Myoadenylate deaminase deficiency in twins with recessive olivopontocerebellar atrophy

Two adult non-identical twins with autosomal recessive olivopontocerebellar degeneration (OPCA) had markedly deficient adenylate deaminase in skeletal muscle homogenates. Ischemic exercise failed to increase the blood ammonia, while lactate increased normally. Glutamate dehydrogenase and NADP-dependent malic enzyme activities in muscle mitochondria of both patients were normal. The significance of adenylate deaminase deficiency in these twins with OPCA is discussed.

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Sommario In due sorelle gemelle biovulari affette da una forma di atrofia olivo-ponto-cerebellare e normale attività della glutammatodeidrogenasi è stato evidenziato un marcato deficit dell'attività dell'adenilato deaminasi nel muscolo scheletrico. Non vi era inoltre aumento dell'ammoniemia dopo test da sforzo ischemico. L'associazione tra atrofia olivo-ponto-cerebellare e difetto di adenilato deaminasi in queste sorelle è probabilmente casuale.

     

Neurological disorders associated with deficiency of glutamate dehydrogenase

Glutamate dehydrogenase (GDH) activity was measured in leukocytes from 88 patients with various types of degenerative neurological disorders affecting primarily the cerebellum and/or the basal ganglia, and 26 healthy control subjects. Twelve patients with slowly progressive multiple-system atrophic disorders were found to have a partial deficiency of this enzyme (52% of control level). The majority of these patients evidenced a constellation of neurological findings consistent with the diagnosis of olivopontocerebellar atrophy, although others were atypical in their neurological manifestations. Thus, GDH-deficient patients were encountered with predominantly extrapyramidal manifestations (atypical Parkinson's disease), cerebellar dysfunction with peripheral neuropathy, or anterior horn cell signs, suggesting that a pleomorphic phenotypic expression of the enzymatic deficiency may occur. Seven cases of GDH deficiency were familial and 5 were sporadic. The former patient group consisted of siblings of either sex, but no parents or offspring were affected. The genetic pattern of the disorder is compatible with autosomal recessive inheritance. Patients with dominantly inherited olivopontocerebellar atrophy or other types of cerebellar or basal ganglia degenerative neurological disorders showed normal GDH activity. Leukocyte GDH was fractionated into “particulate-heat labile” and “soluble-heat stable” components. In the patients the decrease in activity was limited to the “particulate-heat labile” component. A genetic mutation of a GDH “isoenzyme” may occur in some patients with multiple-system degeneration.     

Leukocyte glutamate dehydrogenase activity in patients with degenerative neurological disorders.

Leukocyte glutamate dehydrogenase (GDH) activity was measured in 39 normal subjects, 32 neurological controls, 66 patients with progressive ataxic disorders, 32 with multiple system atrophy, 40 with Parkinson's disease, eight with Steele-Richardson-Olszewski syndrome, eight with juvenile Parkinsonism and four with the dystonia-Parkinsonism syndrome. GDH activity was reproducible to within 10% in leukocyte pellets stored at -70 degrees C for up to 9 months, and did not vary with sex or age in control subjects. There was marked variation in the relative proportions of heat stable and heat labile forms of GDH between control subjects and on repeated assay in the same subject. Total leukocyte GDH activity was similar in normal subjects and neurological controls. Mean total GDH activity was reduced in all patient groups by between 15 to 29% compared with controls. Fourteen patients had total GDH activity below 50% of the control mean, but low values were not specific for any one disease (five had ataxic disorders, four Parkinson's disease, three multiple system atrophy, one juvenile Parkinsonism, and one dystonia-Parkinsonism). The heat labile fraction of GDH represented about 20% of total activity in control subjects, and 27% in the patients with reduced total GDH activity. Thus low GDH activity was not disease-specific in this study, and the heat-labile GDH fraction was not selectively affected. "Reduced" leucocyte GDH activity in some patients may represent no more than the lower end of a normal distribution.     

Differential glutamate dehydrogenase (GDH) activity profile in patients with temporal lobe epilepsy

PURPOSE: Pathophysiologic mechanisms underlying temporal lobe epilepsy (TLE) are still poorly understood. One major hypothesis links alterations in energy metabolism to glutamate excitotoxicity associated with seizures in TLE. The purpose of this study was to determine whether changes in the activities of enzymes critical in energy and neurotransmitter metabolism contributed to the alterations in metabolic status leading to the excitotoxic effects of glutamate. METHODS: Activities of four key enzymes involved in energy metabolism and glutamate cycling in the brain [aspartate aminotransferase (AAT), citrate synthase (CS), glutamate dehydrogenase (GDH), and lactate dehydrogenase (LDH)] were measured in anterolateral temporal neocortical and hippocampal tissues obtained from three different groups of medically intractable epilepsy patients having either mesial, paradoxical, or mass lesion-associated temporal lobe epilepsy (MTLE, PTLE, MaTLE), respectively. RESULTS: We found that GDH activity was significantly decreased in the temporal cortex mainly in the MTLE group. A similar trend was recognized in the hippocampus of the MTLE. In all three patient groups, GDH activity was considerably lower, and AAT and LDH activities were higher in cortex of MTLE as compared with the corresponding activities in hippocampus (p<0.05). In the MTLE cortex and hippocampus, GDH activities were negatively correlated with the duration since the first intractable seizure. CONCLUSIONS: Our results support the hypothesis suggesting major alteration in GDH activity mainly in the MTLE group. It is proposed that significant alterations in the enzyme activities may be contributing to decreased metabolism of glutamate, leading to its accumulation.     

Glutamate dehydrogenase (GDH) deficiency in different types of progressive hereditary cerebellar ataxia

Leukocyte glutamate dehydrogenase (GDH) was studied in 29 patients affected by progressive cerebellar ataxia (PCA) and in 20 healthy controls. Eight GDH-deficient patients, with GDH activity 2 SD below mean value of controls, were identified. GDH deficiency did not identify a subgroup of PCA by characteristic pattern of inheritance and/or age of onset of disease. However, the GDH-deficient patients presented more neurological signs than non-GDH-deficient patients. A significant correlation was observed between GDH deficiency and the presence of extrapyramidal signs, supranuclear palsy, absence of osteotendineal reflexes and neurogenic electromyographical findings.     

Characteristics of oculomotor disorders of a family with Joseph's disease

Summary The oculomotor abnormalities of 12 patients of a large Japanese family with Joseph's disease were investigated and compared with those of 27 patients with olivopontocerebellar atrophy (OPCA). All 12 patients had limitation of upward gaze, impairment of convergence and horizontal gaze nystagmus. However, none had abnormalities of pupillary shape or light reflexes. Impairments of saccadic and pursuit eye movements were frequently present. Further, difficulty of eyelid opening, bulging eyes, impairment of optokinetic and caloric responses and square wave jerks were seen in some of the patients. The autopsy examination of 1 patient revealed marked neuronal loss in the oculomotor nucleus with preservation of the Edinger-Westphal nucleus and neuronal decrease, myelin loss and gliosis of the dorsal midbrain including superior colliculus, pretectum and posterior commissures. Disturbance of upward gaze, sparing of pupillary light reflexes and horizontal gaze nystagmus were frequent and early symptoms. The pattern of oculomotor disturbances is different from that of OPCA and evaluation of the oculomotor system is useful for clinical diagnosis of the disease.     

Effects of in vivo perfusion of glutamate dehydrogenase in the guinea pig cochlea on the VIIIth nerve compound action potential

Glutamate is considered as the best candidate for the neurotransmission between the inner hair cell and the primary efferent neurons in the mammalian cochlea. In order to test its presence in the synapse, a degradative enzyme for glutamate, glutamate dehydrogenase (GDH) was perfused in the cochlea of guinea pigs. The intensity function of the VIIIth nerve compound action potential was recorded as a physiological test. The results show that the GDH induces a decrease in the auditory nerve responsiveness. The threshold elevation observed is dependent upon the enzyme concentration.     

The role of MRI in the diagnosis of olivopontocerebellar atrophy

Under the term of olivopontocerebellar atrophy different nosological pictures are grouped, all characterized by showing clinical signs of deficiency of the structures of the pons and of the cerebellum.The diagnosis of olivopontocerebellar atrophy has been made, until now, by clinical criteria while typical anatomopathological changes are found at the autoptic studies.We describe three patients affected by olivopontocerebellar atrophy, of different types and at different stages of disease.In all cases MRI showed a similar and typical picture of atrophy of the olivary eminences of the medulla oblongata resulting in straightening of the angle usually present on the ventral frontier between pons and medulla oblongata. This diagnostic tool demonstrated thus to be of primary relevance yet in the early phases of the disease.

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Sommario Sotto il termine di atrofia olivo-pontocerebellare si raggruppano quadri nosografici di verosimile diversa origine, caratterizzati tutti dalla presenza di segni clinici deficitari pontini e cerebellari. La diagnosi è stata sino ad ora solo clinica con conferma autoptica del danno pontocerebellare. Sono descritti tre casi di atrofia olivo-pontocerebellare, appartenenti, a tre distinti sottogruppi ed in fasi diverse della malattia. In tutti e tre i casi la MRI ha evidenziato un quadro di atrofia pontina e cerebellare ed una riduzione dimensionale delle olive bulbari che risultava in un allargamento dell'angolo pontobulbare normalmente rilevabile sulla faccia anteriore del tronco in proiezione laterale. L'esame si conferma di importanza diagnostica essenziale nella malattia sin dalle sue fasi iniziali.

     

Neuroradiological correlates of neuropsychological disorders in olivopontocerebellar atrophy (OPCA)

Thirty-two OPCA patients without cortical atrophy were studied. In addition to inspection of films by a neuroradiologist (i.e. “subjective” assessment), five neuroradiological measures were used, namely, the estimation of brainstem ratio, midbrain ratio, fourth ventricular ratio, brachium pontis ratio and bicaudate ratio. The patients were divided into two groups: one with mild and the other with moderate-severe atrophies. The neuropsychological assessment measures were: global memory quotient, verbal learning capacities, recall and recognition, attention, abstract thinking, visuo-spatial and visuo-constructive functioning. Three conclusions emerged: (i) cognitive disturbances in OPCA are related to the degree of cerebellar damage; (ii) these findings are consistent with the concept of anatomic and metabolic neocerebellar → basal ganglia → associative cerebral cortex loops; and (iii) it appears that the role of the neocerebellum in cognition is not exclusive because some other structures (fastigius, vermis) and the fastigial → limbic loops seem to be involved.     

Pontocerebellar hypoplasias: An overview of a group of inherited neurodegenerative disorders with fetal onset

Cerebellar hypoplasia is common to a variety of congenital disorders. Both stable conditions and progressive (degenerative) disorders may cause cerebellar hypoplasia. Pontocerebellar hypoplasia (PCH) is distinct from cerebellar hypoplasias in general, because the ventral pons is affected. Reviewing both clinical and neuropathological evidence, two specific neurogenetic entities are delineated. It is proposed to call these, respectively, type 1 (PCH-1) and type 2 (PCH-2). In type 1 the hallmark is the presence of spinal anterior horn degeneration similar to Werdnig-Hoffmann disease. Presentation in the neonatal period is characterized by respiratory insufficiency, frequent congenital contractures, and a combination of central and peripheral motor signs. Patients die early, usually before 1 year of age. In type 2 the hallmark is the presence of chorea/dystonia, which often severe, while spinal anterior horn pathology is absent. Patients have microcephaly and severely impaired mental and motor development. They frequently die during childhood. Neuronal degeneration in both types of PCH is non-specific. Reactive changes in the degenerated parts appear more extensive in type 1. Examples of both types are given. Differentiation of the two types appears straightforward and possible by clinical means. Carbohydrate-deficient glycoprotein syndrome, one other cause of (ponto)cerebellar hypoplasia, should be excluded in all cases of PCH by appropriate means.     

Investigation of adult-onset multiple acyl-CoA dehydrogenase deficiency associated with peripheral neuropathy

Multiple Acyl-CoA dehydrogenase deficiency (MADD), one of the most common lipid storage myopathies (LSMs), is a heterogeneous inherited muscular disorder that is pathologically characterized by numerous lipid droplets in muscle fibers due to lipid metabolism disturbance. MADD exhibits a wide range of clinical features, including skeletal muscle weakness and multisystem dysfunctions. However, MADD, as well as other types of LSM, associated with peripheral neuropathy has rarely been reported during the past four decades. Here, we present four Chinese patients affected by MADD with peripheral neuropathy in our neuromuscular center. Clinically, these four patients showed skeletal muscle weakness and prominent paresthesia. Muscle biopsy detected characteristic myopathological patterns of LSM, such as obvious lipid droplets in muscle fibers. Sural nerve biopsy revealed a severe reduction in number of myelinated nerve fibers, which is a typical neuropathological pattern of peripheral neuropathy. Causative ETFDH mutations were found in all four cases. The skeletal muscle weakness was rapidly improved after some treatments while paresthesia showed unsatisfactory improvement. The features of previously reported patients of this specific type are also summarized in this paper. We propose that MADD with peripheral neuropathy may be a new phenotypic subtype because the pathology and reaction to riboflavin treatment are different from those of traditional MADD, although further research on the precise pathogenesis and mechanisms is needed.     

Pathology of olivopontocerebellar atrophy with glutamate dehydrogenase deficiency

We report the neuropathologic findings in the first patient with recognized glutamate dehydrogenase (GDH) deficiency to come to postmortem examination. He had progressive cerebellar ataxia beginning at age 21. He died at age 47 of pulmonary emboli. Postmortem examination revealed pancerebellar, olivary, and mild pontine atrophy, demyelination of the posterior columns, degeneration of anterior horn and dorsal root ganglion cells, and reduction of myelinated fibers in the sural nerve. In addition, there was neuronal storage of lipopigment diffusely throughout the CNS and the autonomic neurons, with cell distention, atrophy, and loss in selected areas.     

Late-onset presentation of pyruvate dehydrogenase deficiency.

Two brothers presented in their mid-forties with movement disorders including atypical parkinsonism, choreiform movements, stereotypies, ataxia and dysarthria. Both brothers showed putaminal lucencies on imaging and, in the proband, a deficiency of the pyruvate dehydrogenase complex (PDHC) was found on skin fibroblast assay.     

Olivopontocerebellar atrophy leading to recognition of carbohydrate-deficient glycoprotein syndrome type I

The carbohydrate-deficient glycoprotein (CDG) syndromes are a group of genetic multisystem disorders with invariable involvement of the nervous system including severe olivopontocerebellar atrophy. We report two sets of sibs in whom the diagnosis of CDG syndrome type 1 was recognized at an older age because of marked olivopontocerebellar atrophy seen on MRI. Previous CT findings were interpreted as showing Dandy-Walker malformation. Three of the patients are also among the oldest reported with this syndrome.     

Inositol 1,4,5-trisphosphate metabolism in the cerebella of Lurcher mutant mice and patients with olivopontocerebellar atrophy

We have investigated inositol 1,4,5-trisphosphate (InsP₃) metabolism in cerebellar membranes of normal humans and patients with dominant ataxia (‘C’ kindred), and also in cerebellar microsomes of Lurcher mutant mouse (a suggested model for cerebellar ataxia). Various [³H]InsP₃ metabolites formed separated by HPLC using 3 successive convex gradients of 1.7 M ammonium formate, pH 3.7. [³H]InsP₃ metabolism was rapid and in 15- and 45-day-old control mice cerebella about 50% of [³H]InsP₃ was metabolized within 20 s. In 15-day-old Lurcher mice the rate of [³H]InsP₃ metabolism was significantly low (40% of normal). [³H]InsP₃ metabolism was almost absent in 45-day-old Lurcher mice cerebellar microsomes. The decreased [³H]InsP₃ metabolism was consistent with decreased recovery of the various inositol polyphosphates formed. Similarly, in cerebellar membranes of human patients with olivopontocerebellar (OPCA) a significant decrease in [³H]InsP₃ metabolism was observed when compared with normal controls. These data suggest that altered phosphoinositide turnover may be associated with the onset of neuronal degeneration in human OPCA.     

Survival in multiple system atrophy: a study of prognostic factors in 59 cases

The various clinical features of multiple system atrophy (MSA) make the diagnosis of the disease difficult, especially in its early stages, when signs of differentiated neuroanatomical system involvement have not yet appeared. Mortality studies may be affected by the variability of the diagnostic criteria and selection bias. We used strict clinical and MRI criteria to diagnose MSA in 59 patients. Patients with parkinsonian and cerebellar onset were compared. Median survival time from the onset of the first motor symptom was 7.5 years. Our results indicated a trend (P = 0.09) for the Northwestern University Disability Scale score to correlate with mortality, but we failed to find other characteristics identifying subgroups or predictors for survival.     

The efficacy of combined estrogen and buspirone treatment in olivopontocerebellar atrophy

BACKGROUND: Olivopontocerebellar atrophy (OPCA) is a chronic neurodegenerative disease with symptoms of cerebellar ataxia, parkinsonism, autonomic disturbances and ophthalmoplegia. Buspirone, a 5-HT1(A) agonist could constitute a symptomatic improvement in cerebellar dysfunction whereas estrogen has been investigated for neuroprotection. We conducted an open-labeled pilot trial to assess the efficacy of estrogen with buspirone treatment. PATIENTS AND METHODS: Eighteen patients (7 male and 11 female) with OPCA were randomized into the buspirone (15 mg/day, n=9), or the combined treatment group (estrogen, 0.625 mg/d plus buspirone, n=9). For the clinical rating, International Cooperative Ataxia Rating Scale (ICARS) was used and dysarthria, gaze evoked nystagmus, finger to nose, pronation-supination alternating movement, knee-tibia test, and gait speed were evaluated for 12 months. RESULTS: Buspirone-treated group showed improvements in finger to nose and pronation-supination alternating movement test (p=0.046 and p=0.025, respectively). The combination group (Estrogen+buspirone), however, showed no improvement in cerebellar sub-scales compared to the baseline. CONCLUSIONS: Buspirone treatment showed feasible efficacies for OPCA, while the combined treatment of estrogen and buspirone failed to improve, suggesting estrogen may not have further benefit in cerebellar dysfunction.