Paraneoplastic optic neuropathy and cerebellar ataxia with small cell carcinoma of the lung

Bilateral optic neuropathy and subacute cerebellar ataxia were manifestations of a paraneoplastic neurologic disorder in a woman found to have small cell carcinoma of the lung. Serologic tests revealed a neuronal autoantibody specific for CRMP-5, a 62-kd member of the collapsin response-mediating protein family. Unexplained optic neuropathy in the setting of subacute cerebellar ataxia should cause suspicion of a paraneoplastic disorder and prompt testing for this autoantibody, especially in patients at risk for lung carcinoma.

[Celiac disease can be associated with severe neurological symptoms. Analysis of gliadin antibodies should be considered in suspected cases]

Celiac disease can be associated with a wide spectrum of neurological and psychiatric symptoms (cerebellar ataxia, neuromuscular manifestations, epilepsy, dementia), even in the absence of malabsorption or gastrointestinal symptoms. The case of a 72-year-old man with a rapidly progressive, lethal encephalopathy secondary to celiac disease is reported, together with a review of documented neurological symptoms in celiac disease. The aetiology of these neurological symptoms is unknown, although immunological mechanisms are suspected.

Sporadic cerebellar ataxia associated with gluten sensitivity

A total of 104 patients with sporadic cerebellar ataxia were tested for antigliadin and antiendomysium antibodies. Twelve individuals (11.5%) with gluten sensitivity underwent duodenal biopsy and extensive clinical, electrophysiological, neuropsychological, radiological and laboratory investigations including human leucocyte antigen (HLA) typing. Two patients showed typical changes of gluten-sensitive enteropathy with crypt hyperplasia and mucosal flattening. In five patients, the intraepithelial lymphocyte count was elevated. Sporadic ataxia with gluten sensitivity was found to be tightly linked to the HLA DQB1*0201 haplotype (70%). Neurological symptoms were not related to hypovitaminosis or inflammatory CSF changes. The clinical syndrome was dominated by progressive cerebellar ataxia with ataxia of stance and gait (100%), dysarthria (100%) and limb ataxia (97%). Oculomotor abnormalities were gaze-evoked nystagmus (66.7%), spontaneous nystagmus (33.3%), saccade slowing (25%) and upward gaze palsy (16.7%). Extracerebellar features also included deep sensory loss (58.3%), bladder dysfunction (33.3%) and reduced ankle reflexes (33.3%). In accordance with clinical findings, electrophysiological investigations revealed prominent axonal neuropathy with reduced amplitudes (50%) and abnormal evoked potentials (58.3%). On neuropsychological testing, patients presented with moderate verbal memory and executive dysfunction. All patients had evidence of cerebellar atrophy on MRI. We conclude that sporadic ataxia may be associated with positive antibodies against gliadin. Nevertheless, mucosal pathology does not represent an obligatory condition of ataxia with gluten sensitivity. The fact that the disease is strongly associated with the same HLA haplotypes found in coeliac disease not only demonstrates coeliac disease and ataxia with gluten sensitivity to be part of the same disease entity but supports the hypothesis of an immunological pathogenesis of cerebellar degeneration.

Gluten sensitivity in sporadic and hereditary cerebellar ataxia

Gluten sensitivity, with or without classical celiac disease symptoms and intestinal pathology, has been suggested as a potentially treatable cause of sporadic cerebellar ataxia. Here, we investigated the prevalence of abnormally high serum immunoglobulin A (IgA) and IgG anti-gliadin antibody titers and typical human lymphocyte antigen (HLA) genotypes in 50 patients presenting with cerebellar ataxia who were tested for molecularly characterized hereditary ataxias. A high prevalence of gluten sensitivity was found in patients with sporadic (7/26; 27%) and autosomal dominant (9/24; 37%) ataxias, including patients with known ataxia genotypes indicating a hitherto unrecognized association between hereditary ataxias and gluten sensitivity. Further studies are needed to determine whether gluten sensitivity contributes to cerebellar degeneration in patients with hereditary cerebellar ataxia. Patients with hereditary ataxia (including asymptomatic patients with known ataxia genotype) should be considered for screening for gluten sensitivity and gluten-free diet trials.

A patient with type 1 diabetes mellitus and cerebellar ataxia associated with high titer of circulating anti-glutamic acid decarboxylase antibodies

A 66-year-old Japanese woman presenting with recent onset of type 1 diabetes mellitus and cerebellar ataxia was admitted to our hospital. Physical examination on admission revealed coordinate disturbance due to cerebellar ataxia, and the laboratory examination showed marked hyperglycemia with ketosis and impaired insulin secretion. Anti-glutamic acid decarboxylase (GAD) antibodies in high titer were detected in patient's serum. Immunoblotting showed the patient's serum reacted with a 65 kDa protein in tissue extracts from rat pancreas and cerebellum, and immunohistochemical study produced positive immunostaining in the pancreatic islets of Langerhans, the axons of Purkinje cells and the nerve terminals in the granular layers of cerebellum of the rat. This is the first case presenting with concomitant type 1 diabetes and cerebellar ataxi associated with high titers of circulating anti-GAD antibodies which may play a critical role in the development of the diseases.

Presynaptic inhibition of cerebellar GABAergic transmission by glutamate decarboxylase autoantibodies in progressive cerebellar ataxia

Autoantibodies against glutamic acid decarboxylase (GAD) have been found in stiff-man syndrome, insulin dependent diabetes mellitus, and progressive cerebellar ataxia. A patient with progressive cerebellar ataxia is described who was positive for GAD autoantibodies, and had Sjögren's syndrome. Immunohistochemical studies using CSF and serum samples from the patient showed immunoreactivities in axon terminals of cerebellar GABAergic neurons. A whole cell patch clamp technique recording from rat cerebellar slices showed that the CSF, presumably through GAD autoantibodies, presynaptically inhibited GABAergic transmission. Intravenous administration of immunoglobulin failed to improve clinical symptoms and immunoreactivities examined after therapy. The findings suggest that GAD autoantibodies play a pathogenic part in reducing GABA release in in vitro slices.

Cerebellar ataxia with anti-glutamic acid decarboxylase antibodies: study of 14 patients

BACKGROUND

Antibodies to glutamic acid decarboxylase (GAD-Ab) are described in patients with insulin-dependent (type 1) diabetes mellitus (IDDM), in stiff-man syndrome, and, recently, in a few patients with cerebellar ataxia.

OBJECTIVES

To show a link between GAD-Ab and some patients with cerebellar ataxia and to clarify their clinical and immunologic profiles.

METHODS

Serum samples were selected from 9000 samples of 4 laboratories. The selection criterion was an immunohistochemical pattern compatible with GAD-Ab that was confirmed by radioimmunoassay. We identified 22 patients with stiff-man syndrome and 14 with cerebellar ataxia and GAD-Ab.

RESULTS

Thirteen of the 14 patients with cerebellar ataxia and GAD-Ab were women, and 11 had late-onset IDDM. Patients did not have clinical or radiologic evidence of brainstem involvement. Ten patients had oligoclonal IgG bands in the cerebrospinal fluid, and intrathecal GAD-Ab synthesis was observed in 5 of the 6 patients studied. The level of GAD-Ab of these patients was similar to those with stiff-man syndrome and significantly higher than those with IDDM or with polyendocrine autoimmunity (P<.001). However, the GAD-Ab levels of 6 of the 9 patients with polyendocrine autoimmunity overlapped with those of patients with cerebellar ataxia.

CONCLUSIONS

These results suggest a link between high level of GAD-Ab and some cases of cerebellar ataxia, particularly women with IDDM. If high serum levels of GAD-Ab are detected, the cerebrospinal fluid should be evaluated for the presence of oligoclonal IgG bands and intrathecal synthesis of GAD-Ab to further prove an autoimmune origin of the syndrome.

Paraneoplastic cerebellar degeneration with anti-Purkinje cell antibody associated with primary tubal cancer

In patients with paraneoplastic cerebellar degeneration (PCD) due to gynecologic malignancies, a high titer of anti-Purkinje cell antibody (anti-Yo) has been found. Most patients, however, have limited oncologic disease at the time of onset of neurologic symptoms. We describe 2 cases of PCD due to tubal cancer with anti-Yo antibody. The onset of PCD occurred 4 and 14 months before the detection of cancer, respectively, and the presence of anti-Yo antibody facilitated early laparotomy in both cases. These patients, whose neurologic symptoms have not progressed, have survived without evidence of disease for 81 and 30 months since surgery, respectively. The presence of the anti-Yo antibody in patients with PCD warrants an aggressive approach to diagnosis and treatment of the underlying gynecologic cancer.

Autoantibody screening in subacute cerebellar ataxia

In a retrospective study of 280 sera from patients presenting with cerebellar signs, seven of whom had proved positive for the typical paraneoplastic serum antibodies that were requested by the clinicians, raised concentrations of antibodies to voltage-gated calcium channels or to glutamic acid decarboxylase were detected in a further seven sera. Systematic screening for these and other antibodies in future cases should help in the diagnosis and management of the patients.

Presynaptic impairment of cerebellar inhibitory synapses by an autoantibody to glutamate decarboxylase

Glutamic acid decarboxylase (GAD), the enzyme responsible for converting glutamate to gamma-aminobutyric acid (GABA), is a target of humoral autoimmunity in stiff-man syndrome and subacute cerebellar ataxia. Recently, we found that an anti-GAD autoantibody in the CSF of an ataxic patient selectively suppressed GABA-mediated transmission on cerebellar Purkinje cells without affecting glutamate-mediated transmission. Here, we examine the mechanism by which the autoantibody impaired the inhibitory transmission, using immunohistochemistry and whole-cell recording in rat cerebellar slices. The present results indicate that CSF immunoglobulins prepared from an ataxic patient acted on the presynaptic terminals of GABAergic interneurons and decreased GABA release onto Purkinje cells.

Identification and localization of ataxin-7 in brain and retina of a patient with cerebellar ataxia type II using anti-peptide antibody

Autosomal dominant cerebellar ataxias (ADCAs) are a complex group of neurodegenerative disorders characterized by progressive degeneration of the cerebellum, brain stem and spinal cord. The spinocerebellar ataxia type 7 (SCA7) is associated with pigmentary macular dystrophy and retinal degeneration leading to blindness caused by a CAG/polyglutamine (polyGln) expansion in the coding region of the SCA7 gene/protein. The SCA7 gene codes for ataxin-7, a protein of unknown function. To investigate its cellular and subcellular localization, we have developed a sequence-specific polyclonal antibody against the N-terminal part of the protein. Immunohistochemical analysis indicated that ataxin-7 accumulates as single nuclear inclusion (NI) in the cells of the brain and retina of a SCA7 patient but not of controls. The 1C2 antibody, directed against expanded polyGln, confirmed the aggregation of mutant ataxin-7 in these NIs. Furthermore, ubiquitin was found in these aggregates, suggesting that mutant ataxin-7 is a target for ubiquitin-dependent proteolysis, but resistant to removal. Electron microscopic studies using immunogold labeling showed that ataxin-7 immunoreactive NIs appear as dense aggregates containing a mixture of granular and filamentary structures. Together, these data confirm the presence of NIs in brain and retina of a SCA7 patient, a common characteristic of disorders caused by expanded CAG/polyGln repeats.

Coeliac disease presenting with neurological disorders

It is well known that coeliac disease may be associated with various neurological manifestations. We have had a high index of suspicion of coeliac disease during recent years in our neurological clinic. As a result 10 (7%) out of 144 of our new coeliac patients were detected because of neurological symptoms. The most common neurological manifestations were neuropathy, memory impairment and cerebellar ataxia. In these patient groups screening for coeliac disease with serological antibody tests helps to find patients who may suffer from this disease.

Selective suppression of cerebellar GABAergic transmission by an autoantibody to glutamic acid decarboxylase

Humoral immune response to glutamic acid decarboxylase (GAD) has been implicated in the pathogenesis of stiff-man syndrome and cerebellar ataxia, but the underlying pathomechanism is unclear. Using a whole-cell patch-clamp technique with rat cerebellar slices, we found that immunoglobulins present in the cerebrospinal fluid of an ataxic patient acted presynaptically to cause a selective suppression of GABAergic transmission. This synaptic depression was most likely elicited by an autoantibody to GAD.

Cerebellar ataxia with glutamic acid decarboxylase autoantibodies

Degenerative cerebellar ataxia with autoantibodies against glutamic acid decarboxylase (GAD) is a rare disorder and may represent a subset of ataxias previously classified as idiopathic. The authors report a patient with progressive cerebellar ataxia, insulin-dependent diabetes mellitus, and GAD antibodies who responded to i.v. immunoglobulins.

Risk factors for idiopathic cerebellar ataxia of late onset

In an attempt to identify risk factors for the development of idiopathic cerebellar ataxia (IDCA) we performed a case-control study of 59 IDCA patients. Hypertension and medicine intake were less frequent in IDCA than in neurological controls. Multiple logistic regression yielded an odds ratio (OR) for hypertension of 0.13 (95% confidence interval: 0.00-1.02, P=0.0527) and medicine intake of 0.10 (95% confidence interval: 0.00-0.72, P=0.0157). In contrast, we did not identify an association of IDCA with a number of medical diseases, head trauma, smoking, alcohol intake, rural living and well-water drinking. Some of these factors have been previously shown to be associated with other neurodegenerative diseases. In addition, serum antibody titers against neurotropic viruses were not elevated in IDCA.

Massilia timonae gen. nov., sp. nov., isolated from blood of an immunocompromised patient with cerebellar lesions

A fastidious, slowly growing, strictly aerobic, gram-negative bacterium was isolated from a culture of blood from a 25-year-old man with common variable immunodeficiency. The man had been admitted to hospital with febrile progressive cerebellar ataxia. The use of standard phenotypic schemes did not lead to identification, but sequence analysis demonstrated that the 16S rRNA gene of the isolate was most similar to those of the environmental bacteria Duganella zoogloeoides (formerly Zoogloea ramigera 115) and Telluria mixta. Further characterization of the bacterium by biochemical analysis, electron microscopy, G+C content estimation, and fatty acid analysis demonstrated significant differences between the bacterium and D. zoogloeoides and Telluria species; thus, we propose it as a new taxon with the name Massilia timonae gen. nov., sp. nov.

A patient with breast cancer and paraneoplastic cerebellar syndrome associated with anti-Purkinje cell antibodies: response to CMF chemotherapy

A 41-year-old lady underwent a left mastectomy and axillary clearance in 1992, for T2N0 breast cancer. She remained well until December 1995, when she presented with a rapidly progressive cerebellar ataxia. Full investigations for metastatic disease were negative. A clinical diagnosis of paraneoplastic cerebellar degeneration was confirmed by a high titre of anti-Purkinje cell antibodies. She was treated with cyclophosphomide, methotrexate and 5-fluorouracil. The improvement in neurological symptoms was dramatic and has been maintained by further hormone manipulation (ovarian ablation). The patient now leads a normal life without medication.

[Reversible paraneoplastic cerebellar symptoms. An example of anti-Ri syndrome]

A 67-year-old lady with breast cancer developed diplopia, tinnitus, nausea and vertigo within 2 weeks, followed 2 months later by severe truncal ataxia. Opsoclonus was never observed. She had anti-Ri antibodies and improved substantially after tumor resection and radiation.

Autoantibodies to glutamic acid decarboxylase in three patients with cerebellar ataxia, late-onset insulin-dependent diabetes mellitus, and polyendocrine autoimmunity

BACKGROUND

Glutamic acid decarboxylase (GAD) is the main target of humoral autoimmunity in stiff-man syndrome (SMS) and insulin-dependent diabetes mellitus (IDDM). GAD autoantibodies (GAD-Abs) are reported in a few patients with cerebellar ataxia, but their relevance is unclear. We describe three patients with cerebellar ataxia and GAD-Abs.

METHODS

GAD-Abs were assayed by radioimmunoassay (RIA) and immunohistochemistry and confirmed by immunoblot of recombinant human GAD65. The GAD-Ab levels of the three patients with cerebellar ataxia were compared with those of five with SMS, 49 with IDDM, 64 with cerebellar ataxia of probable degenerative origin without associated autoimmune features, 14 non-IDDM islet cell antibody-positive first-degree relatives of IDDM patients, and 91 normal subjects.

RESULTS

The three patients with ataxia and GAD-Abs were women (mean age, 63 years) with an isolated progressive cerebellar disorder, family history of IDDM, late-onset IDDM, and several positive serum organ-specific autoantibodies. Two patients had autoimmune thyroiditis, and one had pernicious anemia. CSF analysis demonstrated oligoclonal IgG bands and intrathecal synthesis of GAD-Abs. By RIA, GAD-Ab titers from the three patients were similar to those of SMS and significantly higher, without overlap, than the titers of IDDM patients. GAD-Abs were absent in the 64 patients with cerebellar ataxia and no evidence of autoimmune disorders.

CONCLUSIONS

These findings suggest a link of GAD autoimmunity not only with SMS but also with cerebellar dysfunction. GAD-Abs should be sought in patients with cerebellar ataxia who have late-onset IDDM and other organ-specific autoimmune manifestations.