Cutaneous nerve biopsy in patients with symptoms of small fiber neuropathy: a retrospective study.

OBJECTIVES: We aimed to investigate to what extent small fiber tests were abnormal in an unselected retrospective patient material with symptoms suggesting that small fiber neuropathy (SFN) could be present, and to evaluate possible gender differences. METHODS: Nerve conduction studies (NCS), skin biopsy for determination of intraepidermal nerve fiber density (IENFD) and quantitative sensory testing (QST) were performed. Z-scores were calculated from reference materials to adjust for the effects of age and gender/height. RESULTS: Two hundred and three patients, 148 females and 55 males had normal NCS and were considered to have possible SFN. 45.3 % had reduced IENFD, 43.2 % of the females and 50.9 % of the males. Mean IENFD was 7.3 ± 2.6 fibers/mm in females and 6.1 ± 2.3 in males (p<0.001), but the difference was not significant when adopting Z-scores. Comparison of gender differences between those with normal and abnormal IENFD were not significant when Z-scores were applied. QST was abnormal in 50 % of the patients (48.9 % in females and 52.9 % in males). In the low IENFD group 45 cases out of 90 (50 %) were recorded with abnormal QST. In those with normal IENFD 51 of 102 (50 %) showed abnormal QST. CONCLUSIONS: Less than half of these patients had reduced IENFD, and 50 % had abnormal QST. There were no gender differences. A more strict selection of patients might have increased the sensitivity, but functional changes in unmyelinated nerve fibers are also known to occur with normal IENFD. Approval to collect data was given by the Norwegian data protection authority at University Hospital of North Norway (Project no. 02028).

Insomnia and sleep-disordered breathing in FKRP-related limb-girdle muscular dystrophy R9. The Norwegian LGMDR9 cohort study (2020).

Limb-girdle muscular dystrophy R9 (LGMDR9) is a progressive and disabling genetic muscle disease. Sleep is relevant in the patient care as it impacts on health, functioning, and well-being. LGMDR9 may potentially affect sleep by physical or emotional symptoms, myalgia, or sleep-disordered breathing (SDB) through cardiorespiratory involvement. The objective was to investigate the occurrence of insomnia and unrecognized or untreated SDB in LGMDR9, associated factors, and relationships with fatigue and health-related quality of life (HRQoL). All 90 adults in a Norwegian LGMDR9 cohort received questionnaires on sleep, fatigue, and HRQoL. Forty-nine of them underwent clinical assessments and 26 without mask-based therapy for respiration disorders additionally underwent polysomnography (PSG) and capnometry. Among 77 questionnaire respondents, 31% received mask-based therapy. The prevalence of insomnia was 32% of both those with and without such therapy but was significantly increased in fatigued respondents (54% vs 21%). Insomnia levels correlated inversely with mental HRQoL. Among 26 PSG candidates, an apnea-hypopnea index (AHI) ≥ 5/h was observed in 16/26 subjects (≥ 15/h in 8/26) with median 6.8 obstructive apneas and 0.2 central apneas per hour of sleep. The AHI was related to advancing age and an ejection fraction < 50%. Sleep-related hypoventilation was detected in one subject. Fatigue severity did not correlate with motor function or nocturnal metrics of respiration or sleep but with Maximal Inspiratory Pressure (r = - 0.46). The results indicate that insomnia and SDB are underrecognized comorbidities in LGMDR9 and associated with HRQoL impairment and heart failure, respectively. We propose an increased attention to insomnia and SDB in the interdisciplinary care of LGMDR9. Insomnia and pulmonary function should be examined in fatigued patients.

Health-Related Quality of Life in FKRP-Related Limb-Girdle Muscular Dystrophy R9.

BACKGROUND: Limb-girdle muscular dystrophy R9 (LGMDR9) is a chronic progressive hereditary muscle disease, related to the Fukutin Related Protein (FKRP) gene, that may cause major disabilities, cardiomyopathy, and ventilatory failure. Knowledge of how LGMDR9 affects health-related quality of life (HRQoL) is relevant in treatment and care. OBJECTIVE: To investigate HRQoL in the Norwegian LGMDR9 population over 14 months and relation to fatigue and sleep quality. METHODS: Participants (16+ years) of the Norwegian LGMDR9 cohort study completed two HRQoL measures, i.e., Individualized Neuromuscular Quality of Life questionnaire (INQoL) and the 36-item Short Form (SF-36) at baseline, 8, and 14 months and measures of fatigue and sleep quality at 9 months. RESULTS: HRQoL response rate was 84/90 (75 c.826 C > A homozygotes and nine c.826 C > A compound heterozygotes). Compared to Norwegian normative data, all SF-36 domain scores were impaired (p≤0.006) except mental health in males (p = 0.05) and pain scores. During 14 months, perceived muscle weakness and the INQoL index (disease burden) worsened in c.826 C > A homozygotes. Compound heterozygotes reported more dysphagia and physical difficulties than homozygotes and showed a tendency towards worsening in weakness over time but some improvement on the INQoL index. Homozygous females reported generally poorer HRQoL and a higher burden than males. The INQoL index was related to perceived muscle weakness and fatigue, and fatigue to myalgia and mental distress. The prevalence of fatigue and poor sleep was 40% and 49%, respectively. CONCLUSIONS: The 14-month follow-up period shows a worsening of perceived weakness and burden in c.826 C > A homozygotes, which can then be expected. The prevalence and impact of fatigue indicate a need for awareness and treatment of fatigue. Myalgia and mental distress are potential targets in the treatment of fatigue, which future studies need to establish. Sleep issues and gender-specific care needs also require attention in LGMDR9.

Epidemiology and natural history in 101 subjects with FKRP-related limb-girdle muscular dystrophy R9. The Norwegian LGMDR9 cohort study (2020).

We aimed to investigate the epidemiology and natural history of FKRP-related limb-girdle muscular dystrophy R9 (LGMDR9) in Norway. We identified 153 genetically confirmed subjects making the overall prevalence 2.84/100,000, the highest reported figure worldwide. Of the 153 subjects, 134 (88 %) were homozygous for FKRP c.826C>A giving a carrier frequency for this variant of 1/101 in Norway. Clinical questionnaires and patient notes from 101 subjects, including 88 c.826C>A homozygotes, were reviewed, and 43/101 subjects examined clinically. Age of onset in c.826C>A homozygotes demonstrated a bimodal distribution. Female subjects showed an increased cumulative probability of wheelchair dependency and need for ventilatory support. Across the cohort, the need for ventilatory support preceded wheelchair dependency in one third of the cases, usually due to sleep apnea. In c.826C>A homozygotes, occurrence of cardiomyopathy correlated positively with male gender but not with age or disease stage. This study highlights novel gender differences in both loss of ambulation, need for ventilatory support and the development of cardiomyopathy. Our results confirm the need for vigilance in order to detect respiratory insufficiency and cardiac involvement, but indicate that these events affect males and females differently.

Pain and fatigue in primary Sjögren's syndrome.

Chronic fatigue, pain and depression are common in patients with primary Sjögren's syndrome. These phenomena mutually affect each other and have a considerable impact on the patients' quality of life. While pain is usually regarded as a fairly somatic phenomenon, both fatigue and depression have traditionally been regarded as more-or-less of psychological origin. There is an increasing understanding that this picture is multifaceted; that there is a genetic foundation, and that biological mechanisms regulate the clinical expression through activation of evolutionary, deeply conserved neuronal pathways in the brain. This pattern is evident not only in primary Sjögren's syndrome, but also in other systemic inflammatory autoimmune diseases, in cancer and in neurodegenerative diseases like Parkinson's disease. This article will mainly focus on the biology of pain and fatigue. We describe how these factors influence each other, and act with the overarching purpose of defending the organism against harm and danger.

Screening for Fabry disease and Hereditary ATTR amyloidosis in idiopathic small-fiber and mixed neuropathy.

INTRODUCTION: In this study we assessed the value of genetic screening for Fabry disease (FD) and hereditary ATTR amyloidosis in patients with idiopathic small-fiber neuropathy (SFN) or mixed neuropathy in a clinical setting. METHODS: This was a Nordic multicenter study with 9 participating centers. Patients with idiopathic SFN or mixed neuropathy were included. Genetic sequencing of the TTR and GLA genes was performed. RESULTS: There were 172 patients enrolled in the study. Genetic screening was performed in 155 patients. No pathogenic mutations in the TTR gene were found. A single patient had a possible pathogenic variant, R118C, in the GLA gene, but clinical investigation showed no firm signs of FD. DISCUSSION: Screening for hereditary ATTR amyloidosis and FD in patients with idiopathic SFN or mixed neuropathy without any additional disease-specific symptoms or clinical characteristics in a Nordic population appears to be of little value in a clinical setting. Muscle Nerve 59:354-357, 2019.

Segregation analysis in families with Charcot-Marie-Tooth disease allows reclassification of putative disease causing mutations.

BACKGROUND: The identification of disease causing, or putative disease causing, mutations in index patients with Charcot-Marie-Tooth disease (CMT) allows for genetic testing of family members. Relevant variants identified in index patients are of either definite, likely or uncertain pathogenicity. The main objective of this study was to make an evaluation of the family investigations performed as part of the assessment of genetic variants of unknown clinical significance (VUS). METHODS: Between 2004 and 2010 molecular genetic family investigations were requested for 87 family members from 41 families harbouring PMP22dup or genetic variants in GJB1, MPZ, MFN2 and NEFL. Relatives were tested for the family mutation and data from the requisitions were evaluated by means of statistical tools. RESULTS: The results within each indication category are presented and discussed in detail. Twenty-two relatives (9 affected) from eight families were included in the segregation analyses, which invoked reclassification of three MFN2 mutations, two of which were de novo substitutions (c.2146_2148dup, c.692C > T). One MFN2 substitution was downgraded due to non-segregation (c.1709 A > G), and a MPZ substitution (c.103 G > A) upgraded due to segregation with the phenotype in the family. CONCLUSIONS: The results allow for the evaluation of the patient phenotypes ascertained in families, as opposed to the phenotypic descriptions of index patients. They indicate that de novo MFN2 mutations are regularly found in patients with a classical CMT2 phenotype. They also demonstrate the importance of a precise clinical and neurophysiologic diagnosis of affected family members. This particularly applies for the examination of variants of uncertain clinical significance. Finally, the fact that 14,6% of affected relatives tested for (probable or certain) pathogenic mutations were mutation negative, demonstrates that clinical evaluation alone is not always sufficient in order to determine their diagnosis. We believe that the results will aid in the estimation and planning of resources required for the various aspects of family evaluations in CMT.

Small- and large-fiber neuropathy after 40 years of type 1 diabetes: associations with glycemic control and advanced protein glycation: the Oslo Study.

OBJECTIVE: To study large- and small-nerve fiber function in type 1 diabetes of long duration and associations with HbA1c and the advanced glycation end products (AGEs) N-ε-(carboxymethyl)lysine (CML) and methylglyoxal-derived hydroimidazolone. RESEARCH DESIGN AND METHODS: In a long-term follow-up study, 27 persons with type 1 diabetes of 40 ± 3 years duration underwent large-nerve fiber examinations, with nerve conduction studies at baseline and years 8, 17, and 27. Small-fiber functions were assessed by quantitative sensory thresholds (QST) and intraepidermal nerve fiber density (IENFD) at year 27. HbA1c was measured prospectively through 27 years. Serum CML was measured at year 17 by immunoassay. Serum hydroimidazolone was measured at year 27 with liquid chromatography-mass spectrometry. RESULTS: Sixteen patients (59%) had large-fiber neuropathy. Twenty-two (81%) had small-fiber dysfunction by QST. Heat pain thresholds in the foot were associated with hydroimidazolone and HbA1c. IENFD was abnormal in 19 (70%) and significantly lower in diabetic patients than in age-matched control subjects (4.3 ± 2.3 vs. 11.2 ± 3.5 mm, P < 0.001). IENFD correlated negatively with HbA1c over 27 years (r = -0.4, P = 0.04) and CML (r = -0.5, P = 0.01). After adjustment for age, height, and BMI in a multiple linear regression model, CML was still independently associated with IENFD. CONCLUSIONS: Small-fiber sensory neuropathy is a major manifestation in type 1 diabetes of 40 years duration and more prevalent than large-fiber neuropathy. HbA1c and the AGEs CML and hydroimidazolone are important risk factors in the development of large- and small-fiber dysfunction in long-term type 1 diabetes.

The cutaneous nerve biopsy: technical aspects, indications, and contribution.

Skin biopsy with a 3mm disposable circular punch is easy to perform and allows, after proper processing, the visualization of epidermal, dermal, and sweat gland nerve fibers. A technique of sampling the epidermis alone by applying a suction capsule, the "blister" technique, has also been developed. It is most common to stain immunohistochemically for the pan-axonal marker protein gene product 9.5 (PGP 9.5), an ubiquitin C-terminal hydroxylase. The sections are then observed and analyzed with bright-field microscopy or with indirect immunofluorescence with or without confocal microscopy. Most studies report quantification of intraepidermal nerve fiber density displayed in bright-field microscopy. Normative values have been established, particularly from the distal part of the leg, 10cm above the external malleolus. In diabetes mellitus early degeneration of intraepidermal nerve fibers is induced and there is slower regeneration even when there is no evidence of neuropathy. Skin biopsy is of particular value in the diagnosis of small fiber neuropathy when nerve conduction studies are normal. It may also be repeated in order to study the progressive nature of the disease and also has the potential of studying regeneration of nerve fibers and thus the effects of treatment. Inflammatory demyelinating neuropathies may also involve loss of small-diameter nerve fibers and IgM deposits in dermal myelinated nerve fibers in anti-MAG neuropathy. In some cases the presence of vasculitis in skin may indicate a nonsystemic vasculitic neuropathy and in HIV neuropathy intraepidermal nerve fiber density is reduced in a length-dependent manner. In several hereditary neuropathies intraepidermal nerve fiber density may be reduced but other abnormalities can also be demonstrated in dermal myelinated fibers. Some small swellings and varicosities may be present in the distal leg skin biopsy of healthy individuals but large axonal swellings are considered as evidence of a pathological process affecting the normal structure of nerves. The indirect immunofluorescence technique with confocal microscopy provides the opportunity to study the complex structure of sensory receptors and cutaneous myelinated fibers and the innervation of sweat glands, arrector pilorum muscles, and vessels.

Can vitamin D supplementation prevent bone loss in persons with MS? A placebo-controlled trial.

Multiple sclerosis (MS) is a possible cause of secondary osteoporosis. In this phase II trial we assessed whether a weekly dose of 20,000 IU vitamin D(3) prevents bone loss in ambulatory persons with MS age 18-50 years. ClinicalTrials.gov ID NCT00785473. All patients managed at the University Hospital of North Norway who fulfilled the main inclusion criteria were invited to participate in this double-blinded trial. Participants were randomised to receive 20,000 IU vitamin D(3) or placebo once a week and 500 mg calcium daily for 96 weeks. The primary outcome was the effect of the intervention on percentage change in bone mineral density (BMD) at the hip, the spine, and the ultradistal radius over the study period. Of 71 participants randomised, 68 completed. Mean serum 25-hydroxyvitamin D [25(OH)D] levels in the intervention group increased from 55 nmol/L at baseline to 123 nmol/L at week 96. After 96 weeks, percentage change in BMD did not differ between groups at any site. BMD decreased at the hip, by 1.4% in the placebo group (95% CI -2.3 to -0.4, SD 2.7, p = 0.006) and by 0.7% in the treatment group (-1.6 to 0.2, 2.7, p = 0.118), difference 0.7% (-1.9 to 0.7, p = 0.332). Findings were not altered by adjustment for sex or serum 25(OH)D. Supplementation with 20,000 IU vitamin D(3) a week did not prevent bone loss in this small population. Larger studies are warranted to assess the effect of vitamin D on bone health in persons with MS.

[Intravenous IgG for treatment of neuromuscular diseases]. / Intravenøs IgG-behandling av nevromuskulaere sykdommer.

BACKGROUND: Highly purified IgG administered intravenously (IVIG) is used to treat many neurological diseases. MATERIAL AND METHODS: This review is based on articles identified through a search in PubMed and the authors' knowledge and experience within the field. RESULTS: The effect of IVIG has been best documented in the treatment of acute and chronic inflammatory demyelinating polyradiculoneuropathy, multifocal motor neuropathy and acute exacerbation of myasthenia gravis. Some smaller studies support explorative IVIG treatment in other neurological diseases such as Lambert-Eaton myasthenic syndrome, paraproteinemic neuropathy, neuropathy caused by vasculitis, inflammatory myopathies and stiff-person syndrome. INTERPRETATION: IVIG affects the immune system in different ways. Documentation for the effect of such treatment in most neurological diseases remains sparse.

Predictors and prevalence of low bone mineral density in fully ambulatory persons with multiple sclerosis.

The implications of having multiple sclerosis (MS) for bone health are incompletely understood. The aim of this population-based study is to identify past and current exposures that are associated with bone mass in fully ambulatory persons with MS up to age 50 years and to determine the prevalence of low bone mineral density (BMD) in this group. We measured BMD (hips, lumbar spine, forearms), physical function, BMI, and serum 25(OH) vitamin D in 55 women and 25 men with MS. Patients provided information on demographic variables and medical history, as well as past and current vitamin D and calcium intake, physical activity, and lifestyle habits. In regression analyses, BMD levels were adjusted for age, sex, and BMI. At the femoral neck, strong associations were found for walking distance (beta = 0.152; P < 0.001) and age (beta = -0.004; P = 0.003), and less certain associations for male sex (beta = 0.055; P = 0.014) and 10-foot timed tandem walk (-0.008; P = 0.013). At the lumbar spine, walking distance (beta = 0.013; P = 0.006) and possibly physical activity growing up (beta = 0.035; P = 0.028) and male sex (beta = -0.057; P = 0.042), were associated with BMD. At the ultradistal radius, strength of grip (beta = 0.001; P = 0.002), and, less certainly, summer outdoor activities age 16-20 (beta = 0.021; P = 0.009), and age at MS onset (beta = 0.002; P = 0.036) were associated with BMD. Low BMD (z score < or = -2) was present in 19 out of 80 patients. This study shows that MS-related variables as well as past exposures differentially affect BMD at three clinically important skeletal sites. Low BMD is prevalent in these young patients. Bone health should receive attention in care for persons with MS.

NORdic trial of oral Methylprednisolone as add-on therapy to Interferon beta-1a for treatment of relapsing-remitting Multiple Sclerosis (NORMIMS study): a randomised, placebo-controlled trial.

BACKGROUND: Treatment of relapsing-remitting multiple sclerosis with interferon beta is only partly effective, and new more effective and safe strategies are needed. Our aim was to assess the efficacy of oral methylprednisolone as an add-on therapy to subcutaneous interferon beta-1a to reduce the yearly relapse rate in patients with relapsing-remitting multiple sclerosis. METHODS: NORMIMS (NORdic trial of oral Methylprednisolone as add-on therapy to Interferon beta-1a for treatment of relapsing-remitting Multiple Sclerosis) was a randomised, placebo-controlled trial done in 29 neurology departments in Denmark, Norway, Sweden, and Finland. We enrolled outpatients with relapsing-remitting multiple sclerosis who had had at least one relapse within the previous 12 months despite subcutaneous interferon beta-1a treatment (44 microg three times per week). We randomly allocated patients by computer to add-on therapy of either 200 mg methylprednisolone or matching placebo, both given orally on 5 consecutive days every 4 weeks for at least 96 weeks. The primary outcome measure was mean yearly relapse rate. Primary analyses were by intention to treat. This trial is registered, number ISRCTN16202527. FINDINGS: 66 patients were assigned to interferon beta and oral methylprednisolone and 64 were assigned to interferon beta and placebo. A high proportion of patients withdrew from the study before week 96 (26% [17 of 66] on methylprednisolone vs 17% [11 of 64] on placebo). The mean yearly relapse rate was 0.22 for methylprednisolone compared with 0.59 for placebo (62% reduction, 95% CI 39-77%; p<0.0001). Sleep disturbance and neurological and psychiatric symptoms were the most frequent adverse events recorded in the methylprednisolone group. Bone mineral density had not changed after 96 weeks. INTERPRETATION: Oral methylprednisolone given in pulses every 4 weeks as an add-on therapy to subcutaneous interferon beta-1a in patients with relapsing-remitting multiple sclerosis leads to a significant reduction in relapse rate. However, because of the small number of patients and the high dropout rate, these findings need to be corroborated in larger cohorts.

The value of skin biopsy with recording of intraepidermal nerve fiber density and quantitative sensory testing in the assessment of small fiber involvement in patients with different causes of polyneuropathy.

The primary aim of our study was to demonstrate how the diagnostic characteristics of skin biopsy used to evaluate small fiber involvement in patients with different causes of polyneuropathy are intrinsically related to the method used to establish the reference values (cut-off values). We also investigated intraepidermal nerve fiber (IENF) density and abnormalities in quantitative sensory testing (QST) in patients with different causes of polyneuropathy and signs of small fiber involvement. A total of 210 patients with symptoms and signs of polyneuropathy were entered into the study. All patients underwent neurological examination, nerve conduction studies, QST on the thigh and distal part of the calf with detection of warm and cold perception thresholds, and skin biopsy with assessment of IENF density. Cut-off values for IENF density were established from our reference material using Z-scores (calculated from multiple regression analysis), fifth percentile, and receiver operating characteristic (ROC) analysis. Of the patients participating in the study, 65 had an established diagnosis of diabetes mellitus, 70 were classified with idiopathic polyneuropathy, and 75 had other possible causes of polyneuropathy. Forty-five patients met the criteria for small fiber polyneuropathy (SFN), and the remaining 165 had also involvement of large nerve fibers. Of the total patient cohort, 84 (40%) had reduced IENF density based on the Z-score, and 106 patients (50%) had at least one abnormality based on QST. In the SFN group, skin biopsy showed a sensitivity of 31% and a specificity of 98% when reference values were presented with Z-scores. When the fifth percentile was used as the cut-off value (6.7 fibers/mm), sensitivity was 35% and specificity 95%. Applying the ROC analysis with a chosen sensitivity of 78% and specificity of 64%, we had a cut-off point of 10.3 fibers/mm. We conclude that skin biopsy with assessment of IENF is a useful method for investigating patients with SFN. The diagnostic value of the test, however, depends upon on the approach used to estimate the reference values.

Early diabetic neuropathy: thermal thresholds and intraepidermal nerve fibre density in patients with normal nerve conduction studies.

OBJECTIVES: To determine whether neuropathy in diabetic patients with normal nerve conduction studies could be detected by measurements of thermal thresholds and quantification of intraepidermal nerve fibre (IENF) density, and to evaluate differences in parameters between patients with and without neuropathic symptoms. METHODS: A total of 22 patients with and 37 patients without sensory symptoms suggesting distal neuropathy were included. Measurements of warm and cold perception thresholds and skin biopsy for quantification of IENFs were performed distally on the leg. Reference data were used to normalize test results for age and height or gender of individual patients by calculating the Z-scores. RESULTS: IENF density was significantly reduced in both symptomatic and asymptomatic patients compared to controls (p < 0.001), and in patients with symptoms compared to those without (p = 0.01). Thermal thresholds were significantly elevated (more abnormal) in patients with symptoms compared to controls (p < 0.01), but only for cold perception threshold (CPT) (p < 0.001) in the asymptomatic group. When comparing symptomatic and asymptomatic patients, there was no statistically significant difference in thermal thresholds. Depletion of IENFs in skin biopsy was the most frequent abnormal finding in the subgroup of patients with neuropathic symptoms (36 %) followed by abnormal CPT (27 %). CONCLUSION: Patients with diabetes and normal nerve conduction studies had significantly lower IENF density and higher CPT than controls, whether they had symptoms of polyneuropathy or not. In patients with neuropathic symptoms, abnormal IENF density predominated and seemed thus to be the most sensitive tool of detecting small diameter nerve fibre involvement.

Primary Sjögren's syndrome associated neuropathy.

Primary Sjögren's syndrome (PSS) mainly affects exocrine glands and is clinically characterized by keratoconjunctivitis sicca and xerostomia. Among several possible extraglandular manifestations, involvement of the peripheral nervous system may occur with reported frequencies from 10% to 60%. Peripheral nerve manifestations constitute sensory neuropathy, including sensory ganglioneuronopathy, sensorimotor, including polyradiculoneuropathy and demyelinating neuropathy, motor neuropathy, multiple mononeuropathy, trigeminal and other cranial neuropathies, autonomic neuropathy, and mixed patterns of neuropathy. Knowledge of the neurological manifestations of PSS is hampered by evolving classification criteria of PSS over the years, and by use of highly selected patient populations on the basis of a primary neurological diagnosis. Sural nerve biopsy may show vascular or perivascular inflammation of small epineurial vessels (both arterioles and venules) and in some cases necrotizing vasculitis. Loss of myelinated nerve fibers is common and loss of small diameter nerve fibers occurs. Pathology in cases of sensory ganglioneuronopathy consists of loss of neuronal cell bodies and infiltration of T cells. Peripheral neuropathy in PSS often is refractory to treatment although newer biological agents may provide more effective treatment options. Current treatment strategies used in autoimmune neuropathies may be tried depending upon characteristics of the neuropathy and results obtained by a thorough clinical and laboratory investigation.

Medial plantar nerve conduction studies in healthy controls and diabetics.

OBJECTIVE: To collect a reference material of the medial plantar nerve action potential, to test intra/interobserver reliability in healthy controls and to apply the test to a group of patients with diabetes mellitus. METHODS: 98 healthy controls and 50 patients with diabetes mellitus were included. The medial plantar nerve was stimulated orthodromically and recorded with a surface electrode. In the patient group, NCS of motor and sensory nerves and quantitative sensory testing were also performed. RESULTS: Responses of the medial plantar nerve were obtained from all controls except from one aged 72. Amplitude decreased with age (r=-0.68, p<0.0001). Intra/interobserver reliability was acceptable. 52% of the patients had abnormal overall NCS classification. Forty-eight percent had delayed tibial F-response latency. The medial plantar NCS were abnormal in 59% of the cases (47% abnormal NAP amplitude and 39% reduced CV), 59% of those with abnormal NCS had symptoms of sensory polyneuropathy. Only 24% had abnormal sural amplitude. Cold perception threshold was abnormal in more patients (30%) than warmth perception threshold (14%). CONCLUSIONS: Responses were easily obtained in controls under 70 years. In diabetics the amplitudes of the medial plantar nerve were abnormal more often than in the sural nerve. SIGNIFICANCE: The medial plantar nerve response is reliable in patients under 70 years, and intra/interobserver reliability is acceptable.

Ethnic variation of Fc gamma receptor polymorphism in Sami and Norwegian populations.

Receptors for the Fc domain of IgG (Fc gammaR) play a critical role in linking cellular and humoral immunity. The various Fc gammaR genotypes may contribute to differences in infectious and immune-related diseases in various ethnic populations. The Samis are the aboriginal inhabitants of Norway and Fennoscandinavia and differ ethnically from the Norwegians. The distribution of various immune-related diseases has been reported to differ between Sami and Norwegians. This is the first study to evaluate the distribution of Fc gammaR polymorphisms in a Sami population. Two hundred Samis were genotyped for polymorphisms in the Fc gammaRIIA, Fc gammaRIIIA and Fc gammaRIIIB genes. The genotype and allele frequencies were compared with those of 272 healthy Norwegians. The Sami and Norwegian Fc gammaRIIA, Fc gammaRIIIA and Fc gammaRIIIB genotypes differed significantly. The Samis had higher frequencies of the Fc gammaRIIa-H/H131, Fc gammaRIIIa-F/F158 and Fc gammaRIIIb-NA1/NA1 genotypes. The Fc gammaR genotypes were non-randomly distributed in both populations. These findings may be important for the prevalence of autoimmune and infectious diseases in the two populations.

[Optic neuritis--diagnosis, treatment and follow up]. / Optikusnevritt--diagnose, behandling og oppfølging.

A national group of neurologists and ophthalmologists have evaluated guidelines and recommendations for diagnosis, treatment and follow up of optic neuritis based on clinical experience and a review of relevant literature. Optic neuritis is a common, well characterised condition that appears as an isolated syndrome or as a manifestation of multiple sclerosis. Several other diseases must be considered for a differential diagnosis. Corticosteroid treatment of optic neuritis has been investigated in a number of trials, which show that corticosteroid treatment speeds up the recovery of vision without affecting the final visual outcome. The diagnostic procedure and the treatment options have changed over the last few years. Some aspects of investigation, treatment and follow up are still controversial.