Peripheral nerves are pathologically small in cerebellar ataxia neuropathy vestibular areflexia syndrome: a controlled ultrasound study

BACKGROUND AND PURPOSE

Sensory neuronopathy is a cardinal feature of cerebellar ataxia neuropathy vestibular areflexia syndrome (CANVAS). Having observed that two patients with CANVAS had small median and ulnar nerves on ultrasound, we set out to examine this finding systematically in a cohort of patients with CANVAS, and compare them with both healthy controls and a cohort of patients with axonal neuropathy. We have previously reported preliminary findings in seven of these patients with CANVAS and seven healthy controls.

METHODS

We compared the ultrasound cross-sectional area of median, ulnar, sural and tibial nerves of 14 patients with CANVAS with 14 healthy controls and 14 age- and gender-matched patients with acquired primarily axonal neuropathy. We also compared the individual nerve cross-sectional areas of patients with CANVAS and neuropathy with the reference values of our laboratory control population.

RESULTS

The nerve cross-sectional area of patients with CANVAS was smaller than that of both the healthy controls and the neuropathy controls, with highly significant differences at most sites (P < 0.001). Conversely, the nerve cross-sectional areas in the upper limb were larger in neuropathy controls than healthy controls (P < 0.05). On individual analysis, the ultrasound abnormality was sufficiently characteristic to be detected in all but one patient with CANVAS.

DISCUSSION

Small nerves in CANVAS probably reflect nerve thinning from loss of axons due to ganglion cell loss. This is distinct from the ultrasound findings in axonal neuropathy, in which nerve size was either normal or enlarged. Our findings indicate a diagnostic role for ultrasound in CANVAS sensory neuronopathy and in differentiating neuronopathy from neuropathy.

Sensory neuropathy as part of the cerebellar ataxia neuropathy vestibular areflexia syndrome

OBJECTIVE

The syndrome of cerebellar ataxia with bilateral vestibulopathy was delineated in 2004. Sensory neuropathy was mentioned in 3 of the 4 patients described. We aimed to characterize and estimate the frequency of neuropathy in this condition, and determine its typical MRI features.

METHODS

Retrospective review of 18 subjects (including 4 from the original description) who met the criteria for bilateral vestibulopathy with cerebellar ataxia.

RESULTS

The reported age at onset range was 39-71 years, and symptom duration was 3-38 years. The syndrome was identified in one sibling pair, suggesting that this may be a late-onset recessive disorder, although the other 16 cases were apparently sporadic. All 18 had sensory neuropathy with absent sensory nerve action potentials, although this was not apparent clinically in 2, and the presence of neuropathy was not a selection criterion. In 5, the loss of pinprick sensation was virtually global, mimicking a neuronopathy. However, findings in the other 11 with clinically manifest neuropathy suggested a length-dependent neuropathy. MRI scans showed cerebellar atrophy in 16, involving anterior and dorsal vermis, and hemispheric crus I, while 2 were normal. The inferior vermis and brainstem were spared.

CONCLUSIONS

Sensory neuropathy is an integral component of this syndrome. It may result in severe sensory loss, which contributes significantly to the disability. The MRI changes are nonspecific, but, coupled with loss of sensory nerve action potentials, may aid diagnosis. We propose a new name for the condition: cerebellar ataxia with neuropathy and bilateral vestibular areflexia syndrome (CANVAS).

Multiple sclerosis is more prevalent in northern New Zealand than previously reported

BACKGROUND

There have been no studies of multiple sclerosis (MS) prevalence from New Zealand (NZ) in the past two decades, and only one in a northern NZ district. Our impression was that the local prevalence of MS was higher than previously published data would suggest. There is limited access to new treatments for MS in NZ.

AIMS

The present paper aims to: (i). measure the prevalence of definite and probable MS in the Bay of Plenty (BOP), a North Island province, (ii). compare this with previous NZ studies, (iii). study the profile of disability in this population-based group and (iv). determine the proportion of MS patients who receive government funding for modern drug treatment (beta-interferons).

METHODS

Patients were identified from a geographically and demographically defined area of the North Island of NZ, using multiple sources of case ascertainment and modern diagnostic criteria. All clinical records were reviewed and data were supported by a telephone interview. All patients' eligibility for -government-funded treatment with beta-interferon was considered.

RESULTS

Eighty-six patients were identified as residents in BOP, NZ, on 15 January 2001. Excluding 'possible' cases, this represented a prevalence of 50/105 (95% confidence interval 40-62/105). Half of the population-based cohort had a disability defined as 'moderate to severe' (i.e. aids needed to walk, unable to take more than a few steps, or worse). Eleven patients (13%) had a primarily progressive form of MS. Eleven patients (13%) had the relapsing--remitting form of the disease and qualified for -government-funded treatment with beta-interferon.

CONCLUSION

The prevalence of MS in the defined region was twice as high as that reported from an adjacent area, the Waikato, 20 years previous. Our data will help to update NZ prevalence statistics and are of direct relevance to current funding issues for modern treatments which, in NZ, are presently limited to a proportion of patients with relapsing- remitting disease.

Peripheral neuropathy associated with anti-GM2 ganglioside antibodies: clinical and immunopathological studies

GM2 ganglioside is a potential peripheral nerve antigen for neuropathy-associated autoantibodies. However little data are available on their pathogenic effects, if any. In this study we have screened both neuropathy-associated and control sera for anti-GM2 antibodies and subsequently used high titre sera for immunohistological and complement mediated cytotoxicity studies. We identified abnormally elevated anti-GM2 antisera in the normal population, as well as in patients with peripheral neuropathies and other neurological diseases. GM2 antibodies were either mono-reactive, cross-reactive with GM1a, or cross-reactive with GalNAc-GM1b and/or GalNAc-GD1a. All GM2 antisera from neuropathy subjects and normal controls bound to, and were capable of complement-mediated lysis of the NSC-34 cell line which expresses high levels of membrane-associated GM2. However, in immunohistological studies on human and rodent peripheral nervous system tissues, no specific binding was seen with GM2 antisera, either cross-reactive with GalNAc-GM1b and GalNAc-GDla, or with GM1a. These data indicate that although GM2 antisera can lyse neural membranes containing GM2, this antigen(s) is not detectable by standard immunohistological techniques in human or rodent peripheral nerve. This raises doubts about their pathophysiological significance in human autoimmune neuropathy.

Avoiding false positive diagnoses of motor neuron disease: lessons from the Scottish Motor Neuron Disease Register

OBJECTIVES

To describe the frequency and characteristics of those patients initially registered with the Scottish Motor Neuron Disease Register (SMNDR) but who subsequently had a diagnosis other than MND made (false positives), to analyse the features which led to a revised diagnosis, and to draw conclusions which might improve routine neurological practice.

METHODS

The Scottish Motor Neuron Disease Register is a community based, prospective disease register to identify and follow up all incident cases of motor neuron disease in Scotland. Fifty three patients out of a total of 552 registered are presented, who, after initial registration, were later excluded because they failed to satisfy the register's diagnostic criteria.

RESULTS

Seven of these patients were labelled as "MND plus" syndromes and may represent a distinct subset of MND. The remaining 46 patients had an alternative diagnosis made (false positive group), accounting for 8% of the total. In half of these cases, potentially beneficial therapies are available. The predominant reasons which lead to a diagnostic revision were: failure of symptom progression, development of atypical clinical features for MND, and investigation results.

CONCLUSIONS

Patients with MND should undergo thorough and relevant investigations at presentation with the emphasis on neuroradiological imaging and neurophysiology; all patients should be followed up by an experienced neurologist, particularly those in whom symptoms and signs are restricted to either the bulbar or spinal muscles; failure of symptom progression or development of atypical features should lead to an early reassessment; finally, patients should be informed of the diagnosis only when it is secure.

Clinical heterogeneity of familial motor neuron disease: report of 11 pedigrees from a population based study in Scotland. The Scottish Motor Neuron Disease Research Group

Five percent of incident patients with MND in Scotland 1989-1990 had a family history of this disease. This paper assesses the demographic and clinical features of this group.

Motor neuron disease: a disease of old age

There is little information dealing specifically with motor neuron disease (MND) in the elderly. Given current epidemiological trends, geriatricians will be increasingly called upon to diagnose and manage this condition. We report four patients who presented within a six month period to a geriatric medical unit, and place this experience in the perspective of 229 patients from a population-based study of adult-onset MND in Scotland in 1989 and 1990. In 1990 Scotland had a crude annual incidence of MND of 2.25/100,000; the figure for those over 65 is four times greater. MND is more common in men, but the sex ratio was nearly equal over the age of 65. The risk of presenting with bulbar palsy was greater in women, and even higher in elderly women. This, together with increasing age, is the most important negative prognostic factor in MND. Problems with the diagnosis and management of MND in the elderly are highlighted.

Risk factors for motor neuron disease: a case-control study based on patients from the Scottish Motor Neuron Disease Register

In order to identify risk factors for the subsequent development of motor neuron disease (MND) we have carried out a case-control study of incident patients in Scotland, identified using the Scottish Motor Neuron Disease Register. A standard questionnaire was given to 103 patients and the same number of community controls matched on a one to one basis using the general practitioner's (GP) age and sex register. Recall bias was minimised by using GP records to verify the subject's report. There was an overall lifetime excess of fractures in patients, odds ratio (OR) = 1.3 (95% confidence interval (CI), 0.7-2.5) and this was highest in the 5 years before symptom onset (OR = 15, 95% CI, 3.3-654). There was no association with non-fracture trauma but the OR for a manual occupation in patients was 2.6 (95% CI, 1.1-6.3). Both occupational exposure to lead (OR = 5.7, 95% CI, 1.6-30) and solvents/chemicals (OR = 3.3, 95% CI 1.3-10) were significantly more common in patients. No consistent association was found between MND and factors reflecting socioeconomic deprivation in childhood; childhood infections or social class. Our results identify a number of different factors which may contribute to the aetiology of MND.

The prognosis of adult-onset motor neuron disease: a prospective study based on the Scottish Motor Neuron Disease Register

The Scottish Motor Neuron Disease Register (SMNDR) is a prospective, collaborative, population-based project which has been collecting data on incident patients since 1989. In this report we present the clinical features of 229 patients with motor neuron disease (218 sporadic and 11 familial) diagnosed in 1989 and 1990 and compare their prognosis with previous studies of survival. The overall 50% survival from symptom onset was 2.5 years (95% CI, 2.2-3.0) and 5-year survival 28% (95% CI, 20-36%). The presence of progressive bulbar palsy (PBP), either at presentation or developing during the course of the illness, significantly reduced survival and was the most important prognostic indicator. Patients who survived longer than 5 years from symptom onset did not have PBP as part of their presenting illness. The prognosis was worse for women, and this was in part related to the higher frequency of PBP in older women, but age was also an independent adverse risk factor. Differences in survival between this and previous series can probably be explained on the basis of variation in case definition and ascertainment methods.

Utility of Scottish morbidity and mortality data for epidemiological studies of motor neuron disease

OBJECTIVES

To determine the accuracy of (1) hospital discharge data and (2) death certificates, coded as motor neuron disease (MND).

DESIGN

Comparison of data from The Scottish Motor Neuron Disease Register (SMNDR) with routinely collected Scottish Hospital In-Patient Statistics (SHIPS) and death certificate coding.

SETTING

Scotland UK.

PATIENTS

1) 379 adults (> 15 years) discharged for the first time from a Scottish hospital in 1989-90 and (2) 281 deaths in the same period assigned to the International Classification of Diseases (ICD)-9, category 335 (MND).

MAIN OUTCOME MEASURES

The sensitivity and positive predictive value of a diagnosis of MND as retrieved by (1) the Information and Statistics Division of the Common Services Agency for the Scottish Health Service for morbidity data and (2) the Registrar General's office for mortality data, using the SMNDR as the 'gold standard'.

RESULTS

(1) Thirty per cent of adult patients identified as having MND by SHIPS did not have this disease and 23% of patients with MND did not appear on SHIPS. The sensitivity of a diagnosis of MND, as retrieved by SHIPS, was 84% and the positive predictive value was 70% overall. Miscoding of patients with pseudobulbar palsy caused by cerebrovascular disease was the major source of false positive error. The incidence of adult onset sporadic MND was over estimated by SHIPS by a factor of 1.6. (2) Mortality data were more accurate, with a false negative rate of 6% and a positive predictive value of 90%.

CONCLUSIONS

Coded hospital discharge data are an inaccurate record of a diagnosis of MND and cannot, in their present form, be used as a reliable measure of disease incidence in Scotland. Greater care is required in the preparation of discharge summaries and coding if these data are to be useful for health care planning and epidemiological research. SHIPS is, however, an important source of information to achieve a complete sample of patients with MND. There is also a problematic false positive rate for mortality data but this source more closely approximates true incidence.

Antiglycolipid antibodies, immunoglobulins and paraproteins in motor neuron disease: a population based case-control study

The role of humoral autoimmune factors in the pathogenesis of motor neuron disease (MND) is currently under considerable scrutiny. In particular, there have been many reports of abnormal serum immunoglobulin patterns and elevated titres of anti-ganglioside antibodies in patients with MND. However, many of these studies may be biased by the selection criteria for patients and controls. In order to carefully address this issue we obtained 82 blood samples from consecutive MND patients identified through a national MND register in combination with 82 community controls matched for age, sex and geographical area. We used these samples to determine the frequency of monoclonal immunoglobulins (mIgs) and measure the levels of serum immunoglobulins and anti-GM1 ganglioside antibodies in sporadic cases of MND in comparison with normal controls. Serum mIgs detected using high resolution and immunofixation agarose electrophoresis were present in 1.2% of MND patients and 2.4% of controls. Using a highly sensitive isoelectric focusing and immunoblotting method, monoclonal or oligoclonal immunoglobulins were found in 28% of MND patients and 27% of controls. Anti-GM1 antibodies were present in 26% of MND patients and 18% of controls (odds ratio = 1.5, 95%, CI 0.7-3.6) with no significant differences in titres between the 2 groups. Mean immunoglobulin G, A and M levels were equal in 2 groups. Thus, although alterations in these parameters were identified, we were unable to demonstrate any significant difference between MND patients and controls. We conclude that the majority of sporadic cases of MND are unlikely to have an autoimmune basis as judged by the lack of abnormalities in these parameters.

Adult onset motor neuron disease: worldwide mortality, incidence and distribution since 1950

This review examines the commonly held premise that, apart from the Western Pacific forms, motor neuron disease (MND), has a uniform worldwide distribution in space and time; the methodological problems in studies of MND incidence; and directions for future epidemiological research. MND is more common in men at all ages. Age-specific incidence rises steeply into the seventh decade but the incidence in the very elderly is uncertain. A rise in mortality from MND over recent decades has been demonstrated wherever this has been examined and may be real rather than due to improved case ascertainment. Comparison of incidence studies in different places is complicated by non-standardised methods of case ascertainment and diagnosis but there appear to be differences between well studied populations. In developed countries in the northern hemisphere there is a weak positive correlation between standardised, age-specific incidence and distance from the equator. There is now strong evidence for an environmental factor as the cause of the Western Pacific forms of MND. A number of clusters of sporadic MND have been reported from developed countries, but no single agent identified as responsible.

Neurological disease associated with anticardiolipin antibodies in patients without systemic lupus erythematosus: clinical and immunological features

Anticardiolipin antibodies (aCL), one of a group of antiphospholipid antibodies which include the lupus anticoagulant (LA), may occur in association with systemic lupus erythematosus (SLE) and are less commonly detected in other diseases. We retrospectively reviewed the clinical and immunological features of 39 consecutive patients with abnormal aCL identified by one laboratory, to examine the spectrum of neurological disease in those patients without SLE. Fourteen patients in this category are described, 6 of whom did not have evidence of LA. All but 1 presented with neurological symptoms. Stroke and migraine dominated the clinical presentation, but many patients had features to suggest the presence of a hypercoagulable state. This study lends support to the concept of a primary antiphospholipid syndrome.

Migraine occurring for the first time in pregnancy

Nine patients referred for neurological opinion over a 4 yr. period were identified as having migraine occurring for the first time with pregnancy. The nature of their attacks, results of investigation, the progress of the pregnancy and the prognosis for headache post-partum are presented. One patient had common migraine, the remainder, either classical or complicated attacks. Patients presented at variable stages of pregnancy; four developed complications, including pre-eclamptic toxemia in two. The prognosis for headache during the follow up period of up to 54 months was excellent. The factors influencing migraine in pregnancy are discussed.

Adrenoleukodystrophy: manifestations of a protean disorder: report of a recently identified kindred

Adrenoleukodystrophy is an inherited metabolic disorder resulting in accumulation of fatty acids in body tissues, principally the central nervous system. We report a recently identified kindred with this disease to highlight the varied clinical manifestations and recent advances in diagnosis and treatment.

Etiology, prognosis, and hemostatic function after cerebral infarction in young adults

We retrospectively evaluated 66 patients younger than 40 years of age who presented with acute nonhemorrhagic cerebral infarction (n = 63) or transient ischemic attacks (n = 3) to determine the possible etiology and long-term outcome at a mean follow-up interval of 3 years after initial presentation. A probable cause for the stroke was identified in 24 patients (36%); this group included one woman with a history of recurrent spontaneous abortions and a positive test for the presence of the lupus anticoagulant. We performed detailed hemostatic investigations at follow-up in 38 (90%) of the remaining 42 patients in whom the cause of the stroke was unknown or uncertain; results of the basic hemostatic screening tests (including that for fibrinogen) were uniformly normal. All 38 patients demonstrated a normal fibrinolytic response as measured by tissue plasminogen activator release to a standard venous occlusion stress test; concentration of the inhibitor of tissue plasminogen activator was not increased. No abnormalities in the concentrations of the inhibitory proteins C or S or antithrombin III were identified, and none of the 38 patients had evidence of a lupus anticoagulant. Neurologic recovery was complete or the residual disability mild in 46 of 59 (78%) patients. Overall prognosis was excellent and independent of whether a precipitating factor for the stroke could be identified.

Somatosensory evoked potentials following severe head injury: loss of the thalamic potential with brain death

The thalamic component (P17) of the short-latency somatosensory evoked potential (SEP) was assessed to determine its usefulness in patients with severe head injury. Subjects were a group of patients admitted to the Auckland Hospital Critical Care Unit who subsequently died from head injury. In all instances where brain death was unequivocally established and a SEP recording made in close temporal proximity to the time of brain death the P17 potential was absent. When there was evidence of continuing brainstem activity and particularly where prolonged survival occurred following the last SEP recording the P17 potential remained intact bilaterally. This study shows that the presence or absence of the thalamic component of the short-latency SEP provides a reliable electrophysiological measure of brainstem function in patients where brain death has been suspected.

Patent foramen ovale in young stroke patients

The prevalence of patent foramen ovale in patients presenting with non-haemorrhagic stroke or transient ischaemic attacks under the age of 40 years was determined by contrast echocardiography. Studies were performed at rest and with a Valsalva manoeuvre in 40 stroke patients and in an age and sex matched control group. Right-to-left shunting was found in 20 (50%) of the stroke patients and 6 (15%) of the controls (p less than 0.001). Paradoxical embolism through a patent foramen ovale may be an under-recognised cause of stroke in young adults.

Recovery from parainfectious encephalomyelitis

Two patients developed encephalomyelitis following an upper respiratory tract illness presumed to be of viral cause. Both presented with evidence of severe diffuse brain disease and spinal cord involvement. From an apparently devastating illness both completely and rapidly recovered.

A clinical and aetiological study of adult patients hospitalised for acute diarrhoeal disease

Sixty adult patients with diarrhoea discharged from the infectious disease unit, Auckland Hospital in the 15 months from 1 January 1980 were reviewed. Thirty had diarrhoea due to enteric organisms (Campylobacter fetus 8, Shigella 6, Salmonella typhi 4, Salmonella typhimurium 4, Clostridium difficile causing pseudomembranous colitis 3). Other diagnoses included ulcerative colitis and a colonic carcinoma. Eighteen had no specific diagnosis. Combinations of admission fever, faecal leucocytes and leucocytosis increased the likelihood of definitive diagnosis as did prolonged diarrhoea (less than five days) in hospital. A median 3 stools per patient was examined microbiologically: in only six did a second positive follow an initial negative specimen. We now recommend only two stool specimens be examined routinely for diagnosis of enteric bacterial infection. Antibacterial drugs are infrequently needed for adult enteric bacterial diarrhoea (we treated five of 23 in hospital). Local practitioners also manage adult diarrhoea conservatively with only six of 60 patients taking antibacterials as treatment for their diarrhoea before admission.