Motor Organization in Schizencephaly: Outcomes of Transcranial Magnetic Stimulation and Diffusion Tensor Imaging of Motor Tract Projections Correlate with the Different Domains of Hand Function.

OBJECTIVE: Schizencephaly is a rare congenital malformation that causes motor impairment. To determine the treatment strategy, each domain of the motor functions should be appropriately evaluated. We correlated a color map of diffusion tensor imaging (DTI) and transcranial magnetic stimulation (TMS) with the hand function test (HFT) to identify the type of hand function that each test (DTI and TMS) reflects. Further, we attempted to demonstrate the motor neuron organization in schizencephaly. METHOD: This retrospective study was conducted on 12 patients with schizencephaly. TMS was conducted in the first dorsal interosseous (FDI), biceps (BB), and deltoid muscles of the upper extremity, and contralateral MEP (cMEP) and ipsilateral MEP (iMEP) were recorded. The HFT included the grip strength, box and block (B&B), and 9-hole peg test. The schizencephalic cleft was confirmed using magnetic resonance imaging, and the corticospinal tract (CST) was identified using the color map of DTI. The symmetry indices for the peduncle and CST at pons level were calculated as the ratios of the cross-sectional area of the less-affected side and that of the more-affected side. RESULT: In the more-affected hemisphere TMS, no iMEP was obtained. In the less-affected hemisphere TMS, the iMEP response was detected in 9 patients and cMEP in all patients, which was similar to the pattern observed in unilateral lesion. Paretic hand grip strength was strongly correlated with the presence of iMEP (p = 0.044). The symmetry index of the color map of DTI was significantly correlated with the B&B (p = 0.008, R 2 = 0.416), whereas the symmetry index of the peduncle was not correlated with all HFTs. CONCLUSION: In patients with schizencephaly, the iMEP response rate is correlated with the hand function related to strength, while the symmetricity of the CST by the color map of DTI is correlated with the hand function associated with dexterity. Additionally, we suggest the possible motor organization pattern of schizencephaly following interhemispheric competition.

Fumarase Deficiency: A Case With a New Pathogenic Mutation and a Review of the Literature.

Fumarase deficiency (FD) is a rare and severe autosomal disorder, caused by inactivity of the enzyme fumarase, due to biallelic mutations of the fumarase hydratase (FH) gene. Several pathogenic mutations have been published. The article describes an infant with failure to thrive, microcephaly, axial hypotonia, and developmental retardation with increased excretion of fumarate, no activity of fumarase and a homozygous mutation of the FH gene, which was until recently only known as a variant of unknown significance. Carriers of pathogenic mutations in the FH gene are at risk for developing renal cell carcinoma and should therefore be screened. Both parents were healthy carriers of the mutation and had decreased levels of enzyme activity. In addition, the article presents an overview and analysis of all cases of FD reported thus far in the literature.

Combined HIV-1 Tat and oxycodone activate the hypothalamic-pituitary-adrenal and -gonadal axes and promote psychomotor, affective, and cognitive dysfunction in female mice.

The majority of HIV+ patients present with neuroendocrine dysfunction and ~50% experience co-morbid neurological symptoms including motor, affective, and cognitive dysfunction, collectively termed neuroHIV. In preclinical models, the neurotoxic HIV-1 regulatory protein, trans-activator of transcription (Tat), promotes neuroHIV pathology that can be exacerbated by opioids. We and others find gonadal steroids, estradiol (E2) or progesterone (P4), to rescue Tat-mediated pathology. However, the combined effects of Tat and opioids on neuroendocrine function and the subsequent ameliorative capacity of gonadal steroids are unknown. We found that conditional HIV-1 Tat expression in naturally-cycling transgenic mice dose-dependently potentiated oxycodone-mediated psychomotor behavior. Tat increased depression-like behavior in a tail-suspension test among proestrous mice, but decreased it among diestrous mice (who already demonstrated greater depression-like behavior); oxycodone reversed these effects. Combined Tat and oxycodone produced apparent behavioral disinhibition of anxiety-like responding which was greater on diestrus than on proestrus. These mice made more central entries in an open field, but spent less time there and demonstrated greater circulating corticosterone. Tat increased the E2:P4 ratio of circulating steroids on diestrus and acute oxycodone attenuated this effect, but repeated oxycodone exacerbated it. Corticotropin-releasing factor was increased by Tat expression, acute oxycodone exposure, and was greater on diestrus compared to proestrus. In human neuroblastoma cells, Tat exerted neurotoxicity that was ameliorated by E2 (1 or 10 nM) or P4 (100, but not 10 nM) independent of oxycodone. Oxycodone decreased gene expression of estrogen and κ-opioid receptors. Thus, neuroendocrine function may be an important target for HIV-1 Tat/opioid interactions.

Loss of Wwox Causes Defective Development of Cerebral Cortex with Hypomyelination in a Rat Model of Lethal Dwarfism with Epilepsy.

WW domain-containing oxidoreductase (Wwox) is a putative tumor suppressor. Several germline mutations of Wwox have been associated with infant neurological disorders characterized by epilepsy, growth retardation, and early death. Less is known, however, about the pathological link between Wwox mutations and these disorders or the physiological role of Wwox in brain development. In this study, we examined age-related expression and histological localization of Wwox in forebrains as well as the effects of loss of function mutations in the Wwox gene in the immature cortex of a rat model of lethal dwarfism with epilepsy (lde/lde). Immunostaining revealed that Wwox is expressed in neurons, astrocytes, and oligodendrocytes. lde/lde cortices were characterized by a reduction in neurite growth without a reduced number of neurons, severe reduction in myelination with a reduced number of mature oligodendrocytes, and a reduction in cell populations of astrocytes and microglia. These results indicate that Wwox is essential for normal development of neurons and glial cells in the cerebral cortex.

Fumarate hydratase (FH) deficiency in uterine leiomyomas: recognition by histological features versus blind immunoscreening.

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome is a rare autosomal dominant disease caused by germline mutations in the fumarate hydratase (FH) gene. Affected individuals develop cutaneous and uterine leiomyomas and aggressive RCC. To date, only few publications described the frequency and morphology of FH-deficient uterine leiomyomas. We reviewed 22 cases collected over 8 years from routine and consultation files based on distinctive histological features. In addition, we screened 580 consecutive uterine leiomyomas from 484 patients, 23 extra-uterine and 8 uterine leiomyosarcomas, and 6 leiomyomas with bizarre nuclei for FH loss using immunohistochemistry (IHC) on tissue microarrays (TMAs). All 22 FH-deficient cases were suspected on H&E sections and confirmed by FH IHC. Patients' ages ranged from 25 to 70 years (median 36). Seventeen patients had multiple nodules (2-14) measuring up to 11.8 cm. None of the patients had stigmata or family history of the HLRCC syndrome. Histologically, all FH-deficient tumors showed consistent and reproducible features as reported previously. FH loss was detected in 2/534 evaluable leiomyomas (0.4%), but in none of leiomyosarcomas. Two of six leiomyomas with bizarre nuclei were FH-deficient. FH-deficient uterine leiomyomas are rare in routine material (= 0.4%). They can be reliably identified or suspected by consistent morphological features. Our data showed predictive morphology to be superior to blind IHC screening for detecting them. The relationship of FH-deficient uterine smooth muscle tumors to the HLRCC syndrome needs further clarification.

Mutations in the X-linked ATP6AP2 cause a glycosylation disorder with autophagic defects.

The biogenesis of the multi-subunit vacuolar-type H+-ATPase (V-ATPase) is initiated in the endoplasmic reticulum with the assembly of the proton pore V0, which is controlled by a group of assembly factors. Here, we identify two hemizygous missense mutations in the extracellular domain of the accessory V-ATPase subunit ATP6AP2 (also known as the [pro]renin receptor) responsible for a glycosylation disorder with liver disease, immunodeficiency, cutis laxa, and psychomotor impairment. We show that ATP6AP2 deficiency in the mouse liver caused hypoglycosylation of serum proteins and autophagy defects. The introduction of one of the missense mutations into Drosophila led to reduced survival and altered lipid metabolism. We further demonstrate that in the liver-like fat body, the autophagic dysregulation was associated with defects in lysosomal acidification and mammalian target of rapamycin (mTOR) signaling. Finally, both ATP6AP2 mutations impaired protein stability and the interaction with ATP6AP1, a member of the V0 assembly complex. Collectively, our data suggest that the missense mutations in ATP6AP2 lead to impaired V-ATPase assembly and subsequent defects in glycosylation and autophagy.

Cascade Fumarate Hydratase mutation screening allows early detection of kidney tumour: a case report.

BACKGROUND: Fumarate hydratase (FH) deficiency is a rare autosomal recessive disorder which results in a major defect in cellular metabolism. It presents in infancy with progressive encephalopathy, hypotonia, seizures and failure to thrive and is often fatal in childhood. It is caused by mutations in the FH gene (1q42.1) that result in deficiency of the citric acid cycle enzyme fumarate hydratase, resulting in accumulation of fumaric acid. Heterozygous germline mutations in the FH gene predispose to an aggressive autosomal dominant inherited early-onset kidney cancer syndrome: hereditary leiomyomatosis and renal cell cancer (HLRCC). CASE PRESENTATION: Cascade FH mutation screening enabled the early diagnosis of a renal tumour in an asymptomatic parent of a child with fumarate hydratase deficiency, resulting in timely and possibly life-saving treatment. CONCLUSION: While the theoretical risk of kidney cancer in parents of children with recessive fumarate hydratase deficiency is well recognized, to our knowledge this is the first report of a kidney tumour being detected in a parent by screening performed for this indication. This underscores the importance of offering lifelong kidney surveillance to such parents and other heterozygous relatives of children born with fumarate hydratase deficiency.

Neurobehavioural Toxicity of Iron Oxide Nanoparticles in Mice.

Iron oxide nanoparticles (Fe2O3-NPs) are widely used in various biomedical applications, extremely in neurotheranostics. Simultaneously, Fe2O3-NP usage is of alarming concern, as its exposure to living systems causes deleterious effects due to its redox potential. However, study on the neurobehavioural impacts of Fe2O3-NPs is very limited. In this regard, adult male mice were intraperitoneally administered with Fe2O3-NPs (25 and 50 mg/kg body weight) once a week for 4 weeks. A significant change in locomotor behaviour and spatial memory was observed in Fe2O3-NP-treated animals. Damages to blood-brain barrier permeability by Fe2O3-NPs and their accumulation in brain regions were evidenced by Evan's blue staining, iron estimation and Prussian blue staining. Elevated nitric oxide, acetylcholinesterase, lactate dehydrogenase leakage and demyelination were observed in the Fe2O3-NP-exposed brain tissues. Imbalanced levels of ROS generation and antioxidant defence mechanism (superoxide dismutase and catalase) cause damages to lipids, proteins and DNA. PARP and cleaved caspase 3 expression levels were found to be increased in the Fe2O3-NP-exposed brain regions which confirms DNA damage and apoptosis. Thus, repeated Fe2O3-NP exposure causes neurobehavioural impairments by nanoparticle accumulation, oxidative stress and apoptosis in the mouse brain.

Novel mutations in KARS cause hypertrophic cardiomyopathy and combined mitochondrial respiratory chain defect.

Mutations in KARS, which encodes for both mitochondrial and cytoplasmic lysyl-tRNA synthetase, have been so far associated with three different phenotypes: the recessive form of Charcot-Mary-Tooth polyneuropathy, the autosomal recessive nonsyndromic hearing loss and the last recently described condition related to congenital visual impairment and progressive microcephaly. Here we report the case of a 14-year-old girl with severe cardiomyopathy associated to mild psychomotor delay and mild myopathy; moreover, a diffuse reduction of cytochrome C oxidase (COX, complex IV) and a combined enzymatic defect of complex I (CI) and complex IV (CIV) was evident in muscle biopsy. Using the TruSight One sequencing panel we identified two novel mutations in KARS. Both mutations, never reported previously, occur in a highly conserved region of the catalytic domain and displayed a dramatic effect on KARS stability. Structural analysis confirmed the pathogenic role of the identified variants. Our findings confirm and emphasize that mt-aminoacyl-tRNA synthetases (mt-ARSs) enzymes are related to a broad clinical spectrum due to their multiple and still unknown functions.

Deletion of adenosine A2A receptors from astrocytes disrupts glutamate homeostasis leading to psychomotor and cognitive impairment: relevance to schizophrenia.

BACKGROUND: Adenosine A2A receptors (A2AR) modulate dopamine and glutamate signaling and thereby may influence some of the psychomotor and cognitive processes associated with schizophrenia. Because astroglial A2AR regulate the availability of glutamate, we hypothesized that they might play an unprecedented role in some of the processes leading to the development of schizophrenia, which we investigated using a mouse line with a selective deletion of A2AR in astrocytes (Gfa2-A2AR knockout [KO] mice]. METHODS: We examined Gfa2-A2AR KO mice for behaviors thought to recapitulate some features of schizophrenia, namely enhanced MK-801 psychomotor response (positive symptoms) and decreased working memory (cognitive symptoms). In addition, we probed for neurochemical alterations in the glutamatergic circuitry, evaluating glutamate uptake and release and the levels of key proteins defining glutamatergic signaling (glutamate transporter-I [GLT-I], N-methyl-D-aspartate receptors [NMDA-R] and α-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors [AMPA-R]) to provide a mechanistic understanding of the phenotype encountered. RESULTS: We show that Gfa2-A2AR KO mice exhibited enhanced MK-801 psychomotor response and decreased working memory; this was accompanied by a disruption of glutamate homeostasis characterized by aberrant GLT-I activity, increased presynaptic glutamate release, NMDA-R 2B subunit upregulation, and increased internalization of AMPA-R. Accordingly, selective GLT-I inhibition or blockade of GluR1/2 endocytosis prevented the psychomotor and cognitive phenotypes in Gfa2-A2AR KO mice, namely in the nucleus accumbens. CONCLUSIONS: These results show that the dysfunction of astrocytic A2AR, by controlling GLT-I activity, triggers an astrocyte-to-neuron wave of communication resulting in disrupted glutamate homeostasis, thought to underlie several endophenotypes relevant to schizophrenia.

Human diseases of the SSU processome.

Ribosomes are the cellular machines responsible for protein synthesis. Ribosome biogenesis, the production of ribosomes, is a complex process involving pre-ribosomal RNA (rRNA) cleavages and modifications as well as ribosomal protein assembly around the rRNAs to create the functional ribosome. The small subunit (SSU) processome is a large ribonucleoprotein (RNP) in eukaryotes required for the assembly of the SSU of the ribosome as well as for the maturation of the 18S rRNA. Despite the fundamental nature of the SSU processome to the survival of any eukaryotic cell, mutations in SSU processome components have been implicated in human diseases. Three SSU processome components and their related human diseases will be explored in this review: hUTP4/Cirhin, implicated in North American Indian childhood cirrhosis (NAIC); UTP14, implicated in infertility, ovarian cancer, and scleroderma; and EMG1, implicated in Bowen-Conradi syndrome (BCS). Diseases with suggestive, though inconclusive, evidence for the involvement of the SSU processome in their pathogenesis are also discussed, including a novel putative ribosomopathy. This article is part of a Special Issue entitled: Role of the Nucleolus in Human Disease.

Neuroimaging and neurological findings in patients with hypochondroplasia and FGFR3 N540K mutation.

Hypochondroplasia (HCH), an autosomal dominant skeletal dysplasia caused by mutations in the FGFR3 gene, has not been commonly associated with neurological problems. Temporal lobe dysgenesis associated with epilepsy was recently described in single patients. In this retrospective study, we assessed neurological and neuroimaging aspects of 13 FGFR3 (N540K) mutation verified HCH patients in Finland. Eight patients had neurocognitive difficulties, ranging from specific learning disorder (2/13) to mild intellectual disability (5/13) or global developmental delay (1/13). Six of 13 patients had a history of seizures or epilepsy. Eight patients had undergone MRI. They all had structural abnormalities consistent with temporal lobe dysgenesis. Six patients had peritrigonal white matter reduction, and 4 had abnormally shaped lateral ventricles. We recommend a close follow-up of development in patients with HCH and a low threshold for neuroimaging.

The KAT6B-related disorders genitopatellar syndrome and Ohdo/SBBYS syndrome have distinct clinical features reflecting distinct molecular mechanisms.

Genitopatellar syndrome (GPS) and Say-Barber-Biesecker-Young-Simpson syndrome (SBBYSS or Ohdo syndrome) have both recently been shown to be caused by distinct mutations in the histone acetyltransferase KAT6B (a.k.a. MYST4/MORF). All variants are de novo dominant mutations that lead to protein truncation. Mutations leading to GPS occur in the proximal portion of the last exon and lead to the expression of a protein without a C-terminal domain. Mutations leading to SBBYSS occur either throughout the gene, leading to nonsense-mediated decay, or more distally in the last exon. Features present only in GPS are contractures, anomalies of the spine, ribs and pelvis, renal cysts, hydronephrosis, and agenesis of the corpus callosum. Features present only in SBBYSS include long thumbs and long great toes and lacrimal duct abnormalities. Several features occur in both, such as intellectual disability, congenital heart defects, and genital and patellar anomalies. We propose that haploinsufficiency or loss of a function mediated by the C-terminal domain causes the common features, whereas gain-of-function activities would explain the features unique to GPS. Further molecular studies and the compilation of mutations in a database for genotype-phenotype correlations (www.LOVD.nl/KAT6B) might help tease out answers to these questions and understand the developmental programs dysregulated by the different truncations.

21 Mb deletion in chromosome band 13q22.2q32.1 associated with mild/moderate psychomotor retardation, growth hormone insufficiency, short neck, micrognathia, hypotonia, dysplastic ears and other dysmorphic features.

We report on a 9-month old boy carrying a 21 Mb de novo 13q interstitial deletion. The imbalance was detected by chromosomal analysis and investigated by Fluorescence In Situ Hybridization (FISH) and Comparative Genomic Hybridization (array-CGH) using two different platforms: a BAC microarray with 516 kb resolution (Cytochip) and a 15 kb resolution oligonucleotide microarray (Agilent 244K). The deletion has been estimated to span 21.46 Mb on chromosomal bands 13q22.2-13q32.1. The patient has mild/moderate psychomotor retardation, growth hormone insufficiency, hypertelorism, short neck, micrognathia, hypotonia, dysplastic ears and other dysmorphic features. Further investigation revealed that the abnormality is de novo and causative of the patient's phenotype. The described patient is unique among similar rare cases with different deletion breakpoints. It is the first case of 13q22.2q32.1 deletion where the breakpoints are clearly defined, indicating the importance of detailed clinical description and high-resolution genomic analysis for characterization of rare genetic syndromes.

Anisotropy of transcallosal motor fibres indicates functional impairment in children with periventricular leukomalacia.

AIM: In children with bilateral spastic cerebral palsy (CP), periventricular leukomalacia (PVL) is commonly identified on magnetic resonance imaging. We characterized this white matter condition by examining callosal microstructure, interhemispheric inhibitory competence (IIC), and mirror movements. METHOD: We examined seven children (age range 11y 9mo-17y 9mo, median age 15y 10mo, four females, three males) with bilateral spastic CP/PVL (Gross Motor Function Classification System level I or II, Manual Ability Classification System level I) and 12 age-matched controls (age range 11y 7mo-17y 1mo, median age 15y 6mo, seven females, five males). Fractional anisotropy of the transcallosal motor fibres (TCMF) and the corticospinal tract (CST) of both sides were calculated. The parameters of IIC (transcranial magnetic stimulation) and mirror movements were measured using a standardized clinical examination and a computer-based hand motor test. RESULTS: Fractional anisotropy was lower in children with bilateral spastic CP/PVL regarding the TCMF, but not the left or right CST. Resting motor threshold was elevated in children with bilateral spastic CP/PVL whereas measures of IIC tended to be lower. Mirror movements were markedly elevated in bilateral spastic CP/PVL. INTERPRETATION: This study provides new information on different aspects of motor function in children with bilateral spastic CP/PVL. Decreased fractional anisotropy of TCMF is consistent with impairment of hand motor function in children with bilateral spastic CP/PVL. The previously overlooked microstructure of the TCMF may serve as a potential indicator for hand motor function in patients with bilateral spastic CP/PVL.

The usefulness of operant conditioning procedures to assess long-lasting deficits following transient focal ischemia in mice.

In this study, we examined a number of short and long-term sensorimotor, behavioural and cognitive consequences of an experimental ischemia induced by a 60-min right middle cerebral artery occlusion (MCAO) in 129S2 mice. During 14 days after surgery, a classical sensorimotor assessment was conducted using hanging wire test, negative geotaxis test, grip strength test, accelerated rotarod test and locomotor activity-meter. In order to provide a technique for the assessment of more resistant consequences of ischemia on fine psychomotor control, the peak procedure (a modified version of the operant fixed-interval schedule of reinforcement) was used. This procedure also helped to objectify temporal perception in mice five weeks following surgery. On several sensorimotor tests, ischemic mice showed some degree of impairment which rapidly tended to improve after stroke, a profile of results substantially consistent with previous studies. Five weeks post-surgery, ischemic mice tested with the peak procedure exhibited a moderate but yet significant temporal regulation impairment along with a reduced response rate compared to control mice. The present results suggest that the peak procedure and other derived operant schedules of reinforcement may provide useful and sensitive tools for the long-term assessment of both behavioural and cognitive aspects of the consequences of an experimental ischemia.

Mega-corpus callosum, polymicrogyria, and psychomotor retardation: confirmation of a syndromic entity.

A mega-corpus callosum (CC) is not a common manifestation of neurological disease. Previous reports of patients with a constellation of findings including megalencephaly, perisylvian polymicrogyria, distinct facies, psychomotor retardation and mega-corpus callosum were designated as having megalencephaly, mega-corpus callosum, and complete lack of motor development [OMIM 603387; also referred to as megalencephaly-polymicrogyria-mega-corpus callosum (MEG-PMG-MegaCC)] syndrome. Three patients were initially reported with this syndrome, and a fourth was reported recently. Another case had similar findings in utero and upon autopsy. We present an additional patient who conforms to this phenotype; however, he is not megalencephalic, but has a normal head circumference in the setting of short stature. This patient is also noted to have abnormal saccades and mask-like facies. His motor function is more developed than in the other reported patients and was further improved by treatment with L-DOPA/carbidopa, which was started because of his extrapryramidal symptoms and signs which were associated with low cerebral spinal fluid (CSF) catecholamine levels.

[Multiple familial cerebral cavernomatosis]. / Cavernomatosis múltiple cerebral familiar.

INTRODUCTION: Intracraneal vascular malformations are congenital lesions due to alterations in the development of arteriocapillary network. Cavernomas are present in 0.4% of people, and represent 5-13% of all cerebrovascular malformations. They are multilobulated clearly delimited lesions that contain blood at different evolution. Cavernomas can be single or multiple, and sporadic or familial. Inheritance pattern in familial cases is autosomal dominant and three involved genes have been described. CASE REPORTS: We made a retrospective review of clinical histories of two patients diagnosed of multiple familial cavernomatosis. First patient's onset was with partial seizures. Magnetic resonance (MR) showed a frontal cavernoma probable responsible of seizures, and other lesions in frontal and parietal lobes. Second patient consulted for psychomotor delay and behaviour disorder. MR showed multiple cavernomas. In the first patient, one lesion was surgically removed. In second patient, the attitude was expectant. In both cases familial study was done and multiple cavernomas were found in both parents. CONCLUSIONS: Cavernomas are a type of vascular malformations with specific histological features. Usual clinical characteristics are seizures and parenchymatous bleeding. The appearance of MR has permitted the diagnosis of asymptomatic cavernomas and is currently considered to be the technique of choice for this purpose. In familial cases, multiple lesions are found in 84%, often in association with family history of seizures. Surgical treatment must be considered in patients with symptomatic or progressive lesions that are accessible. All cases must be clinically and MR followed.