An oligodendrocyte silencer element underlies the pathogenic impact of lamin B1 structural variants

The role of non-coding regulatory elements and how they might contribute to tissue type specificity of disease phenotypes is poorly understood. Autosomal Dominant Leukodystrophy (ADLD) is a fatal, adult-onset, neurological disorder that is characterized by extensive CNS demyelination. Most cases of ADLD are caused by tandem genomic duplications involving the lamin B1 gene ( LMNB1 ) while a small subset are caused by genomic deletions upstream of the gene. Utilizing data from recently identified families that carry LMNB1 gene duplications but do not exhibit demyelination, ADLD patient tissues, CRISPR modified cell lines and mouse models, we have identified a novel silencer element that is lost in ADLD patients and that specifically targets overexpression to oligodendrocytes. This element consists of CTCF binding sites that mediate three-dimensional chromatin looping involving the LMNB1 and the recruitment of the PRC2 repressor complex. Loss of the silencer element in ADLD identifies a previously unknown role for silencer elements in tissue specificity and disease causation.

Brain MRI features and scoring of leukodystrophy in adult-onset Krabbe disease

Objective

To perform a systematic analysis and scoring of brain MRI white matter hyperintensities (WMH) in adult-onset Krabbe disease.

Methods

We retrospectively collected basic clinical data and the first available brain MRI from patients with confirmed Krabbe disease with first clinical manifestations beyond 10 years of age. Data were obtained from our reference center for lysosomal diseases (n = 6) and from contacted authors of published articles describing patients with adult-onset Krabbe disease (n = 15). T2-weighted fluid-attenuated inversion recovery images of each patient were analyzed and scored using a radiologic score of WMH in a single center.

Results

The corticospinal tract was always affected by WMH (100% of patients), however, with some distinctions along the tract: the precentral gyrus (100%), corona radiata (95%), and posterior internal capsule (81%) were highly abnormal, whereas the mesencephalon (57%), pons (52%), and medulla oblongata (5%) were less affected. WMH were also frequently present in the posterior lateral periventricular white matter (95%), optic radiations (86%), postcentral gyrus (71%), medial lemniscus (62%), and corpus callosum, especially in the isthmus (71%), whereas the genu was always normal. A few patients did not have the classical MRI pattern but extensive hyperintensities (n = 3), or patchy distribution of hyperintensities mimicking an acquired etiology (n = 2), or very subtle hyperintensities of the corticospinal tract (n = 1).

Conclusions

We specified the main locations of WMH, which were observed in the earliest stages of the disease and were also present in patients with atypical MRI pattern, highlighting the importance of radiologic features to guide the diagnosis.

Glucose metabolism in the brain in LMNB1-related autosomal dominant leukodystrophy

OBJECTIVE

LMNB1-related autosomal dominant leukodystrophy is caused by an overexpression of the protein lamin B1, usually due to a duplication of the LMNB1 gene. Symptoms start in 5th to 6th decade. This slowly progressive disease terminates with death. We studied brain glucose metabolism in this disease using 18 F-fluorodeoxyglucose positron emission tomography (PET).

METHODS

We examined 8 patients, aged 48-64 years, in varying stages of clinical symptomatology. Two patients were investigated with quantitative PET on clinical indications after which six more patients were recruited. Absolute glucose metabolism was analyzed with the PVElab software in 6 patients and 18 healthy controls. A semiquantitative analysis using the CortexID software was performed in seven investigations, relating local metabolism levels to global glucose metabolism.

RESULTS

The clinical quantitative PET revealed low global glucose metabolism, with the most marked reduction in the cerebellum. In the PVElab analysis, patients presented low mean glucose metabolism in the cerebellum, brainstem and global grey matter. In the semiquantitative analysis, 2 patients showed a decreased metabolism in the cerebellum and 4 patients a relatively higher metabolism in parts of the temporal lobes. Since none of the patients showed an increased metabolism in the quantitative analysis, we interpret these increases as "pseudo-increases" related to a globally reduced metabolism.

CONCLUSIONS

Global reduction of grey matter glucose metabolism in this white matter disease most likely depends on a combination of cortical afferent dysfunction and, in later stages, neuronal loss. The lowest metabolism in the cerebellum is consistent with histopathological findings and prominent cerebellar symptoms.

Genomic deletions upstream of lamin B1 lead to atypical autosomal dominant leukodystrophy

Objective

Clinical, radiologic, and molecular analysis of patients with genomic deletions upstream of the LMNB1 gene.

Methods

Detailed neurologic, MRI examinations, custom array comparative genomic hybridization (aCGH) analysis, and expression analysis were performed in patients at different clinical centers. All procedures were approved by institutional review boards of the respective institutions.

Results

Five patients from 3 independent families presented at ages ranging from 32 to 52 years with neurologic symptoms that included progressive hypophonia, upper and lower limb weakness and spasticity, and cerebellar dysfunction and MRIs characterized by widespread white matter alterations. Patients had unique nonrecurrent deletions upstream of the LMNB1, varying in size from 250 kb to 670 kb. Deletion junctions were embedded in repetitive elements. Expression analysis revealed increased LMNB1 expression in patient cells.

Conclusions

Our findings confirmed the association between LMNB1 upstream deletions and leukodystrophy previously reported in a single family, expanding the phenotypic and molecular description of this condition. Although clinical and radiologic features overlapped with those of autosomal dominant leukodystrophy because of LMNB1 duplications, patients with deletions upstream of LMNB1 had an earlier age at symptom onset, lacked early dysautonomia, and appeared to have lesser involvement of the cerebellum and sparing of the spinal cord diameter on MRI. aCGH analysis defined a smaller minimal critical region required for disease causation and revealed that deletions occur at repetitive DNA genomic elements. Search for LMNB1 structural variants (duplications and upstream deletions) should be an integral part of the investigation of patients with autosomal dominant adult-onset leukodystrophy.

Evaluation of the INTERPRET decision-support system: can it improve the diagnostic value of magnetic resonance spectroscopy of the brain?

Purpose

We evaluated in a clinical setting the INTERPRET decision-support system (DSS), a software generated to aid in MRS analysis to achieve a specific diagnosis for brain lesions.

Methods

The material consisted of 100 examinations of focal intracranial lesions with confirmed diagnoses. MRS was obtained at 1.5 T using TE 20–30 ms. Data were processed with the LCModel for conventional analysis. The INTERPRET DSS 3.1. was used to obtain specific diagnoses. MRI and MRS were reviewed by one interpreter. DSS analysis was made by another interpreter, in 80 cases by two interpreters. The diagnoses were compared with the definitive diagnoses. For comparisons between DSS, conventional MRS analysis, and MRI, the diagnoses were categorised: high-grade tumour, low-grade tumour, non-neoplastic lesion.

Results

Interobserver agreement in choosing the diagnosis from the INTERPRET database was 75%. The diagnosis was correct in 38/100 cases, incorrect in 57 cases. No good match was found in 5/100 cases. The diagnostic category was correct with DSS/conventional MRS/MRI in 67/58/52 cases, indeterminate in 5/8/20 cases, incorrect in 28/34/28 cases. Results with DSS were not significantly better than with conventional MRS analysis. All definitive diagnoses did not exist in the INTERPRET database. In the 61 adult patients with the diagnosis included in the database, DSS/conventional MRS/MRI yielded a correct diagnosis category in 48/32/29 cases (DSS vs conventional MRS: p = 0.002, DSS vs MRI: p = 0.0004).

Conclusion

Use of the INTERPRET DSS did not improve MRS categorisation of the lesions in the unselected clinical cases. In adult patients with lesions existing in the INTERPRET database, DSS improved the results, which indicates the potential of this software with an extended database.

Electronic supplementary material

The online version of this article (10.1007/s00234-018-2129-7) contains supplementary material, which is available to authorized users.

Intracranial pressure elevations in diffuse axonal injury: association with nonhemorrhagic MR lesions in central mesencephalic structures

OBJECTIVE

Increased intracranial pressure (ICP) in patients with severe traumatic brain injury (TBI) with diffuse axonal injury (DAI) is not well defined. This study investigated the occurrence of increased ICP and whether clinical factors and lesion localization on MRI were associated with increased ICP in patients with DAI.

METHODS

Fifty-two patients with severe TBI (median age 24 years, range 9-61 years), who had undergone ICP monitoring and had DAI on MRI, as determined using T2*-weighted gradient echo, susceptibility-weighted imaging, and diffusion-weighted imaging (DWI) sequences, were enrolled. The proportion of good monitoring time (GMT) with ICP > 20 mm Hg during the first 120 hours postinjury was calculated and associations with clinical and MRI-related factors were evaluated using linear regression.

RESULTS

All patients had episodes of ICP > 20 mm Hg. The mean proportion of GMT with ICP > 20 mm Hg was 5%, and 27% of the patients (14/52) spent more than 5% of GMT with ICP > 20 mm Hg. The Glasgow Coma Scale motor score at admission (p = 0.04) and lesions on DWI sequences in the substantia nigra and mesencephalic tegmentum (SN-T, p = 0.001) were associated with the proportion of GMT with ICP > 20 mm Hg. In multivariable linear regression, lesions on DWI sequences in SN-T (8% of GMT with ICP > 20 mm Hg, 95% CI 3%-13%, p = 0.004) and young age (-0.2% of GMT with ICP > 20 mm Hg, 95% CI -0.07% to -0.3%, p = 0.002) were associated with increased ICP.

CONCLUSIONS

Increased ICP occurs in approximately one-third of patients with severe TBI who have DAI. Age and lesions on DWI sequences in the central mesencephalon (i.e., SN-T) are associated with elevated ICP. These findings suggest that MR lesion localization may aid prediction of increased ICP in patients with DAI.

Acute brain lesions on magnetic resonance imaging in relation to neurological outcome after cardiac arrest

BACKGROUND

Magnetic resonance imaging (MRI) of the brain including diffusion-weighted imaging (DWI) is reported to have high prognostic accuracy in unconscious post-cardiac arrest (CA) patients. We documented acute MRI findings in the brain in both conscious and unconscious post-CA patients treated with target temperature management (TTM) at 32-34°C for 24 h as well as the relation to patients' neurological outcome after 6 months.

METHODS

A prospective observational study with MRI was performed regardless of the level of consciousness in post-CA patients treated with TTM. Neurological outcome was assessed using the Cerebral Performance Categories scale and dichotomized into good and poor outcome.

RESULTS

Forty-six patients underwent MRI at 3-5 days post-CA. Patients with good outcome had minor, mainly frontal and parietal, lesions. Acute hypoxic/ischemic lesions on MRI including DWI were more common in patients with poor outcome (P = 0.007). These lesions affected mostly gray matter (deep or cortical), with or without involvement of the underlying white matter. Lesions in the occipital and temporal lobes, deep gray matter and cerebellum showed strongest associations with poor outcome. Decreased apparent diffusion coefficient, was more common in patients with poor outcome.

CONCLUSIONS

Extensive acute hypoxic/ischemic MRI lesions in the cortical regions, deep gray matter and cerebellum detected by visual analysis as well as low apparent diffusion coefficient values from quantitative measurements were associated with poor outcome. Patients with good outcome had minor hypoxic/ischemic changes, mainly in the frontal and parietal lobes.

Novel SACS mutations associated with intellectual disability, epilepsy and widespread supratentorial abnormalities

We describe eight subjects from two consanguineous families segregating with autosomal recessive childhood onset spastic ataxia, peripheral neuropathy and intellectual disability. The degree of intellectual disability varied from mild to severe and all four affected individuals in one family developed aggressive behavior and epilepsy. Using exome sequencing, we identified two novel truncating mutations (c.2656C>T (p.Gln886*)) and (c.4756_4760delAATCA (p.Asn1586Tyrfs*3)) in the SACS gene responsible for autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS). MRI revealed typical cerebellar and pontine changes associated with ARSACS as well as multiple supratentorial changes in both families as likely contributing factors to the cognitive symptoms. Intellectual disability and behavioral abnormalities have been reported in some cases of ARSACS but are not a part of the characteristic triad of symptoms that includes cerebellar ataxia, spasticity and peripheral neuropathy. Our combined findings bring further knowledge to the phenotypic spectrum, neurodegenerative changes and genetic variability associated with the SACS gene of clinical and diagnostic importance.

MR Imaging of the Lower Spine

The findings on MR imaging of 28 patients with spinal infection and 40 patients with spinal malignant disease were compared. Spinal infections involved one to 4 vertebrae, usually (23/28) 2 vertebrae. The posterior elements were involved with certainty in 26/40 patients with malignancy but in none with infection. In the latter group, the posterior elements might have been involved in 3/28. The intervertebral disk between the infected vertebrae was involved in 26/28 patients and 21/28 had a paravertebral mass. Spinal malignancies affected the vertebrae alone in 19 patients and paravertebral extension was found in 21/40 patients. The intervertebral disk was involved only in one patient with malignancy. The differences in the distribution of the MR findings between spinal infection and spinal malignancy were highly significant (p < 0.001). The highest signal intensity of the infectious lesions on T2-weighted images was equal to or higher than that of the cerebrospinal fluid (CSF) in 26/28 patients. In contrast, the signal intensity of the malignant lesions was hypointense as compared to the CSF in 29/40 patients (p < 0.001). MR is a useful method for differentiating between infection and malignancy in the lower spine; T2-weighted images are especially valuable for differentiation.

Experimental intracerebral and subarachnoid/intraventricular haemorrhages: MR detectability at 0.5 T and 1.5 T

Purpose: To compare the detectability of small experimental intracranial haemorrhages on MR imaging at 0.5 T and 1.5 T, from hyperacute to subacute stages.

Material and Methods: 1 ml of autologous blood was injected into the brain of 15 rabbits to create intraparenchymal haematomas. Since the blood partially escaped into the cerebrospinal fluid (CSF) spaces, detectability of subarachnoid and intraventricular blood was also evaluated. MR imaging at 0.5 T and at 1.5 T was repeated up to 14 days, including T1-, proton density- and T2-weighted (w) spin-echo (SE), FLAIR and T2*-w gradient echo (GE) pulse sequences. The last MR investigation was compared to the formalin-fixed brain sections in 7 animals.

Results: The intraparenchymal haematomas were best revealed with T2*-w GE sequences, with 100% of sensitivity at 1.5 T and 90–95% at 0.5 T. Blood in the CSF spaces was significantly ( p < 0.05) better detected at 1.5 T with T2*-w GE sequences and detected best during the first 2 days. The next most sensitive sequence for intracranial blood was FLAIR. SE sequences were rather insensitive.

Conclusion: 1.5 T equipment is superior to 0.5 T in the detection of intracranial haemorrhages from acute to subacute stages. T2*-w GE sequences account for this result but other sequences are also needed for a complete examination.

Clot Formation in Angiographic Catheters — An in Vitro Comparative Study

Clot formation was compared in 6 brands of angiographic catheters, each of which was tested in 3 states: untreated, heparinized, and albumin-coated. Forty-six samples of each brand in each state (in total 828) were filled with blood from 23 donors and incubated at +37 °C for 5 or 15 min. Physiologic saline was then injected through the catheters at a flow rate of 5 and 50 ml/s, respectively, and any expelled clots identified on a filter. Heparinization reduced the number of clotted catheters at 5 min, but not at 15 min. The only significant difference related to catheter brands was found between the heparinized nylon and polyurethane catheters at 5-min incubation with fewer clotted polyurethane catheters. This difference was not found between the same materials made by two other manufacturers. Albumin coating had no effect on clot formation, but clots were more easily expelled by low-flow injections in albumin-coated and, to a lesser degree, in heparinized than in untreated catheters.

Detection of Soft-Tissue and Skeletal Infections with Ultra Low-Field (0.02 T) Mr Imaging

To evaluate the use of ultra low-field (0.02 T) magnetic resonance (MR) imaging in the diagnosis of musculoskeletal infection, MR examinations with T2 weighted sequences were performed in 61 patients thought to be suffering from one of four major diagnostic categories: Soft-tissue abscesses (n=22), osteomyelitis (n=21), septic arthritis (n=9) and spondylitis (n=9). Infection was confirmed for 37 of these 61 patients. The verified abscesses, arthritis, spondylitis and acute osteomyelitis could be detected by 0.02 T MR. The sensitivity was poor in cases of chronic osteomyelitis. There was one false positive finding in a patient with a possible soft tissue infection. The 0.02 T MR examination failed four times. Two patients were too heavy and another 2 patients had magnetic material in or near the scanning field. Compared with computed tomography and isotope scanning, 0.02 T MR proved a little more informative, but without any statistical significance.

Prevention and Dispersion of Contrast Media Induced Red Cell Aggregates

Red cell aggregation was observed microscopically when human blood and contrast media were mixed on glass slides. Aggregation was more frequent in low-osmolal media: mainly rouleaux were formed in ioxaglate but irregular aggregates in non-ionic media. Aggregation was similar at concentrations of 150 and 300 mg I/ml. Pre-treatment of glass slides with heparinized saline reduced red cell aggregation but saline alone was almost as effective. Most of the irregular aggregates dispersed when saline or heparinized saline was applied to them. Saline and heparinized saline had an identical dispersing effect. After incubation of the aggregates in iopamidol in plastic tubes for one or five minutes, saline was injected into the tubes, and after mixing the solution was poured onto glass slides and examined under the microscope. Only a few small irregular aggregates were detected in 6/60 specimens. It is concluded that ionicity of a flushing medium and shear of the injection are able to disperse red cell aggregates during angiography.

MR follow-up of small experimental intracranial haemorrhages from hyperacute to subacute phase

Purpose: To compare pulse sequences in revealing intracranial bleeding from the hyperacute to subacute phase.

Material and Methods: We injected 0.3-1 ml of autologous blood into the brain of 8 rabbits. MR imaging was performed immediately after haematoma creation and then at determined intervals up to 9-12 days. All images were analysed by two observers. After the last MR investigation, the brain was fixed in formalin. The last MR images were compared to the fixed brain sections and to the histologic findings.

Results: T2*-weighted GE sequences, both conventional spoiled and echoplanar sequences, revealed the intraparenchymal haematomas as hypointensities in all but 1 case, which was negative from the second day onward (a rabbit with 0.3 ml blood injected). The signal patterns remained unchanged during the follow-up. The haematoma sizes and shapes corresponded well to gross pathology. Blood in the cerebrospinal fluid (CSF) space was detected with T2*-weighted GE sequences in a great majority of the examinations during the first 2 days. The cases with the smallest injected volume of blood were negative. SE sequences were rather insensitive. The FLAIR sequence often revealed blood in CSF spaces but not in the brain.

Conclusion: T2*-weighted GE sequences are capable of revealing very small intraparenchymal haemorrhages from the hyperacute to the subacute phase, and blood in CSF spaces during at least the first 2 days.

Magnetic Resonance Imaging of Intracranial Neoplasms at 0.02 Tesla

Sixty-five patients with single or multiple intracranial neoplasms were examined with an MR imager operating at 0.02 tesla. In 56 patients the diagnosis was histologically confirmed. All patients had an abnormal CT finding. MR images were positive in 59 cases, while the lesion remained undetected or equivocal in 6 cases (2 pituitary adenomas and 4 meningiomas). The MR signal intensity of several meningiomas was equal to that of normal brain tissue. Some astrocytomas were better delineated on MRI than on CT. For the study of pituitary lesions, the spatial resolution was unsatisfactory. The ultralow field MR imager was found to be sensitive for the detection of other intracranial neoplasms.

Book Reviews

Paediatric Ultrasound. Edited by H. M. L. Carty. Greenwich Medical Media Ltd., London 2001.

The Pathophysiologic Basis of Nuclear Medicine. Edited by A. H. Elgazzar. Springer-Verlag 2001. ISBN 3-540-65914-5. Price: DEM 349.

Imaging for Students, 2nd edn. By D. A. Lisle & A. Russell. Arnold, London 2001. ISBN 0-340-76231-4.

The Encyclopaedia of Medical Imaging, vols. VI:1 Neuroradiology, and VI:2 Head and Neck Imaging. Edited by H. Pettersson, D. Allison, G. Scotti & R. Hermans. The NICER Institute, Oslo, Norway 2000. ISBN 82-91942-07-2.

Fundamentals of Hand and Wrist Imaging. Edited by G. Guglielmi et al. Springer-Verlag 2001. ISBN 3-540-67854-9. Price: hardcover DEM 399.

Blood Clot Formation in Angiographic Catheters

Human blood was injected into angiographic catheters filled with contrast media or flushing media. The catheters were allowed to stand at 37°C for 10, 20 or 30 min. Physiologic saline was then injected through the catheters, the catheter contents were shaken and filtered, and any clots were identified. Diatrizoate, ioxaglate, iohexol, iopamidol and iopromide were tested. Physiologic and heparinized saline were used as controls. At 10 min, clots were found in 65 per cent of the catheters filled with physiologic saline, in 25 per cent with non-ionic media, in 19 per cent with heparinized saline, and in 4 per cent with ionic contrast media. At 30 min, all catheters with physiologic saline, 85 per cent with non-ionic contrast media, 46 per cent with heparinized saline and 23 per cent with ionic contrast media contained a clot. Although all the contrast media were anticoagulants, a more careful angiographic technique is needed for non-ionic media. All the non-ionic agents showed equal results. Physiologic saline without heparin is not suitable for flushing during angiography.

Extended Anatomical Grading in Diffuse Axonal Injury Using MRI: Hemorrhagic Lesions in the Substantia Nigra and Mesencephalic Tegmentum Indicate Poor Long-Term Outcome

Clinical outcome after traumatic diffuse axonal injury (DAI) is difficult to predict. In this study, three magnetic resonance imaging (MRI) sequences were used to quantify the anatomical distribution of lesions, to grade DAI according to the Adams grading system, and to evaluate the value of lesion localization in combination with clinical prognostic factors to improve outcome prediction. Thirty patients (mean 31.2 years ±14.3 standard deviation) with severe DAI (Glasgow Motor Score [GMS] <6) examined with MRI within 1 week post-injury were included. Diffusion-weighted (DW), T2*-weighted gradient echo and susceptibility-weighted (SWI) sequences were used. Extended Glasgow outcome score was assessed after 6 months. Number of DW lesions in the thalamus, basal ganglia, and internal capsule and number of SWI lesions in the mesencephalon correlated significantly with outcome in univariate analysis. Age, GMS at admission, GMS at discharge, and low proportion of good monitoring time with cerebral perfusion pressure <60 mm Hg correlated significantly with outcome in univariate analysis. Multivariate analysis revealed an independent relation with poor outcome for age (p = 0.005) and lesions in the mesencephalic region corresponding to substantia nigra and tegmentum on SWI (p = 0.008). We conclude that higher age and lesions in substantia nigra and mesencephalic tegmentum indicate poor long-term outcome in DAI. We propose an extended MRI classification system based on four stages (stage I—hemispheric lesions, stage II—corpus callosum lesions, stage III—brainstem lesions, and stage IV—substantia nigra or mesencephalic tegmentum lesions); all are subdivided by age (≥/<30 years).

LMNB1-related autosomal-dominant leukodystrophy: Clinical and radiological course

OBJECTIVE

Duplication of the LMNB1 gene encoding lamin B1 causes adult-onset autosomal-dominant leukodystrophy (ADLD) starting with autonomic symptoms, which are followed by pyramidal signs and ataxia. Magnetic resonance imaging (MRI) of the brain reveals characteristic findings. This is the first longitudinal study on this disease. Our objective is to describe the natural clinical and radiological course of LMNB1-related ADLD.

METHODS

Twenty-three subjects in two families with LMNB1 duplications were studied over two decades with clinical assessment and MRI of the brain and spinal cord. They were 29 to 70 years old at their first MRI. Repeated MRIs were performed in 14 subjects over a time period of up to 17 years.

RESULTS

Pathological MRI findings were found in the brain and spinal cord in all examinations (i.e., even preceding clinical symptoms). MRI changes and clinical symptoms progressed in a definite order. Autonomic dysfunction appeared in the fifth to sixth decade, preceding or together with gait and coordination difficulties. Motor signs developed ascending from spastic paraplegia to tetraplegia and pseudobulbar palsy in the seventh decade. There were clinical, radiological, and neurophysiological signs of myelopathy. Survival lasted more than two decades after clinical onset.

INTERPRETATION

LMNB1-related ADLD is a slowly progressive neurological disease. MRI abnormalities of the brain and spinal cord can precede clinical symptoms by more than a decade and are extensive in all symptomatic patients. Spinal cord involvement is a likely contributing factor to early autonomic symptoms and spastic paraplegia.

A novel AP4M1 mutation in autosomal recessive cerebral palsy syndrome and clinical expansion of AP-4 deficiency

Background

Cerebral palsy (CP) is a heterogeneous neurodevelopmental disorder associated with intellectual disability in one-third of cases. Recent findings support Mendelian inheritance in subgroups of patients with the disease. The purpose of this study was to identify a novel genetic cause of paraplegic CP with intellectual disability in a consanguineous Pakistani family.

Methods

We performed whole-exome sequencing (WES) in two brothers with CP and intellectual disability. Analysis of AP4M1 mRNA was performed using quantitative real-time PCR on total RNA from cultured fibroblasts. The brothers were investigated clinically and by MRI.

Results

We identified a novel homozygous AP4M1 mutation c.194_195delAT, p.Y65Ffs*50 in the affected brothers. Quantitative RT-PCR analysis showed markedly reduced AP4M1 mRNA levels suggesting partial non-sense mediated mRNA decay. Several clinical and MRI features were consistent with AP-4 complex deficiency. However, in contrast to previously reported cases with AP4M1 mutations our patients show an aggressive behavior and a relatively late onset of disease.

Conclusion

This study shows an AP4M1 mutation associated with aggressive behavior in addition to mild dysmorphic features, intellectual disability, spastic paraparesis and reduced head circumference. Our findings expand the clinical spectrum associated with AP-4 complex deficiency and the study illustrates the importance of MRI and WES in the diagnosis of patients with CP and intellectual disability.

The cerebrospinal fluid cytokine signature of multiple sclerosis: a homogenous response that does not conform to the Th1/Th2/Th17 convention

In this cross-sectional study, we wanted to identify key cytokines characteristic of different stages of multiple sclerosis (MS). To this end, cerebrospinal fluid from patients with MS was investigated with a multiplexed fluorescent bead-based immunoassay. In total 43 cytokines were assessed and related to clinical and imaging data. Increased levels of CCL22, CXCL10 and sCD40L characterized relapsing-remitting MS patients with the presence of gadolinium-enhancing lesions; decreased CCL2 and increased CXCL1 and CCL5 were typical of relapsing-remitting MS patients irrespectively of the presence of gadolinium-enhancing lesions. These homogenous patterns of cytokine activation do not conform to conventional Th1/Th2/Th17 responses.

Assessing tissue damage in multiple sclerosis: a biomarker approach

OBJECTIVES

Magnetic resonance imaging (MRI) of the brain and spinal cord is the gold standard for assessing disease activity in multiple sclerosis (MS). MRI is an excellent instrument for determination of accumulated damage to the brain and spinal cord, but tells us little about ongoing tissue damage. In this study, biomarkers of oligodendrocyte, axonal and astrocyte injury were related to MRI and clinical findings and used to assess tissue damage in MS.

MATERIALS AND METHODS

Cerebrospinal fluid from 44 patients with relapsing-remitting MS, 20 with secondary progressive MS and 15 controls were investigated with ELISA to determine levels of myelin basic protein (MBP), neurofilament light (NFL) and glial fibrillary acidic protein (GFAp). Patients underwent MRI of the brain and spinal cord, and gadolinium enhancing lesions, T1 lesions and T2 lesions were counted.

RESULTS

Patients in clinical relapse and patients with nonsymptomatic gadolinium enhancing lesions had high levels of MBP and NFL, indicating ongoing damage to oligodendrocytes and axons. The level of MBP dropped quickly within a week from the onset of a relapse, whereas NFL remained elevated for several weeks and GFAp slowly rose during the course of a relapse. Relapsing-remitting MS patients without gadolinium enhancing lesions had values of MBP, NFL and GFAp similar to controls, while patients with secondary progressive disease had moderately increased values of all biomarkers.

CONCLUSIONS

Analysis of MBP, NFL and GFAp provides direct means to measure tissue damage and is a useful addition to our methods for evaluation of MS.

Recurrence of Susac Syndrome following 23 Years of Remission

Susac syndrome is an autoimmune microangiopathy affecting the brain, retina and inner ear (cochlea and semicircular canals), leading to encephalopathy, branch retinal artery occlusions (BRAOs) and asymmetric neurosensory hearing loss, respectively. The natural history and long-term prognosis are variable as the disease has been shown to be monophasic and self-limiting, polycyclic or chronic continuous. We describe a 35-year-old woman who presented with a sudden hearing loss in the left ear in the 37th week of her second pregnancy. She subsequently developed BRAO in the right eye 2.5 months after having given birth. MRI findings included round lesions in the corpus callosum which are pathognomonic for Susac syndrome. Previous patient records documented encephalopathy, sudden deafness of the right ear and visual field defects in the left eye at the age of 12, followed by permanent hearing and visual defects. We expand on the variability in the course of Susac syndrome as recurrence may occur after as long as 23 years. Cases of monophasic self-limiting Susac syndrome may in fact turn polycyclic with an interval of more than 2 decades between the bouts of the disease. In these cases, suspecting the development of exacerbation early is important in order to start the treatment promptly.

Brain pathology after mild traumatic brain injury: an exploratory study by repeated magnetic resonance examination

OBJECTIVE

To explore brain pathology after mild traumatic brain injury by repeated magnetic resonance examination.

DESIGN

A prospective follow-up study.

SUBJECTS

Nineteen patients with mild traumatic brain injury presenting with Glasgow Coma Scale (GCS) 14-15.

METHODS

The patients were examined on day 2 or 3 and 3-7 months after the injury. The magnetic resonance protocol comprised conventional T1- and T2-weighted sequences including fluid attenuated inversion recovery (FLAIR), two susceptibility-weighted sequences to reveal haemorrhages, and diffusion-weighted sequences. Computer-aided volume comparison was performed. Clinical outcome was assessed by the Rivermead Post-Concussion Symptoms Questionnaire (RPQ), Hospital Anxiety and Depression Scale (HADS) and Glasgow Outcome Scale Extended (GOSE).

RESULTS

At follow-up, 7 patients (37%) reported ≥  3 symptoms in RPQ, 5 reported some anxiety and 1 reported mild depression. Fifteen patients reported upper level of good recovery and 4 patients lower level of good recovery (GOSE 8 and 7, respectively). Magnetic resonance pathology was found in 1 patient at the first examination, but 4 patients (21%) showed volume loss at the second examination, at which 3 of them reported < 3 symptoms and 1 ≥ 3 symptoms, all exhibiting GOSE scores of 8.

CONCLUSION

Loss of brain volume, demonstrated by computer-aided magnetic resonance imaging volumetry, may be a feasible marker of brain pathology after mild traumatic brain injury.

Visualization of the fetal lip and palate: is brain-targeted MRI reliable?

Objective : To evaluate the ability of brain-targeted magnetic resonance imaging (MRI) to assess the anatomy of the fetal upper lip and palate. Design : Two independent readers made a blind retrospective review of 60 brain-targeted MRIs of fetuses from 20 to 38 gestational weeks (GW). Fifty-five MRIs were normal and five had orofacial anomalies, including one isolated cleft lip and four cleft lip and palate. Both normal and cleft MRIs had postnatal confirmation. The upper lip, primary palate, secondary palate, and nasal septum were scored into four levels, from evidently normal to evidently abnormal. In case of a suspected pathology, the readers attempted a diagnosis. Setting : Collaboration between a university hospital and a large private practice MRI center. Results : Interobserver agreement (weighted kappa) was 0.79 for the upper lip, 0.70 for the primary palate, 0.86 for the secondary palate, and 0.90 for the nasal septum. The scoring levels of the readers did not change significantly across gestational age. Normality was correctly scored in 96% to 100% of the normal lips and primary palates and in 93% to 97% of the normal secondary palates depending on the reader. A deviated septum was only scored in two fetuses with unilateral cleft palates. The readers identified all pathological cases. Conclusion : Brain-targeted fetal MRI in experienced hands seems to be highly accurate for the evaluation of the lip and palate in fetuses above 20 GW, regardless of gestational age. The assessment of the secondary palate may be slightly more limited than the lip or primary palate.

Asymmetric development of the hippocampal region is common: a fetal MR imaging study

BACKGROUND AND PURPOSE

Hippocampal development is poorly understood. This study evaluated the normal development of the hippocampal region during the fetal period by using MR imaging.

MATERIALS AND METHODS

MR images of 63 fetuses without intracranial pathology were reviewed independently by 2 radiologists with no knowledge of the fetal GA. Three MR images were performed postmortem and 60 in vivo. The progress of hippocampal inversion was analyzed in coronal sections, and the left and right sides of the hippocampal region were compared in every case.

RESULTS

The fetuses in the postmortem examinations were at GWs 17-18 and in the in vivo examinations, at GWs 19-36. The hippocampal sulcus was open, bi- or unilaterally, in 39 fetuses. The oldest was at GW 32. The sulcus was closed at GW 21 at the earliest, unilaterally. In 26/63 fetuses (41%), the deepening or closure of the hippocampal sulcus or hippocampal inversion was asymmetric; in 23 fetuses, the right side developed faster. A shallow collateral sulcus was found earliest at GW 17. A deep collateral sulcus was visible earliest at GW 26 unilaterally, but in all fetuses from GW 31 onward, it was seen bilaterally. The orientation of the collateral sulcus was not related to the GA.

CONCLUSIONS

There are wide individual temporal variations in the development and the inversion process of the hippocampal sulcus as well as in the formation of the collateral sulcus. Asymmetric development is common, and in most of the asymmetric cases, the right hippocampus develops faster.

Development of the hippocampal region demonstrated by fetal MRI. A preliminary report

Coronal slices of three fetal MRIs performed post mortem and 37 performed in utero, all without intracranial pathology, was assessed. Progress of the hippocampal inversion was analyzed, the left and right sides were compared and occurrence of the collateral sulcus was revealed. The fetuses in the post mortem examinations were at gestation weeks (GW) 17-18 and in the in utero examinations at GW 19-35. The symmetric development of the hippocampal sulcus was revealed in 26 subjects and asymmetric in 14. The non-ovoid hippocampal formation could be evaluated at GW 24 at earliest and an ovoid hippocampus at GW 29. The collateral sulcus could be recognized at GW 17 in post mortem and at GW 22 in in utero examinations. From GW 29 onwards it was seen in all fetuses and it was symmetric in all but one case. Evaluation of the hippocampi is difficult on fetal MRI, especially in in utero examinations. The hippocampal development is not fulfilled at GW 21 as presumed. There is a wide temporal variation in the development of the hippocampal region, and the developmental process does not progress simultaneously in the right and left side of the same individual.

Bilateral and recurrent optic neuritis in multiple sclerosis

OBJECTIVE

To assess the frequency of bilateral and recurrent optic neuritis (ON) in multiple sclerosis (MS) and to compare these results with epidemiological data of ON in neuromyelitis optica (NMO) and recurrent ON without other signs of disease.

METHODS

We identified 472 patients with diagnosis of MS from the Swedish Multiple Sclerosis Register. These patients were evaluated for the presence of ON and whether the ON was the presenting symptom of MS; unilateral or bilateral; monophasic or recurrent.

RESULTS

Twenty-one percent presented with ON as their first manifestation of MS. The proportion of patients developing a second attack of ON before demonstration of other manifestations of MS was 5.5% and the frequency of recurrent bilateral ON as the presenting symptom was 3.8%. Only two patients presented with simultaneously appearing bilateral ON corresponding to 0.42%.

CONCLUSION

Recurrent ON, whether unilateral or bilateral, is a common presentation of MS. As MS is a much more common disease than NMO, care must be taken when evaluating the work-up of patients with recurrent ON. In some cases repeated MRI and lumbar punctures are warranted to improve diagnostic accuracy, even in the presence of the serological marker NMO-IgG.

Genomic duplications mediate overexpression of lamin B1 in adult-onset autosomal dominant leukodystrophy (ADLD) with autonomic symptoms

Adult-onset autosomal dominant leukodystrophy (ADLD) with autonomic symptoms features micturition urgency, constipation, erectile dysfunction, and orthostatic hypotension, usually followed by pyramidal signs and ataxia. Peripheral nerve conduction is normal. The disease is often mistaken for multiple sclerosis in the initial phase. There is a characteristic pattern of white matter changes in the brain and spinal cord on magnetic resonance imaging (MRI), mild atrophy of the brain, and a more marked atrophy of the spinal cord. ADLD is associated with duplications of the lamin B1 (LMNB1) gene but the mechanism by which the rearrangement conveys the phenotype is not fully defined. We analyzed four unrelated families segregating ADLD with autonomic symptoms for duplications of the LMNB1 gene. A single nucleotide polymorphism (SNP) array analysis revealed novel duplications spanning the entire LMNB1 gene in probands from each of the four families. We then analyzed the expression of lamin B1 in peripheral leukocytes by Western blot analysis in five patients from two available families. The protein levels of lamin B1 were found significantly increased. These results indicate that the ADLD phenotype associated with LMNB1 duplications is mediated by increased levels of the lamin B1 protein. Furthermore, we show that a molecular diagnosis for ADLD with autonomic symptoms can be obtained by a direct analysis of lamin B1 in peripheral leukocytes.

Radiological Aspects of Genetic Disorders with Adult-onset CNS Symptoms

Genetic disorders affecting the central nervous system have a wide age range regarding onset of symptoms. A specific disease entity may have childhood onset or adult onset forms, whereas other disease entities may only yield symptoms in adulthood. Symptoms may be neurological or psychiatric including early dementia. It is important to recognize such diseases because the correct diagnosis may yield information on the mode of inheritance, prognosis and have an impact on the patient's treatment. Radiological examinations also provide further knowledge about these diseases and help us in understanding pathophysiology. Examples of some genetic diseases with adult-onset will be presented.

Re-evaluation of the dysequilibrium syndrome

OBJECTIVES

To re-evaluate middle-aged Swedish patients diagnosed with dysequilibrium syndrome (DES) in childhood and to compare their clinical and neuroimaging features to DES with VLDLR gene mutations (DES-VLDR).

MATERIALS AND METHODS

Six patients from five families underwent neurological examination and magnetic resonance imaging (MRI) of the brain. Blood samples from the patients were screened for serum carbohydrate-deficient transferrin (s-CDT; disialotransferrin). The very-low-density lipoprotein receptor (VLDLR) gene was sequenced.

RESULTS

Five patients had non-progressive cerebellar ataxia (NPCA), dysarthria and short stature. Mental retardation and strabismus, characteristic for DES-VLDLR, were inconsistent among our patients. None of our patients had VLDLR mutations or MRI findings characteristic of DES-VLDLR. MRI findings were variable from a normal cerebellum to marked cerebellar hypoplasia or atrophy and signal intensity changes. One patient was diagnosed with congenital disorder of glycosylation type 1a (CDG-1a).

CONCLUSIONS

DES was originally coined on mainly clinical grounds before MRI and specific genetic tests were available, both of which should be used to arrive at an appropriate diagnosis.

Clinical, neuroimaging and neurophysiological features in addicts with manganese-ephedrone exposure

OBJECTIVE

To identify biomarkers supporting the clinical diagnosis of manganism in patients several years after exposure to manganese (Mn).

METHODS

Neurophysiological examinations, magnetic resonance imaging (MRI), single-photon emission computed tomography and fluorodeoxyglycose (FDG) positron emission tomography were performed in four former ephedrone addicts with extrapyramidal symptoms.

RESULTS

Peripheral nervous system was not affected. No patients had reduced uptake of (123)I Ioflupane in the striatum. MRI signal intensities were slightly changed in the basal ganglia. All patients showed a widespread, but not uniform, pathological pattern of FDG uptake with changes mainly located to the central part of the brain including the basal ganglia and the surrounding white matter.

CONCLUSIONS

Presynaptic neurons in the nigrostriatal pathway are intact in Mn-induced parkinsonism after prolonged abstinence from ephedrone. The diagnosis is principally based on clinical signs and the history of drug abuse.

Metabolite concentrations in supraventricular white matter from teenage to early old age: A short echo time 1H magnetic resonance spectroscopy (MRS) study

BACKGROUND

Age- and sex-related changes of metabolites in healthy adult brains have been examined with different (1)H magnetic resonance spectroscopy (MRS) methods in varying populations, and with differing results. A long repetition time and short echo time technique reduces quantification errors due to T(1) and T(2) relaxation effects and makes it possible to measure metabolites with short T(2) relaxation times.

PURPOSE

To examine the effect of age on the metabolite concentrations measured by (1)H MRS in normal supraventricular white matter using a long repetition time (TR) and a short echo time (TE).

MATERIAL AND METHODS

Supraventricular white matter of 57 healthy subjects (25 women, 32 men), aged 13 to 72 years, was examined with a single-voxel MRS at 1.5T using a TR of 6000 ms and a TE of 22 ms. Tissue water was used as a reference in quantification.

RESULTS

Myoinositol increased slightly and total N-acetyl aspartate (NAA) decreased slightly with increasing age. Glutamine/glutamate complex (Glx) showed U-shaped age dependence, with highest concentrations in the youngest and oldest subjects. No significant age dependence was found in total choline and total creatine. No gender differences were found. Macromolecule/ lipid (ML) fractions were reliably measurable only in 36/57 or even fewer subjects and showed very large deviations.

CONCLUSION

The concentrations of several metabolites in cerebral supraventricular white matter are age dependent on (1)H MRS, even in young and middle-aged people, and age dependency can be nonlinear. Each (1)H MRS study of the brain should therefore take age into account, whereas sex does not appear to be so important. The use of macromolecule and lipid evaluations is compromised by less successful quantification and large variations in healthy people.

SPG11 mutations cause Kjellin syndrome, a hereditary spastic paraplegia with thin corpus callosum and central retinal degeneration

Autosomal recessive hereditary spastic paraplegia (ARHSP) with thin corpus callosum (TCC) is genetically heterogenous and approximately 35% of patients carry mutations in either of the SPG11 or SPG15 genes. Disease onset is during the first three decades of life with spastic paraplegia and mental impairment. Peripheral neuropathy and amyotrophy may occur. Kjellin syndrome is characterized by central retinal degeneration in addition to ARHSP-TCC and the disease is associated with mutations in the SPG15 gene. We identified five patients in four unrelated kindreds with spastic paraplegia and mental impairment. Magnetic resonance imaging revealed TCC, atrophy elsewhere in the brain and increased T2 signal intensity in the periventricular white matter. Probands from the four kindreds were screened for mutations in the SPG11 gene. All patients were found homozygous or compound heterozygous for truncating SPG11 mutations of which four are reported for the first time. Ophthalmological investigations revealed that the four index cases have central retinal degeneration consistent with Kjellin syndrome. PET examinations with N-[11C-methyl]-L-deuterodeprenyl (DED) and fluor-18 2-fluorodeoxyglucose (FDG) were performed in two patients with Kjellin syndrome. We observed a reduced glucose uptake in the thalami, anterior cingulum, and sensorimotor cortex indicating neuronal loss, and an increased DED binding in the thalami and pons which suggests astrogliosis. From our results we extend the SPG11 associated phenotype to comprise also Kjellin syndrome, previously found to be associated with mutations in the SPG15 gene. We anticipate that degeneration of the central retina is a common and previously unrecognized feature in SPG11 related disease.

Subjects with intellectual disability and familial need for full-time special education show regional brain alterations: a voxel-based morphometry study

Subjects attending full-time special education (SE) often have multifactorial background for their cognitive impairment, and brain MRI may show nonspecific changes. As voxel-based morphometry reveals regional volume differences, we applied this method to 119 subjects with cognitive impairments and familial need for full-time SE--graded into three levels from specific disorders of cognitive processes (level 1) to intellectual disability (IQ <70; level 3)--and to 43 age-matched controls attending mainstream education (level 0). Subjects in SE groups had smaller global brain white matter (WM), cerebrospinal fluid, and total brain volume than controls. Compared with controls, subjects with intellectual disabilities in SE level 3 showed greater regional gray matter volumes bilaterally in the ventral and dorsal anterior cingulate cortex and smaller regional gray matter volumes in the left thalamus and cerebellar hemisphere. Further, they had greater WM volume in the left frontoparietal region and smaller WM volumes in the posterior limbs of the internal capsules. Subjects in SE level 1 and 2 groups showed the same tendency, but the results were nonsignificant. In conclusion, compared with controls, subjects with intellectual disabilities showed in voxel-based morphometry analysis several regional brain alterations.

Incomplete hippocampal inversion-is there a relation to epilepsy?

Incomplete hippocampal inversion (IHI) has been described in patients with epilepsy or severe midline malformations but also in nonepileptic subjects without obvious developmental anomalies. We studied the frequency of IHI in different epilepsy syndromes to evaluate their relationship. Three hundred patients were drawn from the regional epilepsy register. Of these, 99 were excluded because of a disease or condition affecting the temporal lobes or incomplete data. Controls were 150 subjects without epilepsy or obvious intracranial developmental anomalies. The coronal MR images were analysed without knowledge of the clinical data. Among epilepsy patients, 30% had IHI (40 left-sided, 4 right-sided, 16 bilateral). Of controls, 18% had IHI (20 left-sided, 8 bilateral). The difference was statistically significant (P < 0.05). Of temporal lobe epilepsy (TLE) patients, 25% had IHI, which was not a significantly higher frequency than in controls (P = 0.34). There was no correlation between EEG and IHI laterality. A total of 44% of Rolandic epilepsy patients and 57% of cryptogenic generalised epilepsy patients had IHI. The IHI frequency was very high in some epileptic syndromes, but not significantly higher in TLE compared to controls. No causality between TLE and IHI could be found. IHI can be a sign of disturbed cerebral development affecting other parts of the brain, maybe leading to epilepsy.

Brain magnetic resonance imaging of siblings from families with two or more children with learning or intellectual disabilities and need for full-time special education

BACKGROUND

Several factors are involved in determining a child's need for special education (SE). Thus, the value of brain magnetic resonance imaging (MRI) for subjects with learning and intellectual disabilities is uncertain.

PURPOSE

To evaluate the usefulness of MRI in the diagnostic process of siblings with learning and intellectual disabilities and need for full-time SE.

MATERIAL AND METHODS

Altogether, 119 siblings (mean age 11.9 years) from families in which two or more children attended/had previously attended full-time SE underwent prospective brain MRI. SE grouping included three levels, from specific learning disabilities (level 1) to global intellectual disabilities (level 3). Forty-three controls (level 0, mean age 12.0 years) attended mainstream education groups. Signal intensity and structural abnormalities were analyzed, and areas of the cerebrum, posterior fossa, corpus callosum, vermis and brain stem, and diameters of the corpus callosum were measured. In analyses, all area measurements were calculated in proportion to the total inner skull area.

RESULTS

Abnormal finding in MRI was more common for siblings (n=62; 52%) in SE (58% for level 3; 49% for level 2; 35% for level 1) than for controls (n=13; 16%). The siblings showed enlarged supra- (P<0.001) and infratentorial (P=0.015) cerebrospinal fluid (CSF) spaces and mild corpus callosum abnormalities (P=0.003) compared to controls. Siblings in SE had smaller inner skull area than controls (P<0.001). Further, the relative area of the mesencephalon (P=0.027) and the diameter of the body of the corpus callosum (P=0.015) were significantly smaller than in controls. In binary logistic regression analysis, enlarged supratentorial CSF spaces increased the probability of SE (odds ratio 4.2; P=0.023).

CONCLUSION

Subjects with learning and intellectual disabilities commonly have more MRI findings than controls. Enlarged supratentorial CSF spaces were a frequent finding in siblings in full-time SE.

MR imaging characteristics and neuropathology of the spinal cord in adult-onset autosomal dominant leukodystrophy with autonomic symptoms

BACKGROUND AND PURPOSE

MR imaging findings in adult-onset autosomal dominant leukodystrophy (ADLD) with autonomic symptoms have been described in the brain, but no descriptions of MR imaging findings in the spinal cord have been published. Here, we describe MR imaging findings in the spinal cord in adult-onset ADLD with autonomic symptoms and histopathologic investigations of the spinal cord.

MATERIALS AND METHODS

Twelve subjects from 2 families with adult-onset ADLD with autonomic symptoms identified by clinical investigation underwent MR imaging examination of the spinal cord. Sagittal and transverse sections were obtained. MR imaging examination of the brain was performed in 11 patients. One of the patients underwent postmortem examination, and the spinal cord was subjected to histopathologic analysis.

RESULTS

In all family members with adult-onset ADLD with autonomic symptoms, even in the asymptomatic person, the spinal cord was thin. All examined family members also had a slight general white matter signal intensity (SI) increase in the whole spinal cord, mainly visible in T2-weighted transverse images. The pathologic examination revealed a discrete demyelination in the spinal cord. Brain MR imaging also showed increased T2 SI in the white matter.

CONCLUSIONS

The spinal cord is affected in adult-onset ADLD with autonomic symptoms. Findings consist of atrophy and a diffuse T2 SI increase in the white matter. Transverse images are needed to assess these findings. The typical SI changes of the spinal cord are also present in subjects without clinical symptoms of the disease and with very limited changes in the brain.

Statin-treated familial hypercholesterolemia patients with coronary heart disease and pronounced atherosclerosis do not have more brain lesions than healthy controls in later middle age

BACKGROUND

Clinically silent brain lesions detected with magnetic resonance imaging (MRI) are associated with increased risk for stroke, while stroke risk is controversial in familial hypercholesterolemia (FH).

PURPOSE

To determine whether the occurrence and size of clinically silent brain lesions in FH patients with coronary heart disease (CHD) is higher than in neurologically healthy controls without CHD.

MATERIAL AND METHODS

Brain MRI (1.5T) was performed on 19 DNA-test-verified FH patients with CHD and on 29 cardiovascularly and neurologically healthy controls, all aged 48 to 64 years. All patients were on cardiovascular medication. Intracranial arteries were evaluated by MR angiography. Infarcts, including lacunas, and white matter T2 hyperintensities (WMHI), considered as signs of small vessel disease, were recorded. A venous blood sample was obtained for assessment of risk factors. Carotid and femoral intima-media thicknesses (IMT), assessed with ultrasound, were indicators of overall atherosclerosis.

RESULTS

On intracranial MR angiography, three patients showed irregular walls or narrowed lumens in intracranial carotid arteries. No silent infarcts appeared, and no differences in numbers or sizes of WMHIs between groups were recorded. Patients had greater carotid and femoral IMTs, and a greater number of carotid and femoral plaques. Cholesterol-years score, level of low-density lipoprotein (LDL) cholesterol, and level of high-sensitivity C-reactive protein (hsCRP) of the FH-North Karelia patients were higher than those of the controls, while the level of high-density lipoprotein (HDL) cholesterol in controls was higher.

CONCLUSION

FH patients with CHD and adequate cardiovascular risk-factor treatment showed no difference in the amount or size of clinically silent brain lesions compared to controls, despite patients' more severe atherosclerosis.

The earliest MR imaging and proton MR spectroscopy abnormalities in adult-onset Krabbe disease

BACKGROUND

Adult-onset Krabbe disease is an uncommon form of leukodystrophy. Its magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) manifestations are not well documented.

AIM OF THE STUDY

To describe early MR findings in adult-onset Krabbe disease.

MATERIALS AND METHODS

A 28-year-old woman who had spastic paraparesis and a 5-year history of gait problems underwent MRI of the brain and cervical spine. Proton MRS was performed at 1.5 T using a short echo time. Metabolites were analyzed in the areas of MR signal abnormalities and normal-appearing brain. Six healthy volunteers were examined as controls.

RESULTS

MRI revealed changes in the upper corticospinal tracts, splenium and, minimally, adjacent to the atria of the lateral ventricles. MRS showed decreased creatine, choline, N-acetylaspartate and glutamate and probably elevated lactate in the upper corticospinal tract but not in the normal-appearing frontal lobe. The spinal cord was thin. Laboratory tests verified Krabbe disease.

CONCLUSIONS

These results indicate early involvement of the upper corticospinal tract in adult-onset Krabbe disease. The cases reported earlier had imaging changes indicating a more advanced disease or no MR findings. Thinning of the spinal cord is a new finding in Krabbe disease.

Incomplete inversion of the hippocampus--a common developmental anomaly

Incomplete inversion of the hippocampus, an imperfect fetal development, has been described in patients with epilepsy or severe midline malformations. We studied this condition in a nonepileptic population without obvious developmental anomalies. We analyzed the coronal MR images of 50 women and 50 men who did not have epilepsy. Twenty of them were healthy volunteers and 80 were patients without obvious intracranial developmental anomalies, intracranial masses, hydrocephalus or any condition affecting the temporal lobes. If the entire hippocampus (the head could not be evaluated) were affected, the incomplete inversion was classified as total, otherwise as partial. Incomplete inversion of the hippocampus was found in 19/100 subjects (9 women, 10 men). It was unilateral, always on the left side, in 13 subjects (4 women, 9 men): 9 were of the total type, 4 were partial. It was bilateral in six subjects (five women, one man): four subjects had total types bilaterally, two had a combination of total and partial types. The collateral sulcus was vertically oriented in all subjects with a deviating hippocampal shape. We conclude that incomplete inversion of the hippocampus is not an unusual morphologic variety in a nonepileptic population without other obvious intracranial developmental anomalies.

Association between the aggrecan gene variable number of tandem repeats polymorphism and intervertebral disc degeneration

STUDY DESIGN

Cross-sectional study.

OBJECTIVE

To examine the association between an aggrecan variable number of tandem repeats (VNTR) polymorphism and intervertebral disc degeneration in middle-aged Finnish men.

SUMMARY OF BACKGROUND DATA

An association between the aggrecan VNTR polymorphism and multilevel disc degeneration has been previously reported in young Japanese women.

METHODS

Lumbar discs of 132 men representing 3 occupations (carpenters, machine drivers, and office workers) were evaluated on magnetic resonance imaging, using decreased signal intensity of the nucleus pulposus, disc bulges, and decreased disc height as signs of degeneration. The aggrecan gene VNTR region was analyzed by Southern hybridization.

RESULTS

The allele A26 with 26 repeats was statistically significantly overrepresented among the persons with dark nucleus pulposus. Carrying 2 copies of the A26 allele increased the risk of dark nucleus pulposus (odds ratio = 2.77; 95% confidence interval, 1.24-6.16). Carrying the alleles with either less or more than 26 repeats decreased the risk of dark nucleus pulposus. The carpenters and machine drivers with the A26 allele had a statistically significantly higher risk of disc bulge and decreased disc height than the office workers without the allele.

CONCLUSION

The findings provide additional support for the role of the aggrecan gene VNTR polymorphism in intervertebral disc degeneration.