Primary and Secondary Red Ear Syndrome: Implications for Treatment

Approximately 57 patients with red ear syndrome have been reported in the literature since it was initially described in 1994. The clinical phenotype therefore continues to be defined and no consistent treatment response has been described. We report three new cases of red ear syndrome and suggest that the disorder may exist as a primary trigeminal or cervical autonomic cephalalgia, coexist with other rare trigeminal autonomic cephalalgias, or may be secondary. The pathogenesis in these different circumstances may be distinct, the triggers specific and, when secondary, the disorder may be more resistant to treatment.

Inflammatory hypertrophic cauda equina following intrathecal neural stem cell injection

INTRODUCTION

Potential benefit from stem cell treatments has more patients seeking treatment without understanding possible risks.

METHODS

We describe a woman who presented with progressive bilateral leg pain, numbness, and gait difficulties. A prior stroke, macular degeneration, osteoarthritis, and depression, led her to receive intrathecal neural stem cell therapy overseas 1 year before onset of symptoms.

RESULTS

Imaging showed marked enlargement of lumbosacral roots of the cauda equina, which was not seen before stem cell treatment. Electrodiagnostic studies confirmed chronic multiple lumbosacral radiculopathies. Biopsy of a lumbar dorsal sensory root showed myelinated fiber degeneration and loss, with endoneurial inflammation. The hypertrophic inflammatory cauda equina syndrome was potentially triggered by the prior intrathecal neural stem cell injection.

CONCLUSIONS

Safety of intrathecal stem cell treatments is not routinely regulated in overseas stem cell facilities. We wish to bring this potential complication to the attention of health care providers.

Amyloid-like IgM deposition neuropathy: a distinct clinico-pathologic and proteomic profiled disorder

Some patients with immunoglobulin paraproteinemic neuropathy have intra-nerve deposits that morphologically mimick amyloid, but do no stain with Congo red. Patients with amyloid-like deposits were identified. The nerve amyloid-like aggregates were studied by laser microdissection and dual mass spectrometry. Three male patients, all with IgM gammopathy, and neuropathy were identified. Follow-up, disease duration was 5, 19, and 7 years, respectively. All had progressive asymmetric sensory-onset distal axonal polyneuropathy with late motor involvement. Autonomic symptoms occurred in only one after 13 years of symptoms. None had clinical cardio-renal involvement. One had skin papules with dermal amyloid-like deposits. Endoneurial amyloid-like deposits had granulo-fibrillar ultrastructure. Mass spectrometry of laser-dissected deposits identified IgM pentameric macroglobulin (heavy, light, and joining chains) without amyloid-associated proteins including absent apolipoprotein E and serum amyloid P-component. Amyloid-like neuropathy has distinct clinical, pathologic, and proteomic features which expand the spectrum of IgM neuropathies. Patients have favorable survival, relative absence of autonomic features, and distinct proteomic profiles of the infiltrative protein in nerve.

Superficial siderosis mimicking amyotrophic lateral sclerosis

We report a case of superficial siderosis erroneously diagnosed as amyotrophic lateral sclerosis. The patient's symptoms began 18 years prior with unilateral upper extremity weakness, fasciculations, and hyperreflexia. The patient then developed ataxia and hearing loss 15 years after his original symptoms. The magnetic resonance images revealed superficial siderosis involving the spinal cord and brain. We want to attract attention to superficial siderosis as a rare amyotrophic lateral sclerosis mimic disorder.

Longitudinal study of intraneural perineurioma--a benign, focal hypertrophic neuropathy of youth

The natural history of intraneural perineurioma has been inadequately studied. The aim of this study was to characterize the clinical presentation, electrophysiologic and imaging features and outcome of intraneural perineurioma. We ask if intraneural perineurioma is a pure motor syndrome that remains confined to one nerve and should be treated by surgical resection. We examined the nerve biopsies of cases labelled perineurioma and selected those with diagnostic features. Thirty-two patients were identified; 16 children and 16 adults; 16 males and 16 females. Median age of onset of neurological symptoms was 14 years (range 0.5-55 years) and median age at evaluation was 17 years (range 2-56 years). All patients had motor deficits; however, mild sensory symptoms or signs were experienced by 27 patients; 'prickling' or 'asleep numbness' in 20, mild pain in 13 and sensory loss in 23. The sciatic nerve or its branches was most commonly affected in 15, followed by brachial plexus, radial nerve and ulnar nerve (four each). Magnetic resonance imaging demonstrated nerve enlargement (29/32), T1 isointensity (27/32), T2 hyperintensity (25/32) and contrast enhancement (20/20). Diagnoses were made based on targeted biopsy of the focal nerve enlargement identified by imaging. Neurological impairment was of a moderate severity (median Neuropathy Impairment Score was 12 points, range 2-49 points). All patients had focal involvement with 27 involving one nerve and five involving a plexus (one bilateral). Long-term follow-up was possible by telephone interview for 23 patients (median 36 months, range 2-177 months). Twelve patients also had follow-up neurologic evaluation (median 45 months, range 10-247 months). The median Neuropathy Impairment Score had changed from 12.6 to 15.4 points (P = 0.19). In all cases, the distribution of neurologic findings remained unchanged. Median Dyck Disability Score was 3 (range 2-5) indicating a mild impairment without interfering with activities of daily living. Ten patients judged their symptoms unchanged, nine slightly worse and four slightly better. We conclude intraneural perineurioma is a benign hypertrophic (non onion bulb) peripheral nerve tumour that presents insidiously in young people and is motor predominant with mild sensory involvement. It is most often a mononeuropathy, but a plexopathy can occur. Diagnosis of this condition requires clinical suspicion, imaging, targeted fascicular biopsy of the lesion and expertise of nerve pathologists. As these tumours are static or slowly progressive, remain confined to their original distribution and have low morbidity, they probably should not be resected routinely. Because intensive evaluation is needed for diagnosis, intraneural perineurioma is probably under-recognized.

Clinical and electrodiagnostic findings in copper deficiency myeloneuropathy

INTRODUCTION

Copper deficiency is an increasingly recognised cause of neurological impairment. This retrospective review highlights clinical and electrodiagnostic findings in patients diagnosed at our institution with copper deficiency.

METHODS

Clinical, radiographic and electrodiagnostic findings were reviewed in patients with evidence of copper deficiency. Patients with other potential causes of myelopathy or neuropathy were excluded.

RESULTS

The predominant clinical feature in all six patients was a sensory ataxia, resulting in marked gait unsteadiness. Nerve conduction studies and needle EMG were performed in all patients and revealed a mild to moderate distal, axonal, sensorimotor peripheral neuropathy. Median and tibial somatosensory evoked potentials were abnormal in all five patients in which it was performed, showing impaired conduction in central or proximal peripheral somatosensory pathways.

CONCLUSIONS

This pattern of electrodiagnostic findings suggests that impairment in somatosensory pathways demonstrated by somatosensory evoked potential testing is the main cause of the sensory ataxia in patients with copper deficiency.

Localization of a rapid CSF leak with digital subtraction myelography

A 53-year-old woman with superficial siderosis underwent spinal MR imaging, which demonstrated a large cervicothoracic epidural fluid collection compatible with a CSF leak. Conventional and dynamic CT myelography failed to localize the dural tear because of rapid equilibration of myelographic contrast between the thecal sac and the extradural collection. The superior temporal resolution of digital subtraction myelography precisely localized the CSF leak preoperatively and led to the successful surgical correction of the dural tear.

Clinical and bone density outcomes of tumor-induced osteomalacia after treatment

OBJECTIVE

To report the outcomes of tumor-induced osteomalacia after treatment, particularly related to recovery of bone mass.

METHODS

We review the clinical course of a 61-year-old man extremely debilitated from multiple fractures and neuromuscular weakness due to tumor-induced osteomalacia and report the changes in biochemical markers and bone density after removal of the causative neoplasm.

RESULTS

At the time of diagnosis, the patient's serum phosphorus and 1,25 dihydroxyvitamin D levels were depressed, and his fibroblast growth factor-23 level was markedly elevated. These values normalized 2 days after surgery and remained within their respective reference ranges 4 and 12 months after resection of a mesenchymal tumor. Lumbar bone density values (T-scores) were 0.445 g/cm2 (-5.9) preoperatively, 0.939 g/cm2 (-1.4) 4 months after surgery, and 1.152 g/cm2 (0.7) 12 months after surgery. Left femoral neck values at the same time points were 0.525 g/cm2 (-3.0), 1.035 g/cm2 (-0.8), and 1.184 g/cm2 (1.9). Ultra-distal radius values at the same time points were 0.128 g/cm2 (-7.0), 0.191 g/cm2 (-5.9), and 0.259 g/cm2 (-4.8). In addition, he recovered neuromuscular function and was able to leave his wheelchair.

CONCLUSION

Tumor-induced osteomalacia can be an extremely debilitating disease. With successful localization, identification, and resection of the neoplasm, bone mass and physical function can recover.

Spinal cord astrocytoma presenting as “idiopathic” intracranial hypertension

Increased intracranial pressure is rarely seen in association with spinal tumors. We describe a young, non-obese man who presented with increased intracranial pressure, papilledema and visual obscuration. Multiple cerebrospinal fluid (CSF) examinations with normal or minimally elevated CSF protein lead to the initial diagnosis of idiopathic intracranial hypertension. After a lumboperitoneal shunt placement a progressive thoracic myelopathy developed 7 months after onset of symptoms. The spinal MRI showed a low cervical-upper thoracic intramedullary tumor. Open biopsy confirmed a grade 3 fibrillary astrocytoma. The suspected mechanisms of spinal tumors causing increased intracranial pressure are reviewed as well as three other cases of spinal astrocytomas previously reported in the literature that presented with papilledema and increased intracranial pressure without hydrocephalus. This case illustrates that increased intracranial pressure may in exceptional cases of spinal tumors precede the more typical myelopathic presentation by months and mimic idiopathic intracranial hypertension.

Value of the oral glucose tolerance test in the evaluation of chronic idiopathic axonal polyneuropathy

BACKGROUND

An underlying cause is found in only 7% to 30% of patients with chronic idiopathic axonal polyneuropathy (CIAP). Diabetes mellitus, inherited disorders, toxin exposure, and primary amyloidosis are the most common identified causes of sensory neuropathies affecting both large and small myelinated fibers. Undiagnosed impaired fasting glucose metabolism has been associated with CIAP at a higher frequency rate than in the general population. This increased prevalence rate was identified using the 2-hour oral glucose tolerance test (2h-OGTT) and a previous version of the American Diabetes Association (ADA) guidelines.

OBJECTIVES

To determine the prevalence of abnormal fasting glucose metabolism in patients with CIAP and to compare the value of determining fasting plasma glucose levels using revised (2003) ADA criteria with the 2h-OGTT for predicting abnormal fasting glucose metabolism.

PATIENTS

In this 24-month retrospective study, 100 consecutive patients were identified with no known cause for CIAP, including diabetes mellitus, between January 2003 and January 2005. All had both a fasting plasma glucose test and a 2h-OGTT in addition to a complete neurological examination. Neurophysiological studies, computer-assisted sensory examination, and quantitative sudomotor axonal reflex testing were used to classify CIAP into subtypes according to nerve fiber involvement.

RESULTS

The prevalence of undiagnosed abnormal fasting glucose metabolism was found to be nearly 2-fold higher (62%) in patients with CIAP than in similar age-matched general population groups (33%). Using the 2003 revised ADA criteria, 39 patients (39%) had abnormal fasting plasma glucose metabolism (36 with impaired fasting glucose, 3 with diabetes mellitus), while the 2h-OGTT provided an even higher diagnostic rate of 62% (62 patients; P<.001) of impaired fasting glucose metabolism (38 with impaired glucose tolerance, 24 with diabetes mellitus). The abnormal glucose metabolism rates were found to be similar across the 3 subtypes (sensorimotor, pure sensory, and small-fiber neuropathy) of CIAP (P = .60, .72, and .61).

CONCLUSIONS

This study adds to emerging evidence that abnormal glucose metabolism may be a risk factor for CIAP. Even with revised (2003) ADA criteria, the 2h-OGTT provides additional diagnostic information to the health care professional in the evaluation of CIAP. Subtypes of CIAP are equally likely to have abnormal glucose metabolism.

Delayed ulnar neuropathy at the wrist following open carpal tunnel release

Open carpal tunnel release is a common and successful treatment of median neuropathy at the wrist (carpal tunnel syndrome). We report a case of delayed ulnar neuropathy at the wrist with onset 2 months after open carpal tunnel release. Clinical findings, electrophysiological studies, magnetic resonance imaging, and surgical exploration demonstrated ulnar nerve compression at Guyon's canal resulting from translocation of the carpal tunnel contents. To our knowledge, this is an unreported complication of open carpal tunnel release that merits wide appreciation.

Multifocal Motor Neuropathy with Conduction Block: Current Issues in Diagnosis and Treatment

Multifocal motor neuropathy (MMN) with conduction block is an acquired, autoimmune-mediated neuropathy that is responsive to treatment. The clinical history is one of slowly, progressive distal weakness, which more commonly involves the upper extremities, and it affects mainly young adults. Physical examination reveals weakness without sensory loss in the distribution of individual nerves. Atrophy may be present, but hyperreflexia and spasticity are not seen. Electrophysiological studies reveal motor conduction blocks at sites not prone to compression with normal sensory responses. Immunoglobulin M anti-GM1 titers may be elevated. Treatment with human immunoglobulin or cyclophosphamide has been shown to improve strength in the majority of patients with MMN in the short term. However, motor strength and function may gradually decline over years in spite of long-term therapy.

Probable adult polyglucosan body disease

Adult polyglucosan body disease is a clinicopathologic entity characterized by progressive upper and lower motor neuron dysfunction, sensory loss in the lower extremities, sphincter dysfunction, and occasionally dementia. Pathologically, numerous large polyglucosan bodies are noted in peripheral nerves, cerebral hemispheres, and the spinal cord, as well as in other systemic tissues. We present a case of probable adult polyglucosan body disease based on clinical history and examination, magnetic resonance images, and sural nerve biopsy findings.

Symptoms of 100 patients with electromyographically verified carpal tunnel syndrome

To determine the symptoms of carpal tunnel syndrome (CTS), screening evaluations were performed in 244 consecutive patients with sensory symptoms in the hand and unequivocal slowing of median nerve conduction at the wrist. This yielded 100 patients thought to have no explanation other than CTS for their upper limb complaints. These patients completed a hand symptom diagram (HSD) and questionnaire (HSQ) about their symptoms. CTS symptoms were most commonly reported in median and ulnar digits, followed by median digits only and a glove distribution. Unusual sensory patterns were reported by some patients. Based on the HSQ, paresthesias or pain proximal to the wrist occurred in 36.5% of hands. The usefulness of the HSD and HSQ for diagnosis was determined by asking three physicians, blinded to the diagnosis, to rate the likelihood of CTS in the patients with CTS and in 50 patients with other causes of upper extremity paresthesia. The sensitivities of the instruments ranged from 54.1% to 85.5%. Combining the HSD and HSQ ratings increased the range of sensitivities to 79.3% to 93.7%.

Peripheral neuropathy caused by proteolipid protein gene mutations

Pelizaeus-Merzbacher disease (PMD) is a dysmyelinating disorder of the central nervous system typically caused by duplications or missense mutations of the proteolipid protein (PLP) gene. Most investigators have found that peripheral nerve function and structure is normal in PMD patients. We have found that null mutations of the PLP gene cause demyelinating peripheral neuropathy, whereas duplications and a proline 14 to leucine mutation do not affect nerve function. A family with a nonsense mutation at position 144, which affects only PLP but not the alternatively spliced gene product DM20, has a very mild syndrome, including normal peripheral nerve function. Our findings suggest that DM20 alone is sufficient to maintain normal nerve function and that there may be domains of PLP/DM20 that have a relatively more active role in the peripheral nervous system compared with that in the central nervous system.

Proteolipid protein is necessary in peripheral as well as central myelin

Alternative products of the proteolipid protein gene (PLP), proteolipid protein (PLP) and DM20, are major components of compact myelin in the central nervous system, but quantitatively minor constituents of Schwann cells. A family with a null allele of PLP has a less severe CNS phenotype than those with other types of PLP mutations. Moreover, individuals with PLP null mutations have a demyelinating peripheral neuropathy, not seen with other PLP mutations of humans or animals. Direct analysis of normal peripheral nerve demonstrates that PLP is localized to compact myelin. This and the clinical and pathologic observations of the PLP null phenotype indicate that PLP/DM20 is necessary for proper myelin function both in the central and peripheral nervous systems.

Immune brachial plexus neuropathy: suggestive evidence for an inflammatory-immune pathogenesis

We report brachial plexus biopsy findings from two Australian and two American patients with brachial plexus neuropathy. There were florid multifocal mononuclear inflammatory cell infiltrates. Present evidence suggests that these brachial neuropathies have an immune basis.

Duchenne muscular dystrophy: deficiency of dystrophin-associated proteins in the sarcolemma

Dystrophin, the protein product of the Duchenne muscular dystrophy (DMD) gene, is a major component of the subsarcolemmal cytoskeleton and exists in a large oligomeric complex tightly associated with several sarcolemmal glycoproteins which provide a linkage to the extracellular matrix protein, laminin. In the present study, we investigated the status of the dystrophin-associated proteins in the skeletal muscle from 17 DMD patients of various ages. The results revealed a dramatic reduction in all of the dystrophin-associated proteins in the sarcolemma of DMD muscle compared with normal muscle and muscle from a variety of other neuromuscular diseases. This abnormality was common in all 17 DMD patients, irrespective of age. Our results indicate that the absence of dystrophin leads to the loss in all of the dystrophin-associated proteins, which renders DMD muscle fibers susceptible to necrosis. The analysis of dystrophin-associated proteins is important in the assessment of experimental therapies that attempt to replace dystrophin in DMD muscle.

Peripheral neuropathies associated with monoclonal proteins

Peripheral neuropathies associated with monoclonal proteins have received considerable attention as a clinically important group of chronic late-onset neuropathies. When a monoclonal protein is found in patients with peripheral neuropathy of unknown cause, as occurs in 10% of such cases, usually no associated disease is discovered; hence MGUS. Less often, disorders such as multiple myeloma, AL amyloidosis, Waldenström's macroglobulinemia, osteosclerotic myeloma, and lymphoma are found. Demyelinating neuropathies associated with MGUS of all classes, but particularly IgM, Waldenström's macroglobulinemia, and osteosclerotic myeloma typically follow an indolently progressive course, and frequently respond to treatments aimed at interfering with putative underlying immune mechanisms. By contrast, axonal neuropathies associated with MGUS, multiple myeloma, and AL amyloidosis have generally shown no response to therapy. Recently, IgM monoclonal and polyclonal antibodies directed against human peripheral nerve antigens including MAG and various glycolipids such as GM1 ganglioside have been found in patients with specific neuropathy syndromes. Anti-MAG antibodies occur in predominantly sensory demyelinating neuropathies, whereas elevated titers of anti-GM1 ganglioside antibodies are associated with lower motor neuron syndromes with multifocal motor conduction block. Although the evidence for autoimmune mechanisms in some monoclonal protein-associated neuropathies is mounting, a causal connection between monoclonal proteins and these neurologic syndromes has yet to be established.

Linkage localization of facioscapulohumeral muscular dystrophy (FSHD) in 4q35

Fasioscapulohumeral muscular dystrophy (FSHD) has recently been localized to 4q35. We have studied four families with FSHD. Linkage to the 4q35 probes D4S163, D4S139, and D4S171 was confirmed. We found no recombinants helpful in detailed localization of the FSHD gene. Two of our families include males with a rapidly progressive muscle disease that had been diagnosed, on the basis of clinical features, as Duchenne muscular dystrophy. One of these males is available for linkage study and shares the haplotype of his FSHD-affected aunt and cousin.

Class II antigen expression in peripheral neuropathies

The expression of class II antigen was studied in sural nerve biopsies from patients with peripheral neuropathies. These included patients with chronic demyelinating polyradiculoneuropathy (CIDP), non-immune mediated neuropathies of diverse etiologies and controls without evidence of neuropathy. The major finding in CIDP was a marked increase in class II expression on Schwann cells. Endoneurial Schwann cell staining to the same degree as in CIDP was seen in diabetic symmetric proximal motor neuropathy, neuropathies associated with monoclonal gammopathies and hereditary sensory and autonomic neuropathy type 1. In the control nerves and the other non-immune mediated neuropathies class II expression was mainly restricted to endothelial and perineurial cells. Increased endoneurial expression of class II antigen was found to correlate with elevated cerebrospinal fluid (CSF) protein levels but not with other clinical variables or demyelination as defined by electrophysiologic criteria or teased fiber analysis. The increased expression of class II antigen on Schwann cells may be indicative of a breakdown in immunological tolerance but should not be used as a diagnostic marker for dysimmune neuropathies due to overlap with non-immune mediated neuropathies.

Utilization of dietary precursors for carnitine synthesis in human adults

Endogenous synthetic pathways are presumed to be sufficient to provide adequate amounts of carnitine to meet the needs of the body. However, circulating carnitine levels of strict vegetarian adults and children, and particularly of infants fed carnitine-free formulas, are significantly lower than normal. Therefore, we investigated loci at which rates of carnitine synthesis may be restricted in human adults. Excess amounts of the carnitine precursors lysine plus methionine, epsilon-N-trimethyllysine or gamma-butyrobetaine were fed as supplements to a low carnitine diet for 10 d. Rate of carnitine synthesis was estimated by changes in carnitine excretion and changes in serum and muscle carnitine levels. Dietary gamma-butyrobetaine dramatically increased carnitine production, epsilon-N-trimethyllysine had a somewhat smaller effect, and lysine plus methionine had even less effect on carnitine synthesis. We conclude that carnitine synthesis is not limited by the activity of gamma-butyrobetaine hydroxylase. Carnitine synthesis from exogenous epsilon-N-trimethyllysine is limited either by enzymatic processes that lead to the final intermediate, gamma-butyrobetaine, or by the ability of this substrate to enter tissues capable of carrying out these transformations.

Axonal signals regulate expression of glia maturation factor-beta in Schwann cells: an immunohistochemical study of injured sciatic nerves and cultured Schwann cells

Glia maturation factor-beta (GMF-beta) is a 17 kDa protein purified and sequenced from bovine brains. Using the monoclonal antibody G2-09 directed against GMF-beta, we previously demonstrated endogenous GMF-beta in astroblasts, Schwann cells, and their tumors in culture. In the present study, we have used indirect immunofluorescence microscopy with G2-09 to examine the effects of transection, crush, and regeneration of sciatic nerve on the expression of GMF-beta in Schwann cells in situ and to study the time course of GMF-beta induction in Schwann cells in vitro. For comparison, a parallel study was carried out with monoclonal antibodies directed against nerve growth factor (NGF) receptor. We found that (1) neither GMF-beta nor NGF receptor was detectable in intact sciatic nerves, (2) all Schwann cells of the distal segment of the transected nerve expressed GMF-beta as early as 3 d after axotomy that persisted up to 3 weeks, (3) axonal regeneration repressed the Schwann cell expression of GMF-beta, (4) isolated Schwann cells derived from rat sciatic and adult human sural nerves developed intracellular GMF-beta in culture following an initial lag period, and (5) the induction of Schwann cell NGF receptor coincided temporally with that of GMF-beta in the transected nerve and in culture. These results show that the expression of GMF-beta in Schwann cells, as is the case with the NGF receptor, is induced by the loss of the normal axon-Schwann cell contact. We propose that the induction of GMF-beta, as well as NGF receptor, in Schwann cells after nerve injury plays a role in axonal regeneration.

Endogenous immunoreactive glia maturation factor-like molecule in cultured rat Schwann cells

Using the monoclonal antibody G2-09 raised against bovine glia maturation factor (GMF), we demonstrated that cultured rat Schwann cells and Schwannoma cells, but not their conditioned media, possessed endogenous GMF-like immunoreactivity. The presence of immunoreactive GMF correlated well with GMF bioactivity. The GMF-like factor in Schwann cells was characterized by immunodotting, immunofluorescence, immunoadsorption and immunoblotting. Immunofluorescence confirmed the intracellular location of GMF. Immunoadsorption completely eliminated the GMF-like bioactivity from the cell extracts. Immunoblotting identified a protein band with a molecular weight of 14,000. Thus, the evidence strongly supports the argument that the GMF-like factor in rat Schwann cells is identical with GMF from the bovine brain. The GMF-like molecule in Schwannoma cells showed properties similar to those in Schwann cells, but for unknown reasons was not detectable by immunofluorescence. The presence of GMF in cultured rat Schwann cells suggests that the factor may play a role in the peripheral nervous system.

Schwann cell-conditioned medium supports neurite outgrowth and survival of spinal cord neurons in culture

The effect of Schwann cell-conditioned medium (SCM) on the development in vitro of spinal cord neurons was studied. Spinal cord neurons from 18-day-old rat embryos were cultured in serum-free conditioned medium obtained from confluent rat Schwann cells. In cultures fed SCM, the cells developed typical neuronal morphology and were identified by indirect immunofluorescence using a monoclonal antibody to neurofilament protein. SCM stimulated neurite outgrowth and supported survival of spinal cord neurons. Preliminary characterization suggests that the neurotrophic factor in SCM appears to be a protein with a molecular weight greater than 8000 daltons.

Prediction of early beneficial response to plasma exchange in Guillain-Barré syndrome

We attempted to identify predictive factors of early beneficial response to plasmapheresis in Guillain-Barré syndrome (GBS). We reviewed 24 patients with typical severe GBS who underwent plasmapheresis and analyzed their outcome at one month. One group of 14 patients, designated as responders, improved dramatically, while ten patients showed little response. Age was the only important clinical predictor, with responders being younger. No other clinical variable (sex, preceding illness, severity, timing of plasmapheresis, cranial nerve involvement, or cerebrospinal fluid findings) reached significance. Among electrophysiologic parameters obtained before plasmapheresis, the amplitudes of compound muscle action potentials with distal stimulation of median and peroneal nerves were significantly reduced in non-responders. Plasmapheresis may improve only a subgroup of patients with GBS. Among patient characteristics, age and amplitudes of compound muscle action potentials are important predictors of early responsiveness.

Response to immunosuppressive therapy in patients with hereditary motor and sensory neuropathy and associated dysimmune neuromuscular disorders

We encountered 2 patients with hereditary motor and sensory neuropathy (HMSN) type I who had marked weakness developing during several months superimposed on chronic peroneal muscular atrophy. Further studies disclosed a chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) in one patient and CIDP associated with polymyositis in the other. Both patients responded to prednisone and azathioprine with substantial improvement. Patients with HMSN who develop rapid progression of weakness should be evaluated for superimposed, potentially treatable dysimmune neuromuscular disorders.

Developmental Foix-Chavany-Marie syndrome in identical twins

Foix, Chavany, and Marie described a syndrome of faciopharyngoglossomasticatory diplegia resulting from bilateral anterior opercular infarction. We describe identical twins who have a developmental form of the syndrome. The twins, aged 41 years, were the product of a normal pregnancy and birth, but had subsequent delayed motor milestones, seizures, poor language development, mild mental retardation, drooling, absent gag reflexes, inability to protrude the tongue, brisk jaw jerks, impaired fine finger movements, symmetrical brisk reflexes, flexor plantar responses, and mildly spastic gait. Magnetic resonance imaging showed bilateral perisylvian cortical dysplasia compatible with polymicrogyria and incomplete opercular formation.

Movement disorders associated with chronic GM2 gangliosidosis. Case report and review of the literature

A 24-year-old man presented with dystonia, dementia, amyotrophy, choreoathetosis, and ataxia. Partial hexosaminidase A deficiency was documented in serum and leukocytes and confirmed by rectal biopsy with ganglion cells containing membranous cytoplasmic bodies. A brief review of the literature reveals that tremor, dystonia and choreoathetosis are common but neglected symptoms associated with chronic GM2 gangliosidosis.

Somatosensory evoked potentials in motor neuron disease

We studied median somatosensory evoked potentials (SEPs) in an unselected series of 30 patients with sporadic motor neuron disease (MND). SEPs were affected in 17 patients (57%), with a higher incidence of abnormality in amyotrophic lateral sclerosis and bulbar palsy than in progressive muscular atrophy. In a majority of patients, simultaneous bilateral stimulation of the median nerve revealed a delay or absence of scalp-recorded central N32 and/or N60, leaving the earlier peaks intact. In the remaining cases, the N19 peak was asymmetrically prolonged. These findings suggest common involvement of somatosensory pathways in MND, either at cortical or subcortical levels, and correlate with neuropathologic reports of neuronal degeneration beyond the primary motor system.

Chronic long-interval plasma exchange in myasthenia gravis

Plasma exchange, when used in conjunction with azathioprine to treat chronic symptoms of myasthenia gravis, can usually be discontinued after a limited period of time without reappearance of symptoms. Patients who cannot be weaned from the procedure are often treated with more potent immunosuppressants to overcome exchange dependence. In view of the cumulative risks of more intensive daily immunosuppression, continuation of intermittent plasma exchange can be an acceptable alternative provided the interexchange interval (IEI) is relatively long. We describe two exchange-dependent patients in whom plasma exchange has been used for 4 1/2 and five years to control their symptoms. In both patients, who also received azathioprine, the IEI gradually lengthened to nine or 12 weeks over two to three years, without the introduction of new immunosuppressants. These cases illustrate that long-term plasma exchange is feasible and effective in selected exchange-dependent patients with myasthenia gravis.

Glia maturation factor promotes proliferation and morphologic expression of rat Schwann cells

Glia maturation factor (GMF) is an acidic protein with a molecular weight of about 20,000 daltons, found in the adult brain of many species. Previously GMF was observed to stimulate the proliferation and subsequent maturation of rat astroblasts in culture. We investigated the effects of GMF on Schwann cells. Schwann cells were dissociated from rat sciatic nerve and purified by means of antimitotic agents and by selective immunoadsorption of contaminating fibroblasts. Cultured Schwann cells after 3 passages assumed a flat polygonal shape. Exposure of the cells to GMF converted the cells to the elongated, spindle morphology typical of Schwann cells. GMF also stimulated a 7-fold increase in DNA synthesis when compared with control cultures grown in F10 medium containing 5% fetal calf serum. The mitogenic activity of GMF was still detectable at 5 ng protein/ml medium. The maximal effect on DNA synthesis occurred 72 h after the initial exposure to GMF. Although the cells were positive for the Schwann cell marker Ran-1, GMF failed to induce the production of myelin-associated glycolipids (galactocerebroside) and proteins (Po) nor did it induce the astrocytic marker glial fibrillary acidic protein (GFAP). The effects of GMF on Schwann cells extend its biological role beyond the central nervous system.

Purification of rat Schwann cells from cultures of peripheral nerve: an immunoselective method using surfaces coated with anti-immunoglobulin antibodies

We report a method for deriving purified rat Schwann cells by immunoselective removal of fibroblasts. Contaminating fibroblasts labeled with antibody against specific surface marker Thy 1.1 are bound on plastic surfaces coated with a second antibody. The efficacy of the method is demonstrated by flow cytometry and by specific Schwann cell Ran-1 immunofluorescence.

First report of mosaic trisomy 12 in a liveborn individual

Trisomy 12 mosaicism was found in a 36-year-old woman with minor anomalies, neuromuscular abnormalities, and moderate mental retardation. Trisomy 12 was present in 13% of the lymphocytes but not in skin fibroblasts. Previous reports of dup (12p) and dup(12q) are reviewed. To our knowledge this is the first report of a "complete" trisomy 12 in a liveborn individual.

Peripheral neuropathy associated with monoclonal gammopathy. Studies of intraneural injections of monoclonal immunoglobulin sera

A causal relationship between paraproteinemia and neuropathies has been suggested. We studied three patients with chronic sensorimotor polyneuropathy associated with plasma cell dyscrasia and monoclonal gammopathies (IgGK, IgMK, IgA lambda). Sural nerve biopsies showed mild (2 cases) to moderate loss of myelinated fibers (1 case). Teased single fiber studies showed segmental demyelination-remyelination in two patients. Direct immunofluorescence demonstrated immune deposits of the myelin sheath of the same specificity as the serum paraprotein, IgGK (1 of 3 cases). Treatment with prednisone, melphalan or chlorambucil, and plasmapheresis resulted in remission (1 case), partial improvement (1 case), or had no effect (1 case), although reduction of monoclonal immunoglobulin occurred in all. To investigate the role the paraproteins might play in the pathogenesis of the neuropathy, patients' serum was injected intraneurally into rat sciatic nerves. None of the animals developed weakness, slowing of in vitro conduction of sciatic nerve, or significant evidence of demyelination by light- or electron-microscopy or teased single fiber studies 48 hours postinjection. Similar injections of rabbit serum with experimental allergic neuritis (EAN) produced focal segmental demyelination. Our studies employing an in vivo bioassay technique failed to establish antimyelin activity of monoclonal immunoglobulin sera.

Disulfiram neuropathy: a neurofilamentous distal axonopathy

Disulfiram is used to treat alcoholism and is known to cause peripheral neuropathy: few reports of biopsied human nerves have revealed axonal degeneration and loss of myelinated fibers. We studied a 22-year-old woman with severe sensorimotor neuropathy following treatment with disulfiram for 6 months. Histologic studies of the sural nerve revealed a neurofilamentous axonopathy with rare enlarged axons distended by neurofilaments. Disulfiram is converted enzymatically to carbon disulfide, which causes neurofilamentous distal axonopathy in animals. Similar changes in human nerve after disulfiram administration suggest that carbon disulfide is the toxic agent.

Peripheral neurofibromatosis and peroneal muscular atrophy

We studied four patients with peripheral neurofibromatosis and a neuropathy that had the clinical characteristics of peroneal muscular atrophy. Nerve conduction velocities were slowed by less than 40% of normal, and electromyography demonstrated denervation. Sural nerve biopsies from two patients, which were macroscopically free of nerve sheath tumors, were studied by recording the compound action potentials in vitro and by morphometry. These studies demonstrated a chronic axonal neuropathy with reactive Schwann cell changes. Peroneal muscular atrophy in association with neurofibromatosis may be due to progressive neuronal degeneration and may represent another, uncommon manifestation of peripheral neurofibromatosis.

Peripheral Nerve unmyelinated axons following lumbar sympathectomy

One year after bilateral lumbar sympathectomy for Raynaud's syndrome, a young woman underwent fascicular biopsy of the sural nerve to help elucidate the cause of lower limb pain. The morphological features, density, and diameter spectrum of unmyelinated fibers were normal. The sympathetic nervous system appears to contribute few, if any, axons to the total population of unmyelinated axons in this cutaneous nerve.

Chronic tetanus: clinical report and histochemistry of muscle

A patient who was partially immune to tetanus developed nonfulminant tetanus after a minor injury. Manifestations of the disease persisted for over 17 months. Electrophysiologic studies revealed an absent silent period in the masseter muscle, large-amplitude F-responses, and denervation. A muscle biopsy showed neurogenic atrophy with reinnervation. This observation supports the existence of chronic tetanus and provides morphologic evidence for a peripheral action of tetanus toxin in humans.

Brachial plexus involvement in familial pressure-sensitive neuropathy: electrophysiological and morphological findings

Two family members with hereditary pressure-sensitive neuropathy are reported. One patient presented atypically with acute brachial plexus neuropathy following transaxillary removal of the first rib. Electrophysiological studies showed slowing of motor nerve conduction in clinically affected and unaffected nerves. In vitro recording of the compound action potential of the subclinically involved sural nerve showed pronounced slowing in conduction of large and small myelinated fiber groups. These alterations correlated with morphological studies of the sural nerve that showed tomacula with acute and healed segmental demyelination. An inherited, generalized neuropathy manifested by a morphological abnormality of myelination may render peripheral nerves unduly susceptible to mechanical trauma, including positional pressure or traction effects during general anesthesia.

Animal models of alcoholic neuropathy: morphologic, electrophysiologic, and biochemical findings

A chronic high alcohol intake was induced in rats through the use of two procedures: the schedule-induced polydipsia technique and the liquid diet technique. Rats consumed 11-12 g of ethanol per kilogram body weight per day for 16 to 18 weeks. Morphologic evidence of a mild distal axonal neuropathy in the ventral caudal nerve was proposed. The red blood cell transketolase levels were normal, indicating that the rats were not deficient in thiamine and suggesting that the axonal degeneration was due to the direct toxic effect of alcohol. Axonal transport studies demonstrated a significant increase in the amount of acetylcholinesterase transported in an orthograde direction in the sciatic nerves of alcohol-exposed rats, and indicated no change in the transport of choline acetyltransferase or in the specific binding of colchicine by neurotubulin.

Inflammatory myopathy in oculopharyngeal dystrophy

A 75-year-old French-Canadian woman with familial oculopharyngeal dystrophy demonstrated histopathologic alterations similar to those of idiopathic polymyositis. A second biopsy obtained 15 months later was more consistent with previously reported cases. It is suggested that certain patients with oculopharyngeal dystrophy may pass through an initial phase of secondary muscle inflammation similar to that seen in some other heritable myopathies.