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Biomedical subjects

S Kuwabara

Publications and source records attributed to S Kuwabara.

At least 19 recordsLinked to original sources
PubMed2007

Anti-MuSK-positive myasthenia gravis: neuromuscular transmission failure in facial and limb muscles.

The presence of antibodies against muscle-specific receptor tyrosine kinase (MuSK) appears to define a subgroup of patients with myasthenia gravis (MG) characterized by weakness predominant in bulbar, facial and neck muscles compared with anti-acetylcholine receptor (AChR) antibody-positive MG. To investigate the patterns and severity of neuromuscular transmission failure in different muscles in MuSK-positive MG, we performed single fiber electromyography (SFEMG) in the facial (frontalis) and limb (extensor digitorum communis, EDC) muscles in three anti-Musk-positive patients, and compared results with those of 11 anti-AChR-positive patients. Only one of the three MuSK-positive patients had abnormal jitter in EDC, but all the three showed clearly increased jitter in the frontalis. By contrast, the AChR-positive patients showed similarly abnormal jitter for the two muscles. These results suggest that when the diagnosis of anti-MuSK-positive MG is suspected, SFEMG should be performed in most prominently affected muscles.

Antibodies↗
PubMed2006

Spectrum of neurological diseases associated with antibodies to minor gangliosides GM1b and GalNAc-GD1a.

The authors reported the neurological disease spectrum associated with autoantibodies against minor gangliosides GM1b and GalNAc-GD1a. IgG and IgM antibody reactivity against gangliosides GM1, GM2, GM1b, GD1a, GalNAc-GD1a and GQ1b was investigated in sera from 7000 consecutive patients who had various neurological conditions. The clinical diagnoses for 456 anti-GM1b-positive patients were Guillain-Barré syndrome (GBS, 71%), atypical GBS with preserved deep tendon reflexes (12%), Fisher syndrome (10%), Bickerstaff's brainstem encephalitis (2%), ataxic GBS (2%) and acute ophthalmoparesis (1%). For 193 anti-GalNAc-GD1a-positive patients, the diagnoses were GBS (70%), atypical GBS (16%), Fisher syndrome (10%) and Bickerstaff's brainstem encephalitis (3%). Of the patients with GBS or atypical GBS, 28% of 381 anti-GM1b-positive and 31% of 166 anti-GalNAc-GD1a-positive patients had neither anti-GM1 nor anti-GD1a antibodies. Of those patients with Fisher syndrome, Bickerstaff's brainstem encephalitis, ataxic GBS or acute ophthalmoparesis, 33% of 67 anti-GM1b-positive, and 52% of 25 anti-GalNAc-GD1a-positive patients had no anti-GQ1b antibodies. Autoantibodies against GM1b and GalNAc-GD1a are associated with GBS, Fisher syndrome and related conditions. These antibodies should provide useful serological markers for identifying patients who have atypical GBS with preserved deep tendon reflexes, ataxic GBS, Bickerstaff's brainstem encephalitis or acute ophthalmoparesis, especially for those who have no antibodies to GM1, GD1a or GQ1b. A method to prepare GM1b was developed.

Adolescent↗
PubMed2006

Aldose reductase inhibition alters nodal Na+ currents and nerve conduction in human diabetics.

BACKGROUND: In diabetic nerves, activation of the polyol pathway via an aldose reductase and the resulting impairment of the Na(+)-K(+) pump would lead to a decreased transaxonal Na+ gradient and thereby reduced nodal Na+ currents. OBJECTIVE: To investigate whether the aldose reductase inhibitor (ARI) epalrestat improves nodal Na+ currents and nerve conduction in human diabetic neuropathy. METHODS: The authors conducted a 6-month, open clinical trial with an ARI, epalrestat, in 30 patients with mild-to-moderate diabetic neuropathy. The latent addition technique and measurements of the strength-duration time constant were used to estimate nodal persistent Na+ currents in median motor axons. Excitability testing and extensive nerve conduction studies including F-wave analyses were performed before and 1 and 6 months after the initiation of treatment with oral epalrestat. RESULTS: Within a month of the start of treatment, there was a significant improvement in nerve conduction, particularly in conduction times across the carpal tunnel and F-wave latencies. The results of latent addition (p < 0.05) and strength-duration time constant (p = 0.06) suggested increased nodal persistent Na+ currents. At 6 months, nerve conduction continued to improve. CONCLUSIONS: Aldose reductase pathway inhibition could rapidly increase nodal Na+ currents and thereby improve the slowing of nerve conduction, presumably because of a restoration of the membranous Na+ gradient.

Adult↗
PubMed2006

Autologous peripheral blood stem cell transplantation for POEMS syndrome.

Polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes syndrome is a rare multisystem disorder. Overproduction of vascular endothelial growth factor (VEGF) by plasmocytoma could be responsible for the symptoms. The authors treated four patients with high-dose chemotherapy and autologous peripheral blood stem cell transplantation. Within 6 months, symptoms associated with rapid normalization of serum VEGF levels improved.

Adult↗
PubMed2006

Long term prognosis of chronic inflammatory demyelinating polyneuropathy: a five year follow up of 38 cases.

BACKGROUND: Little is known about long term prognosis and course after immune treatments in chronic inflammatory demyelinating polyneuropathy (CIDP). OBJECTIVE: To study long term outcomes and prognostic factors in patients with CIDP. METHODS: Clinical and electrophysiological findings, responses to immune modulating treatments, and outcomes five years after the start of treatment were reviewed in 38 CIDP patients. RESULTS: Patients were treated with corticosteroids (89%), immunoglobulin infusion (45%), or plasmapheresis (34%), and 58% received combined therapy. Five years after treatment was begun, 10 (26%) of the patients had complete remission (lasting >2 years with normal nerve conduction studies), and 23 (61%) had partial remission (able to walk) with (26%) or without (34%) immune treatments. The remaining five patients (13%) still had severe disability (unable to walk) or treatment dependent relapses. Patients with complete remission more often had subacute onset, symmetrical symptoms, good response to initial corticosteroid treatment, and nerve conduction abnormalities predominant in the distal nerve terminals. In contrast, insidious onset, asymmetrical symptoms, and electrophysiological evidence of demyelination in the intermediate nerve segments were associated with refractoriness to treatment or treatment dependent relapse. CONCLUSIONS: The long term prognosis of CIDP patients was generally favourable, but 39% of patients still required immune treatments and 13% had severe disabilities. Mode of onset, distribution of symptoms, and electrophysiological characteristics may be prognostic factors for predicting a favourable outcome.

Adult↗
PubMed2006

Serum matrix metalloproteinase-3 levels correlate with disease activity in relapsing-remitting multiple sclerosis.

BACKGROUND: Adhesion molecules and matrix metalloproteinases (MMPs) are known to be relevant to the ongoing development and disappearance of areas of demyelination in the white matter of the CNS of multiple sclerosis (MS) patients. This study examined whether serum matrix metalloproteinase-3 (MMP-3) levels correlate with disease activity in MS. METHODS: Serum MMP-3 levels in 47 consecutive patients with relapsing-remitting MS were measured by immunoassay every 4 weeks over a 15 month period. RESULTS: During the study period, 48 clinical relapses occurred. Serum MMP-3 levels within 1 month of relapse were significantly higher than during the remission phase. Sequential analysis showed that serum MMP-3 levels had increased transiently at the time of clinical relapse but returned to the normal range within a month. CONCLUSIONS: Circulatory MMP-3 levels are correlated with disease activity in relapsing-remitting MS. This may contribute to the breakdown of the blood-brain barrier at the time of relapse.

Adult↗
PubMed2006

Abnormal muscle responses in hemifacial spasm: F waves or trigeminal reflexes?

OBJECTIVE: In patients with hemifacial spasm (HFS), abnormal muscle responses (AMR) are frequently present. The objective of this study was to investigate whether the afferent input of AMR is mediated by antidromic facial nerve stimulation or orthodromic trigeminal nerve stimulation. METHODS: AMR in the orbicularis oris muscle were recorded in 28 patients with HFS. When AMR were present, they were recorded after subthreshold stimulation of the facial nerve and weak stimulation delivered to the skin. RESULTS: AMR were recordable in 24 (86%) of the patients, and usually consisted of the early constant component (mean onset latency, 10.0 ms) and late variable component (35.3 ms), similar to R1 and R2 of the blink reflex. The early or late components of AMR, or both, were frequently elicited after subthreshold stimulation of the facial nerve (43%) and skin stimulation (88%). CONCLUSIONS: AMR are likely to be mediated by trigeminal afferent inputs, rather than antidromic activation of the facial nerve, and are a type of trigeminal reflex.

Adult↗
PubMed2006

[C-reactive protein, white blood cell and body temperature following cardiovascular surgery, as predicting factors of postoperative infection].

The aim of this study is to clarify the relationship between CRP and postoperative infection after cardiovascular surgery. We had 5 cases of surgical site infection, and 3 cases of infective endocarditis (IE) among 57 patients selected for this study out of 405 patients who had undergone cardiovascular surgery from May 1995 to March 2005. CRP, WBC and body temperature (BT) were evaluated during 1 week after the operation. Our results showed not only that the mean value of CRP level in the 49 non-infection patients attained the peak on the 2nd or 3rd day after the operation (18.2 +/- 4.7 and 17.7 +/- 5.7 mg/dl), but also that each patient in this group showed the same pattern of CRP sequence. CRP in the 5 cases of postoperative infection showed different patterns from that in the non-infection group. CRP in 3 cases of valve replacement for IE showed significantly higher level than that in 16 cases of valve replacement without IE through 1 week after the surgery. WBC level in the non-infection group reached the peak just after the operation (11.3 +/- 4.4 x 10(3)/microl) and then decreased gradually during 1 week after the operation. WBC in the 3 cases of valve replacement for IE, did not show different sequence pattern from that in the 16 cases of valve replacement without IE. WBC in a case of postoperative mediastinal infection showed a similar pattern of sequence to that in the non-infection group although it showed a remarkably high level of CRP sequence through 1 week after the surgery. BT in the non-infection group became the lowest just after the operation and reached the peak 8 hours after the operation. It then decreased gradually during 1 week after the operation. Our study demonstrates that CRP sequence after the surgery might be useful to detect postoperative infection after cardiovascular surgery.

Aged↗
PubMed2005

Patterns and serial changes in electrodiagnostic abnormalities of axonal Guillain-Barré syndrome.

BACKGROUND: In Guillain-Barré syndrome (GBS), anti-ganglioside antibodies are strongly associated with the acute motor axonal neuropathy (AMAN) form, but there are also cases of the demyelinating form of GBS (acute inflammatory demyelinating polyneuropathy [AIDP]) with anti-ganglioside antibodies. OBJECTIVE: To elucidate the patterns and sequential changes in electrodiagnostic abnormalities of anti-ganglioside-positive GBS. METHODS: Detailed serial electrodiagnostic findings were reviewed for 51 patients with GBS. Anti-ganglioside antibodies were measured by ELISA. RESULTS: Antibodies to GM1, GM1b, GD1a, or GalNAc-GD1a were present in 25 patients. Of these, 12 (48%) showed the AMAN pattern, 5 (20%) the AIDP pattern, and 3 (12%) isolated F-wave absence in the first examination. All five patients with the AIDP pattern showed prolonged distal latencies, but three eventually showed the AMAN pattern or rapid normalization. The remaining two still had similarly prolonged distal latencies in weeks 4 to 6, but the serial changes were distinct from those in the anti-ganglioside-negative AIDP patients who showed progressive increases in distal latencies over 2 months after onset. CONCLUSIONS: Besides the simple axonal degeneration pattern, patients with anti-ganglioside-positive Guillain-Barre syndrome can show transient conduction slowing/block in the distal or proximal nerve segments, mimicking demyelination, but anti-ganglioside antibodies do not appear to be associated with acute inflammatory demyelinating polyneuropathy.

Adult↗
PubMed2005

HyperIgEaemia in patients with juvenile muscular atrophy of the distal upper extremity (Hirayama disease).

BACKGROUND: Juvenile muscular atrophy of the distal upper extremity (Hirayama disease) is characterised by anterior horn cell loss in the lower cervical cord, presumably caused by anterior displacement of the dural sac during neck flexion. A recent report suggests that atopy and IgE may contribute to anterior horn damage. OBJECTIVE: To investigate whether IgE is a contributing factor in Hirayama disease. METHODS: Serum total IgE and allergen specific IgE were examined in 20 consecutive patients, and their correlations with clinical profiles investigated. RESULTS: Past or present history of allergy/atopy was found in only four patients (20%), but serum IgE was raised in 14 (70%). Patients with hyperIgEaemia had more severe clinical disabilities than those without (p = 0.01). In patients whose history of Hirayama disease was less than five years, serum total IgE was higher than in those with the disease for five years or more (p = 0.05). CONCLUSIONS: The results suggest that hyperIgEaemia is often associated with Hirayama disease and can facilitate its pathophysiology, particularly in the early phases of the disease. HyperIgEaemia does not appear to involve the anterior horn cells primarily.

Adolescent↗
PubMed2005

Patterns and severity of neuromuscular transmission failure in seronegative myasthenia gravis.

OBJECTIVES: To compare the clinical and electrophysiological features of myasthenia gravis (MG) patients with (seropositive) or without (seronegative) antibodies to acetylcholine receptor. To investigate whether antibodies to muscle specific kinase (MuSK) and ryanodine receptor (RyR) are associated with particular features. METHODS: Clinical profiles and single fibre electromyography (SFEMG) in the extensor digitorum communis (EDC) were reviewed in consecutive 57 seropositive and 13 seronegative patients. Antibodies to MuSK and RyR were measured by immunoassays. RESULTS: Of the 13 seronegative patients, four (31%) were positive for MuSK antibodies and seven (54%) were positive for RyR antibodies, including all four MuSK positive patients. Clinical features were similar at presentation for seropositive and seronegative patients, but MuSK positive patients frequently developed myasthenic crises. Despite the similar clinical severities at the time of examination, the proportion with positive jitter (93% of seropositive patients, 50% of MuSK positive patients, and 44% of MuSK negative patients) and the extent of jitter (mean consecutive difference: 76 micros in seropositive patients, 36 micros in MuSK positive patients, and 30 micros in MuSK negative patients) were less in seronegative MG patients compared with seropositive MG patients. CONCLUSIONS: Seronegative MG is heterogeneous with respect to the presence of antibodies to MuSK. Impairment of neuromuscular synaptic transmission in EDC is less marked in seronegative than seropositive MG despite the similar clinical severity. This discrepancy may partly reflect the distribution of affected muscles in seronegative patients, but it is possible that other factors, such as impaired excitation-contraction coupling resulting from RyR antibodies, contribute to the clinical phenotype.

Adult↗
PubMed2005

Recovery patterns and long term prognosis for axonal Guillain-Barré syndrome.

BACKGROUND: Little is known about the long term prognosis for patients the severe acute motor axonal neuropathy (AMAN) form of Guillain-Barré syndrome (GBS), unlike those with acute inflammatory demyelinating neuropathy (AIDP). OBJECTIVE: To clarify the long term prognosis for patients with AMAN. METHODS: Clinical recovery and outcome in 97 consecutive GBS patients were reviewed. RESULTS: Electrodiagnostic criteria showed that 44 patients (45%) had AMAN, 33 (34%) had AIDP, and 20 (21%) were unclassified. Most of the severely affected patients had received plasmapheresis or immunoglobulin therapy. Slow recovery (inability to walk independently at six months after onset) was found in six of the AMAN patients (14%) and in two of the AIDP patients (6%). Of the six AMAN patients, four could walk independently one year after the onset, and the other two could walk independently at 28 and 57 months after onset. Of the two AIDP patients, one could walk at nine months after the onset while the other died of pneumonia seven months after onset. CONCLUSIONS: AMAN electrodiagnosis is not always a marker of poor recovery. Almost all the severe AMAN patients who had slow recoveries over the first six months could eventually walk independently, although some required several years.

Adolescent↗
PubMed2004

Does Campylobacter jejuni infection elicit "demyelinating" Guillain-Barre syndrome?

BACKGROUND: Campylobacter jejuni enteritis is the most common antecedent infection in Guillain-Barré syndrome (GBS). C. jejuni-related GBS is usually acute motor axonal neuropathy (AMAN), but previous reports described many cases of the demyelinating subtype of GBS (acute inflammatory demyelinating polyneuropathy [AIDP]) after C. jejuni infection. OBJECTIVE: To investigate whether C. jejuni infection elicits AIDP. METHODS: In 159 consecutive patients with GBS, antibodies against C. jejuni were measured using ELISA. Antecedent C. jejuni infection was determined by the strict criteria of positive C. jejuni serology and a history of a diarrheal illness within the previous 3 weeks. Electrodiagnostic studies were performed weekly for the first 4 weeks, and sequential findings were analyzed. RESULTS: There was evidence of recent C. jejuni infection in 22 (14%) patients. By electrodiagnostic criteria, these patients were classified with AMAN (n = 16; 73%) or AIDP (n = 5; 23%) or as unclassified (n = 1) in the first studies. The five C. jejuni-positive patients with the AIDP pattern showed prolonged motor distal latencies in two or more nerves and had their rapid normalization within 2 weeks, eventually all showing the AMAN pattern. In contrast, patients with cytomegalovirus- or Epstein-Barr virus-related AIDP (n = 13) showed progressive increases in distal latencies in the 8 weeks after onset. CONCLUSION: Patients with C. jejuni-related Guillain-Barré syndrome can show transient slowing of nerve conduction, mimicking demyelination, but C. jejuni infection does not appear to elicit acute inflammatory demyelinating polyneuropathy.

Adolescent↗
PubMed2004

Trigeminal afferent input alters the excitability of facial motoneurons in hemifacial spasm.

OBJECTIVE: To investigate whether skin or muscle afferent input via the trigeminal nerve alters the excitability of facial motoneurons in hemifacial spasm (HFS). METHODS: Botulinum toxin type A (BTX) was injected only to the orbicularis oculi (O. oculi) muscle of 21 patients with idiopathic HFS, and the excitability of the orbicularis oris (O. oris) motoneurons was monitored. The synkinetic response (SR) of the blink reflex and abnormal muscle response (AMR) were recorded from the O. oris before and after treatment. RESULTS: BTX injections produced marked to moderate improvement in the O. oculi of all 21 patients and in the O. oris of 17 (81%). The rectified areas of SR1 and SR2 were smaller after treatment. In particular, the AMR area showed a reduction (p = 0.02). CONCLUSIONS: The significant lessening of spasms in the O. oris after BTX injection to the O. oculi and the concomitant reduction in excitability of O. oris neurons are consistent with the hypothesis that in HFS, skin or muscle afferent volleys via the trigeminal nerve enhance the excitability of facial nerve motoneurons.

Action Potentials↗
PubMed2003

Differences in patterns of progression in demyelinating and axonal Guillain-Barré syndromes.

BACKGROUND: Immune treatments are recommended for patients with Guillain-Barré syndrome (GBS) who cannot walk independently, but a considerable number of GBS patients are in the progressive phase at the first examination. OBJECTIVE: To investigate whether progression patterns differ in demyelinating and axonal subtypes of GBS. METHODS: Clinical, laboratory, and electrophysiologic data on 131 consecutive patients with GBS were reviewed. Patients were classified as having acute inflammatory demyelinating polyneuropathy (AIDP) or acute motor axonal neuropathy (AMAN) based on electrodiagnostic criteria. RESULTS: Forty-one patients had AIDP, 62 AMAN, and 28 were unclassified. Age, sex, and Hughes Functional Grading Scale score at the first medical examination did not differ for the AIDP and AMAN patients. Mean periods between neurologic onset and first examination (5.3 vs 4.2 days; p = 0.01) and neurologic onset and nadir (18.0 vs 11.5 days; p = 0.001) were longer for the AIDP group. In the subgroup of those with mild disability (able to walk independently at the first neurologic examination), 88% of the AMAN patients had reached the nadir, whereas 65% of the AIDP patients had reached it. The remaining 35% progressed to it over the next 1 to 2 weeks and were unable to walk at nadir. CONCLUSIONS: The patterns and speeds of progression differ in AMAN and AIDP, AMAN having a rapid progression and an early nadir. AIDP patients frequently have a significantly long progression after the first examination; therefore, they need to be carefully monitored.

Acute Disease↗