Alterations in resting-state network dynamics along the Alzheimer's disease continuum

Human brain activity is intrinsically organized into resting-state networks (RSNs) that transiently activate or deactivate at the sub-second timescale. Few neuroimaging studies have addressed how Alzheimer's disease (AD) affects these fast temporal brain dynamics, and how they relate to the cognitive, structural and metabolic abnormalities characterizing AD. We aimed at closing this gap by investigating both brain structure and function using magnetoencephalography (MEG) and hybrid positron emission tomography-magnetic resonance (PET/MR) in 10 healthy elders, 10 patients with subjective cognitive decline (SCD), 10 patients with amnestic mild cognitive impairment (aMCI) and 10 patients with typical Alzheimer's disease with dementia (AD). The fast activation/deactivation state dynamics of RSNs were assessed using hidden Markov modeling (HMM) of power envelope fluctuations at rest measured with MEG. Correlations were sought between temporal properties of HMM states and participants' cognitive test scores, whole hippocampal grey matter volume and regional brain glucose metabolism. The posterior default-mode network (DMN) was less often activated and for shorter durations in AD patients than matched healthy elders. No significant difference was found in patients with SCD or aMCI. The time spent by participants in the activated posterior DMN state did not correlate significantly with cognitive scores, nor with the whole hippocampal volume. However, it correlated positively with the regional glucose consumption in the right dorsolateral prefrontal cortex (DLPFC). AD patients present alterations of posterior DMN power activation dynamics at rest that identify an additional electrophysiological correlate of AD-related synaptic and neural dysfunction. The right DLPFC may play a causal role in the activation of the posterior DMN, possibly linked to the occurrence of mind wandering episodes. As such, these data might suggest a neural correlate of the decrease in mind wandering episodes reported in pathological aging.

[An update on treatment of dementia and Alzheimer's diseases?]

Major and minor neurocognitive disorders are common and increase with age. In the 70s, similarities between " senile " and " presenile " dementia led to their homogenization in a unique illness, the Alzheimer's disease. Systematic specific psychosocial support of patients and caregivers is crucial and allows to discuss an advance care plan. We propose such a multidisciplinary program and discuss some of them. Various drugs and a variety of possible physiopathogenic targets are actually studied and should in the near future offer new therapeutics in dementia and Alzheimer's disease.

[Signs and symptoms of major neurocognitive disorders]

Cognitive disorders are a common problem, especially for older people. Dementia, recently renamed "major neurocognitive disorder" in DSM-5 is a complex subject. Age, vascular risk factors, subjective decline and its objectivation, are all risk factor for such neurocognitive disorders. Face to minor neurocognitive disorder, decline seemed more associated with the presence of structural atrophy or functional metabolic modification. It seems however more and more clear that, at least actually, such a diagnosis should not be done as early as possible but well timely and individually correct. This patient-centred approach requires the peculiar involvement of its familial, general physician. But when early detection tools will be used, for any legitimate reason, it will also be important to address specialized teams. In case of neurocognitive disorders, particularly major, psychoeducative programs are the most effective therapeutic on both patient and caregiver qualities of live. Such multidisciplinary program of care for patients with neurocognitive disorder and his/her caregiver has just obtained a financial agreement via the specific protocol 3 and should be known to be efficient.

[Dementia, end of life and euthanasia]

Among legislative criteria granting the right to practice euthanasia or assisted suicide, there are systematically four major elements. Precisely, any request must be voluntary, persistent, to be well thought and well informed. Such euthanasia raises numerous difficult questions in case of dementia. It also justifies thinking about possibilities that can offer specific arrangements of anticipated demands in such peculiar cases. Empirical experiences show us that it applies with difficulties in practice. Finally, to avoid that a big majority of these demands would find themselves not applied in practice, it would certainly be necessary to add to it structural valuation of advance care planning, and assure its recognition and development. These should not be limited to a single pathological target but would address all of us to increase advance care planning initiation, which remains the most limiting factor of such any early but continuous procedure.

[Biomarkers of the Alzheimer's disease: concepts and clinical case]

Concepts and knowledge evolve gradually our ways of diagnosing and treating many diseases, but also our views and some kind of stigmatization that could be associated with them. Alzheimer's disease seems to evolve over several years before leading any perceptible clinical sign. To redefine its semantics seems thus essential. This way, new diagnostic criteria should allow refining diagnosis in case of dementia but also and especially before the apparition of any clinical manifestations or in case of mild suggestive cognitive disorders. Moreover, they allow, in case of other cognitive disorders presentations (aphasia or apraxia), diagnosing its unusual atypical form. However, the possibility that they also offer to set such diagnosis of Alzheimer's disease to people who do not present any slights clinical signs raises numerous ethical considerations, especially in view of the current absence of curative treatment. Noteworthy that, in theory, a biomarker is the objective indicator of a biological process associated with the pathogenicity. In Alzheimer's disease, pathogenicity and scientific bases to propose these biomarkers remains at least controversial. All of these crucial questions leading to their exclusive use by team specialized in their practices and interpretations. An exemplary clinical case is presented.

The Addenbrooke's Cognitive Examination Revised is as effective as the original to detect dementia in a French-speaking population

INTRODUCTION

This paper presents the validation of the French version of the Addenbrooke's Cognitive Examination Revised (ACE-R).

METHODS

The variability of the 3 versions of the ACE-R (A, B and C), performed by the same observer, hence mainly 2 or 3 times on 119 patients showing no progression, was first calculated by Cronbach's alpha coefficient, t test and linear regression. The alpha coefficients of the 3 versions were obtained showing that the ACE-R versions can be considered as one, and an analysis of the interobserver variability was performed by Cohen's kappa coefficient, t test and linear regression on 12 patients. Eventually, we performed a receiver operating characteristic (ROC) analysis to compare the sensitivities and specificities to detect dementia of the ACE, the ACE-R and Mini Mental State Examination on 319 consecutive patients.

RESULTS

The ROC areas of sensitivities and specificities of the ACE and ACE-R were very similar. Two cutoffs were identified at 83/100 and 89/100 with a specificity to normality of 98.6% if the ACE-R score was ≥83 and a sensitivity to dementia of 98.4% if the ACE-R score was ≤89.

CONCLUSION

ACE-R in French is as reliable and valid as the original version to detect dementia.

[Evaluation of our psycho-educative program by participating caregivers]

Facing difficulties due to dementia syndromes, systemic care is necessary. Amongst therapies assessed specifically to caregivers, psychoeducative steps seem to be the strongest effective one on neuropsychiatrics symptoms. Psychoeducations tend to teach the caregivers to modify their interactions with patients via a better understanding of illnesses and patients. Our training "Pour mieux vivre avec la maladie d'Alzheimer", applied in groups of eight to twelve persons, consists in twelve sessions of two hours each. To assure the biggest possible availability, we recently incorporated the concomitant coverage of patients into artistic workshops. These sessions of art-therapy realized in parallel to our psychoeducative program will thus be estimated according to the same rigorous methodology. The critical evaluations realized by participants at the end of our program reflect the outcome of our main objective (to teach to modify interactions with the patients) while contributing to the improvement of social contacts and to the learning of calling to existing helps. These preliminary results strongly argue for the pursuit and even extension of this kind of caregiver's management.

[New promising caregiver's psychoeducation training program: a Belgian experience in dementing disorders]

Facing difficulties due to dementia syndromes, systemic care is necessary. But nevertheless, caregivers are generally lacking in medical welfare. Therapies assessed specifically to caregivers are missing. Amongst these, psychoeducative steps seem to be the strongest effective's one on neuropsychiatrics symptoms. Psychoeducations tend to learn to caregivers to modify their interactions with patients via a better understanding of illnesses and patients. Our training "Pour mieux vivre avec la maladie d'Alzheimer ", done in groups of eight to twelve persons, is constituted of twelve sessions of two hours each. Complete formation includes behavioural and cognitive aspects of the disease and proposes some multidimensional approach which content at least pedagogical, psychological and cognitivo behavioural aspects. We illustrate here with the use of two peculiar cases that our program can reach its objectives. These preliminary results strongly argue for the pursuit and even extension of this kind of caregiver's management.

[An unusual hospitalization under constraint]

The case report describes a 45-year old man presenting of the behavioral problems and an aphasia of Wernicke, hospitalized under constraint. The urinary screening in the search of psychotropic substances is positive for the cannabis and the amphetamines. The neurological localization is confirmed by cerebral CT-scan. The discussion relates on the differential diagnosis between a schizophasia and an aphasia of Wernicke, on the difficulty of a somatic diagnosis among patients agitated under the effect of a drug and to the tendency to hospitalize those too quickly under constraint, on the noxious effect of drugs on the brain.

[Misdiagnosis of sinus thrombosis with reversible posterior leucoencephalopathy]

Reversible posterior leucoencephalopathy and cerebral venous thrombosis share many symptoms. Both of them may lead to coma, and cause epilepsy or focal neurological signs. Moreover, diffuse leucoencephalopathy can be observed in both cases. Cerebral venous thrombosis needs anticoagulation which is not a riskless treatment. We describe a case of reversible posterior leucoencephalopathy in an hypertensed, seventy-year old man, presenting with a left lateral sinus hypoplasia whose clinical history and paramedical results first suggested a cerebral veinous thrombosis. Our case shows the misleadings a congenital vascular asymmetry can induce when confronted with a subacute coma.

The French Addenbrooke's cognitive examination is effective in detecting dementia in a French-speaking population

We evaluated the sensitivity and specificity of our French version of Addenbrooke's cognitive examination (ACE) to detect dementia in our patient population. One hundred and fifty-eight cases were included in the study. In our patient series, the sensitivity for diagnosing dementia with a Mini-Mental State Examination (MMSE) score of < or = 24/30 was 48.5%, the sensitivity of an MMSE score of < or = 27/30 was 82.5% with a specificity of 72.1%, the sensitivity of an ACE score of < or = 83/100 was 86.6% with a specificity of 70.5% and the sensitivity of an ACE score of < or = 88/100 was 97.9% with a specificity of 59%. We conclude that the French version of the ACE is a very accurate test for the detection of dementia, and should be widely used in clinical practice.

Could visual neglect induce amblyopia?

Oculomotor nerve disease is a common cause of diplopia. When strabismus is present, absence of diplopia has to induce the research of either uncovering of visual fields or monocular suppression, amblyopia or blindness. We describe the case of a 41-year-old woman presenting with right oculomotor paresis and left object-centred visual neglect due to a right fronto-parietal haemorrhage expanding to the right peri-mesencephalic cisterna caused by the rupture of a right middle cerebral artery aneurysm. She never complained of diplopia despite binocular vision and progressive recovery of strabismus, excluding uncovering of visual fields. Since all other causes were excluded in this case, we hypothesise that the absence of diplopia was due to the object-centred visual neglect. Partial internal right oculomotor paresis causes an ocular deviation in abduction; the image being perceived deviated contralaterally to the left. Thus, in our case, the neglect of the left image is equivalent to a right monocular functional blindness. However, bell cancellation test clearly worsened when assessed in left monocular vision confirming that eye patching can worsen attentional visual neglect. In conclusion, our case argues for the possibility of a functional monocular blindness induced by visual neglect. We think that in presence of strabismus, absence of diplopia should induce the search for hemispatial visual neglect when supratentorial lesions are suspected.

Infectivity of Plasmodium falciparum gametocytes in patients attending rural health centres in western Kenya

BACKGROUND

Experimentally studying the transmission of the malaria parasite and its regulating factors requires availability of human blood donors carrying infectious gametocytes. The difficulty of identifying gametocyte carriers from the community is often limited due to financial and human resources constraints. The available alternative is rural health centres where malaria patients go for treatment. In this study, the potential of recruiting volunteers and acquiring infectious blood for experimental infections from rural health centers in malaria endemic area was examined through routine patient diagnosis.

OBJECTIVE

To examine the patients presenting at rural health centers for the potential to carry sexual stage malaria parasite and test their infectivity to Anopheles gambiae mosquitoes.

SETTING

Mbita Health Centre, Mbita Town Ship, Suba District, western Kenya.

METHODOLOGY

Routine survey of all patients attending Mbita Health Centre with suspected malaria. Patients were examined for Plasmodium falciparum trophozoites and gametocytes. Gametocyte-positive volunteers were recruited for their potential to infect Anopheles mosquitoes via membrane feeding.

RESULTS

Three thousand nine hundred and eighty seven patients were screened between May 2000 and April 2001. Plasmodium falciparum was the predominant parasite species and P. malariae being the only minor species, accounting for 0.9% of malaria cases. Clinical malaria varied with age and prevailed throughout the year with a slight seasonality. Gametocyte prevalence was low (0.9-6.6%), and gametocyte densities were generally very low with a geometric mean of 39 gametocytes per microl blood. Children aged > 5 years constituted 67% of all gametocyte carriers. Only 22 volunteers with mean gametocytes density of 39.62 per microl blood (range: 16-112) were recruited for study of parasite infectiousness to laboratory-reared mosquitoes. Only two patients infected 1% of 1099 mosquitoes with one or two oocysts.

CONCLUSION

The low gametocyte densities or other possible host and vector related factors regulating infectivity of gametocyte carriers to mosquitoes may have caused the poor infections of mosquitoes. This study indicates that rural health centers in malaria-endemic areas may not be suitable for recruiting infectious gametocyte donors for studies of vector competence. They are suitable for passive clinical case surveillance and for evaluation of the effects of control measures.

[Memantine (Ebixa), glutaminergic modulator]

Alzheimer's disease (AD) is the most common etiology of dementia. Its incidence increases with age following an exponential trend of line between 60 and 90 years old. Anti-cholinesterasic drugs reduce modestly AD symptoms. However, they have no basic impact on the pathological evolution of the disease. Memantine offers another therapeutic approach in AD with a dissimilar mechanism of action, confronting neurotoxic effects of glutamate overload. It prevents the elevation of glutamate which destroys cholinergic neurons by inhibiting the N-methyl-D-aspartate (NMDA) receptors. Its clinical efficiency has been demonstrated during 28 weeks with 20 mg/day, in patients presenting moderate or severe AD and mild or moderately vascular dementia. Its use in association with anti-cholinesterasic (donepezil) revealed more interesting results with a significant improvement of cognitive functions and activities of daily live, compared to association placebo-donepezil. We are waiting for results of further lenghter studies, including more, well-defined, patients.

Is the Addenbrooke?s Cognitive Examination effective to detect frontotemporal dementia?

We evaluated the Addenbrooke's cognitive examination (ACE), a simple instrument to differentiate frontotemporal dementia (FTD) from Alzheimer's disease (AD), in our dementia patients clinic population. The Verbal-Language/Orientation-Memory (VLOM) ratio, which compares its language and memory scores, determines whether FTD or AD is more likely. The ACE was translated into French with adaptation maintaining the number of words in the name and address learning and delayed recall test, and with cultural adaptation for the semantic memory. The 85 included subjects had no evidence of two or more organic pathologies, after at least six months of follow-up, and an MMSE score>or=20/30. Patients with cognitive impairment due to alcohol intake were excluded. The diagnosis of a specific dementing illness was based on the consensus of the neurologist and neuropsychologists in the team. Thereafter, another neurologist expert in dementia, blinded to the ACE result and to the diagnosis and treatment, reviewed all cases files and proposed a diagnosis. A diagnostic agreement was reached for 79 cases (92.9%) with 40 (50.6%) dementia: 25 AD (62.5 %), 9 FTD (22.5 %). We estimated that the sensitivity for detecting dementia of an ACE score<or=83/100 was 90% with a specificity of 64.1%. When the ACE score was<or=88/100, the sensitivity for diagnosing FTD of a VLOM ratio<2.2 was 11.1% with a specificity of 88 % and the sensitivity for diagnosing AD of a VLOM ratio>3.2 was 72%,with a specificity of 69.4%. We conclude that, when used as originally proposed, ACE is very accurate for the detection of dementia, but much less effective in discriminating the most common frontal variant of FTD.

Antiphospholipid antibodies and ischemic neuropathy following cardiac surgery

Sciatic nerve palsy is an uncommon complication of cardiac surgery and is thought to be induced by a combination of reduced femoral artery blood flow, small vessel vascular disease or prolonged hypoxia. We here describe a new case which is the first described with transient elevation of antiphospholipid antibodies. Although transient elevation of lupus coagulation inhibitor is known to occur frequently in patients treated in an intensive care unit, there are very few data about the possible role of antiphospholipid antibodies in the generation of ischemic neuropathies. We can not prove that the ischemic neuropathy in our case has been favored by the presence of lupus coagulation inhibitor and antiphospholipid antibodies as the occurrence of the symptoms seemed to precede the transient elevation of lupus coagulation inhibitor. This case suggests that antiphospholipid antibodies and lupus coagulation inhibitor should be included in the work up of patients who present nerve damage after cardiac surgery but further studies are needed to ascertain this association.

Effects of the oral form of ondansetron on cerebellar dysfunction. A multi-center double-blind study

The aim of this study was to assess the efficacy and the safety of ondansetron administered orally in patients with a cerebellar disorder. The study was a randomised, multi-center, double-blind trial. The patients were randomised either to oral ondansetron 8 mg or to placebo twice daily for seven days. Cerebellar dysfunction was quantified before and after treatment using the International Cooperative Ataxia Rating Scale (ICARS). We performed a global analysis (total scores), we analysed by subscores (4 subscores: oculomotor, speech, kinetic, postural) and subgroups (4 subgroups: Cerebellar Cortical Atrophy (CCA), Multiple Systemic Atrophy (MSA), Familial Cerebellar Degeneration (FCD) and miscellaneous cerebellar disorders), and we also performed an analysis by individual test items. We investigated whether ondansetron and placebo had different effects upon ICARS total scores and subscores in the 4 subgroups considered together or separately. For p values < 0.05, we subsequently applied the Mann-Whitney test to compare ondansetron and placebo effect for each individual item. We evaluated 45 of the 46 patients included. No effect was found in global analysis. We found no difference in the analysis of the ICARS subscores. Concerning the individual test items, there was a significant difference between the placebo and ondansetron for the finger-to-nose test (p = 0.049), the Heel-to-Knee test (HK); (p = 0.03), the Body Sway Eyes Closed (p = 0.017) and the Body Sway Eyes Open (BSEO); (p = 0.014). There was no significant difference for tremor in upper limbs (p = 0.32) or for gait (p = 0.49). The Mann-Whitney test showed a greater effect of ondansetron than placebo for BSEO in miscellaneous disorders (p = 0.013) and for HK in FCD (p = 0.036), but ondansetron was deleterious for HK in CCA (p = 0.019). Our study showed no effect of oral ondansetron on global cerebellar dysfunction. The analysis by subgroups showed that the oral form of ondansetron (a) is deleterious for coordination in patients with CCA, (b) has no effect upon tremor in upper limbs, and (c) has a mild effect upon posture and coordination in lower limbs in some subgroups of ataxic diseases.

[Frontal dementia or dementia praecox? A case report of a psychotic disorder with a severe decline]

INTRODUCTION

Many authors have described these last years the difficulty to establish a differential diagnosis between schizophrenia and frontotemporal dementia. However treatment and prognosis of these two separate diseases are not the same. Schizophrenia is a chronic syndrome with an early onset during teenage or young adulthood period and the major features consist of delirious ideas, hallucinations and psychic dissociation. However a large variety of different symptoms describes the disease and creates a heterogeneous entity. The diagnosis, exclusively defined by clinical signs, is then difficult and has led to the research of specific symptoms. These involve multiple psychological processes, such as perception (hallucinations), reality testing (delusions), thought processes (loose associations), feeling (flatness, inappropriate affect), behaviour (catatonia, disorganization), attention, concentration, motivation (avolition), and judgement. The characteristic symptoms of schizophrenia have often been conceptualised as falling into three broad categories including positive (hallucination, delision), negative (affective flattening, alogia, avolition) and disorganised (poor attention, disorganised speech and behaviour) symptoms. No single symptom is pathogonomonic of schizophrenia. These psychological and behavioural characteristics are associated with a variety of impairments in occupational or social functioning. Cognition impairments are also associated with schizophrenia. Since the original clinical description by Kraepelin and Bleuler, abnormalities in attentional, associative and volitional cognitive processes have been considered central features of schizophrenia. Long term memory deficits, attentional and executive dysfunctions are described in the neurocognitive profile of schizophrenic patients, with a large degree of severity. The pathophysiology of schizophrenia is not well known but may be better understood by neuronal dysfunctions rather than by a specific anatomical abnormality. Frontotemporal lobar degeneration (FTLD) is one of the most common causes of cortical dementia. FTLD is associated with an anatomical atrophy that can be generalised, with a frontotemporal or focal lobar predominance. Histologically there is severe neuronal loss, gliosis and a state of spongiosis. In a minority of case Pick cells and Pick bodies are also found. The usual clinical features of FTLD are divided in three prototypic syndromes: frontotemporal dementia (FTD), progressive non-fluent aphasia (PA) and semantic dementia (SD). FTD is the most common clinical manifestation of FTLD. FTD is first characterised by profound alteration in personality and social conduct, characterised by inertia and loss of volition or social disinhibition and distractibility. There is emotional blunting and loss of insight. Speech output is typically economical, leading ultimately to mutism, although a press of speech may be present in some overactive, disinhibited patients. Memory is relatively preserved in the early stage of the disease. Cognitive deficits occur in the domains of attention, planning and problems solving, whereas primary tools of language, perception and spatial functions are well preserved. PA is an initial disorder of expressive language, characterised by effortful speech production, phonologic and grammatical errors. Difficulties in reading and writing also occur but understanding of word meaning is relatively well preserved. In SD a severe naming and word comprehension impairment occur on the beginning in the context of fluent, effortless, and grammatical speech output. There is also an inability to recognise the meaning of visual percepts. The clinical syndromes of FTLD are associated with the brain topography of the degeneration. So considerable clinical overlap can exist between schizophrenia and FTLD and the object of the following case report is to remind the difficulty to make a differential diagnosis between these two pathologies.

CASE REPORT

A 34 year old non-married man is admitted in mental health district of a general hospital for behavioural disturbances that include repeated aggressions towards his family. At initial interview visual and auditives hallucinations are described. The patient doesn't care about these abnormalities and a poverty of speech is observed. The affects, globally blunted, show some degree of sadness however. The patient's birth and early development were unremarkable. At the age of 26, the patient dismissed from his job because of poor performance and absenteeism. He spent a lot of time watching TV, showed poverty of speech and become sometimes angry and violent without an explanation. He was hospitalised for several months and a schizophrenia including predominant negative features, hallucinations and delusion was diagnosed. He was treated with bromperidol, could go back to home and was followed by a general practitioner for 8 years. The patient had a stereotyped way of life during these years with a poor communication and little activity. During the months preceding the current hospitalisation, these characteristics and avolition emphasised, urinary incontinence appeared. The patient receives risperidone 8 mg/day associated with citalopram 40 mg/day during several months of hospitalisation. No significant evolution is observed regarding apathic and stereotyped way of live. The capacity of communication remains very poor. Neurocognitive assessments reveal multiple and severe dysfunctions. Memory, executive and attentional tasks are extremely disturbed. Physical and neurological examinations reveal an isolated bilateral Babinski sign. Cerebral scanner and magnetic resonance show bifrontal atrophy and PET scan is normal. There are no significant abnormalities found on blood and urine samples and on lumbar puncture. The patient is sent to a chronic neuropsychiatric hospital and the treatment is stopped. One year later, a comparative evaluation is realised. The general clinical state shows no evolution. Neurocognitive assessments are repeated and severe dysfunctions are observed with more perseverations.

DISCUSSION

A diagnosis of FTLD for this patient can be discussed regarding clinical features, neurocognitive testings and neuroradiological findings. Schizophrenia is a major differential diagnosis. Psychotic symptoms like hallucinations and age of onset are essential observations for the diagnosis of schizophrenia but can not exclude FTLD. Memory, intellectual functions, executive and attentional abilities may all be disturbed in schizophrenia and FTLD. Cerebral abnormalities well established in schizophrenia are lateral ventricles enlargements. Frontal lobar atrophy is a major argument for FTLD and is only a sporadic finding in schizophrenic populations. Schizophrenia and FTLD could be comorbid diseases by several ways.

CONCLUSION

A differential diagnosis between schizophrenia and FTLD is difficult to establish. Schizophrenia is a heterogeneous disease with a large variety of cognitive dysfunctions. Neurocognitive tools may improve our knowledge of schizophrenia.

The cerebellum may be directly involved in cognitive functions

Neuropsychological deficits may occur in infratentorial strokes. Only minor cognitive disturbances are reported in unilateral anterior cerebellar lesions. Here, the authors describe a patient with bilateral anterior ponto-cerebellar ischemic lesions associated with major neuropsychological deficits. Cerebral PET and SPECT demonstrated no metabolic defect in supratentorial areas.

[Encephalomyelopathy associated with monoclonal gammapathy]

We describe the case of a patient with a particular form of presumably immune-mediated encephalomyelitis associated with a monoclonal cold agglutin gammapathy. Systematic autopsy showed predominantly demyelinating lesions of the brain and spinal cord. The lesions were assumed to be the immune-mediated consequences of the underlying hematologic condition. Similarity with certain paraneoplastic syndromes is underlined.