MSA: From basic mechanisms to experimental therapeutics.

Multiple system atrophy (MSA) is a rare and fatal neurodegenerative disorder characterized by rapidly progressive autonomic and motor dysfunction. Pathologically, MSA is mainly characterized by the abnormal accumulation of misfolded α-synuclein in the cytoplasm of oligodendrocytes, which plays a major role in the pathogenesis of the disease. Striatonigral degeneration and olivopontecerebellar atrophy underlie the motor syndrome, while degeneration of autonomic centers defines the autonomic failure in MSA. At present, there is no treatment that can halt or reverse its progression. However, over the last decade several studies in preclinical models and patients have helped to better understand the pathophysiological events underlying MSA. The etiology of this fatal disorder remains unclear and may be multifactorial, caused by a combination of factors which may serve as targets for novel therapeutic approaches. In this review, we summarize the current knowledge about the etiopathogenesis and neuropathology of MSA, its different preclinical models, and the main disease modifying therapies that have been used so far or that are planned for future clinical trials.

New Radiologic Findings of Hypertrophic Olivary Degeneration in 2 Patients with Brainstem Lymphoma.

BACKGROUND: Hypertrophic olivary degeneration (HOD) is a rare neurological condition of trans-synaptic degeneration caused by disruption of the dentatorubro-olivary pathway. We present new radiologic findings of HOD in 2 cases of brainstem lymphoma. CASE DESCRIPTION: A 35-year-old woman (Case 1) and a 69-year-old man (Case 2) presented with remarkably similar clinical courses. The primary lesion was located at the dorsal pons extending to the midbrain. Pathologic diagnosis of diffuse large B-cell lymphoma was obtained after surgical resection. Complete remission of the primary lesion was achieved by treatment with 3 courses of high-dose methotrexate and radiotherapy. Arterial spin-labeling and T2-weighted imagings showed high signal intensity in the inferior olive (IO) at some time after the operation. Slight contrast enhancement in the IO was also found in Case 1. These radiologic findings nearly misled us into a diagnosis of recurrence of lymphoma. Signal intensity in the IO on arterial spin-labeling imaging changed with time. Normalized regional cerebral blood flow (rCBF) in the IO was defined as a percentage of rCBF to the global cerebral blood flow calculated using automated software. Chronologic change in normalized rCBF in the IO revealed a large peak in Case 1, but only a mild increase in Case 2. Neurological findings demonstrated severe oculopalatal tremor in Case 1 and mild palatal tremor in Case 2. CONCLUSIONS: Hyperperfusion and contrast enhancement in the IO were found in 2 patients with HOD. These findings may be confused with recurrence of malignant tumor.

Converging Patterns of α-Synuclein Pathology in Multiple System Atrophy.

We aimed to determine patterns of α-synuclein (α-syn) pathology in multiple system atrophy (MSA) using 70-µm-thick sections of 20 regions of the central nervous system of 37 cases with striato-nigral degeneration (SND) and 10 cases with olivo-ponto-cerebellar atrophy (OPCA). In SND cases with the shortest disease duration (phase 1), α-syn pathology was observed in striatum, lentiform nucleus, substantia nigra, brainstem white matter tracts, cerebellar subcortical white matter as well as motor cortex, midfrontal cortex, and sensory cortex. SND with increasing duration of disease (phase 2) was characterized by involvement of spinal cord and thalamus, while phase 3 was characterized by involvement of hippocampus and amygdala. Cases with the longest disease duration (phase 4) showed involvement of the visual cortex. We observed an increasing overlap of α-syn pathology with increasing duration of disease between SND and OPCA, and noted increasingly similar regional distribution patterns of α-syn pathology. The GBA variant, p.Thr408Met, was found to have an allele frequency of 6.94% in SND cases which was significantly higher compared with normal (0%) and other neurodegenerative disease pathologies (0.74%), suggesting that it is associated with MSA. Our findings indicate that SND and OPCA show distinct early foci of α-syn aggregations, but increasingly converge with longer disease duration to show overlapping patterns of α-syn pathology.

Unilateral Symptomatic Hypertrophic Olivary Degeneration Secondary to Midline Brainstem Cavernous Angioma: A Case Report and Review of the Literature.

BACKGROUND: Hypertrophic olivary degeneration (HOD) is a rare phenomenon in the dento-rubro-olivary pathway caused by lesion or disruption of the fibers of the Guillain-Mollaret triangle. Hemorrhage of pontine and midbrain cavernous angiomas can rarely lead to HOD portending neurologic deterioration and possible concomitant life-threatening complications; for this reason, it may define a poignant consideration in planning intervention. CASE DESCRIPTION: The patient was a 57-year-old woman with known midbrain-pontine cavernous angioma. For several years, the lesion had been stable, as shown by imaging follow-up, until 10 months before the patient presented with falls, dysarthria, and headache. Imaging showed some decrease in size as well as blood product around the cavernous angioma, suggesting interim period hemorrhage and interval development of HOD. CONCLUSIONS: The literature regarding imaging recommendations for stable cavernous angioma in the midbrain-pontine junction is reviewed. The implication of HOD for patient outcome is discussed and a comment is made on how the development of HOD may affect management of the cavernous angioma.

A nationwide survey of PMM2-CDG in Italy: high frequency of a mild neurological variant associated with the L32R mutation.

PMM2-CDG (PMM2 gene mutations) is the most common congenital disorder of N-glycosylation. We conducted a nationwide survey to characterize the frequency, clinical features, glycosylation and genetic correlates in Italian patients with PMM2-CDG. Clinical information was obtained through a questionnaire filled in by the referral physicians including demographics, neurological and systemic features, neuroimaging data and genotype. Glycosylation analyses of serum transferrin were complemented by MALDI-Mass Spectrometry (MALDI-MS). Between 1996 and 2012, data on 37 Italian patients with PMM2-CDG were collected. All the patients with a severe phenotype were unable to walk unaided, 84 % had severe intellectual disability and 81 % microcephaly. Conversely, among 17 mildly affected patients 82 % had independent ambulation, 64 % had borderline to mild intellectual disability and 35 % microcephaly. Epilepsy and stroke-like events did not occur among patients with the mild phenotype. The rate and extent of systemic involvement were more pronounced in severely affected patients. The L32R misfolding mutation of the PMM2 gene occurred in 70 % of the patients with the mild phenotype and was associated with a less severe underglycosylation of serum Tf at MALDI-MS analyses. Despite their different disease severity, all patients had progressive (olivo)ponto-cerebellar atrophy that was the hallmark clinical feature for the diagnosis. A mild neurological phenotype of PMM2-CDG marked by preserved ambulatory ability and autonomy and associated with L32R mutation is particularly frequent in Italy. PMM2-CDG should be considered in patients with even mild developmental disability and/or unexplained progressive cerebellar atrophy.

Corticobasal degeneration with olivopontocerebellar atrophy and TDP-43 pathology: an unusual clinicopathologic variant of CBD.

Corticobasal degeneration (CBD) is a disorder affecting cognition and movement due to a progressive neurodegeneration associated with distinctive neuropathologic features, including abnormal phosphorylated tau protein in neurons and glia in cortex, basal ganglia, diencephalon, and brainstem, as well as ballooned neurons and astrocytic plaques. We identified three cases of CBD with olivopontocerebellar atrophy (CBD-OPCA) that did not have α-synuclein-positive glial cytoplasmic inclusions of multiple system atrophy (MSA). Two patients had clinical features suggestive of progressive supranuclear palsy (PSP), and the third case had cerebellar ataxia thought to be due to idiopathic OPCA. Neuropathologic features of CBD-OPCA are compared to typical CBD, as well as MSA and PSP. CBD-OPCA and MSA had marked neuronal loss in pontine nuclei, inferior olivary nucleus, and Purkinje cell layer. Neuronal loss and grumose degeneration in the cerebellar dentate nucleus were comparable in CBD-OPCA and PSP. Image analysis of tau pathology showed greater infratentorial tau burden, especially in pontine base, in CBD-OPCA compared with typical CBD. In addition, CBD-OPCA had TDP-43 immunoreactive neuronal and glial cytoplasmic inclusions and threads throughout the basal ganglia and in olivopontocerebellar system. CBD-OPCA met neuropathologic research diagnostic criteria for CBD and shared tau biochemical characteristics with typical CBD. These results suggest that CBD-OPCA is a distinct clinicopathologic variant of CBD with olivopontocerebellar TDP-43 pathology.

Congenital disorder of glycosylation type Ia: heterogeneity in the clinical presentation from multivisceral failure to hyperinsulinaemic hypoglycaemia as leading symptoms in three infants with phosphomannomutase deficiency.

We describe three patients with congenital disorder of glycosylation (CDG) type Ia, all of whom had persistent hyperinsulinaemic hypoglycaemia responding to diazoxide therapy as a common feature. The first patient, an infant girl, presented with recurrent vomiting, failure to thrive, liver impairment, hypothyroidism and a pericardial effusion. The second patient, also female, had a milder disease with single organ involvement, presenting as isolated hyperinsulinaemic hypoglycaemia, not associated with any cognitive impairment. The third patient, a boy presented with multi-organ manifestations including congenital hypothyroidism, persistent hyperinsulinaemic hypoglycaemia, coagulopathy, olivopontocerebellar hypoplasia and recurrent pancreatitis. All three patients had a type 1 serum transferrin isoform pattern, and were subsequently found to have low phosphomannomutase activity, confirming the diagnosis of CDG type Ia. Our findings emphasize that CDG should be considered as a differential diagnosis in patients with persistent hyperinsulinaemic hypoglycaemia and that it may even occasionally be the leading symptom in CDG Ia.

Pontocerebellar hypoplasia associated with respiratory-chain defects.

Pontocerebellar hypoplasias are congenital disorders of brain morphogenesis which include such diverse etiologies as carbohydrate-deficient glycoprotein syndrome type 1, cerebromuscular dystrophies (Walker-Warburg syndrome, Fukuyama syndrome, muscle-eye-brain disease) and at least two types of autosomal recessive neurodegenerations known as pontocerebellar hypoplasia type I and II. Pontocerebellar hypoplasia type 1 is a lethal phenotype and clinical features include congenital contractures, respiratory insufficiency, central and peripheral motor dysfunction and spinal anterior horn degeneration. Type 2 is characterized by progressive microcephaly, extrapyramidal dyskinesia and normal spinal cord findings. In this paper, we describe a girl, born at 33 weeks of gestation, presenting with respiratory insufficiency and multiple contractures. MRI scan of the brain demonstrated pontocerebellar hypoplasia and cortical and diffuse periventricular white matter abnormalities. Postmortem examination showed pontocerebellar hypoplasia with extensive gliosis of the periventricular white matter and of the basal ganglia with normal spinal cord findings. Histology of skeletal muscle was normal. Biochemical analysis demonstrated multiple deficiencies of respiratory chain enzymes in skin fibroblasts. This case demonstrates a lethal phenotype of pontocerebellar hypoplasia without spinal cord abnormalities associated with a respiratory-chain disorder. The diagnostic workup in a patient whose brain image shows pontocerebellar hypoplasia should include a search for respiratory-chain impairment.

Supratentorial atrophy in spinocerebellar ataxia type 2: MRI study of 20 patients.

There have been only few studies of brain magnetic resonance imaging (MRI) in spinocerebellar ataxia (SCA) type 2. We investigated 20 SCA2 patients, from 11 Sicilian families, and 20 age-matched control subjects using MRI. Our data confirm that olivopontocerebellar atrophy (OPCA) is the typical pattern in SCA2. We found no significant correlation between infratentorial atrophy, disease duration, or the number of CAG repeats in our SCA2 patients, but there was supratentorial atrophy in 12 patients, with a significant correlation between supratentorial atrophy and disease duration. OPCA appears to represent the "core" of the SCA2: however, central nervous system involvement is not limited to pontocerebellar structures. We therefore consider central nervous system degeneration in SCA2 as a widespread atrophy. MRI is helpful in diagnosing SCA, but it is not diagnostic in the absence of clinical and molecular studies. We suggest that serial MRI may play a role in evaluating "in vivo" the progressive steps of neurodegeneration in SCA2, for a better comprehension of the pathophysiology of this disorder.

[The cerebellar cortical atrophy syndrome]. / Sindrom kortikal'noi mozzhechkovoi atrofii.

The results of the observation of 44 patients with cerebellar syndrome of different etiology are presented. Together with careful study of anamnestic and clinical data some additional examinations were performed: senso- and pallesthesiometry, thermovisional investigation, vestibulometry, electroencephalo-, electromyography, computer tomography. The study allowed to reveal both the cause of the disease and to refer etiologically late cerebellar cortical ataxia to alcohol factor. On the basis of the comparison of clinical neurological data with paraclinical observation differential diagnostic criteria were defined for Marie-Foix-Alajouanine's late cortical cerebellar atrophy in alcoholism, in the cases of the hereditary predisposition as well as of unclear genesis, in Holmes olivocerebellar atrophy, in Menzel, Hunt and Déjérine-Thomas olivopontocerebellar degeneration.

Exclusion of the gene locus for spinal muscular atrophy on chromosome 5q in a family with infantile olivopontocerebellar atrophy (OPCA) and anterior horn cell degeneration.

Two sisters with infantile OPCA plus spinal muscular atrophy (SMA) are reported. Both showed severe hypotonia and psychomotor delay from birth, and in addition, nystagmoid eye movements and vision impairment were evident. Cerebellar hypoplasia with cystic dilatation was seen by neuro-imaging methods. Pathoanatomically, a marked cerebellar hypoplasia and neuronal loss in the basal ganglia, brainstem and anterior horns were found in the deceased girl. Linkage studies with polymorphic markers of the region 5q11.2-q13.3 flanking the gene locus for infantile SMA showed identical parental haplotypes in the patients and their older healthy sister. It can be concluded that the gene locus for infantile SMA on chromosome 5q is not responsible for infantile OPCA plus anterior horn cell degeneration in the described family which might apply to this disorder in general.

[MRI and SPECT of adrenoleukodystrophy (cerebello-brainstem dominant form)--a case report].

We reported a 28-year-old man with adrenoleukodystrophy showing neurological features of olivopontocerebellar atrophy. He had a 11-year history of Addison's disease. ACTH stimulation produced no rise in the plasma cortisol level. The ratios of C24:0/C22:0, C25:0/C22:0, and C26:0/C22:0 in fatty acids of sphingomyelin from plasma were all increased. MRI showed the atrophy of brainstem and cerebellum and the abnormal hyperintense lesions of the bilateral pyramidal tracts in the brainstem and internal capsule. 99mTc-HM PAO SPECT showed hypoperfusion of the deep white matter, frontal lobes, temporal lobes, and cerebellum. We suggest that SPECT may be useful for detection of subclinical lesions in ALD.

Brain lesions in alcoholics.

Brain lesions in alcoholics are multifactorial in origin. Ethanol neurotoxicity, Wernicke's encephalopathy, hepatocerebral degeneration, head trauma, central pontine myelinolysis, Marchiafava-Bignami syndrome, pellagra, and premorbid pathological conditions, such as fetal alcohol syndrome, may all contribute to cognitive dysfunction in alcoholics. With the exception of ethanol neurotoxicity, all of these conditions are associated with specific neuropathological lesions. Wernicke's encephalopathy, the neurological syndrome of thiamine deficiency, is frequently overlooked during life and may cause global dementia as well as the more familiar Korsakoff's amnestic syndrome. Distinguishing ethanol neurotoxicity from nutritional deficiency can be facilitated by magnetic resonance imaging, which can visualize some of the specific macroscopic lesions of Wernicke's encephalopathy, central pontine myelinolysis, cerebellar degeneration, and Marchiafava-Bignami syndrome. Computerized morphometric studies of alcoholic brains have revealed ventricular enlargement, selective loss of subcortical white matter, and alterations in neuronal size, number, architecture, and synaptic complexity. These lesions tend to be more severe when there is coexisting nutritional deficiency or liver disease, suggesting that ethanol neurotoxicity may not be the sole cause. A search for similar lesions in nonalcoholic Wernicke's encephalopathy and nonalcoholic liver disease will help determine the specificity of these lesions.

[A case of progressive multisystem damage of the central nervous system with suspected olivopontocerebellar atrophy type I]. / Przypadek postepujacego wieloukladowego uszkodzenia osrodkowego ukladu nerwowego podejrzanego o I typ zaniku oliwkowo-mostowo-mózdzkowego.

A case of progressive multisystem damage to the central nervous system was observed in a patient aged 36 years. On the ground of family history, disease course, clinical findings and results of laboratory investigations type I of olivo-ponto-cerebellar atrophy according to McKusick's classification was suspected.

[Olivopontocerebellar atrophy: clinical analysis of 100 cases].

The clinical features in 100 patients suffered from olivopontocerebellar atrophy (OPCA) and their genetic trait were studied. The diagnosis was verified in all cases with computed tomography, demonstrating the atrophy of cerebellum and brainstem, vascular, neoplastic, infectious and any other organic disorder suspected were excluded. 53 out of 100 cases were sporadic (SOPCA) and the remainder (47 cases) was familial (FOPCA). The age of onset in SOPCA group was 36.1 +/- 14.95 (M +/- SD) in average, while in FOPCA group was 28.9 +/- 11.8. It seems that the symptoms in FOPCA group develop earlier than that in SOPCA group (P less than 0.05). All 47 cases of FOPCA group belong to 36 families in which altogether 166 persons were involved. According to pedigree patterns, there were 26 families inherited as autosomal dominant trait and probably so in another 5 families. Autosomal recessive trait could be confirmed in 2 families, in which the parents of proband were consanguineous, and in 3 other families autosomal recessive trait of inheritance was highly suspected. Anticipation was demonstrated in 26 families with dominant inheritance. Generally, ataxia and weakness of legs develop as initial symptoms in 88% of cases, then followed by dysarthria, and ataxia of upper extremities. The rapid alternating test of hand was impaired in 95% of patients, however, tension tremor was revealed only in 53% of patients. A method for assessing the ataxia quantitatively was proposed, our data suggest that the quantitative alternating test in the upper extremity and the measurement of base-width in lower extremity seem to be valuable in identifying the intensity of ataxia.

Phenotypic variation in 2 Huntington's disease families with linkage to chromosome 4.

Variability of expression of the Huntington's disease (HD) gene is illustrated in 2 families with linkage of DNA restriction fragment length polymorphism to the short arm of chromosome 4. In 1 family, affected persons from 3 generations show 50-year variation of onset age. The member with the latest onset age (67) died at 91 with autopsy-confirmed HD. The next generation had hypotonic chorea beginning in the 4th decade with death in the 5th. In the 3rd generation, a rigid patient, inheriting the illness from an affected father, had a much earlier onset at 16, while her siblings had chorea beginning in the 3rd decade. In the 2nd family, several members had cerebellar signs, chorea, and dementia. MRI and CT revealed olivoponto-cerebellar and striatal atrophy. These phenotypes may be the result of different allelic genes at the HD locus or unlinked autosomal modifying loci influencing the expression of the HD gene.