Neurologic Conditions Associated with Cavus Foot Deformity.

The cavus foot deformity is an often less understood deformity within the spectrum of foot and ankle conditions. The hallmark concern is the possibility of an underlying neurologic or neuromuscular disorder. Although a proportion of these deformities are idiopathic, a significant majority do correlate with an underlying disorder. The appropriate evaluation of this deformity, in coordination within the multidisciplinary scope of health care, allows for a timely diagnosis and understanding of the patient's condition. We provide an abbreviated survey of possible underlying etiologies for the patient with the cavus foot deformity as a reference to the foot and ankle surgeon.

Mutations in Spliceosomal Genes PPIL1 and PRP17 Cause Neurodegenerative Pontocerebellar Hypoplasia with Microcephaly.

Autosomal-recessive cerebellar hypoplasia and ataxia constitute a group of heterogeneous brain disorders caused by disruption of several fundamental cellular processes. Here, we identified 10 families showing a neurodegenerative condition involving pontocerebellar hypoplasia with microcephaly (PCHM). Patients harbored biallelic mutations in genes encoding the spliceosome components Peptidyl-Prolyl Isomerase Like-1 (PPIL1) or Pre-RNA Processing-17 (PRP17). Mouse knockouts of either gene were lethal in early embryogenesis, whereas PPIL1 patient mutation knockin mice showed neuron-specific apoptosis. Loss of either protein affected splicing integrity, predominantly affecting short and high GC-content introns and genes involved in brain disorders. PPIL1 and PRP17 form an active isomerase-substrate interaction, but we found that isomerase activity is not critical for function. Thus, we establish disrupted splicing integrity and "major spliceosome-opathies" as a new mechanism underlying PCHM and neurodegeneration and uncover a non-enzymatic function of a spliceosomal proline isomerase.

Disorders of mitochondrial dynamics in peripheral neuropathy: Clues from hereditary neuropathy and diabetes.

Peripheral neuropathy is a common and debilitating complication of diabetes and prediabetes. Recent clinical studies have identified an association between the development of neuropathy and dyslipidemia in prediabetic and diabetic patients. Despite the prevalence of this complication, studies identifying molecular mechanisms that underlie neuropathy progression in prediabetes or diabetes are limited. However, dysfunctional mitochondrial pathways in hereditary neuropathy provide feasible molecular targets for assessing mitochondrial dysfunction in neuropathy associated with prediabetes or diabetes. Recent studies suggest that elevated levels of dietary saturated fatty acids (SFAs) associated with dyslipidemia impair mitochondrial dynamics in sensory neurons by inducing mitochondrial depolarization, compromising mitochondrial bioenergetics, and impairing axonal mitochondrial transport. This causes lower neuronal ATP and apoptosis. Conversely, monounsaturated fatty acids (MUFAs) restore nerve and sensory mitochondrial function. Understanding the mitochondrial pathways that contribute to neuropathy progression in prediabetes and diabetes may provide therapeutic targets for the treatment of this debilitating complication.

[Epileptic encephalopathies]. / Encefalopatias epilepticas.

According to the International League Against Epilepsy's (ILAE) Commission on Classification and Terminology, the term 'epileptic encephalopathy' reflects the notion that epileptic activity in itself can contribute to the genesis of severe cognitive or behavioural disabilities, beyond what could be expected from the pathology underlying the epilepsy. However, in many cases it is difficult to define the boundary between the relative contribution of the epileptic seizures and the underlying cause in the genesis of cognitive deficits. Some epileptic syndromes, such as those of West, Lennox-Gastaut or Dravet, are associated to a high probability of encephalopathic traits. The most frequent causes of epileptic encephalopathy are hypoxic-ischaemic encephalopathy, brain malformations, including cortical dysplasias, chromosomal or genetic disorders, tuberous sclerosis and metabolic diseases.

TITLE: Encefalopatias epilepticas.Segun la Comision de Clasificacion y Terminologia de la Liga Internacional contra la Epilepsia (ILAE), el termino 'encefalopatia epileptica' refleja la nocion de que la actividad epileptica en si misma puede contribuir a la genesis de graves discapacidades cognitivas o comportamentales, mas alla de lo que seria de esperar de la patologia subyacente a la epilepsia. No obstante, en muchos casos resulta dificil deslindar la contribucion relativa de las crisis epilepticas y la causa subyacente en la genesis de los deficits cognitivos. Algunos sindromes epilepticos, como los de West, Lennox-Gastaut o Dravet, se asocian con una alta probabilidad de rasgos encefalopaticos. Las causas mas frecuentes de encefalopatia epileptica son la encefalopatia hipoxico-isquemica, las malformaciones cerebrales, incluyendo las displasias corticales, las alteraciones cromosomicas o geneticas, la esclerosis tuberosa y las enfermedades metabolicas.

[Hypotonic syndrome in the newborn infant]. / Síndrome hipotónico del lactante.

Hypotonia is understood to refer to a pronounced decrease in muscle tone that affects normal motor development and that may affect the axial muscles as well as those of the limbs and, sometimes, the face. It is a very challenging clinical picture because it consists in a fairly wide range of conditions that affect different areas of the central and peripheral nervous system and may be the expression of pathologies that can be either benign or of an uncertain prognosis. These cover myopathies, metabolic disorders, diseases based on genetic causes, pathologies affecting the endocrine glands and progressive or chronic diseases, among other aetiologies. The important development of medicine today has made a number of tools available to the examiner with which to refine or pronounce a diagnosis. Such instruments include the developments achieved in genetic research, together with studies conducted in imaging and optical and electronic microscopy. However, in spite of having all this material available for use, it is still the clinical features that allow a rational use to be made of these advances to be able to point towards the possible causation, topographic location and developmental control. It is useful, for the diagnostic approach and the use of auxiliary methods, to know the topographic location of the disorder, whether it is situated in the brain, the cerebellum, the stem, the spinal cord, the peripheral nerves, the myoneural junction or the muscle.

TITLE: Sindrome hipotonico del lactante.Entendemos como hipotonia la disminucion acentuada del tono muscular que afecta al desarrollo motor normal y que puede afectar a la musculatura axial y de los miembros y, en ocasiones, a la facial. Es un cuadro que genera un gran desafio ya que, en su universo, comprende una serie bastante amplia de condiciones que afectan a distintas areas del sistema nervioso, tanto central como periferico, y que pueden ser expresion de patologias de corte benigno o de pronostico reservado. Abarcan miopatias, alteraciones metabolicas, enfermedades de corte genetico, endocrinopatias y enfermedades progresivas o cronicas, entre otras causas. El gran desarrollo de la medicina actual ha logrado poner a disposicion del examinador multiples herramientas que permiten afinar o aseverar el diagnostico, entre las que destacan los desarrollos logrados en las investigaciones geneticas, asi como los estudios de imagenes y de microscopia optica y electronica. Sin embargo, pese a toda esta oferta, sigue siendo la clinica la que permite usar racionalmente estos avances y orientar hacia la posible etiologia, localizacion topografica y control evolutivo. Es de utilidad, para el enfoque diagnostico y la utilizacion de metodos auxiliares, que la localizacion topografica de la afectacion ya este esta ubicada en el cerebro, el cerebelo, el tallo, la medula, los nervios perifericos, la union mioneural o el musculo.

[Clinical and therapeutic aspects in Tunisian patients with dystonia: a 5-year prospective study]. / Aspects cliniques et thérapeutiques des dystonies en Tunisie : étude prospective sur cinq ans.

INTRODUCTION: Studies of dystonia are heterogeneous and there are no studies on this disease in Tunisia. The aim of our study was to determine the frequency of dystonia in the hospital population, to identify different forms of dystonia according to age of onset, distribution, to determine etiologies and to describe treatment. METHODS: We conducted a prospective study over a 5-year period (from January 2005 to November 2009) including all patients diagnosed with dystonia and followed at the Child and Adolescent Neurology Department and "Movement Disorders and Botulinum Toxin" consultation of the National Institute of Neurology of Tunis. RESULTS: Two hundred patients were included (2.2% of our patients). Mean age was 26.4±21.4 years and sex ratio H:F 1.3. Consanguinity rate was 29%. Main features of dystonia were action dystonia (78.5%), generalized forms (47%) and secondary forms (58%). A pyramidal syndrome and other movement disorders were the most common signs associated with dystonia (36.5% and 33.5% respectively). In the group of secondary dystonia, mains etiologies were dystonia due to exogenic agent (56%), neuro-metabolic diseases (26%), hereditary degenerative disease (13%) and psychogenic dystonia (5%). Dystonia was primary in 44% (84 patients). Different treatments were used and a dramatic improvement in some patients was noted with levodopa and botulinum toxin injections. A multidisciplinary approach associated with medical treatment led to recovery or improved prognosis. DISCUSSION AND CONCLUSION: Very few studies have been devoted to reporting a large series of dystonic patients. Our study is the first to describe both primary and secondary dystonia in 200 Tunisian patients. The presence of familial dystonia in our country suggests a genetic origin. Further work including genetic analysis with a screening of known mutations responsible for dystonia and the informative families with unknown mutations would be useful. Specific studies designed to identify new genes causal in dystonia are needed.

Slowly progressive encephalopathy with hearing loss due to a mutation in the mtDNA tRNA(Leu(CUN)) gene.

Pathogenic mutations in the tRNA(Leu(UCN)) gene of mitochondrial DNA (mtDNA) have been invariably accompanied by skeletal myopathy with or without chronic progressive external ophthalmoplegia (CPEO). We report a young woman with a heteroplasmic m.12276G>A mutation in tRNA(Leu(UCN)), who had childhood-onset and slowly progressive encephalopathy with ataxia, cognitive impairment, and hearing loss. Sequencing of the 22 tRNA mitochondrial genes is indicated in all unusual neurological syndromes, even in the absence of maternal inheritance.

Ataxias with autosomal, X-chromosomal or maternal inheritance.

Heredoataxias are a group of genetic disorders with a cerebellar syndrome as the leading clinical manifestation. The current classification distinguishes heredoataxias according to the trait of inheritance into autosomal dominant, autosomal recessive, X-linked, and maternally inherited heredoataxias. The autosomal dominant heredoataxias are separated into spinocerebellar ataxias (SCA1-8, 10-15, 17-23, 25-30, and dentato-rubro-pallido-luysian atrophy), episodic ataxias (EA1-7), and autosomal dominant mitochondrial heredoataxias (Leigh syndrome, MIRAS, ADOAD, and AD-CPEO). The autosomal recessive ataxias are separated into Friedreich ataxia, ataxia due to vitamin E deficiency, ataxia due to Abeta-lipoproteinemia, Refsum disease, late-onset Tay-Sachs disease, cerebrotendineous xanthomatosis, spinocerebellar ataxia with axonal neuropathy, ataxia telangiectasia, ataxia telangiectasia-like disorder, ataxia with oculomotor apraxia 1 and 2, spastic ataxia of Charlevoix-Saguenay, Cayman ataxia, Marinesco-Sjögren syndrome, and autosomal recessive mitochondrial ataxias (AR-CPEO, SANDO, SCAE, AHS, IOSCA, MEMSA, LBSL CoQ-deficiency, PDC-deficiency). Only two of the heredoataxias, fragile X/tremor/ataxia syndrome, and XLSA/A are transmitted via an X-linked trait. Maternally inherited heredoataxias are due to point mutations in genes encoding for tRNAs, rRNAs, respiratory chain subunits or single large scale deletions/duplications of the mitochondrial DNA and include MELAS, MERRF, KSS, PS, MILS, NARP, and non-syndromic mitochondrial disorders. Treatment of heredoataxias is symptomatic and supportive and may have a beneficial effect in single patients. **Please see page 424 for abbreviation list.

Early-onset neurodegenerative disease of the cerebellum and motor axons.

We describe a novel hereditary neurodegenerative disease of infancy affecting an Aboriginal family from northern Manitoba, Canada. The parents are nonconsanguineous, without a family history of neurodegenerative diseases. Four of 10 siblings (three males and one female) presented with neurologic abnormalities including arthrogryposis, seizures, and severe developmental delay shortly after birth. In two children, cerebellar atrophy and mild cerebral atrophy were documented on neuroimaging. Two children, a boy who died at age 40 months and a girl who died at age 22 months, underwent muscle biopsies at 3 weeks and 4 months of age, respectively. The biopsies revealed fiber-size variability in the boy, and grouped atrophy with fiber-type grouping in the girl. Two boys who died at ages 7.5 and 37 months underwent autopsies that indicated severe atrophy of the cerebellar hemispheres (especially the inferior lobules and vermis), hypomyelination of white-matter fascicles in the striatum, severe atrophy of corticospinal tracts in the brainstem and spinal cord, and atrophy of the anterior spinal roots. In the spinal cord, motor neuron cell bodies and the posterior columns were spared. This clinical entity likely represents a novel neurodegenerative disease of the cerebellum and long motor axons.

Defects in tongue papillae and taste sensation indicate a problem with neurotrophic support in various neurological diseases.

Neurotrophic support of developing neurons by neurotrophins is of critical importance in the development of fungiform papillae and taste buds. A number of neurological disorders show a decrease or increase in fungiform papillae or taste sensation. These can be grouped into disorders with reduced papillae (Machado-Joseph disease, Stüve-Wiedemann syndrome, familial dysautonomia, dystonia musculorum, and Behçet's disease) and those with taste defects only (Alzheimer's disease, Huntington's disease, hereditary sensory and autonomic neuropathy type IV, and diabetes mellitus). In addition, Parkinson's disease results in increased taste sensation. Here, we hypothesize that the main problem in these disorders is either not enough or too much neurotrophic support. Proneurotrophic drugs such as some antidepressants and aldose reductase inhibitors may prove useful in the treatment of these sensory and central nervous system disorders. Similarly, antineurotrophic drugs may also be useful in Parkinson's disease. Here we show that the protein involved in familial dysautonomia, IKAP, localizes to keratin filaments in HeLa cells, suggesting a role for the keratin cytoskeleton in neurotrophic support.

Aceruloplasminemia: a novel mutation in a family with marked phenotypic variability.

Hereditary aceruloplasminemia (HA) is a rare inherited disease characterized by anemia, iron overload, diabetes, and neurodegeneration. HA is caused by the homozygous mutation of the ceruloplasmin (CP) gene. We report two siblings with markedly different phenotypes carrying a novel mutation: a homozygous deletion of two nucleotides (1257-1258 TT del) causing the premature stop of the Cp protein translation (Y401X). An early diagnosis of iron overload was made in the female sibling who was subsequently treated with deferoxamine. At the age of 54, her neurologic symptoms were limited to mild akinetic signs and a history of seizures; moreover, her fasting blood glucose level never exceeded 120 mg/dL. The male sibling, who had not received any specific treatment for HA, developed severe diabetes at the age of 32 and at 48 manifested a progressively disabling neurologic disease. Possible physiopathological bases of these intrafamilial phenotypic variations are discussed.

Cognitive and behavioral assessment in the early stages of neurodegenerative extrapyramidal syndromes.

Parkinson's disease (PD), Dementia with Lewy Bodies (DLB), Progressive Supranuclear Palsy (PSP) and Corticobasal Degeneration Syndrome (CBDS) are the most common neurodegenerative extrapyramidal syndromes. Beyond motor symptoms, cognitive dysfunctions and behavioral disturbances are reported. Neuropsychological and neuropsychiatry features in the early stages, however, are under-investigated, and few comparison studies are available yet. The aim of the present study was to evaluate the cognitive and behavioral profile in the early stages of neurodegenerative extrapyramidal syndromes. Thirty-nine PD, 27 DLB, 16 CBDS, and 24 PSP were recruited. Groups were matched for global cognitive and motor impairment. The overall sample showed a common neuropsychological core characterized by visuospatial deficits. Although in the early stage of the disease, a high presence of behavioral disturbances was detected, depression and anxiety were the most common disorders, followed by apathy and sleep disturbances. The observation of overlapping clinical entities points the attention on the need of adjunctive diagnostic markers for early differential diagnosis.

Neuronal intranuclear hyaline inclusion disease showing motor-sensory and autonomic neuropathy.

BACKGROUND: Neuronal intranuclear hyaline inclusion disease (NIHID), a rare neurodegenerative disease in which eosinophilic intranuclear inclusions develop mainly in neurons, has not yet been described to present as hereditary motor-sensory and autonomic neuropathy. METHODS: Patients in two NIHID families showing peripheral neuropathy were evaluated clinically, electrophysiologically, and histopathologically. RESULTS: In both families, patients had severe muscle atrophy and weakness in limbs, limb girdle, and face; sensory impairment in the distal limbs; dysphagia, episodic intestinal pseudoobstruction with vomiting attacks; and urinary and fecal incontinence. No patients developed symptoms suggesting CNS involvement. Electrophysiologic study showed the reduced motor and sensory nerve conduction velocities and amplitudes, and also extensive denervation potentials. In sural nerve specimens, numbers of myelinated and unmyelinated fibers were decreased. In two autopsy cases, eosinophilic intranuclear inclusions were widespread, particularly in sympathetic and myenteric ganglion neurons, dorsal root ganglion neurons, and spinal motor neurons. These neurons also were decreased in number. CONCLUSION: Patients with neuronal intranuclear hyaline inclusion disease (NIHID) can manifest symptoms limited to those of peripheral neuropathy. NIHID therefore is part of the differential diagnosis of hereditary motor-sensory neuropathy associated with autonomic symptoms. Intranuclear hyaline inclusions in Schwann cells and in the myenteric plexus may permit antemortem diagnosis of NIHID.

[The role of the immune system in hereditary demyelinating neuropathies]. / Die Rolle des Immunsystems bei hereditären demyelinisierenden Neuropathien.

Hereditary neuropathies, e.g., Charcot-Marie-Tooth (CMT) disease, are inherited diseases of the peripheral nervous system causing chronic progressive motor and sensory dysfunction. Most neuropathies are due to mutations in myelin genes such as PMP22, P0, and the gap junction protein Cx32. Myelin mutant mice are regarded as suitable animal models for several forms of hereditary neuropathies and are important neurobiological tools for the evaluation of pathogenetic and therapeutic concepts in hereditary neuropathies. Using these animal models we could recently show that the immune system is involved in the pathogenesis of hereditary neuropathies. Due to the phenotypic similarities we also consider the immune system important for human inherited neuropathies, in particular since several case reports demonstrate a beneficial effect of immune therapies in patients with hereditary neuropathies. In this review we compare findings from animal models and human disease to elucidate the role of the immune system in hereditary neuropathies.