Neuroradiological findings (MRS, MRI, SPECT) in infantile neuronal ceroid-lipofuscinosis (infantile CLN1) at different stages of the disease.

Infantile neuronal ceroid-lipofuscinosis (infantile CLN1) is a progressive and uniformly fatal lysosomal storage disease of the nervous system. The purpose of this study was to compare the findings of various radiological examinations of the brain in the course of infantile CLN1 in order to evaluate the relative usefulness of the methods and their potential for monitoring therapeutic interventions. We examined eight infantile CLN1 patients, 51 studies, in various stages of the disease--preclinical to late stage--with proton magnetic resonance spectroscopy (1H-MRS), MRI, and perfusion SPECT, and in addition three benzodiazepine (BZ) receptor ligand SPECT studies. Both 1H-MRS and MRI showed abnormal findings before clinical manifestations of the disease. Cortical hypoperfusion and loss of cortical BZ receptors revealed by SPECT appeared simultaneously with clinical signs. After the age of 4 years MRI and SPECT alterations progressed minimally, whereas 1H-MRS showed progressive deterioration of neurometabolism. Of the four methods used in this study, MRI proved to be the most practicable for diagnosing infantile CLN1; the final diagnosis of infantile CLN1 is confirmed by the characteristic clinical picture and DNA or PPT enzyme analysis. The combination of 1H- MRS and MRI could be most useful for monitoring therapeutic interventions.

Hematopoietic stem cell transplantation in infantile neuronal ceroid lipofuscinosis.

OBJECTIVE: To study the effect of allogeneic hematopoietic stem cell transplantation (SCT) on the clinical course of infantile neuronal ceroid lipofuscinosis (INCL), a lysosomal storage disease. BACKGROUND: INCL is a progressive encephalopathy with severe neuronal loss, especially in the cerebral and cerebellar cortex and retina. Autofluorescent lipopigments constitute the typical storage material in INCL. The disease is caused by recessive mutations in the palmitoyl protein thioesterase 1 (PPT1) gene. PPT1 is a depalmitoylating enzyme, which is transported to lysosomes through the mannose-6-phosphate receptor-mediated pathway, and participates in the lysosomal degradation of fatty acylated proteins. METHODS: Three patients with INCL received transplants and were followed up after SCT at the Hospital for Children and Adolescents at the University of Helsinki. The first patient rejected the first graft at the age of 7 months and had mild symptoms of INCL at the second transplantation at 11 months. The two other patients were asymptomatic when they received their transplants at the age of 4 months. RESULTS: PPT1 enzyme activity was normalized in peripheral leukocytes, but remained low in the CSF and resulted only in a mild and transient amelioration of the classic INCL. All patients who received transplants developed INCL by the age of 2 or 3 years. CONCLUSIONS: More experimental animal and cell culture studies are needed to determine the in vivo function of PPT1. SCT currently cannot be recommended as therapy for INCL.

Clinical and neuroradiological diagnostic aspects of neuronal ceroid lipofuscinoses disorders.

Early diagnosis is mandatory for avoiding further cases in families with hereditary metabolic brain disorders. This review lists the most important clinical symptoms and neuroradiological findings at the early stage of the seven most common childhood neuronal ceroid lipofuscinoses (NCL) types. In the infantile type the typical magnetic resonance imaging (MRI) findings can be seen even before the clinical signs. In the classic late infantile type (CLN2), MRI is less informative but in this and in the variant late infantile type CLN6 the characteristic neurophysiological findings are present at an early stage, although not in the Finnish variant CLN5. In the latter, the clinical diagnosis depends on ophthalmological and MRI findings. The combination of ophthalmological deficits and vacuolated lymphocytes is highly characteristic of the juvenile type (CLN3). A new NCL type, Northern epilepsy (CLN8), is also briefly reviewed.

CSF insulin-like growth factor-1 in infantile neuronal ceroid lipofuscinosis.

BACKGROUND: Infantile neuronal ceroid lipofuscinosis (INCL) is a progressive encephalopathy in which the patients are severely disabled by the age of 3 years. It is characterized by cerebral atrophy, selective loss of cortical neurons, and secondary loss of axons and myelin sheaths of the white matter. INCL has been shown to result from a palmitoyl protein thioesterase deficiency. The authors suggested that insulin-like growth hormones and apoptosis might play a role in the pathogenesis of INCL. METHODS: The authors measured insulin-like growth factor-1 (IGF-1) and IGF binding protein 3 (IGFBP-3) in the CSF of patients with INCL by radioimmunoassay at an early stage when myelin was starting to diminish. RESULTS: The authors found low CSF IGF-1 but normal IGFBP-3 in patients with INCL compared with control subjects. Also, they observed apoptotic cell death in biopsies of INCL patients. CONCLUSIONS: Because the IGF system seems to be important for early brain development, myelination, and neuroprotection, the authors suggest that the pathology in INCL may be associated with low CSF IGF-1.

A rapid fluorogenic palmitoyl-protein thioesterase assay: pre- and postnatal diagnosis of INCL.

A deficiency of palmitoyl-protein thioesterase (PPT) was recently shown to be the primary defect in infantile neuronal ceroid lipofuscinosis (INCL). The available enzyme assays are complicated and impractical for diagnostic use. We have recently developed a new, fluorometric assay for PPT based on the sensitive fluorochrome 4-methylumbelliferone, requiring an overnight incubation to measure PPT. Now we have synthesized an analogue of this substrate which allows PPT determinations in 1 h. This improved PPT assay is simple, sensitive, and robust and will facilitate the definition of the full clinical spectrum associated with a deficiency of PPT. PPT activity was readily detectable in fibroblasts, leukocytes, amniotic fluid cells, chorionic villi, plasma, and cerebrospinal fluid from controls. PPT activity was profoundly deficient in these tissues and fluids from INCL patients. Similarly, a deficiency of PPT activity was demonstrated in patients with the variant juvenile NCL with GROD. These results show the feasibility of rapid pre- and postnatal diagnosis of INCL and its variants.

Aspartylglucosaminuria: radiologic course of the disease with histopathologic correlation.

Twelve living patients (aged 19 months to 32 years) with aspartylglucosaminuria were examined by magnetic resonance imaging (MRI), and the magnetic resonance (MR) images of 16 health volunteers (aged 4 to 32 years) were used as controls. One patient was examined twice. Postmortem MRI and histopathologic analysis were done on the brains of four additional adult patients. Signal intensities determined quantitatively on T2-weighted images differed significantly between patients and controls, being higher from the white matter (P < .0002) and lower from the thalami (P < .03) in the patients. The generally increased signal intensity of the white matter was most obvious in the young patients, with many focal areas of very high signal intensity in the subcortical white matter. The subcortical white matter showed a somewhat increased signal intensity even at the age of 32 years. In two of the four postmortem MR images, the distinction between the gray and white matter was still poor. At histopathologic analysis, the basic cortical cytoarchitecture was generally preserved but most neurons contained vacuoles, which were also found in the neurons of the deep gray matter. In two of the four autopsy cases the white matter showed diffuse pallor of myelin staining and some gliosis. Thus aspartylglucosaminuria is primarily a gray-matter disease also affecting white matter by delaying myelination.

EEG and evoked potentials in infantile neuronal ceroid-lipofuscinosis.

Sixteen children with infantile neuronal ceroid-lipofuscinosis (INCL), age range 0.5 to 5.4 years, were studied using EEG, electroretinograms (ERG), visual evoked potentials (VEP) and somatosensory evoked potentials (SEP). Electroencephalography was the first of these examinations to reveal abnormalities, however the EEG may be normal at the preclinical stage. The first abnormality to appear was an attenuated reaction to passive eye opening and closing which was followed by disturbances in background activity and diminution in amplitude, and by disappearance of sleep spindles. The gradual disappearance of posterior rhythm reactivity and of sleep spindles suggests that thalamic dysfunction progresses with time. EEG inactivity appeared by the age of 3 years. Evoked potentials were normal in the early stages of the disease. SEP showed abnormalities at Stage 2 (1.7 years), while ERG and VEP abnormalities appeared at Stage 3 (by the age of 2.5 years). All neurophysiological reactions examined were abolished by the age of 4 years. Follow-up EEG gives important hints as to the early diagnosis of INCL. Progression of the disease can be followed by evoked potentials which may also be helpful in the differential diagnostics.

MRI of neuronal ceroid lipofuscinosis. II. Postmortem MRI and histopathological study of the brain in 16 cases of neuronal ceroid lipofuscinosis of juvenile or late infantile type.

Postmortem MRI was carried out on the formalin-fixed brains of 14 patients with juvenile (JNCL) and two with late infantile neuronal ceroid lipofuscinosis, one of variant and the other of classical type. Two patients with JNCL had also undergone MRI during life. After MRI, specimens for histopathological analysis were taken from standard areas of the cerebral cortex, deep nuclei and white matter. The signal intensity of the periventricular white matter was usually higher than that of the peripheral white matter, a finding which correlated with the severe periventricular loss of myelin and gliosis observed histologically. The signal intensity was usually lower in the thalamus than in the putamen; in some patients the signal intensity of the thalamus was equal to or even lower than that of the white matter. However, myelin loss, gliosis, the storage process or neuronal loss in the thalamus did not correlate with the MRI findings. Since in one patient with JNCL the ante- and postmortem MRI did not differ basically, it appears probable that the periventricular changes detected in vivo on MRI are due to the severe loss of myelin and gliosis observed in this study. However, changes resulting from the fixation process must be considered, when postmortem and in vivo MRI are correlated.

Brain perfusion SPECT abnormalities in neuronal ceroid lipofuscinoses.

Brain perfusion was studied with the Tc-99m-HMPAO SPECT method in 19 INCL patients, 21 JNCL patients and 5 patients with Jansky-Bielschowsky variant disease (JBVD). The typical SPECT findings at an early stage of INCL were bilateral anterior frontal, posterior temporoparietal and occipital hypoperfusion, whereas reduction in cerebellar perfusion appeared later. However, perfusion of basal ganglia and thalami, although atrophic on MRI, was usually well preserved up to the terminal stage. All JNCL patients except one had at least one hypoperfused area. Mild hypoperfusion was usually located in the parietal and occipital lobes and cerebellum, whereas more severe hypoperfusion was observed in the temporal lobes. In JNCL, SPECT revealed lesions not detected on CT. All JBVD patients had supra- and infratentorial hypoperfusion, which was usually bilateral. This study shows that although in NCLs brain hypoperfusion can appear prior to structural abnormalities seen on MRI or CT, such abnormalities are not always associated with significant hypoperfusion.

Lamotrigine therapy in infantile neuronal ceroid lipofuscinosis (INCL).

Since 1990, altogether 16 INCL patients received lamotrigine (LTG) because of intractable epilepsy. The response to LTG was favorable in 15/16 children. The severity of seizures decreased significantly in 15/16 patients, the frequency of seizures decreased in 14/16, and the effects were maintained. In addition, LTG had a beneficial effect on the well-being of 14/16 children. LTG failed to maintain it's efficacy in monotherapy. No severe side effects were found.

MRI of neuronal ceroid lipofuscinosis. I. Cranial MRI of 30 patients with juvenile neuronal ceroid lipofuscinosis.

We studied 30 patients with juvenile neuronal ceroid lipofuscinosis (JNCL). The patients (aged 6-25 years) and 43 age-matched healthy volunteers underwent MRI. After visual assessment, the signal intensity was measured on T2-weighted images in numerous locations. The thickness of the cortex and corpus callosum and the dimensions of the brain stem were measured. Mild to moderate cerebral atrophy was found in 14 of 30 patients, most of them over 14 years of age; 5 older patients had mild to moderate cerebellar atrophy. There was reduction in the size of the corpus callosum and brain stem. The thalamus, caudate nucleus and putamen appeared to give low signal in patients from the ages of 7, 11 and 11 years, respectively. In contrast, the signal intensity measured from the thalamus in these patients showed only a slight (insignificant) decrease compared with controls. The most significant alteration, an increase in measured signal intensity, was found in the white matter (P < 0.0001), even in the youngest patients. The MRI findings correlated significantly with decreased intelligence, speech disturbances and motor problems. Although MRI findings in JNCL do not appear very specific and the visual changes develop relatively late, the absence of pathological MRI findings in the very early stage of the disease may play a part in differential diagnosis of the different types of NCL. Furthermore, the MRI findings may be used in assessing severity and prognosis, particularly in young patients.

Brain perfusion SPECT in infantile neuronal ceroid-lipofuscinosis (INCL). Comparison with clinical manifestations and MRI findings.

We studied brain perfusion in 19 patients with infantile neuronal ceroid-lipofuscinosis (INCL), aged 13 months to 11 years, using 99mTc-HMPAO single photon emission computed tomography (SPECT). SPECT findings were compared with clinical manifestations and MRI findings. The typical SPECT findings at an early stage of INCL were bilateral anterior frontal, posterior temporoparietal and occipital hypoperfusion. Initially cerebral hypoperfusion was localized and symmetrical, whereas atrophic findings were more generalized. Reduction in cerebellar perfusion appeared later, as did cerebellar atrophy. Progression from mild to severe cerebral and cerebellar hypoperfusion was rapid, corresponding to the clinical progression. However, the perfusion of deep grey matter structures (basal ganglia and thalami), although atrophic on MRI, was often well preserved up to the terminal stage. Severe perfusion defects in INCL, which appeared approximately at the age of four, were associated with grave clinical manifestations and neuropathologic findings. Particularly, the early SPECT perfusion abnormalities may assist in the differential diagnosis between INCL and other neurode-generative diseases.

MRI evaluation of the brain in infantile neuronal ceroid-lipofuscinosis. Part 1: Postmortem MRI with histopathologic correlation.

The purpose of this study was to correlate postmortem magnetic resonance imaging (MRI) with histopathologic findings in brains of a series of autopsied patients with infantile neuronal ceroid-lipofuscinosis, a recessively inherited progressive encephalopathy. Eight formalin-fixed brains (age range at death, 7 to 13 years) were examined with MRI. One patient had also undergone brain MRI 2 years before death. Histopathologic analyses were made from standard areas selected on the basis of the MRI scans. Postmortem MRI findings did not differ significantly from the findings in the patient who was also examined during life. Typical findings were extreme cerebral atrophy and hypointensity of the gray-matter structures in relation to the white matter on T2-weighted images, a pattern the reverse of normal. Characteristic histologic findings were almost complete loss of cortical neurons and secondary loss of axons and myelin sheaths in the white matter. The drastically altered relative intensities of the gray- and white-matter structures on the MRI scans reflected replacement of the neurons with hypertrophic astrocytes and/or macrophages filled with storage material.

MRI evaluation of the brain in infantile neuronal ceroid-lipofuscinosis. Part 2: MRI findings in 21 patients.

The purpose of this study was to demonstrate the course of infantile neuronal ceroid-lipofuscinosis with brain magnetic resonance imaging (MRI) in children aged 3 months to 11 years. Twenty-one patients and 46 neurologically normal controls of the same age were examined. The images were evaluated visually; then signal intensities were measured and related to those of references. MRI abnormalities were detectable before clinical symptoms. The radiologic picture of the brain varied with the duration of the disease. Pathognomonic MRI findings in the early stage of the disease were generalized cerebral atrophy, strong thalamic hypointensity to the white matter and to the basal ganglia, and thin periventricular high-signal rims from 13 months onward on T2-weighted images. In patients over 4 years old, cerebral atrophy was extreme, and the signal intensity of the entire white matter was higher than that of the gray matter, which is the reverse of normal. This study showed that the abnormalities seen on MRI progress rapidly during the first 4 years of life, then stabilize, in conformity with the clinical and histopathologic pictures of infantile neuronal ceroid-lipofuscinosis.

MRI of the normal brain from early childhood to middle age. I. Appearances on T2- and proton density-weighted images and occurrence of incidental high-signal foci.

The magnetic resonance images of 67 healthy subjects aged 4-50 years were studied for differences in general signal intensity between the different brain structures, the frequency of focal intensity changes in the brain, and variations in size of the cerebrospinal fluid (CSF) spaces. In adults over 25 years of age the thalamus gave lower signal than the putamen or caudate nucleus. Definite periventricular high signal was found in the white matter of one third of subjects of all ages. Small (< 5 mm in diameter) high signal foci were found in the cerebral white matter on T2-weighted images in 27% of subjects (20% of healthy children and adolescents and 34% of adults). They gave high signal on both short and long echoes in 11% of children and adolescents and in 22% of adults; 51% of all foci gave high signal with both echoes. This does not support the hypothesis that they are caused mainly by enlarged Virchow-Robin spaces. Of the high signal foci on T2-weighted images, 86% were in watershead areas. Two foci were found in one subject in the periventricular watershed area (beside the tips of the frontal horns) and they were never seen in the other deep white matter regions. In healthy, relatively young subjects with no known risk factors, high signal foci other than Virchow-Robin spaces, were common; neither their prevalence nor their number correlated with age in this series. A few slightly large sulci were found in some adults.

MRI of the normal brain from early childhood to middle age. II. Age dependence of signal intensity changes on T2-weighted images.

We examined 66 healthy volunteers aged 4 to 50 years by magnetic resonance imaging (MRI) and the signal intensity was measured on T2-weighted images in numerous sites and correlated with age and sex. Using distilled water and cerebrospinal fluid (CSF) as references on each slice, we calculated the signal intensities of the brain structures. Calculated ratios between structures did not change with age, except for those of the globus pallidus and thalamus, in which the signal intensities decreased more rapidly. The signal intensities of other brain structures changed equally but this could not be discerned visually and quantitative measurements were required. The signal intensities in the white and deep grey matter decreased rapidly in the first decade and then gradually to reach a plateau after the age of 18 years. Maturation of the brain thus seems to continue until near the end of the second decade of life. No sex differences were found. Quantitative analysis requires intensity references. The CSF in the tips of the frontal horns seems to be as reliable as an external fluid reference for intensity, and can be used in routine examinations provided the frontal horns are large enough to avoid partial volume effect.

Phenotypic variation and magnetic resonance imaging (MRI) in Salla disease, a free sialic acid storage disorder.

Salla disease (SD) is a recessively inherited lysosomal storage disorder particularly common in the Finnish population. Patients with SD are normal at birth, but develop psychomotor delay and ataxia during the first year of life. Phenotypic variation of SD is wide, ranging from severely disabled children to mentally retarded adults capable of living under sheltered conditions. In the present study four unusually severely affected patients were investigated by detailed clinical examination, magnetic resonance imaging (MRI) and analysis of the excretion of free sialic acid in urine. MRI study, reported here for the first time, revealed a similarly defective myelination pattern in seven patients. The myelination process seemed to cessate at the level of an infant of a few months of age. Genetic linkage study of the families of the severely affected patients suggested linkage to the recently discovered SD locus on the long arm of chromosome 6. Locus heterogeneity therefore is an unlikely explanation of the phenotypic variation in SD.

Early differential diagnosis of infantile neuronal ceroid lipofuscinosis, Rett syndrome, and Krabbe disease by CT and MR.

PURPOSE: To compare early radiologic findings in three clinically similar progressive encephalopathies of childhood. METHODS: Brain CT and/or MR studies were done in 57 children 3 to 36 months of age: 16 with infantile neuronal ceroid lipofuscinosis, 5 with Rett syndrome, 6 with Krabbe disease, and 30 control subjects with normal neurologic status. In addition, previous descriptions in the literature were collected. RESULTS: No significant changes were seen in Rett syndrome. Early atrophy was found in infantile neuronal ceroid lipofuscinosis and in Krabbe disease, being more severe in the latter. The thalami were hyperdense in 4 of 13 patients with infantile neuronal ceroid lipofuscinosis and in 1 of 4 patients with Krabbe disease (in the literature in 12 of 30 examinations). Cerebral calcifications and density abnormalities in the cerebral and cerebellar white matter were seen in Krabbe disease only. On MR, the white matter changes in the two diseases were differently located. In every patient with infantile neuronal ceroid lipofuscinosis, decreased T2 signal was seen in the thalami and periventricular high-signal rims after the age of 13 months. Hypointensity of the thalami and basal ganglia was seen in both diseases, but Krabbe disease showed more variations. Abnormalities of cerebellar intensity were found in Krabbe disease only. CONCLUSIONS: CT and MR are of value in the differential diagnosis of these three diseases. MR especially facilitates the early diagnosis of infantile neuronal ceroid lipofuscinosis.

The normal brain stem from infancy to old age. A morphometric MRI study.

Our purpose was to develop a method of measuring the size of the brain stem by routine MRI and to determine brain stem dimensions in a normal population. We examined 174 subjects, aged 4 months to 86 years, with no known brain disease. Sagittal midline diameters of the mesencephalon, pons and medulla oblongata were measured on sagittal T1-weighted images, coronal diameters from axial T2-weighted images. The adult midsagittal diameter of the mesencephalon was reached at the age of 6 years, and decreased slightly after 45-50 years. Pontine dimensions increased until the age of 20 years and did not subsequently decrease. The midsagittal and midcoronal diameters of the medulla oblongata stopped increasing at the ages of 6 and 8 years, respectively. Minimal reduction in the midsagittal diameter occurs after 50 years. Normal ranges for each dimension were recorded. Knowledge of the normal variation in size of the brain stem can be helpful in the investigation of neurodegenerative diseases. The method described is rapid and needs no additional hard- or software. An additional finding was an increase in large vermian sulci in subjects over 50 years of age.