial palsy, fiber loss, fibular nerve compound muscle action potential amplitudes, and the nerve conduction velocities.     

Peculiarities of extracellular potentials produced by deep muscles. Part 2: motor unit potentials

The potential fields generated by single fibres far from the sources are non-propagating. This suggests that there should be differences in the features of surface motor unit (MU) potentials (MUPs) detected from deep and superficial muscles. We explored the features using a simulation approach. We have shown that the non-propagating character and similar shapes among surface MUPs recorded over a wide area above deep muscles with monopolar or longitudinal single differential (LSD) electrodes are natural. Contrary to close distances, at large radial distances single differentiation did not emphasize MUP main phase relative weight. The position of the end plate area could be estimated with LSD detections only for MUs with long (123 mm) almost symmetric fibres. With short fibres, the LSD main phase was masked by the outlined terminal phases. This could be misleading in MUP analysis since the terminal phases reflect standing sources. The highly asymmetric fibres could yield peculiar MUP shapes resembling MUPs of two distinct MUs. We have shown that the relative weight of terminal phases at large fibre-electrode distance decreases under abnormal peripheral conditions. However, the changes in membrane depolarization due to fatigue or pathology could be assessed non-invasively also from deep muscles.     

Electrophysiological assessment in neurogenic thoracic outlet syndrome.

OBJECTIVES: To evaluate the value of different electrophysiological techniques in the diagnosis of neurogenic thoracic outlet syndrome (TOS). MATERIALS AND METHODS: Two females, aged 22 and 30 years, with progressive weakness and wasting of the right hand with slight sensory disturbances. Needle EMG, motor and sensory conduction along median and ulnar nerves, sensory conduction of medial (MACN) and lateral (LACN) antebrachial cutaneous nerves. RESULTS: Chronic neurogenic atrophy in small hand muscles, more severe in lateral part of thenar eminency, reduced compound muscle action potentials (CMAPs) more severe by median than ulnar stimulation, and reduced amplitude of the SNAPs of ulnar and MACN were the main findings consistent with neurogenic TOS. Both patients had right cervical rib in radiography. CONCLUSIONS: Electrophysiological study is useful in the diagnosis of neurogenic TOS. Reduced amplitude of MACN and ulnar nerve SNAPs, predominant denervation in thenar eminency, and reduced amplitude of CMAPs, more by median than by ulnar stimulation, are consistent with the diagnosis.     

Pathologic findings in the adrenal glands of autopsied patients with acquired immunodeficiency syndrome

A morphologic evaluation was carried out on adrenal glands from 128 autopsied patients with the acquired immunodeficiency syndrome (AIDS). The adrenal gland was compromised in 99.2% of the cases, with distinct pathological features and infectious agents. Inflammatory infiltrates were observed in 99.2% of the cases with a predominance of mononuclear cells in 97.4%, affecting mainly the medulla. Necrosis, fibrosis, hemorrhages and neoplasias were observed. We also described 3 (2.3%) cases of calcification located in the adrenal gland central vein (AGCV). This is seldom mentioned in the literature. Cytomegalovirus was the most frequent infectious agent, observed in 48.4% of cases. Balamuthia mandrillaris, a free living ameba, was found in one case affecting the entire gland. We also found a nest of Trypanosoma cruzi in the musculature of the AGCV. The presence of the nest of T cruzi in AGCV may play a role in the reactivation of this infection in immunosuppressed individuals. Pathologic processes and opportunistic infections may contribute to the alterations in the adrenal gland that lead to multiple organ failure observed in terminal AIDS patients.