A Bloembergen-Purcell-Pound 13C NMR relaxation study of the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate.

The molecular structure and rotational motion of the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) were studied over a wide temperature range using the Bloembergen-Purcell-Pound 13C NMR spin-lattice relaxation method and NOE factors. Examination of the spin-lattice relaxation times (T1) and the rates (R1 = 1/T1) of the 1-butyl-3-methylimidazolium cation reveals the relative motions of each carbon in the imidazolium cation. The rotational characteristics of the [BMIM] cation are supported by ab-initio molecular structures of [BMIM][PF6] using density functional theory (DFT) and Hartree-Fock (HF) methods. The ab-initio gas phase structures of [BMIM][PF6] indicate that the 1-butyl-3-methylimidazolium C2 hydrogen, the ring methyl group, and the butyl side-chain hydrogen atoms form hydrogen bonds with the hexafluorophosphate anion.

Cerebral vasculitis in a case of Sydenham's chorea.

A 10-year-old girl with acute-onset hemichorea had multiple areas of abnormal signal seen on magnetic resonance imaging of the brain, associated with middle and anterior cerebral artery vasculitis seen on cerebral angiography. Her serology and clinical course were supportive of the diagnosis of Sydenham's chorea. Other causes of cerebral vasculitis were excluded. Follow-up studies revealed resolution of changes seen on magnetic resonance imaging and partial resolution of angiographic abnormalities. This is the first report of abnormal cerebral angiography in Sydenham's chorea.

Efficacy of lamotrigine in refractory neonatal seizures.

A newborn infant with seizures of unknown etiology that were refractory to treatment with phenobarbitone, phenytoin, midazolam, clonazepam, and vigabatrin is reported. The introduction of the new antiepileptic drug lamotrigine was followed by rapid and sustained control of the seizures.

Dermoid of cavernous sinus resulting in isolated oculomotor nerve palsy.

Intracranial dermoid cysts and acquired oculomotor nerve palsies are individually rare in childhood. This report describes a 4-year-old boy with acute oculomotor nerve palsy and pupillary sparing secondary to a dermoid within the lateral wall of the cavernous sinus. The clinical signs resolved after complete surgical excision of the tumor with no evidence of recurrence on computed tomography 1 year later. This is the first case report in childhood of a dermoid within the cavernous sinus and of an isolated oculomotor nerve palsy due to a dermoid cyst.

Normal values for the two-point discrimination test.

A 2-point discrimination study was conducted with 112 normal children, ages 2-13 years. The goal was to determine the age at which children can reliably cooperate in performing the 2-point discrimination test and to discover the normal values on the fingertips and feet for different ages, as well as to study the changes in these values with age. It was found that from age 6 years and older all children could perform the test and that discrimination ability improved with age, but was only of statistical significance for the feet parameters.

ACTH treatment in intractable seizures of childhood.

Between 1980 and 1989, 21 children suffering from intractable seizures other than infantile spasms were treated with intramuscular ACTH at the Children's Hospital Camperdown. Five patients had two courses of ACTH therapy, 24% of patients had a good response (group A), 56% responded transiently (group B) and 20% did not respond (group C). Group A had normal development and no neurological deficits prior to seizures. A favourable response was not observed in patients with partial seizures, 90% of the patients who responded had a recurrence of seizures. Mean time to recurrence was 9.0 +/- 7.3 months in group A and 1.6 +/- 2.0 months in group B. Hypokalaemia, hypertension and infection were found in 42.9%, 33.3% and 19.1% respectively. ACTH also had effects on concurrent anti-epileptic drug levels.

Membrane plasma exchange in experimental allergic neuritis: effect on antibody levels and clinical course.

The effect of membrane plasma exchange on the course of chronic experimental allergic neuritis in rabbits is described. Using miniature membrane plasma separators conscious animals were treated with 4 exchanges over 5 days removing one plasma volume per procedure and using a non-immunogenic gelatin plasma solution as replacement. Comparisons of clinical scores between control and treated groups indicated that treated animals received significant benefit from plasma exchange (day 1 post-treatment P less than 0.002; day 3 post-treatment P less than 0.01). However, relapse was observed in all plasma exchanged animals such that by day 8 post-treatment there was no significant difference in clinical scores between the two groups. Quantitation of anti-myelin IgG and IgM by ELISA assay showed that 55-60% of circulating antibody was removed per exchange. Rapid post-exchange antibody rebound was observed for both IgG and IgM so that pre-exchange levels were re-established within 24-48 h. However, no significant overshoot in circulating levels of anti-myelin IgG nor IgM could be observed. It is probable that long-term remission as a result of therapeutic plasma exchange is a function of effective circulating plasma removal and if present, the suppression of ongoing antigenic stimuli.

Linear response curves from an ELISA assay: measurement of anti-myelin IgG and IgM during experimental allergic neuritis.

An ELISA method for generating linear dose-response curves for measuring anti-myelin IgG and IgM is described. Linearity is achieved without logarithmic transformations. This test is used to measure plasma levels of anti-myelin antibodies in rabbits with EAN. Results are expressed as relative concentrations of antibody in arbitary mass units with 95% confidence limits fitted by inverse prediction. In the 8 animals studied, appearance of anti-myelin antibody always preceded onset of clinical signs and neither anti-myelin IgG nor IgM could be detected in any animal pre-inoculation. Five out of 8 animals displayed steady and progressive increases in anti-myelin IgG with the remaining 3 animals showing plateaus in IgG levels 21-30 days post-inoculation. Increases in anti-myelin IgG were generally parallelled by increases in disease severity. However, 2 animals showed recovery and relapse from EAN with no change in plasma levels of anti-myelin IgG. Patterns of production of anti-myelin IgM varied with some animals displaying early peaks while others showed gradual increases.

Phenobarbital compared with carbamazepine in prevention of recurrent febrile convulsions. A double-blind study.

In a double-blind trial, children who had recurrent and/or complex febrile convulsions were treated with either phenobarbital sodium or carbamazepine. Forty children were suitable for analysis; 19 were receiving carbamazepine, and 21 were receiving phenobarbital. Of the carbamazepine-treated patients, nine (47%) had recurrent convulsions despite therapeutic levels of the drug, while only two (10%) of the phenobarbital-treated patients suffered further seizures. These results confirm previous findings suggesting that carbamazepine is not as effective in the prophylactic treatment of febrile convulsions as phenobarbital.

F-wave in experimental allergic neuritis.

The conduction velocity of volleys in motor fibres causing F waves, in addition to distal latency and to maximal motor conduction velocity of volleys in fibres causing the M response, were measured in the hindlimbs of control guinea pigs and rabbits and in those with experimental allergic neuritis (EAN). The spinal roots and sciatic nerves were examined histologically in the animals with EAN. The conduction time to the F wave was abnormal in the presence of normal maximal conduction velocity in fibres causing the M waves in 14% of the guinea pigs and 7% of the rabbits. However, conduction time to the F wave was prolonged in the presence of normal maximal motor conduction velocity in one case where no pathological abnormalities were found in the ventral roots and in some instances, F wave conduction time was within the normal range when ventral root and peripheral nerve demyelination was present. These findings highlight some of the problems in interpretation of F wave studies in man.

Effects of plasmapheresis on the course of experimental allergic neuritis in rabbits.

Experimental allergic neuritis was induced in 30 rabbits with extract of bovine peripheral nerve in complete Freund's adjuvant. Of the 22 animals that completed the study, nine animals were plasmapheresed within two weeks of inoculation and 13 animals served as controls. The plasmapheresed animals developed a less severe form of EAN than the controls. Differences were apparent in clinical weakness, weight loss, degree of dispersion of the muscle action potential and histological changes.

Spasmus nutans: a mistaken identity.

Three patients around the age of 1 year had signs and a clinical course that suggested the diagnosis of spasmus nutans. One child had nystagmus and head nodding with normal fundi, but persistent failure to thrive that suggested a hypothalamic lesion from the onset. The second child had nystagmus, head nodding, and a head tilt, and a confident diagnosis of spasmus nutans was made. The third child had unilateral nystagmus with no other abnormalities, and when improvement occurred, spasmus nutans was throught to be the most likely diagnosis. All three patients had tumors that involved the third ventricular region and optic chiasm.

Benign acute childhood myositis.

Four school children, aged 6 to 9 years, had acute postinfectious myositis. The prodromal illness usually involved the upper respiratory tract, but gastrointestinal symptoms were also seen. Fever and nonspecific malaise were characteristic. After cessation of the illness, myalgia involved the calves and thighs. Arm and neck muscles were less frequently affected. Weakness was less marked than muscle pain. Serum creatine phosphokinase (CPK) was markedly increased in all cases. Myalgia and CPK levels subsided in less than a week, although one child was not back to normal for 4 weeks. Two children had electromyography, and patchy myopathic changes were found. Viral studies were not helpful in any of the cases.