Ken Ohyama

Clinicopathologic features of folate-deficiency neuropathy

Objective: The clinical significance and characteristics of neuropathy caused by folate deficiency remain to be established. Methods: We examined the clinicopathologic features of 18 consecutive patients with neuropathy caused by folate deficiency who presented with low serum folate levels but normal blood thiamine and serum cobalamin levels in the absence of chronic alcoholism. Results: Symptoms were relatively uniform, characterized by slowly progressive polyneuropathy with predominant involvement of the lower extremities, with a tendency to manifest as sensory rather than motor neuropathy and predominant deep rather than superficial sensory loss. The electrophysiologic features were consistent with axonal neuropathy. The histopathologic features of sural nerve biopsy specimens indicated large fiber–predominant axonal loss without segmental demyelination. Although macrocytosis was found in 7 patients, only 3 patients exhibited hemoglobin levels less than 10 g/dL. During the same study period, we found 12 patients who had low blood thiamine levels but normal serum folate and cobalamin levels without chronic alcoholism. Compared with patients who had thiamine-deficiency neuropathy, patients with a folate deficiency showed significantly slower progression (p < 0.01), a tendency to manifest sensory neuropathy (p < 0.05), predominant deep sensory loss (p < 0.01), and preservation of biceps tendon reflexes (p < 0.05). Conclusions: Folate-deficiency neuropathy was characterized by a slowly progressive and sensory-dominant pattern, which was different from thiamine-deficiency neuropathy (i.e., beriberi neuropathy). This study demonstrates the importance of folate deficiency in the differential diagnosis of neuropathy, particularly in countries where folic acid fortification has not yet been practiced.

IgG4-related neuropathy: a case report.

IMPORTANCE The newly recognized entity IgG4-related disease (IgG4-RD) is characterized by an elevated IgG4 serum concentration and tissue infiltration by IgG4-positive plasma cells. We describe, for the first time, the clinical features and nerve biopsy findings of a patient with IgG4-RD who presented with neuropathy in the extremities. OBSERVATIONS A 55-year-old man had histopathologically defined IgG4-RD that manifested as sensory-motor neuropathy. The neuropathic features were multiple mononeuropathies with electrophysiological findings suggestive of axonal neuropathy. Marked thickening with abundant collagen fibers and infiltration of IgG4-positive plasma cells were observed in the epineurium of the biopsied sural nerve. A moderate degree of myelinated fiber loss without evidence of segmental demyelination was present, whereas necrotizing vasculitis was not found. Oral prednisolone therapy ameliorated the neuropathic symptoms. CONCLUSIONS AND RELEVANCE This case of IgG4-RD presented as sensory-motor neuropathy with pain and sclerosis of the skin in the extremities. The differential diagnosis of neuropathy should include IgG4-RD.

Axonal loss influences the response to rituximab treatment in neuropathy associated with IgM monoclonal gammopathy with anti-myelin-associated glycoprotein antibody

Polyneuropathy associated with anti-Myelin-Associated Glycoprotein (MAG) antibody is a well-defined immune-mediated disease that develops in individuals with IgM monoclonal gammopathy. Factors related to response to rituximab treatment in anti-MAG neuropathy have not been clarified so far. We prospectively evaluated the clinical status, immunological changes, and electrophysiological parameters before and 12 months after rituximab treatment in 7 patients with anti-MAG neuropathy. Pathological indices of sural nerve biopsy specimens before rituximab treatment were investigated. Overall, 4 patients improved by more than 5% either clinical scale, expressed according to the Medical Research Council (MRC) sum score or sensory sum score (SSS) 12 months after rituximab treatment. The modified Rankin Scale (mRS) scores improved in 2 patients. With respect to the relationship between the response to rituximab treatment and the clinicopathological findings, short disease duration and preservation of nerve fiber density were significantly related. The immunohistochemical assessment suggested that low-intensity binding of anti-IgM antibody to the myelin sheath may contribute to the degree of response to rituximab treatment. The degree of axonal loss and the deposition of pathogenic autoantibodies in myelinated fibers may determine the therapeutic response to rituximab treatment in anti-MAG neuropathy.

Immunoglobulin G4-related pathologic features in inflammatory neuropathies

Objective: To evaluate the pathologic significance of immunoglobulin G4 (IgG4) in patients with inflammatory peripheral neuropathy. Methods: We clinicopathologically examined 149 consecutive patients with peripheral neuropathy who had clusters of inflammatory cells with or without vasculitis in sural nerve biopsy specimens and in whom we were able to assess the serum IgG4 levels. Results: Elevation of serum IgG4 levels and infiltration of IgG4-positive plasma cells, which are currently defined as the diagnostic criteria for IgG4–related disease, were found in 35 and 29 patients, respectively. In the 44 patients exhibiting either elevated serum IgG4 levels or IgG4-positive cell infiltration, the diagnoses prior to the examination of IgG4 in serum and pathologic samples included microscopic polyangiitis (12 patients) and eosinophilic granulomatosis with polyangiitis, or Churg-Strauss syndrome (19 patients). Thirty-four patients (77%) had findings of vasculitis as indicated by the destruction or obstruction of the vessel walls. Sixteen (36%) of these patients had fibrinoid necrosis. Axonal degeneration without evidence of demyelination was observed irrespective of the presence of vasculitis. The extent of fibrosis, assessed as the fibrotic area in the epineurium, significantly correlated with the grade of IgG4-positive cell infiltration (p < 0.01). Conclusions: Elevated serum IgG4 levels and infiltration of IgG4-positive plasma cells were observed in a subgroup of patients with inflammatory neuropathy, particularly in patients diagnosed with primary systemic vasculitis, including microscopic polyangiitis. Epineurial IgG4-positive plasma cell infiltration correlated with the extent of epineurial fibrosis.

Mononeuritis multiplex with tumefactive cellular infiltration in a patient with reactive lymphoid hyperplasia with increased immunoglobulin G4–positive cells

We describe a 54-year-old man with mononeuritis multiplex and reactive lymphoid hyperplasia with increased immunoglobulin G4 (IgG4)-positive cells. Asymmetrical numbness and weakness had advanced stepwise for 6 years. Serum immunoglobulin G, IgG4, and immunoglobulin E levels were elevated, whereas M protein was not detected. Chest and abdominal computed tomography showed generalized lymphadenopathy. Inguinal lymph node biopsy revealed expansion of the interfollicular area with infiltration of IgG4-positive cells, of which the absolute number was greater than 100 per high-power field, and the percentage of IgG4+/immunoglobulin G+ plasma cells was 33%. Sural nerve biopsy disclosed axonal neuropathy with tumefactive lymphoid infiltrate in epineurium, but IgG4-positve plasma cells and fibrosis were not detected. Symptoms and laboratory data were improved with oral glucocorticoid therapy at a dose of 0.6 mg/kg per day. Although the causal mechanisms of neuropathy should be determined in future studies, peripheral nerve involvement may occur in patients with reactive lymphoid hyperplasia with increased IgG4-positive cells.

[Clinicopathological features of neuropathy associated with IgG4-related disease].

The newly recognized entity IgG4-related disease (IgG4-RD) is characterized by an elevated IgG4 serum concentration, swelling of organ, and tissue infiltration by IgG4-positive plasma cells with fibrosis. IgG4-RD has been reported in various organs. In the field of neurology, hypophysitis and hypertrophic pachymeningitis have been known to be related to IgG4-RD, while reported patients with neuropathy manifesting features compatible to IgG4-RD. The features of IgG4-related neuropathy are characterized by sensory-motor neuropathy, mononeuritis multiplex pattern, and predominant involvement of distal portions of the lower extremities. In the sural nerve biopsy specimens, fibrosis and IgG4-positive plasma cell infiltration in the epineurium and decreased myelinated fiber density due to axonal degeneration were observed. IgG4-RD should be considered as the differential diagnosis of neuropathy.

Muscle atrophy in chronic inflammatory demyelinating polyneuropathy: a computed tomography assessment

Muscle atrophy is generally mild in patients with chronic inflammatory demyelinating polyneuropathy (CIDP) compared with the severity and duration of the muscle weakness. Muscle atrophy was evaluated using computed tomography (CT) in patients with CIDP.

Autonomic manifestations in acute sensory ataxic neuropathy: A case report

Acute sensory ataxic neuropathy (ASAN) is known to occur with acute and monophasic sensory ataxia. Although autonomic dysfunctions have been reported, no detailed descriptions are currently available. We describe a case of ASAN in which the autonomic manifestations were systematically investigated. Although the patient did not complain of any autonomic symptoms, except for photophobia due to mydriasis, autonomic testing revealed widespread autonomic dysfunctions. Norepinephrine and dobutamine infusion test indicated the presence of sympathetic dysfunction. Additionally, the pupillary response to pilocarpine revealed the presence of parasympathetic dysfunction. In conclusion, widespread, subclinical autonomic dysfunctions may be present in ASAN patients.

Vasculitic Neuropathy Following Exposure to a Glyphosate-based Herbicide

We herein report a case of peripheral neuropathy following exposure to large amounts of glyphosate-based herbicide. A 70-year-old man suffered from pain and purpura in the left sole following exposure to glyphosate-based herbicide. Pain and purpura spread to the opposite side and increased in severity. Mild weakness of the lower limbs was also observed. A sural nerve biopsy revealed the infiltration of lymphocytes around small vessels in the epineurium with numerous eosinophils, deposition of hemosiderins and focal axonal degeneration, compatible with findings of vasculitic neuropathy. Glyphosate-based herbicides should be recognized as a causative agent of vasculitic neuropathy.

Clinicopathologic features of folate-deficiency neuropathyAuthor Response

Koike et al.1 reported a slowly progressive, prevalent sensory polyneuropathy in patients with folate deficiency, which shows some distinctive clinical features with respect to thiamine-deficiency neuropathy.2 However, as the authors mention, the clinical manifestations of folate deficiency may be indistinguishable from those of cobalamin deficiency because of their interaction in one carbon metabolic pathway.3 In addition, thiamine is poorly absorbed during folate deficiency, because of frequent diarrhea as a result of damaged gastrointestinal mucosa. …