Sudden Sensorineural Hearing Loss: MR Imaging.

Hearing loss greater than 30 dB over three contiguous pure-tone frequencies occurring within a three day period is defined as sudden hearing loss. It is usually sensorineural (SSNHL), unilateral and appears as an otologic emergency. SSNHL has many possibile etiologies such as: labyrinthine viral infection, ischemic or hemorrhagic illness, trauma, immuno-mediated inner ear disease, tumor, inner ear malformation, and an imbalance between perilymphatic and endolymphatic fluid pressure. Nevertheless in almost 80% of cases SSNHL belongs to the idiopathic category because the etiology is unknown. The aim of this study was to test the diagnostic impact of two MR devices. Fifteen cases of SSNHL studied with a 1.5 T unit in our hospital between January 2006 and December 2008 within two weeks of the onset were retrospectively evaluated. Since January 2009 three more patients affected by SSNHL have been scanned with a 3T MR unit. We discuss the diagnostic sensitivity, clinical usefulness and the cost-benefit ratio of the MR systems.

Diffusion tensor MRI and MR spectroscopy in long lasting upper motor neuron involvement in amyotrophic lateral sclerosis.

Upper motor neuron (UMN) dysfunction in Amyotrophic Lateral Sclerosis (ALS) is not easy to identify clinically: Diffusion Tensor Imaging (DTI) and single-voxel Magnetic Resonance Spectroscopy (H-MRS) can identify markers of UMN involvement. The aim of this study was to correlate brain DTI and MRS data with clinical parameters in ALS patients (PALS). We studied 32 PALS using Magnetic Resonance Imaging. The subjects were subdivided into definite/probable (D/P) and possible/suspected (P/S). DTI indices included Fractional Anisotropy (FA) and averaged Apparent Diffusion Coefficient (avADC). Anatomical areas were sampled by positioning regions of interest along corticospinal tracts, from the precentral cortex to the bulb. H-MRS voxels were localized bilaterally in precentral regions. D/P-PALS showed significantly lower FA values than healthy controls in almost all regions, whereas P/S-PALS FA values were significantly lower only in the left precentral gray matter (GM), right precentral white matter (WM), cerebral peduncles (CP), left hemipons, and left bulbar pyramid (BP). Significantly higher avADC values were observed in the D/P-PALS right precentral GM, precentral WM, right semioval center-posterior limb of the internal capsule (SC-PLIC), and left CP; and in the precentral WM, right SC-PLIC, left CP, and right hemipons of P/S-PALS. With increasing disability, only D/P-PALS showed significantly reduced FA values in the left precentral WM and hemipons, and increased avADC values in the precentral WM. Significantly lower N-acetylaspartate (NAA)/creatine-phosphocreatine complex (Cr) and higher choline (Cho)/Cr and myoinositol (mI)/Cr ratios were found in D/P-PALS, while only higher Cho/Cr and mI/Cr ratios were found in P/S-PALS. Our data highlight the usefulness of DTI and H-MRS in assessing UMN involvement. Given FA sensitivity and specificity, despite the small number of PALS, our findings support its use as a diagnostic marker in D/P-PALS.

Visual function and EEG reactivity in infants with perinatal brain lesions at 1 year.

The aim of this study was to examine the correlation between EEG, visual, and brain MRI findings in 19 term infants with perinatal brain lesions. All 19 had their visual acuity and visual fields assessed and had an EEG and a brain MRI performed at 1 year of age. Four of the five infants with normal optic radiations and occipital cortices on MRI had normal vision. Involvement of optic radiations and occipital cortices was only associated with visual abnormalities in eight of 14 infants. The correlation between visual abnormalities and EEG findings was stronger. All infants with a completely normal EEG from the posterior regions had normal vision and all those with an EEG non-reactive to eye closure had visual abnormalities, irrespective of MRI data. A reactive EEG with other abnormal features (such as spikes, rapid or slow activities) was accompanied by abnormal vision in five of eight participants. Results suggest that there is a better correlation between visual function and EEG activity than between visual function and involvement of the classical visual areas of the occipital cortex and optic radiations on brain MRI at 1 year of age.

Reorganisation of the sensorimotor cortex after early focal brain lesion: a functional MRI study in monozygotic twins.

Sensorimotor cortical reorganization after early brain lesions was studied by means of fMRI in two pairs of monozygotic twins, in each of which one member had a focal brain injury. This offered a unique opportunity to reduce the wide intersubject variability of the controls often found in similar studies. Activation images were acquired during a motor task (sequential opposition finger movements) and a sensory task (passive brushing of palm and fingers). During the tasks with the recovered hand, constant findings in the lesioned subjects were the activation of the undamaged areas adjacent to lesion site and the activation of the ipsilateral sensorimotor cortex. Bilateral activation of the primary sensorimotor cortex was never observed in the healthy co-twin controls.

Visual function in children with hemiplegia in the first years of life.

The aim of this study was to evaluate the incidence of visual function abnormalities in children with infantile hemiplegia, and the relation between visual abnormalities and type of lesion, as shown by brain MRI. Visual function was tested (grating acuity, visual field size, binocular optokinetic nystagmus [OKN], and ocular movements) in a group of 47 children with congenital or early acquired hemiplegic cerebral palsy (mean age 25 months, range 8 to 52 months). The cohort was subdivided into four groups according to MRI findings: brain malformations (n=5), abnormalities of the periventricular white matter (n=20), cortical-subcortical lesions (n=16), and non-progressive postnatal brain injuries (n=6). More than 80% of the children showed abnormal results in at least one visual test: acuity was the least impaired function, while visual field and OKN were abnormal in more than 50% of the cohort. No specific correlation could be identified between the type and timing of the lesions and visual function. Unlike adults with stroke, visual field defects were not always related to contralateral damage in the optic radiations or in the visual cortex. These results indicate that visual abnormalities are common in children with hemiplegia, and that they cannot always be predicted by MRI. All children with hemiplegia need a detailed assessment of visual function.

Fetal intracranial hemorrhage: is minor maternal trauma a possible pathogenetic factor?

OBJECTIVE: The occurrence of fetal intracranial hemorrhage before labor has been repeatedly observed. The aim of this study was to evaluate the sonographic appearance of fetal intracranial hemorrhage in relation to its location. Possible causative factors were also evaluated. DESIGN: Five consecutive cases of fetal intracranial hemorrhage were identified at a single ultrasound unit between 1996 and 1999. In utero magnetic resonance imaging was also performed in four of these cases. Autopsy was performed after pregnancy termination or intrauterine fetal death (one case of each), and neurological follow-up was initiated in the three surviving infants. RESULTS: Hydrocephaly was the predominant sonographic finding associated with intraventricular or subependymal hemorrhage; sonography provided the correct diagnosis in the former (two cases), whereas magnetic resonance imaging was necessary in the latter. Massive intraparenchymal hemorrhage was depicted as an irregular echoic mass, whereas extradural hemorrhage had a cystic appearance. History of minor maternal physical trauma without maternal or placental injury was elicited in all cases. Ultrasound examinations performed before or shortly after the trauma were available in all cases and showed normal fetal anatomy. CONCLUSIONS: The sonographic appearance of fetal intracranial hemorrhage is variable, depending on its location. Even though sonography detected an intracranial anomaly in all cases, magnetic resonance imaging was necessary to establish the hemorrhagic nature of isolated subependymal and extradural hemorrhage. The similarity of histories involving minor maternal physical trauma in all cases, together with the absence of any known factor predisposing to fetal hemorrhage, may suggest that trauma is at least a contributing factor to the pathogenesis of fetal intracranial hemorrhage.

Reversible brain creatine deficiency in two sisters with normal blood creatine level.

We describe a new creatine metabolism disorder in 2 young sisters who suffered from mental retardation and severe language delay. Blood examination, investigation of the most common neurometabolic disorders, and brain magnetic resonance imaging were normal. Diagnosis was established only by means of in vivo proton magnetic resonance spectroscopy, which disclosed generalized depletion of creatine in the brain. Creatine monohydrate oral administration led to almost complete brain creatine level restoration along with improvement of the patients' disabilities.

Correlation between visual function, neurodevelopmental outcome, and magnetic resonance imaging findings in infants with periventricular leucomalacia.

AIM: To evaluate the correlation between visual function and neurodevelopmental outcome in children with periventricular leucomalacia at 1 and 3 years. METHOD: Visual acuity, visual field, ocular motility, and optokinetic nystagmus were tested in 29 infants with periventricular leucomalacia by brain magnetic resonance imaging. All infants also had a structured neurological examination and a Griffiths developmental assessment. RESULTS: 21 of the infants showed at least one abnormality of visual function. The degree of visual impairment-that is, the number of visual tests showing abnormal results-correlated well with the results on developmental assessment at both ages. CONCLUSION: Multivariate analysis showed that visual impairment was the most important variable in determining the neurodevelopmental scores of these infants, more than their motor disability and the extent of their lesions on magnetic resonance imaging.

MRI and clinical characteristics of children with hemiplegic cerebral palsy.

Magnetic resonance imagings of 91 children with hemiplegic cerebral palsy were analysed with the aim of clustering their features into fairly homogeneous forms. In addition, the different clinical patterns of each form were described. Four main types of lesion were distinguished: form 1 (13 cases), which comprised brain malformations, form 2 (41 subjects), which grouped abnormalities of the periventricular white matter, form 3 (27 children), which was represented by cortical-subcortical lesions, and form 4 (10 subjects), which grouped non-progressive postnatal brain injuries. None of the children had normal MRI and a high incidence of bilateral lesions was found, especially in form 2. A left motor involvement was prevalent in the sample and was noted in all but the third form. The severity of impairment was mainly moderate in forms 1 and 3, mild in the others. The upper limb was found to be more affected in all forms except the second one, which presented a greater involvement of the lower limb. Mental retardation occurred in about one-third of the children with forms 1 and 4, less often in the other two. Seizures occurred in about half of the children with forms 1 or 3, while the incidence was lower in forms 4 and 2. A strong correlation between the presence of seizures and mental retardation was observed. The results of this study show the importance of MRI in the evaluation of children with hemiplegic cerebral palsy.

Clinical outcome and magnetic resonance imaging of carbon monoxide intoxication. A long-term follow-up study.

The clinical and neuroradiological outcome of carbon monoxide (CO) intoxication was evaluated prospectively in 30 patients over a follow-up period of 3 years. Among the patients studied, 22 had been acutely exposed to CO while 8 were chronically exposed. One month after CO poisoning, 12 of the 22 patients with acute intoxication showed magnetic resonance imaging (MRI) abnormalities: 6 also had neurological sequelae and 6 were asymptomatic. The remaining 10 patients showed neither MRI abnormalities nor neurological sequelae. During the 3-year follow-up, 4 of the patients with both MRI abnormalities and neurological sequelae improved in both clinical features and MRI findings. One of the 6 asymptomatic patients with MRI abnormalities developed a progressive cognitive impairment 2 months after acute intoxication, with a concomitant severe worsening of the MRI lesions. Among the 10 patients with neither MRI abnormalities nor neurological sequelae, only 1 developed neurological sequelae after a clear period of 4 months. In the group of patients who experienced chronic CO intoxication, only 1 presented with a neuropsychiatric syndrome which improved at follow-up. Brain MRI showed white matter lesions which remained unchanged at control scan after 1 year. In conclusion, we observed that some patients with severe CO poisoning and neurological sequelae may fully regain normal functions after approximately 1 year. The presence of MRI lesions 1 month after CO poisoning did not accurately predict the subsequent outcome. The observation of a clear period longer than the usual 2-40 day interval in 2 patients should be considered for careful planning of follow-up and for prognosis in CO-poisoned patients.

Epilepsy and malformations of the cerebral cortex.

Abnormal cortical development is increasingly recognized as a cause of human epilepsy. Development of the cerebral cortex involves three distinct but overlapping processes consisting of neuronal and later glial proliferation, neuronal migration and cortical organization. Cortical malformations can originate from abnormalities of any or all of these processes. Certain malformations are known to be genetically determined, while for others a genetic origin has been hypothesized. In addition, there are some that may be linked to prenatal insult. Some malformations are notably more epileptogenic than others. In specific forms, epileptogenesis appears to originate from intrinsic properties of the dysplastic tissue, and is stereotyped in expression. Cortical malformations are also known that are affected by age-related influence and may be accompanied by different epileptic syndromes, sometimes with good long-term outcome. In patients with intractable seizures which are symptomatic of a cortical malformations it is necessary to diagnose the type of malformation and the associated epileptic syndromes and to assess the characteristics of epileptogenesis. Planning of surgical treatment of the associated epilepsy must rely on careful evaluation of all these informations.

Late whiplash syndrome: a clinical and magnetic resonance imaging study.

Cervical hyperextension injuries are common and are associated with significant morbidity. Clinically two syndromes are described: "acute" whiplash syndrome and "late" whiplash syndrome (in which the patients are still symptomatic after six months despite normal physical and radiological examination). In order to clarify the pathology of the persistent pain in late whiplash syndrome we performed a cervical spine magnetic resonance imaging (MRI) in 33 consecutive patients suffering from this condition. Twenty-six patients (78.8%) showed MRI abnormalities, the most common MRI finding (57.6%) was pre-existent spondylosis. Indeed, the group of patients with spondylosis and other MRI changes had higher clinical scores than those without MRI abnormalities as measured by a three-point grading system based upon the symptoms and signs shown. Several MRI changes, most of them already demonstrable by standard X-ray were seen among 33 patients suffering from late whiplash syndrome. Although no one of these findings appears to be specific and certainly related to the previous neck injury, they could represent a risk factor for a longer pain duration.

Reversible pseudoatrophy of the brain and mental deterioration associated with valproate treatment.

PURPOSE: To describe an 11-year-old girl with symptomatic localization-related epilepsy and normal intelligence who developed reversible mental deterioration and pseudoatrophic brain changes while receiving valproate (VPA). METHODS: Assessment of mental function using Wechsler Intelligence Scale for Children-III (WISC) and Raven's Progressive Matrices (PM), EEG recordings while awake and asleep, and brain magnetic resonance imaging (MRI), were performed at the beginning of VPA therapy, after 2 years and 8 months of treatment and following VPA discontinuation. RESULTS: After 2 years and 6 months on VPA (< or = 26 mg/kg/day) the girl insidiously developed mental deterioration (loss of 18 IQ points and drop in age-adjusted PM score from the 95th to the 50th percentile) associated with MRI-documented pseudoatrophy of the brain. Onset of severe cognitive impairment coincided with serum VPA concentrations near 100 microg/ml. There were no other manifestations of drug toxicity or hyperammonemia. Background EEG activity was normal. Reduction of VPA dosage and subsequent discontinuation 4 months later resulted in disappearance of clinical symptoms with a 20-point improvement at IQ testing and recovery of previous PM score. Repeat MRI showed disappearance of pseudoatrophic changes. CONCLUSIONS: The striking cognitive improvement and reversal of pseudoatrophic brain changes following VPA discontinuation strongly suggest a drug-induced condition. Based on this and previous reports, the syndrome of VPA-associated mental deterioration and pseudoatrophy of the brain appears to encompass different but possibly related clinical entities, which include parkinsonism with cognitive deterioration, mental deterioration with signs of VPA-toxicity, and isolated mental deterioration, as seen in our patient. A drug-induced effect should be considered whenever cognitive deterioration and imaging findings of brain atrophy occur in VPA-treated patients.

Prenatal diagnosis of periventricular hemorrhage by fetal brain magnetic resonance imaging.

Following the incidental diagnosis of triventricular hydrocephalus in a fetus 34 weeks after the mother's last menstrual period, during an uneventful pregnancy, 1.5-T brain magnetic resonance (MR) was carried out. A subependymal hemorrhage, which had not been revealed by transabdominal ultrasound, was found; this finding was confirmed by neonatal brain ultrasound and MR. Fetal MR allowed identification of the hemorrhage as the cause of the hydrocephalus and also established its time of occurrence. Unexplained hydrocephalus should be included among the indications for fetal MR.

Intravenous immunoglobulin versus corticosteroid in treatment of Graves' ophthalmopathy.

We compared the effectiveness of systemic corticosteroids with the use of high-dose intravenous immunoglobulin (IVIG) in the treatment of Graves' ophthalmopathy. This was performed as a prospective, nonrandomized study including a blinded ophthalmological and orbital computed tomographic (CT) evaluation. The two groups of patients were not significantly different in relation to sex composition, age distribution, duration of Graves' disease, and ophthalmopathy and previous hyperthyroidism. All patients were followed up by endocrinologic evaluation and blinded ophthalmological (before therapy = B, at the end of therapy = E, and 6 months after the end = 6M) and orbital CT (B and E) evaluations. Twenty-seven patients treated with IVIG were followed up after the end of treatment for an average of 21 months (range 12 to 48 months). Soft tissue involvement (NOSPECS) improved or disappeared in 32 of 35 (90%) patients treated with IVIG and in 25 of 27 (92.5%) patients treated with corticosteroids. Diplopia improved or disappeared in 22 of 29 (75%) patients treated with IVIG and in 16 of 20 (80%) patients treated with corticosteroids. The results observed by clinical evaluation were confirmed with orbital CT score in 30 IVIG patients and in the corticosteroid-treated patients; a significant reduction of extraocular muscle thickness was observed after treatment in both groups. Proptosis improved or disappeared in 20 of 31 (65%) patients treated with IVIG and in 15 of 24 (62%) patients treated with corticosteroids. Mean values of proptosis evaluated by Hertel's exophthalmometer showed a slight reduction both in IVIG as well as in corticosteroid-treated patients. It is interesting to observe that in 28 IVIG-treated patients in whom it was possible to evaluate soft tissue involvement, proptosis and diplopia in the period between the fifth and sixth month from the start of therapy, the most important part of the amelioration (if responders) was already obtained at that time. Responder patients were defined in relation to the decrease in the highest NOSPECS class or grade. Among IVIG-treated patients 26 of 34 (76%) responded; while in the corticosteroid group 18 of 27 (66%) responded to treatment. The prevalences of patients who responded to the treatments were not significantly different in the two groups (Chi-square). The initial values of the subjective eye score were similar in the two groups, and a significant reduction was observed in both. Major side effects requiring discontinuation of the corticosteroid therapy were observed in two patients with hemorrhagic gastritis and in one patient with manic-depressive psychosis. Among 15 patients submitted to the evaluation of bone mineral content before and after corti-costeroid therapy, 4 presented signs of osteoporosis and 3 a reduction of bone mineral content. Moderate and minor side effects were more frequently noted in steroid-treated patients than in the IVIG group. These data suggest that IVIG is safe and effective in reducing the eye changes in patients with Graves' ophthalmopathy.

MRI findings and sensorimotor development in infants with bilateral spastic cerebral palsy.

The correlation between MRI findings and sensorimotor development was investigated in a group of 48 infants with bilateral spastic cerebral palsy (CP). The ages at MRI examination and cognitive assessment were fairly homogeneous (mean 15 months and 17 months, respectively). The following MRI parameters were scored: size of lateral ventricles, extension of white matter lesions and of white matter reduction, thinning of corpus callosum, presence and size of cystic areas, dimension of subarachnoid spaces and presence of cortical abnormalities. Cognitive assessment included Griffiths Developmental Scales and Uzgiris-Hunt Scales. The patients were subdivided into six classes according to intellectual level (DSM-III-R). For the whole group a highly significant correlation was found between all MRI parameters and the level of cognitive development. This result was probably due to the inclusion of 14 untestable, severely mentally retarded infants, who showed very severe MRI abnormalities. However, when the untestable infants were excluded from the analysis, it was the presence of cysts and the entity of white matter reduction that correlated with both Griffiths Scales and Uzgiris-Hunt Scales. These results indicate the clinical value of MRI findings and particularly of white matter abnormalities for early identification of sensorimotor impairment in infants with bilateral spastic CP.

MRI and MR angiography of vertebral artery dissection.

A review of 4,500 angiograms yielded 11 patients with dissection of the vertebral arteries who had MRI and (in 4 patients) MR angiography (MRA) in the acute phase of stroke. One patient with incidental discovery at arteriography of asymptomatic vertebral artery dissection and two patients with acute strokes with MRI and MRA findings consistent with vertebral artery dissection were included. Dissection occurred after neck trauma or chiropractic manipulation in 4 patients and was spontaneous in 10. Dissection involved the extracranial vertebral artery in 9 patients, the extra-intracranial junction in 1, and the intracranial artery in 4. MRI demonstrated infarcts in the brain stem, cerebellum, thalamus or temporo-occipital regions in 7 patients with extra- or extra-intracranial dissections and a solitary lateral medullary infarct in 4 patients (3 with intracranial and 1 with extra-intracranial dissection). In 2 patients no brain abnormality related to vertebral artery dissection was found and in one MRI did not show subarachnoid haemorrhage revealed by CT. Intramural dissecting haematoma appeared as crescentic or rounded high signal on T1-weighted images in 10 patients examined 3-20 days after the onset of symptoms. The abnormal vessel stood out in the low signal cerebrospinal fluid in intracranial dissections, whereas it was more difficult to detect in extracranial dissections because of the intermediate-to-high signal of the normal perivascular structures and slow flow proximal and distal to the dissection. In two patients examined within 36 h of the onset, mural thickening was of intermediate signal intensity on T1-weighted images and high signal on spin-density and T2-weighted images. MRA showed abrupt stenosis in 2 patients and disappearance of flow signal at and distal to the dissection in 5. Follow-up arteriography, MRI or MRA showed findings consistent with occlusion of the dissected vessel in 6 of 8 patients.

Bilateral parasagittal parietooccipital polymicrogyria and epilepsy.

We describe 9 patients with a bilateral malformation of cortical development, centered around the parasagittal and mesial aspects of the parietooccipital cortex, with magnetic resonance imaging findings suggestive of polymicrogyria. No familial distribution or etiologic factors were identified. Location in a watershed area between anterior and posterior cerebral arteries suggests postmigratory perfusion failure as the underlying cause. In most patients the malformation was detected by magnetic resonance imaging after computed tomography scans with 10-mm-thick sections were considered normal. Seizures, present in all, had started between the ages of 20 months and 15 years (mean, 9 years) and were intractable in 7. Complex partial seizures with or without minor automatisms were the most frequent ictal pattern. In only 4 patients these were preceded by symptoms indicating posterior onset. Interictal electroencephalograms showed both diffuse and bilateral parietooccipital or temporal abnormalities. The range of IQ scores indicated average intelligence to mild retardation. Several patients presented deficits on neuropsychological tasks requiring performance under time constraints, suggesting that the malformation may result in cognitive slowing. Early diagnosis of this malformation may be difficult because of the lack of neurological signs, relatively late seizure onset, difficulty in localizing seizure onset, and inability to recognize the cortical abnormality on computed tomography scans.

Correlation between cerebral visual impairment and magnetic resonance imaging in children with neonatal encephalopathy.

To identify brain lesions most often associated with cerebral visual i mpairment (CVI) after neonatal encephalopathy and to evaluate the prognostic value of MRI for visual outcome, the authors reviewed visual assessments and brain MRI of 80 infants and young children with documented perinatal hypoxic-ischaemic and/or haemorrhagic insults. MRIs were classified according to the severity of lesions at the optic radiations and at the visual cortex; visual acuity was tested with the acuity card procedure. Among the 48 children found to have a CVI, 42 had moderate to severe lesions of the optic radiations and 19 had lesions of the visual cortex. In both cases visual acuity was statically correlated with MRI grading, but the damage at the optic radiations was the better predictor. Early detection of abnormal MR findings in the visual cortex and especially, at the optic radiations may indicate which infants with neonatal encephalopthy should receive longitudinal visual assessment and specific rehabilitation and educational management.