[A case of acute cerebellar ataxia following infectious mononucleosis accompanied by intrathecal anti-glutamate receptor δ2 antibody]

An 18-year-old woman was admitted because of sore throat and pain in the epigastric region. On admission, she presented with swollen tonsils and hepatosplenomegaly. Blood examinations revealed the presence of atypical lymphocytes, liver damage and anti-VCA IgM and IgG antibodies. These findings led to diagnosis of infectious mononucleosis. After admission, her condition improved, but on hospital day 4, she suddenly developed cerebellar ataxia in the trunk and four limbs. Cranial MRI findings were normal. Cerebrospinal fluid (CSF) collected on hospital day 6 showed normal cell counts and normal concentrations of protein and glucose. EB virus DNA and anti-VCA IgM and IgG antibodies were negative and glutamate receptor δ2 antibody was positive in CSF collected on hospital day 11. We diagnosed acute cerebellar ataxia (ACA) and performed methylprednisolone pulse therapy. After this therapy, her cerebellar ataxia improved over a few days. This is the first reported case of ACA after EB virus infection presenting with glutamate receptor δ2 antibody in CSF. The glutamate receptor δ2 subunit is expressed on cerebellar Purkinje cells. Therefore, the presence of the antibody may be associated with cerebellar dysfunction. In the present case, secondary immune reactions after EB virus infection may have produced the antibody.

Opposing roles for CXCR3 signaling in central nervous system versus ocular inflammation mediated by the astrocyte-targeted production of IL-12

CXCR3 and its ligands are important for the trafficking of activated CD4(+) T(H)1 T cells, CD8(+) T cells, and natural killer cells during inflammation. Recent functional studies demonstrate a more diverse role of CXCR3 in inflammatory diseases of the central nervous system (CNS). We examined the impact of CXCR3 on a less complex interferon-γ-dependent, type 1 cell-mediated immune response in the CNS, induced in mice by the transgenic production of glial fibrillary acidic protein IL-12 (GF-IL12) by astrocytes and retinal Müller cells. GF-IL12 mice develop ataxia because of severe cerebellar inflammation but have little overt ocular disease. Surprisingly, CXCR3-deficient GF-IL12 mice (GF-IL12/CXCR3KO) have drastically reduced ataxia but developed cataracts, severe ocular inflammation, and eye atrophy. Most GF-IL12/CXCR3KO mice had minimal cerebellar inflammation but severe retinal disorganization, loss of photoreceptors, and lens destruction in the eye. The number of CD3(+), CD11b(+), and natural killer 1.1(+) cells were reduced in the CNS but highly increased in the eyes of GF-IL12/CXCR3KO compared with GF-IL12 mice. High levels of interferon-γ, IL-1, tumor necrosis factor α, CXCL9, CXCL10, and CCL5 were found in GF-IL12 cerebelli and GF-IL12/CXCR3KO eyes. Our findings demonstrate key but paradoxical functions for CXCR3 in IL-12-induced immune disease in the CNS, promoting inflammation in the brain yet restricting it in the eye. We conclude that the function of CXCR3 in cellular immune disease is driven by a common trigger and is controlled by tissue-specific factors.

[A case of persistent cerebellar ataxia complicated by conversion disorder--confirmed by positive cerebrospinal fluid glutamate receptor delta2 and epsilon2 antibodies]

We recently encountered a 13-year-old girl who developed persistent cerebellar symptoms one month after mixed measles/rubella vaccination, making it difficult to distinguish this condition from conversion disorders. Severe truncal ataxia was the initial manifestation in this case. The patient had no abnormalities in objective tests but began to show extraordinary circadian variations in certain parameters. Her cerebellar symptoms were thus considered to possibly be associated with conversion disorders. Later, she tested positive for cerebrospinal fluid anti-glutamic acid receptor (GluR) delta2 antibody. The lymphocyte stimulation test yielded a positive reaction to GluRdelta2 antigen. In addition, in the chronic stage SPECT revealed reduced cerebellar blood flow. She was thus diagnosed as having persistent cerebellar ataxia due to autoimmune mechanisms and modification of cerebellar symptoms due to secondary conversion disorders. Our experience with this case suggests that checking cerebrospinal fluid for anti-GluRdelta2 antibody is possibly useful for distinguishing between conversion disorders and cerebellar ataxia due to autoimmune mechanisms.

Gluten sensitivity: associated sporadic cerebellar ataxia in Taiwan

PURPOSE

Gluten sensitivity (GS) is related to the pathogenesis of sporadic or hereditary ataxia.

METHODS

Total of 194 healthy controls and patients with either hereditary ataxia (n=207) or sporadic ataxia (n=361) were tested for the circulating gluten-related autoantibodies which serve as biomarkers to interpret the existence of GS.

RESULTS

The incidences of GS in each population were 1% in normal subjects, 2% in hereditary ataxia patients and 9% in sporadic ataxia patients. High serum level of anti-gliadin IgG/IgA and t-transglutaminase IgA were disclosed at the sporadic ataxia patients compared with normal subjects. However, the anti-gliadin IgG is more specific to the disease of sporadic ataxia.

CONCLUSION

Relatively higher incidence of GS was found in the population of sporadic ataxia patients but not in either normal subjects or hereditary ataxia patients in Taiwan. Anti-gliadin IgG still is a very powerful indicator to implicate the immune-related sporadic ataxia and we conclude that GS-related sporadic ataxia exists in Taiwan with linkage to autoimmune events.

[A case of recurrent paraneoplastic cerebellar ataxia with antibodies to GluR epsilon 2 causally related to ganglioneuroma]

Acute cerebellar ataxia (ACA) in childhood following viral infection is a self-limited disease. We present a boy with recurrent episodes of paraneoplastic cerebellar ataxia associated with a ganglioneuroma. A 20-month-old boy developed the first episode of cerebellar ataxia after nonspecific respiratory tract infections. During this episode he showed a wide gait and truncal ataxia with intention tremor and horizontal nystagmus. Our initial diagnosis was ACA, and gradual improvement of ataxia was observed thereafter. At 2 years and 6 months, similar cerebellar symptoms recurred after respiratory tract infections. Speech difficulty and cognitive problems developed thereafter. We suspected paraneoplastic syndrome. Computed tomography revealed a retroperitoneal tumor, and autoantibodies against GluR epsilon 2 were detected in the cerebrospinal fluid. After the tumor resection, the cerebellar symptoms did not recur and speech difficulty and cognitive problems improved gradually. Recent neuroimaging and neuropsychological studies have revealed that cerebellar function contributes to higher brain functions including cognition and learning. We will follow up this patient's long-term cognitive function and consider special educational support and programs.

Recurrent and reversible cerebellar ataxia with concomitant episodes of hyperthyroidism: a new autoimmune syndrome

A new disorder with possible autoimmune background is described in a 67-year-old man. He had experienced episodes of cerebellar ataxia induced by infections over the last 40 years. In 1963 he had thyrotoxicosis. The patient underwent bilateral subtotal thyroidectomy. Recently it has been possible to detect involvement also of his remaining thyroid gland, with findings compatible with hyperthyroidism concomitant with his cerebellar atixia.

Intravenous immunoglobulin therapy for autoantibody-positive cerebellar ataxia

OBJECTIVE

It has been reported that autoimmune cerebellar ataxias, such as anti-glutamic acid decarboxylase (GAD)-antibody-positive cerebellar ataxia and gluten ataxia, are treatable. Here, we examined the therapeutic efficacy of intravenous immunoglobulin (IVIg) on autoantibody-positive cerebellar ataxia.

PATIENTS AND METHODS

IVIg therapy was administered in seven autoantibody-positive cerebellar ataxia patients. Therapeutic efficacy was examined in terms of its effects on clinical symptoms and changes in brain perfusion using single photon emission computed tomography (SPECT).

RESULTS

Treatment was effective in four cerebellar cortical atrophy patients (two anti-GAD antibody-positive and two anti-gliadin antibody-positive) and in one anti-thyroid antibody-positive spinocerebellar ataxia type 3 (SCA3) patient, but not in two multiple system atrophy (MSA) patients. All four IVIg effective patients who underwent SPECT showed apparent increases in cerebellar perfusion.

CONCLUSION

If cerebellar ataxia with an autoimmune mechanism is suspected and radiological findings do not reveal MSA, it is worth considering immunotherapy including IVIg.

Reversibility of cerebellar GABAergic synapse impairment induced by anti-glutamic acid decarboxylase autoantibodies

Anti-glutamic acid decarboxylase autoantibodies (GAD-Abs) are found in some patients with cerebellar ataxia. We reported previously that CSF IgGs depress cerebellar GABAergic synaptic transmissions by a presynaptic mechanism. Using whole-cell recordings from rat cerebellar slices, we found in the present study that CSF IgG-induced depressive effects were abolished by absorption of GAD-Abs using recombinant GAD. Furthermore, forskolin, an activator of cAMP, recovered the CSF IgG-induced reduction of GABA release. Our results provide evidence that GAD-Abs in the CSF elicited physiopathological effects on cerebellar GABA synapses in vitro and that such synaptic impairment was reversible.

[Steroid treatment in four cases of anti-GAD cerebellar ataxia]

INTRODUCTION

Few neurological diseases are linked with anti-glutamic acid decarboxylase antibodies (GAD-ab); stiff man syndrome is an example. Cerebellar ataxia is a new feature of this expanding spectrum. No therapeutic trial is yet available in these diseases. We here report on four patients suffering from cerebellar ataxia linked with GAD-ab and review the data in the literature on this recently described syndrome.

METHOD

We conducted an open trial with monthly pulsed steroids. Steroid pulses were given six months followed with placebo for another six months. Main clinical and biological parameters were monitored monthly (International Cooperative Cerebellar Ataxia Rating Scale [ICARS] and GAD-ab).

RESULT

The clinical response was found limited and inconstant. Transient decline in GAD-ab level was noted in two patients. Moreover, GAD-ab level was found highly variable and did not correlate with clinical parameters.

DISCUSSION

Cerebellar ataxia with GAD-ab is an increasingly described syndrome. Outcome can be severe, leading to definitive cerebellar atrophy. Diagnosis is supported by high level of serum GAD-ab with intrathecal secretion. Experimental data have suggested a direct excitotoxic effect of GAD-ab on Purkinje cells. Response to various treatments is often disappointing. Improvement has been obtained with veinoglobulins in individual patients. A weak clinical and biological response was associated with monthly steroid pulses.

Acute cerebellar ataxia and consecutive cerebellitis produced by glutamate receptor delta2 autoantibody

Acute cerebellar ataxia is usually a self-limited benign disease, which may develop in children after certain viral infections or vaccinations. There are several reports of acute cerebellar ataxia associated with autoantibodies. Glutamate receptor delta2, a member of the glutamate receptor family, is predominantly expressed in cerebellar Purkinje cells and plays a crucial role in cerebellar functions. To date anti-GluRdelta2 autoantibody was detected in a patient with chronic cerebellitis. Herein, an 18-month-old boy presented with cerebellar ataxia 9 days following a mild respiratory tract infection. Although cerebellar ataxia gradually improved, it worsened yet again following mumps and varicella virus infection. Cerebro-spinal fluid examination and magnetic resonance imaging of the brain demonstrated pleocytosis and meningeal enhancement, respectively. Furthermore, glutamate receptor delta2 autoantibody was detected in serum and cerebro-spinal fluid. Thus, we believe that the glutamate receptor delta2 autoantibody may play a role in cerebellar ataxia and consecutive cerebellitis.

Post-malaria neurological syndrome: clinical and laboratory findings in one patient

Post-malaria neurological syndrome (PMNS) is a rare complication of malaria. It follows recovery from an episode of Plasmodium falciparum malaria and is characterised by symptoms and signs of encephalopathy. Patients usually improve without any specific treatment. The pathogenesis is unknown, but it is probably immunologically mediated. The objective of this case study is to describe the first Italian patient with PMNS. A 60-year-old Italian man developed acute P. falciparum malaria after a stay in French Guinea. Twenty days after recovering from malaria, he became confused, developed generalised weakness, limb tremors, shivering and dizziness. These symptoms continued for three days, then resolved spontaneously. Neuroimaging was normal. Cerebrospinal fluid analysis revealed breakdown of the blood/brain barrier, without oligoclonal bands and normal IgG index. Our patient presented a mild diffuse encephalopathy suggestive of a generic activation of the immune system without any specific reaction against antigens within the CNS.

Epilepsy and cerebellar ataxia associated with anti-glutamic acid decarboxylase antibodies

Anti-glutamic acid decarboxylase (GAD) antibodies are described in stiff-person syndrome and also in other neurological syndromes, including cerebellar ataxia and epilepsy. This paper reports the case of a patient who had chronic focal epilepsy, upbeat nystagmus and cerebellar ataxia, associated with a polyautoimmune response including anti-GAD antibodies. Both gait and nystagmus improved markedly after immunosuppressive treatment with corticosteroids and azathioprine. After the introduction of benzodiazepines, previously refractory seizures were completely controlled. Anti-GAD antibodies should be actively sought out in pharmacoresistant epilepsy, particularly if other neurological abnormalities are present. Combined treatment with immunosuppressants and gammahydroxybutyric acidergic agents may be highly effective.

Selective loss of Purkinje cells in a patient with anti-glutamic acid decarboxylase antibody-associated cerebellar ataxia

Anti-glutamic acid decarboxylase antibody is associated with the development of progressive cerebellar ataxia and slowly progressive insulin-dependent diabetes mellitus. Previously, the neurophysiological characteristics of IgG in the cerebrospinal fluid of a patient with anti-glutamic acid decarboxylase antibody-associated progressive cerebellar ataxia and slowly progressive insulin-dependent diabetes mellitus were reported. Using a voltage-gated whole-cell recording technique, it was observed that the IgG in the cerebrospinal fluid of the patient selectively suppressed the inhibitory postsynaptic currents in the Purkinje cells. The patient died from aspiration pneumonia. Postmortem examination showed almost complete depletion of the Purkinje cells with Bergmann gliosis. Therefore, the main cause of cerebellar ataxia observed in this case may be attributed to the near-complete depletion of the Purkinje cells. In this paper, the pathomechanisms underlying Purkinje cell damage are discussed.

Un nouveau cas d'ataxie cérébelleuse à anticorps anti-GAD traité par corticoïdes et initialement séronégatif

INTRODUCTION

Cerebellar ataxia with antiglutamic acid decarboxylase antibodies (GAD-ab) is an exceptional newly recognized autoimmune disorder. The cerebellar ataxia may occur in isolation or be associated with stiff man syndrome another rare GAD-Ab induced disorder of central nervous system.

EXEGESIS

A 38-year-old woman with a past history of Graves disease presented with insidious cerebellar symptoms including ataxic gait, dysmetria, dysarthria, and oscillopsia. A thorough survey of markers of paraneoplastic cerebellar ataxia and collagen diseases was negative. Her serum contained high level of GAD-ab (647.2 U/ml) and MRI evidenced pure cerebellar atrophy leading to diagnosis of autoimmune cerebellar ataxia. Under corticosteroids, cerebellar symptoms partially improved, but serum GAD-ab titre dramatically decreased.

CONCLUSION

Testing for GAD-ab may be indicated in patients with idiopathic cerebellar ataxia, particularly mature women with organ-specific autoimmune diseases. Corticosteroids must be started to prevent irreversible cerebellar atrophy.

Paraneoplastic rhombencephalitis and brachial plexopathy in two cases of amphiphysin auto-immunity

Amphiphysin, a synaptic vesicle protein, is an auto-immune target in rare cases of paraneoplastic neurological disorders. We report two additional cases with distinct neurological syndromes and paraneoplastic anti-amphiphysin antibodies. The first patient, a 59-year-old man, presented with cerebellar and cranial nerve dysfunction and small cell lung carcinoma. The second, a 77-year- old woman, presented with left brachial plexopathy followed by sensorimotor neuropathy and breast carcinoma.

Autoantibodies in postinfectious acute cerebellar ataxia

The authors found serum immunoglobulin M (IgM) autoantibody in a patient with typical acute cerebellar ataxia (ACA) and identified the antigen molecule as triosephosphate isomerase (TPI). TPI antigenicity to the patient's antibody was the highest in the cerebellar tissue. Eight of 23 patients with ACA had increased IgM anti-TPI antibody titers vs those of healthy controls. Preceding Epstein-Barr virus infection was confirmed serologically in all 8 patients. Anti-TPI antibody decreased with clinical improvement.

Ataxie avec sensibilité au gluten, mythe ou réalité ?

INTRODUCTION

Gluten ataxia refers to the association of idiopathic ataxia despite exhaustive investigations with gluten sensitivity defined by anti-gliadin antibodies (AGA) presence in blood. This is a controversial concept.

PATIENTS AND METHODS

We screened 33 patients, who were hospitalized in 2003 and had subacute or chronic ataxia for presence of circulating AGA. Twelve patients were positive and their clinical and biological features were studied.

RESULTS

Among the twelve patients, we concluded that gluten ataxia was present in only eight, including one case of celiac disease. Among these eight patients, five had the usual features of gluten ataxia (progressive cerebellar ataxia affecting mainly lower limbs), but one patient presented unusual left cerebellar hemisyndrome and the two others displayed polyneuropathy with proprioceptive ataxia. Cerebellar atrophy was confirmed with magnetic resonance imaging in five cases and association with other antibodies was found in six cases. Among the four other patients positive for AGA, investigations revealed one case of multiple sclerosis, one case of late-onset Friedreich ataxia, one case of basilar tuberculous meningitis and one case of type 2 diabetes.

CONCLUSION

Screening for AGA presence should be systematically performed at presentation of patients with unknown etiology ataxia; in the event AGA are present without any other etiology, treatment with gluten-free diet must be discussed. However, the responsibility of AGA in the pathogenesis of neurological signs is highly debatable and further experimental work is required. Two pathophysiological hypotheses are suggested: (1) overexpression of cerebellar epitopes, in case of primary cerebellar pathology, leading to excessive immune response directed against these epitopes; and (2) molecular mimicry with cross-reactivity of antigens usually directed against gliadin, but also recognizing Purkinje cells epitopes.

Gluten sensitivity in Japanese patients with adult-onset cerebellar ataxia

OBJECTIVE

Gluten sensitivity is associated with multiple neurological abnormalities including gluten ataxia, motor neuron disease-like neuropathy, small fiber type neuropathy, cognitive impairment, and even parkinsonism. We investigated whether or not gluten sensitivity is involved in Japanese patients with idiopathic cerebellar ataxia with extracerebellar presentation.

PATIENTS OR MATERIALS

Fourteen patients with idiopathic cerebellar ataxia with extracerebellar presentation (autonomic instability, parkinsonism, or pyramidal dysfunction in varying combinations) were screened for anti-gliadin antibodies (AGA) to analyze for the presence or absence of gluten sensitivity. Patients with typical MR findings of multiple system atrophy of the cerebellar type were excluded. As disease controls without cerebellar ataxia, 9 patients with Parkinson's disease and 18 patients with amyotrophic lateral sclerosis were screened for AGA. Forty-seven normal controls were also screened for AGA.

RESULTS

We found a high prevalence of AGA in 5 (36%) of 14 cerebellar ataxia patients, but in only 1 (4%) of 27 disease controls without cerebellar ataxia (odds ratio, 14.4; 95% CI, 1.41147; p<0.05) and in only 1 (2%) of 47 normal controls (odds ratio, 25.6; 95% CI, 2.66246; p<0.001). Among the cerebellar ataxia patients, atypical features such as sensorimotor neuropathy and/or mild cognitive impairment were more prevalent in the AGA-positive group (60%) than in the AGA-negative group (0%). In one of the ataxic patients with AGA, a gluten-free diet had positive effects on neurological symptoms and nutritional status.

CONCLUSION

Gluten sensitivity is involved in at least some of the unexplained neurological symptoms of Japanese patients with adult-onset, sporadic cerebellar ataxia.

Cerebellar ataxia, peripheral neuropathy, "gluten sensitivity" and anti-neuronal autoantibodies

"Gluten sensitive" neurological syndromes (ataxia, peripheral neuropathy, and other conditions) have been hypothesised in patients with various idiopathic neuropathologies, detectable anti-gliadin antibodies and HLA-DQ2 or DQ7. Further investigation of these cases has suggested a high incidence of anti-neuronal antibodies (anti-Purkinje, anti- neuronal nuclear, anti-GAD). This study investigates this contentious area. Over a two-year period, from a local UK population base of two million, seeing over 5000 general neurology referrals per year, we collected 20 cases with idiopathic ataxia, and 32 with idiopathic peripheral neuropathy, and referred them all for blinded antibody testing. 30 adult healthy blood donors, and 7 cases of hereditary ataxia were used as control subjects. Anti-gliadin antibodies (IgG and or IgA) were found in 40% of cases with idiopathic ataxia, 34% with idiopathic peripheral neuropathy, 17% healthy blood donors and 43% with hereditary ataxia. None was positive for antiPurkinje cell or anti-neuronal nuclear antibodies. Only two patients with idiopathic ataxia were positive for antiGAD antibodies (one also being anti-gliadin positive). We were unable to confirm the findings of other groups. First, cases of so-called "gluten sensitive" neurological syndromes were extremely rare in our centre. Second, our idiopathic cases, whether they be gliadin antibody seropositive or not (i.e. "gluten sensitive" or not) were rarely neuronal autoantibody positive.

Cerebellar ataxia and acute motor axonal neuropathy associated with Anti GD1b and Anti GM1 antibodies

The anti-GD1b antibody is known to bind to the cerebellar granular layer or spinocerebellar Ia fibers. A few cases of anti-GD1b positive acute inflammatory demyelinating polyneuropathy with prominent cerebellar ataxia were reported. Recently, we encountered a middle-aged woman with Guillain Barré syndrome (GBS) with severe cerebellar ataxia and relatively mild motor weakness. Anti-GD1b Ig G antibody and anti-GM1 Ig G antibody titers were markedly elevated in her serum. She was diagnosed with acute motor axonal neuropathy (AMAN) with prominent cerebellar ataxia based on the results of the serial nerve conduction study suggesting axonal neuropathy. This case presents the clinico-pathogenic role of autoantibodies to the GD1b and the GM1 in acute inflammatory neuropathy.