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Pontocerebellar hypoplasia consists of a rare heterogeneous group of congenital neurodevelopmental disorders characterized by hypoplasia and atrophy of the cerebellar cortex, dentate and pontine nuclei, and inferior olives. Lineer nevoid hyperpigmentation is a rare skin condition characterized by whorls and streaks of hyperpigmented macules in a reticulate pattern along Blaschko's lines. Herein we present a three year-old male patient with pontocerebellar hypoplasia associated with nevoid hyperpigmentation on the upper part of the body. Besides he has some dysmorphic features including microcephaly, triangular chin, long philtrum, long hand fingers, flexion contracture in all of the distal phalanges of both hands, and strabismus.

Pontocerebellar Hypoplasia (PCH) is group of very rare, inherited progressive neurodegenerative disorders with prenatal onset. Up to now seven different subtypes have been reported (PCH1-7). The incidence of each subtype is unknown. All subtypes share common characteristics, including hypoplasia/atrophy of cerebellum and pons, progressive microcephaly, and variable cerebral involvement. Patients have severe cognitive and motor handicaps and seizures are often reported. Treatment is only symptomatic and prognosis is poor, as most patients die during infancy or childhood. The genetic basis of different subtypes has been elucidated, which makes prenatal testing possible in families with mutations. Mutations in three tRNA splicing endonuclease subunit genes were found to be responsible for PCH2, PCH4 and PCH5. Mutations in the nuclear encoded mitochondrial arginyl- tRNA synthetase gene underlie PCH6. The tRNA splicing endonuclease, the mitochondrial arginyl- tRNA synthetase and the vaccinia related kinase1 are mutated in the minority of PCH1 cases. These genes are involved in essential processes in protein synthesis in general and tRNA processing in particular. In this review we describe the neuroradiological, neuropathological, clinical and genetic features of the different PCH subtypes and we report on in vitro and in vivo studies on the tRNA splicing endonuclease and mitochondrial arginyl-tRNA synthetase and discuss their relation to pontocerebellar hypoplasia.

The pontocerebellar hypoplasias are a heterogeneous group of rare and devastating conditions characterized by multiple structural abnormalities of the ventral pons, inferior olive, and cerebellum. Here, we briefly review these conditions and discuss genes recently discovered to be involved in pontocerebellar hypoplasia pathogenesis. We then present data that exclude several genes important for cerebellar development as causes of pontocerebellar hypoplasia-4 and pontocerebellar hypoplasia-5, and we demonstrate that not all cases of clinically defined pontocerebellar hypoplasia-4 result from mutations in TSEN54. We conclude that classification based on clinical, imaging, and neuropathological findings does not differentiate between pontocerebellar hypoplasia subtypes with different genetic causes.

We present three siblings with a precise onset of fetal seizure-like activity who had severe olivopontocerebellar hypoplasia (OPCH) and degeneration. Autopsies at 20, 27, and 37 weeks gestation showed diffuse central nervous system volume loss that was most marked for the cerebellum and brain stem structures. Neuropathological abnormalities included dysplastic, C-shaped inferior olivary nuclei, absent or immature dentate nuclei, and cell paucity more marked for the cerebellar vermis than the hemispheres. Delayed development was seen in layer 2 of the cerebral cortex and in Purkinje cells of the cerebellum. Prenatal monitoring defined a developmental window of 16-18 weeks gestation when ultrasonic assessment of cerebellar width was used for prenatal diagnosis. We discuss our findings in the context of the differential diagnosis for infantile (O)PCH and propose a classification scheme for the pontocerebellar hypoplasias. These patients represent the earliest reported with OPCH and provide unique information regarding the developmental neuropathology of this condition.

Parenchymatous cerebellar cortical atrophy (CCA) usually presents with a "pure" cerebellar ataxia. We describe a patient with a sporadic, late-onset progressive cerebellar ataxia plus cognitive decline and chorea who had CCA at post mortem. We discuss this unique case in the current context of classification of idiopathic cerebellar ataxia., (Copyright 2003 Movement Disorder Society)

We present two siblings with pontocerebellar hypoplasia who have progressive microcephaly, mental and motor retardation, truncal ataxia, strabismus, and progressive spasticity and hyperreflexia of the lower limbs. Extrapyramidal dyskinesia and epilepsy, other main clinical features of pontocerebellar hypoplasia, are absent. The older sibling also has a high arched palate, triangular-shaped face, thoracolumbar scoliosis, pectus carinatum, kyphosis, cubitus valgus, arachnodactyly, long extremities, and a tall stature, which were not previously reported in association with pontocerebellar hypoplasia. The clinical phenotype should be expanded, especially within type II, with the reports of additional cases.

Pontocerebellar hypoplasia (PCH) is a very rare congenital (autosomal recessive) condition with fetal onset. Only a few cases have been published on the basis of both clinical data (symptoms/neuroradiological imaging) and autopsy results. This paper reports on such a case involving a 1.5-year-old male infant. The child suffered from severe psychomotor delay, extrapyramidal dyskinesia and epileptic seizures, but did not exhibit signs of spinal muscular atrophy as related to PCH type 1. Magnetic resonance imaging (MRI) at the age of 6 months demonstrated olivo-pontine and bilateral cerebellar hypoplasia. The boy was unexpectedly found dead. Autopsy disclosed a severe aspiration of gastric contents as the final cause of death. The neuropathological examination confirmed PCH type 2 (according to Barth [Brain Dev., 15 (1993) 411-422]) with marked microcephaly and olivopontocerebellar hypoplasia. Histologically, decreased density of olivo-pontine neurons, reduction of granular and Purkinje's cell layers of the cerebellum, slight astroglial proliferation and fragmented appearance of the dentate nuclei were observed. The immunohistochemical expression pattern was determined using antibodies against glial fibrillary acidic protein, synaptophysin and neurofilament protein. Summarizing, typical features of PCH type 2 were present and proved by clinical course, MRI and autopsy. Despite severe symptoms due to a natural disease this rare neurogenetic entity can become of forensic interest, when sudden unexpected death occurs.

Three affected members of a family with olivopontocerebellar atrophy IV (Schut-Haymaker type) of autosomal dominant inheritance are presented. The five types of olivopontocerebellar atrophy are differentiated on the basis of clinical symptoms and the mode of inheritance. Its clinical symptoms are varied but the cerebellar ataxia of different extent is present in every case which may be followed by pyramidal and extrapyramidal symptoms. Clear differentiation from the other types is based on the destruction of the nuclei of cranial cerebral nerves (IX, X, XII).

Measurement of monoamine metabolites in cerebrospinal fluid (CSF) has been one of the few methods available to study monoamine transmitter function in the human central nervous system (CNS). It has steadily proved to be of much use in clinical research of neurological and psychiatric diseases, in which altered functions of central monoamine neurotransmitters have been identified. In this work 3-methoxy-4-hydroxyphenylethylglycol (MHPG), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) were quantified in normal CSF and in patients with untreated Parkinson's disease (PD) and olivopontocerebellar atrophy (OPCA). Normal CSF was obtained from 162 patients at the time of spinal anesthesia for surgery. Reference values for monoamine metabolites were established for normal adult lumbar CSF. Up to the age of 70 years no relation of monoamine metabolite concentration with age or sex were encountered. In individuals above 70 years of age higher levels of MHPG, HVA, and 5-HIAA were present in women, while in men only higher levels of MHPG could be detected. A strong correlation between 5-HIAA and HVA concentrations were observed in all groups. PD patients exhibited normal CSF metabolite levels, but an altered 5-HIAA/HVA ratio, favoring 5-HIAA. Dominant and recessive OPCA differed essentially in HVA concentration-diminished in the first group and elevated in the last. Comparing the results obtained in PD and dominant OPCA, we suggest that the decrease of CSF HVA in the latter group might not reflect nigrostriatal degeneration as we previously thought. Possibly another factor influencing dopamine function in the CNS is involved.

Signs of atrophy on cranial CT were investigated in 35 patients diagnosed as suffering from autosomal dominant (n = 21) or idiopathic (n = 14) cerebellar ataxia. Thirteen patients with a pure cerebellar syndrome were examined after at least 4 years of disease (mean duration 10.5 years) and were classified as cerebellar atrophy (CA). Twenty-two patients with additional non-cerebellar signs were classified as olivo-ponto-cerebellar atrophy (OPCA). Four (30%) of the patients with CA had atrophy of the brain stem in addition. Of the 22 patients with OPCA, 9 (40%) had atrophy of the cerebellum only. In patients with CA or OPCA correlation of clinical signs with severity of atrophy on CT was poor. Atrophy on CT often fails to differentiate autosomal dominant or idiopathic cerebellar ataxias in CA or OPCA: patients with CA can also have atrophy of the brain stem and patients with OPCA do not necessarily show brain stem atrophy.

Machado-Joseph disease is an autosomal dominant spinocerebellar degeneration. It expresses itself clinically with variable expression. Type one patients have early onset with a rapid progression of symptoms including spasticity, rigidity and myokymia. Type two patients are the most common phenotype with ataxia and spasticity. Type three patients develop progressive ataxia with variable amyotrophy. All patients have ophthalmoparesis and normal mental status. The neuropathology consists of neuronal loss and gliosis in the substantia nigra, motor cranial nuclei, dentate nucleus of the cerebellum, and variable neuronal loss with gliosis in the cerebellar cortex and neostriatum. The cerebral cortex is normal histologically. The inferior olivary nuclei are normal, thus separating this disease from olivopontocerebellar atrophy (OPCA). The disease has a worldwide distribution including families described in Portugal, the Azores, Spain, Italy, United States, Canada, Brazil, China, Taiwan, and Japan. The gene has not been mapped for this disease but the locus on chromosome 6p mapped for most families with OPCA has been excluded for this disorder.

Experience is described in 25 patients from southern New England with Machado-Joseph Disease, examined serially at annual screening clinics. The disorder is dominantly inherited, with a wide range of phenotypic variation. Core clinical features described include ataxia, nystagmus, dysarthria, facial fasciculations, and lid retraction, producing a characteristic staring expression. In addition, young onset patients have spasticity, extrapyramidal rigidity, and dystonic manifestations. Late onset patients often have distal atrophy and sensory loss. Postural instability is often an early feature. We discuss the distinction of this entity from the olivopontocerebellar atrophies.

Olivocerebellar pontine degeneration of the Wadia type is characterized by progressive symmetrical cerebellar ataxia, slow eye movements, absent deep tendon reflexes, autosomal dominant inheritance, and onset between the second and fourth decades. The only available treatments are genetic counseling, social and psychological support, and physiotherapy. This article presents a case of this subtype of hereditary ataxia and a review of the literature.

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.

The study of 15 cases of progressive cerebellar atrophies, and especially of the olivopontocerebellar atrophy, that was investigated both clinically and anatomically, has attempted to evidence particularities and correlations existing between these two types of atrophy. Olivopontocerebellar atrophy appears to be an abiotrophy of the cerebellum, considered to be spontaneous, sporadic, and sometimes with a hereditary familial background. It is a systemic disease, predominantly of the neocerebellum and involving the cerebellopedal system. It is at the opposite end of Holmes-type atrophies, and of the cerebello-olivary atrophies of the young (I. T. Niculescu, Th. Hornet, 1936) which mainly involve the paleocerebellum. The disease has a polymorphous symptomatology, it has a slow, progressive evolution with mostly cerebellar signs, with extrapyramidal phenomena and psychical disturbances due to lesions of the telencephalic pathways, and sometimes of the spinal, cerebellar and bulbar proprioceptive afferences, with spinal and bulbar involvement (Cezar Ionel, 1949, 1972).