Cerebellar and brainstem involvement in familial juvenile nephronophthisis type I

We report on an 11-year-old boy with familial juvenile nephronophthisis type I associated with cerebellar ataxia and nystagmus, but not with ocular motor apraxia. An MRI revealed hypoplasia of the brainstem and vermis, and an enlargement of the fourth ventricle. A molecular genetic analysis demonstrated a homozygous deletion including the NPHP1 gene. These findings suggest that NPHP1 may play an important role in the normal development of the brainstem and the cerebellum as well as renal tissue.     

Motor-related functional subdivisions of human lateral premotor cortex: epicortical recording in conditional visuomotor task.

OBJECTIVE: To clarify the functional subdivisions of the human lateral premotor cortex (PM) in the visuomotor control. METHODS: Event-related potentials (ERPs) were epicortically recorded from PM in 5 epilepsy patients. S1-Go/NoGo choice delayed reaction time (RT), S1-warned S2-Go simple RT and control fixation paradigms were compared using paired visual stimuli (S1, S2). RESULTS: Signal-related activity peaked at 176-194 ms after S1 in the ventrorostral PM (PMvr) in all 3 paradigms, indicating its role in signal perception. Early set-related activity was recorded with its peak <810 ms after S1 in the dorsorostral PM (PMdr) and was larger in the choice than in the simple RT paradigm, suggesting its role in signal selection. Its cognitive component was recorded as surface-positive transients at PMdr, while its motoric aspect, seen as negative transients, extended to the caudal PM. Late sustained set-related activity was observed in preparation for hand movement in the caudal PM at the hand and face positive motor areas. After presentation of S2, movement-related activity was observed at the hand sensorimotor area for motor execution, following the signal-related activity at PMvr. CONCLUSIONS: The present ERP study suggests the temporally sequential representation of predominantly 'cognitive' function in the rostral PM and 'motor' function in the caudal PM. SIGNIFICANCE: The rostrocaudal cognitive-motor gradient was demonstrated in the lateral premotor cortex in humans by means of an epicortical ERP approach.     

Subclinical central pontine myelinolysis following liver transplantation

Central pontine myelinolysis (CPM) is a demyelinating disorder of unknown origin that almost exclusively affects the central portion of the basis pontis, and is one of the fatal neurological complications after liver transplantation. We describe two children with CPM detected incidentally after liver transplantation. To our knowledge, this is the first report of CPM diagnosed antemortem in children who had undergone liver transplantation. In our patients, there were no clinical manifestations associated with CPM. We conclude that, including silent cases such as our patients, CPM may be more prevalent than previously appreciated following liver transplantation.     

Velamentous cord insertion caused by oblique implantation after in vitro fertilization and embryo transfer

We present a case of a 36-year-old pregnant female after intracytoplasmic sperm injection. Ultrasonographic examination at 8?weeks' gestation revealed umbilical cord insertion with a viable fetus located on the septum membrane of dichorionic twin pregnancy near the anterior wall, while the other fetus was observed to have vanished. Next, this umbilical cord was seen to connect to the anterior wall and the placenta developed on the posterior wall later in the pregnancy. As a result, velamentous cord insertion with long membranous umbilical vessels developed at the time of delivery. The present case indicates that the assessment of the cord insertion site during the early gestation period is very important to predict any abnormality of the cord insertion site at the time of delivery. Furthermore, this case is valuable to understand the pathophysiological development of the placenta and velamentous cord insertion.     

IFN-inducible protein 10 (CXCL10) regulates tubular cell proliferation in renal ischemia-reperfusion injury

Although renal tubular cell proliferation after acute tubular necrosis is an important and essential response in the recovery of renal dysfunction in acute renal failure, the precise factors and mechanisms of tubular cell regeneration remain unclear. Here, we describe our studies using a neutralizing antibody (Ab) against interferon-inducible protein of 10 kDa (IP-10; CXCL10) that indicate a role for CXCL10 in tubular cell proliferation after renal ischemia-reperfusion injury. Tissue necrosis and interstitial infiltrating numbers were comparable between anti-CXCL10 Ab-treated and control mice treated with IgG at the 24 and 48 h time points after reperfusion. In contrast, the numbers of Ki67-positive proliferating tubular cells were significantly increased in anti-CXCL10 Ab-treated mice 48 h after reperfusion. In accordance with the in vivo findings,in vitro studies using murine tubular epithelial cells indicated an antiproliferative effect of CXCL10 upon the intensity of cell proliferation and the number of Ki67-positive cells. These data suggest that CXCL10 plays a role in the regulation of tubular cell proliferation following renal ischemia-reperfusion injury.     

Aberrant somatosensory-evoked responses imply GABAergic dysfunction in Angelman syndrome

A role for gamma-aminobutyric acid (GABA)ergic inhibition in cortical sensory processing is one of the principle concerns of brain research. Angelman syndrome (AS) is thought to be one of the few neurodevelopmental disorders with GABAergic-related genetic involvement. AS results from a functional deficit of the imprinted UBE3A gene, located at 15q11-q13, resulting mainly from a 4-Mb deletion that includes GABA(A) receptor subunit genes. These genes are believed to affect the GABAergic system and modulate the clinical severity of AS. To understand the underlying cortical dysfunction, we have investigated the primary somatosensory-evoked responses in AS patients. Subjects included eleven AS patients with a 15q11-q13 deletion (AS Del), two AS patients without a 15q11-q13 deletion, but with a UBE3A mutation (AS non-Del), six epilepsy patients (non-AS) and eleven normal control subjects. Somatosensory-evoked fields (SEFs) in response to median nerve stimulation were measured by magnetoencephalography. The N1m peak latency in AS Del patients was significantly longer (34.6+/-4.8 ms) than in non-AS patients (19.5+/-1.2 ms, P<0.001) or normal control subjects (18.4+/-1.8 ms, P<0.001). The next component, P1m, was prolonged and ambiguous and was only detected in patients taking clonazepam. In contrast, SEF waveforms of AS non-Del patients were similar to those of control individuals, rather than to AS Del patients. Thus, GABAergic dysfunction in AS Del patients is likely due to hemizygosity of GABA(A) receptor subunit genes, suggesting that GABAergic inhibition plays an important role in synchronous activity of human sensory systems.     

A Flow-Through Capnometer for Obstructive Sleep Apnea

Introduction

Capnogram is often distorted due to aspiration of expired gas when a sidestream capnometer is used for non-intubated, spontaneously breathing condition. The purpose of this study was to make a flow-through capnometer without aspiration and to check if this capnometer precisely detected apnea during obstructive sleep apnea (OSA).

Methods

(1) Flow-through capnometer The capnometer consisted of a flow-through etCO₂ sensor, cap-ONE^®, and an accompanying capnometer. The size of cap-ONE^® was small enough to be fitted under the nose where gas expired from the nose and the mouth passed through. Thus, the expired gas to be measured is directly blown into the cap-ONE^®. (2) The cap-ONE^® using a spontaneously breathing model Capnograms obtained by the cap-ONE^® and sidestream capnometers during nasal and oral breathing under normal and reduced ventilation were compared with a reference capnogram. (3) Clinical study with OSA patients With nineteen OSA patients capnograms during apnea events diagnosed as OSA by polysomnography were examined using the cap-ONE^®. (4) Simulation study with an OSA model Apnea in which inspiratory flow was zero and small expiratory flows repeated was produced. Capnograms and apnea detection were compared between the cap-ONE^® and sidestream capnometers.

Results

In the spontaneouly breathing model capnograms and etCO₂ of the cap-ONE^® during nasal and oral breathing were almost identical with the reference capnogram but those of sidetream capnometers during oral breathing were significantly reduced. In the clinical study 41% of total OSA events showed capnograms with prolonged and elevated phase with small ripples. In a simulation study reduction of CO₂ tension during no-inspiration was small and apnea was successfully detected with the cap-ONE^®. However, with sidestream capnometers the reduction of CO₂ tension was large and apnea was not detected.

Conclusions

We concluded that the cap-ONE^® can record capnograms with minimum distortion and detect apnea reliably during OSA.

     

Downbeat positioning nystagmus is a common clinical feature despite variable phenotypes in an FHM1 family

Clinical examinations and mutational analyses were carried out in three patients of a Japanese familial hemiplegic migraine (FHM) pedigree. Each affected member demonstrated a broad clinical spectrum that included hemiplegic migraine with progressive cerebellar ataxia, migraine without aura, and episodic ataxia. Despite this variability, all members exhibited marked downbeat positioning nystagmus, and magnetic resonance images (MRI) all showed cerebellar atrophy predominantly of the cerebellar vermis. All affected members had a T666M missense mutation in the protein encoded by the CACNA1A gene (calcium channel, voltage-dependent, P/Q type, alpha 1A subunit). Although clinical features associated with the T666M CACNA1A mutation are highly variable, downbeat positioning nystagmus may be an important clinical feature of this disease.