SPECT changes and their correlation with EEG changes in tuberculous meningitis

OBJECTIVE: In tuberculous meningitis (TBM) blood flow may be altered due to associated vasculitis, hydrocephalus and raised intracranial pressure. Electroencephalography (EEG) and single photon emission computed tomography (SPECT) provide information about electrical activity and regional cerebral blood flow respectively. This study aims at the correlation of EEG and SPECT changes in patients with TBM. METHOD: Sixteen patients with TBM whose age ranged between 5 and 62 years and 3 of whom were females were subjected to clinical, radiological (CT and/or MRI), EEG and SPECT studies using 99mTc ethylene cystine dimer (ECD). Ten patients were in stage III and 3 each in stage II and stage I meningitis. Cranial CT scan was carried out in 15 and MRI in 4 patients. Hydrocephalus was present in 9, infarction in 7 and tuberculoma in 5 patients. RESULTS: SPECT studies were abnormal in all except 2 patients revealing basal ganglionic hypoperfusion in 14 and focal cortical hypoperfusion in 9 patients. The EEG was abnormal in 11 patients which included delta slowing in 5, theta slowing in 6, frontal intermittent rhythmic delta activity (FIRDA) in 3 and epileptiform discharges in 2 patients. All the patients with abnormal EEG had abnormal SPECT study except 1. In 4 patients, EEG was normal although there was subcortical hypoperfusion on SPECT. In spite of high frequency of focal cortical hypoperfusion (9 patients), EEG revealed focal abnormality in 3 patients only. CONCLUSION: It can be concluded that the SPECT reveals more frequent abnormalities compared to EEG and CT scan. Cortical hypoperfusion with or without basal ganglia hypoperfusion is associated with FIRDA and diffuse delta slowing on EEG.     

Vitamin B12 deficiency neurological syndromes: a clinical,MRI and electrodiagnostic study

BACKGROUND: Vegetarianism is an important cause of vitamin B12 deficiency, especially in countries like India. We managed 17 patients with neurological syndrome due to vitamin B12 deficiency in a tertiary care referral teaching hospital which caters to relatively affluent population. AIM: To evaluate neurophysiological and MRI changes in patients presenting with vitamin B12 deficiency neurological syndrome and interpret these is the light of reported autopsy findings. SETTING: Tertiary care referral teaching hospital. METHODS: Patients with vitamin B12 deficiency neurological syndrome diagnosed by low serum vitamin B12 and/or megaloblastic bone marrow were subjected to clinical evaluation and spinal MRI. The neurophysiological tests included nerve conduction studies, tibial somatosensory evoked potential (SEP), motor evoked potential (MEP) and visual evoked potential (VEP) studies. The recovery was defined on the basis of 6 months Barthel Index score into complete, partial or poor. RESULTS: There were 17 patients with vitamin B12 deficiency neurological syndrome, 3 were females and 12 lactovegetarian. The clinical syndrome was that of myelopathy in 8, myeloneuropathy in 5, dementia myelopathy in 3 and neuropathy in 1 patient. All the patients had impaired joint position and vibration sensation in the lower limbs and 4 had in upper limbs as well. Lower limbs were spastic in 13 and upper limbs in 2 patients. Spinal MRI revealed T2 hyperintensity in cervicodorsal region in 6 and cord atrophy in 3 patients. Sural nerve conduction was abnormal in 8 and peroneal conduction in 5 patients. In one patient all sensory nerve conductions were unrecordable but motor conductions were normal. Tibial SEP was abnormal in 12 out of 15 and lower limb MEP in 8 out of 12 patients. P100 latency of VEP was prolonged in 7 out of 13 patients. Right to left asymmetry was present in tibial SEP in 4 and VEP in 2 patients. At 6 months followup 2 patients improved completely, 7 partially and 3 had poor recovery. Clinical recovery correlated with MEP but not with SEP or MRI changes. CONCLUSION: The evoked potential and MRI changes in vitamin B12 deficiency neurological syndrome are consistent with focal demyelination of white matter in spinal cord and optic nerve. Myelopathic presentation is commoner and SEP is more frequently abnormal. The outcome at 6 months correlated with MEP changes.     

The Foot and Mouth Disease Virus Type O Outbreak of 1992 Is Not Related to Vaccine Strain (O/R2/75)

Vaccination is the only pragmatic approach to control foot and mouth disease in India. Strict quality control measures are essential to supply potent vaccine to the field application, in addition to monitoring the performance of the vaccine in the field. During the process of monitoring, an outbreak of FMD in vaccinated animals caused by type “O” virus in Tanjavur district of Tamil Nadu and a type “O” virus from unvaccinated herd of Karnataka were studied. Field isolates and vaccine virus were sequenced and analyzed. Data indicated that the virus from the outbreak in vaccinated cattle was a variant which could escape neutralization by antibodies against vaccine virus. This revised version was published online in August 2006 with corrections to the Cover Date.     

Identification and characterization of aquaporin-2 water channel mutations causing nephrogenic diabetes insipidus with partial vasopressin response

Congenital nephrogenic diabetes insipidus (NDI) is a rare disease caused most often by mutations in the vasopressin V2 receptor (AVPR2). We studied a family which included a female patient with NDI with symptoms dating from infancy. The patient responded to large doses of desmopressin (dDAVP) which decreased urine volume from 10 to 4 I/day. Neither the parents nor the three sisters were polyuric. The patient was found to be a compound heterozygote for two novel recessive point mutations in the aquaporin-2 (AQP2) gene: L22V in exon 1 and C181W in exon 3. Residue Cys181 in AQP2 is the site for inhibition of water permeation by mercurial compounds and is located near to the NPA motif conserved in all aquaporins. Osmotic water permeability (Pf) in Xenopus oocytes injected with cRNA encoding C181W-AQP2 was not increased over water control, while expression of L22V cRNA increased the Pf to approximately 60% of that for wild-type AQP2. Co-injection of the mutant cRNAs with the wild-type cRNA did not affect the function of the wild-type AQP2. Immunolocalization of AQP2-transfected CHO cells showed that the C181W mutant had an endoplasmic reticulum-like intracellular distribution, whereas L22V and wild-type AQP2 showed endosome and plasma membrane staining. Water permeability assays showed a high Pf in cells expressing wild-type and L22V AQP2. This study indicates that AQP2 mutations can confer partially responsive NDI.      

The role of size, sequence and haplotype in the stability of FRAXA and FRAXE alleles during transmission

Factors involved in the stability of trinucleotide repeats during transmission were studied in 139 families in which a full mutation, premutation or intermediate allele at either FRAXA or FRAXE was segregating. The transmission of alleles at FRAXA, FRAXE and four microsatellite loci were recorded for all individuals. Instability within the minimal and common ranges (0-40 repeats for FRAXA, 0-30 repeats for FRAXE) was extremely rare; only one example was observed, an increased in size at FRAXA from 29 to 39 repeats. Four FRAXA and three FRAXE alleles in the intermediate range (41-60) repeats for FRAXA, 31-60 for FRAXE) were unstably transmitted. Instability was more frequent for FRAXA intermediate alleles that had a tract of pure CGG greater than 37 although instability only occurred in two of 13 such transmissions: the changes observed were limited to only one or two repeats. Premutation FRAXA alleles over 100 repeats expanded to a full mutation during female transmission in 100% of cases, in agreement with other published series. There was no clear correlation between haplotype and probability of expansion of FRAXA premutations. Instability at FRAXA or FRAXE was more often observed in conjunction with a second instability at an independent locus suggesting genomic instability as a possible mechanism by which at least some FRAXA and FRAXE mutations arise.      

The Essential Oil of Perilla ocimoides: A Rich Source of Rosefuran

The essential oil of a strain of PERILLA OCIMOIDES from Bangladesh, cultivated at Lucknow, after GC-MS investigations afforded rosefuran ( 1) as the major constituent (58%) along with 17 others including beta-caryophyllene, perilla ketone ( 2), perillene, alpha-cedrene, germacrene-D, and isobis-abolene.     

A study of the neurotoxic effect of MDMA (‘ecstasy') on 5-HT neurones in the brains of mothers and neonates following administration of the drug during pregnancy

1. It is well established that 3,4-methylenedioxymethamphetamine (MDMA or ‘ecstasy'') is neurotoxic and produces long term degeneration of cerebral 5-hydroxytryptamine (5-HT) nerve terminals in many species. Since MDMA is used extensively as a recreational drug by young people, it is being ingested by many women of child bearing age. We have therefore examined the effect of administering high doses of MDMA to rats during pregnancy on the cerebral content of both the dams and the neonates.
2. MDMA (20 mg kg⁻¹, s.c.) was injected twice daily on days 14–17 of the gestation period. The initial dose produced a marked hyperthermic response in the dam which was progressively attenuated in both peak height and area under the curve following further doses of the drug. The body weight of the dams decreased during the period of treatment.
3. There was a modest decrease in litter size (−20%) of the MDMA-treated dams.
4. The concentration of 5-HT and its metabolite 5-HIAA was decreased by over 65% in the hippocampus and striatum and 40% in the cortex of the dams 1 week after parturition. In contrast, the content of 5-HT and 5-HIAA in the dorsal telencephalon of the pups of the MDMA-treated dams was the same as that seen in tissue from pups born to control animals.
5. Administration of MDMA (40 mg kg⁻¹, s.c.) to adult rats increased thiobarbituric acid reacting substances (TBARS) in cortical tissue 3 h and 6 h later, indicating increased lipid peroxidation. No increase in TBARS was seen in the cortical tissue of 7–10 day neonates injected with this dose of MDMA 3 h or 6 h earlier.
6. The data suggest that exposure to MDMA in utero during the maturation phase does not produce damage to 5-HT nerve terminals in the foetal rat brain, in contrast to the damage seen in the brains of the mothers. This may be due to MDMA being metabolized to free radical producing entities in the adult brain but not in the immature brain or, alternatively, to more effective or more active free radical scavenging mechanisms being present in the immature brain.

     

Comparison of open and arthroscopic subacromial decompression

We retrospectively reviewed 68 patients (70 shoulders) who underwent either open or arthroscopic acromioplasty performed by a single surgeon (JPI) for chronic impingement syndrome in the presence of an intact rotator cuff. Group 1 consisted of 24 shoulders that had open acromioplasty and group 2 consisted of 46 shoulders that had arthroscopic acromioplasty. The minimum follow-up was 12 months for both groups. There was no statistical difference in mean postoperative shoulder scores between the operative groups. However, there were more excellent results in the open group as compared with the arthroscopic group (54.2% vs 41.9%, respectively). In addition, there was a higher percentage of poor results in group 2 as compared with group 1 (27.9% vs 16.6%, respectively). Arthroscopic acromioplasty was associated with shorter hospital stays and faster achievement of maximal pain relief as compared with open acromioplasty. Examination of postoperative radiographs often revealed subacromial calcifications. These calcifications were more frequent after arthroscopic acromioplasty and were associated with a worse result.