Radiation Induced Lumbar Plexopathy (RILP) in Patients of Cancer Cervix Treated by IMRT Technique: A Study of Dosimetry and Clinical Correlation

PURPOSE/OBJECTIVE(S)

To assess the Dosimetric parameters of lumbo sacral plexus in carcinoma cervix patients treated with concurrent chemo-radiation by Intensity modulated radiotherapy (IMRT) technique & to clinically correlate these Dosimetric parameters with the lumbo sacral plexus toxicity.

MATERIALS/METHODS

Total twenty-four patients were included in this study between December 2020 to December 2021. They were all treated by Intensity modulated radiotherapy (IMRT) technique. Radiotherapy dose delivered was 50Gy in 25 fractions at 2Gy/#, it was followed by 3 applications of intracavitary brachytherapy of 7Gy/ fraction each. The lumbo-sacral plexus was delineated according to guidelines given by Sun and Xi et al. No dose constraint was prescribed to the lumbo-sacral plexus prior to the treatment. Magnetic resonance imaging (MRI) of bilateral lumbo-sacral plexus test was done prior to the treatment and 12 months' post treatment. Dose received by the lumbo-sacral plexus was calculated DVH parameters was evaluated. The lumbo-sacral plexus toxicity was assessed by the 10-point questionnaire pre-treatment & post treatment and was compared. Assessment of toxicity was done by RTOG (Radiation Therapy Oncology Group) scoring criteria.

RESULTS

Out of the 24 patients treated, 7 patients had gross nodes which were treated with a boost dose of 60 Gy. Out of these patients 9 patients (37.5%) developed signs and symptoms of radiation induced lumbar plexopathy (RILP). Among these patients, the most common symptom was weakness in the lower limbs followed by impaired leg movement and activities interfering daily activities such as walking, squatting and getting up from the chair. Other positive findings included stiffness, lower limb pain, lower back ache radiating the lateral aspect of the thigh and numbness of the lower limbs. Total prescribed dose to 95% of the planned target volume ranged from 49.2Gy - 61.9 Gy (median - 57 Gy). The mean volume of the LS plexus was 128 cc (range, 92- 143 cc). The mean of the D-max of LS plexus was 56.2 Gy (range, 43.2 Gy- 61.9 Gy). The V30 Gy was received by 84 % of LS plexus, whereas V40, V50, V60 was received by 64 %, 13 % and 4%. The most common significant findings on MRI post treatment were unilateral thickening of the nerve roots followed by hyperintensity in T2 weighted image and STIR sequencing. Mild contrast uptake and edema were present in the nerve roots.

CONCLUSION

Radiation induced lumbar plexopathy (RILP) is one of the late complications after chemoradiotherapy in patients of carcinoma cervix, which is often misdiagnosed or missed on follow up. Therefore, lumbar plexus must be contoured in all pelvic malignancies which are treated by chemoradiotherapy with IMRT technique as it prevents dose dumping in that region. Further studies with longer follow up are needed.

A comparative study of rectal volume variation in patients with prostate cancer: A tertiary care center study

INTRODUCTION

Every day variations in rectal filling in prostate cancer radiotherapy can significantly alter the delivered dose distribution from what was intended. The goal of this study was to see if the time of treatment delivery affected the rectal filling.

METHODS

This is a retrospective study which included 50 patients with localized prostate cancer treated with volumetric modulated arc therapy (VMAT) to the primary and regional lymph nodes. Cone Beam Computed Tomography (CBCT) image-sets were done for all patient's daily setup verification. The radiation therapist contoured the rectum on all CBCT image sets. The rectal volumes delineated on CBCT and the planning CT image sets were compared. The change in rectal volumes between morning and afternoon treatments were calculated and compared.

RESULTS

A total of 1000 CBCT image sets were obtained on 50 patients in the morning and afternoon. The percentage variation of the CBCT rectal volumes over the planning CT scan was 16.57% in the AM group and 24.35% in the PM group.

CONCLUSION

The percentage change in rectal volume was significantly lesser in AM group compared to PM group and therefore morning treatments may result in dose distribution that is close to the intended dose distribution.

IMPLICATIONS FOR PRACTICE

In prostate cancer radiotherapy our study suggests that a simple technique of changing the time of treatment from afternoon to morning can help to reduce the rectal volume.

Meta-analysis comparing the efficacy of dobutamine versus milrinone in acute decompensated heart failure and cardiogenic shock

Objective

This study aims to evaluate the difference between dobutamine and milrinone in patients presenting with acute decompensated heart failure (AHF).

Background

Inotropes are indicated for treating AHF, especially in patients with concomitant hypoperfusion indicative of cardiogenic shock. However, previous studies have not identified the optimal inotrope. We sought to compare outcomes associated with milrinone versus dobutamine in patients with AHF.

Methods

A systematic literature search was performed to identify relevant trials from inception to August 2021. Our primary outcome of interest was mortality. Analysis was sub-categorized according to subpopulation, including AHF, AHF with cardiogenic shock (AHF-shock), AHF with a bridge to transplantation (AHF-BTT), and AHF with destination therapy (AHF-DT). Summary effects were calculated using a fixed-effects model as risk ratio or mean difference with 95% confidence intervals for all the clinical endpoints.

Results

Ten studies, including one randomized controlled trial with 21,106 patients, were included in the analysis (4918 patients were in the Milrinone group, while 15188 were in the Dobutamine group). Milrinone was associated with a lower risk of mortality in patients with AHF [relative risk (RR) 0.87; confidence interval (CI):0.79–0.97; p<0.05, heterogeneity I2=0%] with event rates of 9.4% vs. 9.8% [number needed to treat (NNT) of 250]. Milrinone was also associated with improved mortality with RR 0.76 (0.79–0.95; p<0.05) in patients with AHF-DT. There was a non-significant trend towards improved mortality in AHF-shock patients. However, AHF-BTT patients had a non-significant trend towards improved mortality with dobutamine. There was no difference between the two strategies for the outcomes of acute kidney injury, initiation of renal replacement therapy, mechanical ventilation, arrhythmias, symptomatic hypotension, and length of hospital stay (LOS) in the overall population. Intensive care unit (ICU) LOS was lower in AHF-shock patients in the milrinone group, whereas dobutamine was associated with a lower length of ICU stay in AHF patients.

Conclusion

The cumulative data comparing milrinone with dobutamine indicate an overall marginal benefit of milrinone compared to dobutamine in the totality of patients with AFH with or without cardiogenic shock, and whether or not they are bridged to transplantation or destination assist device. More appropriately powered prospective studies are needed to identify a conclusive benefit of one inotrope over another.

Funding Acknowledgement

Type of funding sources: None.

Corticosteroid-associated lupus pancreatitis: a case series and systematic review of the literature

BACKGROUND

Acute pancreatitis is an uncommon complication that occurs in 0.85% to 4% of patients with systemic lupus erythematosus (SLE). In some patients, it occurs within days to weeks of starting medium-to-high dose corticosteroids. The authors have used the term 'corticosteroid-associated lupus pancreatitis' for these patients, and they report a case series and perform a systematic review of previously published reports.

METHODS

For the purpose of this study, corticosteroid-associated lupus pancreatitis was defined as occurrence of acute pancreatitis in patients with SLE (fulfilling the 1997 ACR), within 3 weeks of starting therapy with medium-to-high dose corticosteroids - either newly initiated or escalated from a lower dose. All patients with SLE admitted in the last 2.5 years in a North Indian university hospital were reviewed, and those with pancreatitis who fulfilled the above criteria were included in the case series. For the systematic review, a PUBMED search using the keywords 'lupus' and 'pancreatitis' was performed, and reports in English were reviewed for an association with corticosteroids.

RESULTS

Among 420 admissions of SLE patients, six patients (1.4%) fulfilled criteria for corticosteroid-associated lupus pancreatitis. All were female, with mean age and disease duration of 19.7 ± 3.3 and 3.8 ± 2.5 years respectively. All had active disease and developed acute pancreatitis within 48-72 hours of newly initiating medium-to-high dose corticosteroids (in three patients) or escalating them to medium-high dose (in three patients). After the development of pancreatitis, corticosteroids were continued in all except one patient. In addition, two patients received pulse methylprednisolone, two received pulse cyclophosphamide and one was started on azathioprine. Three patients died during hospitalization, all with severe pancreatitis. On systematic review, among 451 cases of lupus pancreatitis reported, 23 (5%) fulfilled criteria for 'corticosteroid-associated lupus pancreatitis'. A majority of them had pancreatitis within 3 days of starting treatment with medium-to-high dose corticosteroids. The mortality in these patients was 37.5%.

CONCLUSION

In a small but substantial proportion of patients with lupus who develop pancreatitis, it occurs within days to weeks of starting medium-to-high dose corticosteroids. Many of these patients continue to receive corticosteroids, and some receive more aggressive immunosuppression. However, they have significant mortality, and further studies are required to identify appropriate treatment in this subgroup of patients.

Pharmacophore based virtual screening for identification of marine bioactive compounds as inhibitors against macrophage infectivity potentiator (Mip) protein of Chlamydia trachomatis

Macrophage infectivity potentiator (Mip) is the virulence factor fromChlamydia trachomatisthat is primarily responsible for causing sexually transmitted diseases (STDs) and blindness.

Social impairments in Rett syndrome: characteristics and relationship with clinical severity

BACKGROUND

While behavioural abnormalities are fundamental features of Rett syndrome (RTT), few studies have examined the RTT behavioural phenotype. Most of these reports have focused on autistic features, linked to the early regressive phase of the disorder, and few studies have applied standardised behavioural measures. We used a battery of standardised measures of behaviour and functioning to test the following hypotheses: (1) autistic behaviour is prominent throughout childhood in RTT; (2) autistic features are more salient in individuals with milder presentation; (3) severity of autistic behaviour is associated with a wider range of behavioural problems; and (4) specific MECP2 mutations are linked to more severe autistic behaviour.

METHODS

Eighty MECP2 mutation-positive girls with RTT (aged 1.6-14.9 years) were administered: (1) the Screen for Social Interaction (SSI), a measure of autistic behaviour suited for individuals with severe communication and motor impairment; (2) the Rett Syndrome Behaviour Questionnaire (RSBQ), covering a wide range of abnormal behaviours in RTT; (3) the Vineland Adaptive Behavior Scales (VABS); and (4) a modified version of the Rett Syndrome Severity Scale (RSSS). Regression analyses examined the predictive value of age and RSSS on autistic behaviour and other behavioural abnormalities. T-tests further characterised the behavioural phenotype of individual MECP2 mutations.

RESULTS

While age had no significant effect on SSI or RSBQ total scores in RTT, VABS Socialization and Composite scores decreased over time. Clinical severity (i.e. RSSS) also increased with age. Surprisingly, SSI performance was not related to either RSSS or VABS Composite scores. Autistic behaviour was weakly linked with the RSBQ Hand behaviour factor scores, but not with the RSBQ Fear/Anxiety factor. Clinical (neurological) severity did not predict RSBQ scores, as evidenced by the analysis of individual MECP2 mutations (e.g. p.R106W, p.R270X and p.R294X).

CONCLUSIONS

Our data suggest that in RTT, autistic behaviour persists after the period of regression. It also demonstrated that neurological and behavioural impairments, including autistic features, are relatively independent of one another. Consistent with previous reports of the RTT phenotype, individual MECP2 mutations demonstrate complex associations with autistic features. Evidence of persistent autistic behaviour throughout childhood, and of a link between hand function and social skills, has important implications not only for research on the RTT behavioural phenotype, but also for the clinical management of the disorder.

White matter impairment in Rett syndrome: diffusion tensor imaging study with clinical correlations

BACKGROUND AND PURPOSE

RTT, caused by mutations in the methyl CPG binding protein 2 (MeCP2) gene, is a disorder of neuronal maturation and connections. Our aim was to prospectively examine FA by DTI and correlate this with certain clinical features in patients with RTT.

MATERIALS AND METHODS

Thirty-two patients with RTT underwent neurologic assessments and DTI. Thirty-seven age-matched healthy female control subjects were studied for comparison. With use of a 1.5T MR imaging unit, DTI data were acquired, and FA was evaluated to investigate multiple regional tract-specific abnormalities in patients with RTT.

RESULTS

In RTT, significant reductions in FA were noted in the genu and splenium of the corpus callosum and external capsule, with regions of significant reductions in the cingulate, internal capsule, posterior thalamic radiation, and frontal white matter. In contrast, FA of visual pathways was similar to control subjects. FA in the superior longitudinal fasciculus, which is associated with speech, was equal to control subjects in patients with preserved speech (phrases and sentences) (P = .542), whereas FA was reduced in those patients who were nonverbal or speaking only single words (P < .001). No correlations between FA values for tracts and clinical features such as seizures, gross or fine motor skills, and head circumference were identified.

CONCLUSIONS

DTI, a noninvasive technique to assess white matter tract pathologic features, may add specificity to the assessment of RTT clinical severity that is presently based on the classification of MeCP2 gene mutation and X-inactivation.

Two cases with progressive cystic leukoencephalopathy

Leukoencephalopathies with cystic changes in the white matter on magnetic resonance imaging are aetiologically heterogeneous neurological disorders seen in children. A group of leukoencephalopathies characterised by white matter lesions progressing to multifocal cystic degeneration has been reported in various disorders, including mitochondrial enzyme deficiencies, leukodystrophies, and infectious processes. We report two patients with leukoencephalopathy showing progressive cystic changes on serial MRI, and magnetic resonance spectroscopy resembling progressive cavitating leukoencephalopathy.

Selective cerebral volume reduction in Rett syndrome: a multiple-approach MR imaging study

BACKGROUND AND PURPOSE

Previous studies have examined volumetric abnormalities in Rett syndrome (RTT), using MR imaging and focusing on selective changes. However, these studies preceded the identification of MECP2 as the gene mutated in most RTT cases. We studied regional brain volume changes as noted by MR imaging in girls with RTT who had mutations in the MECP2 gene and more or less severe clinical outcomes to further characterize the neuroanatomy of RTT and its correlations with clinical severity.

MATERIALS AND METHODS

Complementary semiautomated Talairach- and voxel-based approaches were used to study spoiled gradient-recalled acquisition sequence MR imaging scans from 23 girls with MECP2 mutations/RTT, including a pair of discordant monozygotic twins and 25 age-matched control girls. Both absolute and relative volumetric changes were examined to account for the well-documented global reduction in brain volume seen in RTT.

RESULTS

Absolute volumetric reductions were observed throughout the brain in RTT. Selective/relative decreases in parietal lobe gray matter, particularly in the dorsal parietal region, and mild, diffuse reductions in cortical white matter were observed in the RTT group compared with control subjects. In girls with RTT and a more severe phenotype, anterior frontal lobe volumes were relatively more reduced. Twin comparisons revealed selective preservation of the occipital cortex.

CONCLUSION

Selective reductions of dorsal parietal gray matter and preservation of the occipital cortex seem to be basic neuroanatomic features of RTT, whereas preferential reduction of the anterior frontal lobe appears to be a correlate of clinical severity in this disorder. The most affected brain regions include those that may underlie key functional deficits observed in RTT.

Enhanced cell death in MeCP2 null cerebellar granule neurons exposed to excitotoxicity and hypoxia

Rett syndrome (RTT) is associated with mutations in the transcriptional repressor gene MeCP2. Although the clinical and neuropathological signs of RTT suggest disrupted synaptic function, the specific role of methyl-CpG binding protein 2 (MeCP2) in postmitotic neurons remains relatively unknown. We examined whether MeCP2 deficiency in central neurons contributes to the neuropathogenesis in RTT. Primary cerebellar granule neuronal cultures from wild-type (WT) and MeCP2-/- mice were exposed to N-methyl-d-aspartate (NMDA) and AMPA-induced excitotoxicity and hypoxic-ischemic insult. The magnitude of cell death in MeCP2-/- cells after excitotoxicity and hypoxia was greater than in the WT littermate control cultures and occurred after shorter exposures that usually, in the WT, would not cause cell death. Pretreatment with the growth factor fibroblast growth factor 1 (FGF-1) under conditions at which WT cells showed complete neuroprotection, only partially protected MeCP2-/- cells. To elucidate specifically the effects of MeCP2 knockout (KO) on cell death, we examined two death cascade pathways. MeCP2-/- neurons exposed to 6 h of hypoxia exhibited enhanced activation of the proapoptotic caspase-3 and increased mitochondrial release of apoptosis inducing factor (AIF) compared with WT neurons, which did not show significant changes. However, pretreatment with the caspase inhibitor ZVAD-FMK had little or no effect on AIF release and its subcellular translocation to the nucleus, suggesting caspase-independent AIF release and their independent contribution to hypoxia-induced cell death. Reintroduction of intact MeCP2 gene in MeCP2-/- cells or MeCP2 gene silencing by MeCP2siRNA in WT cells further confirmed the differential sensitivity of the WT and MeCP2-/- cells and suggest a direct role of MeCP2 in cell death. These results clearly demonstrate increased cell death occurred in neurons lacking MeCP2 expression via both caspase- and AIF-dependent apoptotic mechanisms. Our findings suggest a novel, yet unknown, role for MeCP2 in central neurons in the control of neuronal response to cell death.

Spinal metastasis from renal cell carcinoma, 31 years following nephrectomy--case report

Most renal cell carcinomas recur or metastasize within 2 years. We present a 62-year-old lady with metastatic renal cell carcinoma in the spine, 31 years following nephrectomy of the primary tumor. This is the longest interval between diagnosis of primary renal cell carcinoma and metastasis reported in the literature.

Clinical and electrophysiological presentation of pronator syndrome

Median neuropathy at the elbow (pronator syndrome [PS]) is rare compared to compression at the wrist. We sought to evaluate the clinical/electrophysiological parameters of this focal neuropathy. Between 1992 and 2002, we retrospectively reviewed records of eighty-three limbs in seventy-two patients with PS. Electrodiagnostic data as well as clinical symptoms, physical findings, demographic information and treatment modalities were examined. The main symptoms were forearm pain, numbness and weakness. One patient (two limbs) had nocturnal paresthesias. Twenty-five limbs (30%) showed decreased median forearm velocity. Fifty-four (65%) had abnormal median sensory studies of either abnormal conduction velocity or amplitude. Needle exam showed an abnormality of at least one median innervated muscle, abductor pollicis brevis, flexor carpi radialis, or pronator teres, in 70% (58/83). Sixteen limbs were identified as having undergone surgical decompression. In the surgical group, 10/16 (63%) were found to have constriction with a band which was released during surgery. Eight of the sixteen patients who underwent surgery were found to have documented improvement. Eleven patients (13%) had undergone previous surgery for Carpal Tunnel Syndrome (CTS) without benefit. The clinical and electrophysiological features of PS are quite different from patients with CTS. Proper localization is crucial to treatment options. Surgery can provide benefit in selected cases.

Cystic leukoencephalopathy without megalencephaly: A distinct disease entity in 15 children

OBJECTIVE

To describe a distinctive syndrome of nonprogressive encephalopathy, normo- or microcephaly, and early onset of severe psychomotor impairment in 15 white patients, including two siblings and two first cousins.

METHODS AND RESULTS

MRI revealed bilateral cysts in the anterior part of the temporal lobe and white matter abnormalities with pericystic abnormal myelination and symmetric lesions in frontal and occipital periventricular regions. None of the usual inborn errors of metabolism/infectious diseases associated with leukoencephalopathy and bilateral anterior temporal lobe cysts were detected.

CONCLUSIONS

These patients' clinical signs and cranial MRI abnormalities are strikingly similar and may represent a distinctive disease with autosomal-recessive inheritance: cystic leukoencephalopathy without megalencephaly.

Thromboelastography in abruptio placentae

The purpose of this study was to document thromboelastographic (TEG) changes in abruptio placentae and to compare these results with that of conventional tests used to monitor coagulation. This was a prospective study of 30 patients with abruptio placentae. All coagulation investigations including the TEG were performed on admission, immediately following delivery, and after periods of 4 hours and 24 hours. Results showed that standard coagulation tests detected coagulation abnormalities except the platelet count returned to normal limits within 24 hours of delivery. There was strong correlation between fibrinogen levels and the TEG parameters, ma and k time (r=0.8). There was moderate correlation between platelet count and ma (r=0.6). In conclusion, minor abnormalities in the clotting profile are clinically unimportant. The TEG does not detect such minor abnormalities because of its inherent ability to test the coagulation cascade as a whole. Major abnormalities are clinically relevant and the TEG detect 75% of them. Further, the TEG establishes the diagnosis of hypercoagulability an early sign of disseminated intravascular coagulation. Although standard laboratory tests are still necessary to detect coagulation abnormalities on admission, the TEG is a useful test in large obstetric units where laboratory results are not immediately available for the purposes of monitoring and treating ongoing coagulation defects.

Leukoencephalopathy, cerebral calcifications, and cysts

We describe three cases of the rare syndrome of leukoencephalopathy, brain calcifications, and cysts. Conventional MRI, proton spectroscopy, and diffusion-weighted imaging yielded additional information on the disease. Imaging findings favor increased water content rather than a demyelinating process in the pathophysiology of this disease. Clinical features of Coats disease and consanguinity were also encountered.

Indian Agarwal megalencephalic leukodystrophy with cysts is caused by a common MLC1 mutation

BACKGROUND

A distinct clinical syndrome characterized by megalencephaly, mild to moderate cognitive decline, slowly progressive spasticity, ataxia, occasional seizures, and extensive white matter changes with temporal cysts by imaging studies has been described in a particular ethnic group (Agarwals) in India. This disorder is very similar to megalencephalic leukoencephalopathy with subcortical cysts (MLC), a newly characterized leukodystrophy whose molecular basis was recently shown to be mutations in a gene (KIAA0027) that has been renamed MLC1.

OBJECTIVE

To determine if this disorder among the Agarwals is due to mutations in MLC1 by a mutation screening study conducted on affected Agarwal patients.

METHODS

Genomic DNA from these Indian leukodystrophy patients was screened for mutations in the entire coding region, including the exon-intron boundaries, of the MLC1 gene.

RESULTS

Thirty-three affected individuals whose clinical and imaging presentations were consistent with MLC were screened. All were from northern India and included 31 known Agarwals, 1 non-Agarwal, and 1 adopted patient whose ethnicity is unknown. All 31 Agarwal patients tested positive for a homozygous insertion of a cytosine in exon 2. The adopted patient was homozygous for A157E. No mutation in the coding region was found in the non-Agarwal patient.

CONCLUSIONS

Indian patients with megalencephaly and MRI changes that show extensive white matter changes with temporal cysts should raise suspicion for MLC. Members of the Agarwal ethnic group affected with the disorder present with a mildly progressive course and show a common mutation (320insC) in the MLC1 gene, suggesting a founder effect.

A videotaped intervention to enhance child control and reduce anxiety of the pain of dental injections

AIM

While the psychological literature shows that perceptions of uncontrollability contribute to anxiety and other pathologies, interventions that enhance perceived control have been shown to reduce anxiety. This study attempted to assess a brief videotape to enhance child perceived control in a dental setting.

METHODS

101 children aged 7-9 years completed warm-up procedures and viewed either: a) the experimental intervention, a 2 minutes video of a dentist explaining what an injection will feel like and proposing hand raising as a signal mechanism; or b) the control condition, a 2 minutes video of Disneyland. Fear of dental injections was assessed on a 10 cm visual analogue scale before and after the intervention.

RESULTS

In the experimental group there was a significant fear reduction from pre- to post-intervention, while this was not the case in the control group. Children with higher pre-existing levels of fear benefited more from the intervention than children with lower levels of fear.

CONCLUSION

The results of this pilot study suggest that intervention packages that impact child control have promise in lowering anxiety.

MRI and proton MRSI in women heterozygous for X-linked adrenoleukodystrophy

OBJECTIVE

To utilize neuroimaging procedures to assess the extent of cerebral involvement in female subjects heterozygous for X-linked adrenoleukodystrophy (X-ALD).

METHODS

Brain MRI studies were performed in 76 female subjects heterozygous for X-ALD (mean age 43 years, range 8 to 75 years). Sixty-five had clinical evidence of spinal cord involvement resembling that in males with adrenomyeloneuropathy (AMN), two had clinical evidence of cerebral involvement, and nine showed no neurologic abnormality. Readers blinded to clinical findings further analyzed abnormal MRI studies. In eight women whose MRI results were normal, four-slice long echo time MRS imaging (MRSI) studies were performed and compared to those of eight age-matched controls.

RESULTS

MRI results were normal in 65 subjects and abnormal in 11. In eight of the latter group, the MRI changes were judged to be due to causes other than X-ALD. Lesions were attributed to X-ALD in the remaining three. Two of these patients had lesions that resembled those in male patients with cerebral X-ALD. In one patient with a mild AMN-like syndrome, brain MRI abnormalities were confined to the corticospinal tract. When compared to those of controls, MRSI studies in eight female patients with normal results on brain MRI showed a significant reduction of N-acetylaspartate/creatine and N-acetylaspartate/choline ratios in the internal capsule and corticospinal projection fibers. The N-acetylaspartate/choline ratio was significantly reduced in the parieto-occipital white matter and the choline/creatine ratio was significantly increased in the frontal white matter.

CONCLUSION

Brain involvement demonstrable by MRI is rare in female subjects heterozygous for X-ALD, including those who have clinical evidence of spinal cord involvement. Nevertheless, N-acetylaspartate levels are reduced in the corticospinal projection fibers in female subjects with normal results on MRI, suggesting axonal dysfunction.

Associations between MeCP2 mutations, X-chromosome inactivation, and phenotype

Rett syndrome is a neurodevelopmental disorder of early postnatal brain growth in girls. Patients show a normal neonatal period with subsequent developmental regression and a loss of acquired skills (communication and motor skills), deceleration of head growth, and development of typical hand stereotypies. Recent studies have shown that mutations in the X-linked methyl CpG binding protein 2 gene (MeCP2) cause most typical cases of Rett syndrome. The MeCP2 gene encodes a protein that binds methylated cytosine residues of CpG dinucleotides and mediates, with histone deacetylases and transcriptional repressors, the transcription "silencing" of other genes. Girls with Rett syndrome exhibit mosaic expression for the MeCP2 defect at the cellular level, with most patients showing random X-inactivation and approximately equal numbers of cells expressing the normal MeCP2 gene and the mutated MeCP2 gene. In rare cases, females with a MeCP2 mutation escape phenotypic expression of the disorder because of nonrandom X-inactivation and the preferential inactivation of the mutated MeCP2 allele. Nonrandom patterns of X-inactivation may also contribute to the clinical variability often seen in girls with Rett syndrome. The spectrum of clinical phenotype caused by MeCP2 mutations is wide, including milder "preserved speech" variants, the severe congenital Rett variant, and a subset of X-linked recessive mental retardation in boys. Studies have shown that atypical and classical Rett syndrome can caused by the same MeCP2 mutations, indicating clinical phenotype is variable even among girls with the same MeCP2 mutation. The relationship between type of MeCP2 mutation, X-inactivation status, and clinical phenotype of Rett syndrome is complex and likely involves other environmental and polygenic modifiers.

Molecular findings in symptomatic and pre-symptomatic Alexander disease patients

BACKGROUND AND OBJECTIVE

Alexander disease is a slowly progressive CNS disorder that most commonly occurs in children. Until recently, the diagnosis could only be established by the histologic finding of Rosenthal fibers in brain specimens. Mutations in the glial fibrillary acidic protein (GFAP) gene have now been shown in a number of biopsy- or autopsy-proven patients with Alexander disease. A prospective study on patients suspected to have Alexander disease was conducted to determine the extent to which clinical and MRI criteria could accurately diagnose affected individuals, using GFAP gene sequencing as the confirmatory assay.

METHODS

Patients who showed MRI white matter abnormalities consistent with Alexander disease, unremarkable family history, normal karyotype, and normal metabolic screening were included in this study. Genomic DNA from patients was screened for mutations in the entire coding region, including the exon-intron boundaries, of the GFAP gene.

RESULTS

Twelve of 13 patients (approximately 90%) were found to have mutations in GFAP. Seven of those 12 patients presented in infancy with seizures and megalencephaly. Five were juvenile-onset patients with more variable symptoms. Two patients in the latter group were asymptomatic or minimally affected at the time of their initial MRI scan. The mutations were distributed throughout the gene, and all involved sporadic single amino acid heterozygous changes that changed the charge of the mutant protein. Four of the nine changes were novel mutations.

CONCLUSIONS

In symptomatic and asymptomatic patients with a predominantly frontal leukoencephalopathy by MRI, GFAP gene mutation analysis should be included in the initial diagnostic evaluation process for Alexander disease.

Subunits of the translation initiation factor eIF2B are mutant in leukoencephalopathy with vanishing white matter

Leukoencephalopathy with vanishing white matter (VWM) is an inherited brain disease that occurs mainly in children. The course is chronic-progressive with additional episodes of rapid deterioration following febrile infection or minor head trauma. We have identified mutations in EIF2B5 and EIF2B2, encoding the epsilon- and beta-subunits of the translation initiation factor eIF2B and located on chromosomes 3q27 and 14q24, respectively, as causing VWM. We found 16 different mutations in EIF2B5 in 29 patients from 23 families. We also found two distantly related individuals who were homozygous with respect to a missense mutation in EIF2B2, affecting a conserved amino acid. Three other patients also had mutations in EIF2B2. As eIF2B has an essential role in the regulation of translation under different conditions, including stress, this may explain the rapid deterioration of people with VWM under stress. Mutant translation initiation factors have not previously been implicated in disease.