[Postinfectious family case of acute necrotizing encephalopathy caused by RANBP2 gene mutation]. / Un cas familial d'encéphalopathie nécrosante aiguë post-infectieuse associé à une mutation du gène RANBP2.

UNLABELLED: Acute necrotizing encephalopathy is a rare neurologic disease most often triggered by a febrile viral event affecting an otherwise healthy infant. The clinical course is characterized by rapid deterioration of the neurological condition that often leads to coma and requires intensive care. The diagnosis is usually suggested by MRI, which shows symmetrical and focal necrotic lesions of thalami. Acute necrotizing encephalopathy has been linked in recent studies to an autosomal-dominant mutation of the gene for the protein RAN-binding protein 2. CASE REPORT: We report three cases in siblings of Tunisian origin. Two of them presented with acute necrotizing encephalopathy at the age of 9 months in the immediate aftermath of a viral infection. The molecular study conducted in the family showed that both patients and their mother were carriers of the missense mutation gene RAN-binding protein 2. COMMENTS: Although the role of Ran BP2 protein is incompletely known, mutation of the RANBP2 gene causes rare, reversible central neurologic disorders. Suspected diagnosis is facilitated by MRI, which shows specific lesions of multifocal, symmetric involvement of the thalami, brainstem tegmentum, supratentorial white matter, and cerebellum. Due to the low frequency of the disease and its non-specific clinical presentation, the diagnosis of acute necrotizing encephalopathy is a major challenge, while preventative measures can be proposed in familial mutation.

Evolution of abnormal eye movements in Wernicke's encephalopathy: correlation with serial MRI findings.

A 33-year-old woman with Wernicke's encephalopathy (WE) due to poor oral intake after allogeneic stem cell transplantation for acute myeloid leukemia showed a sequential development of bilateral gaze-evoked nystagmus (GEN), rightward gaze palsy, and upbeat nystagmus. Initial MRIs obtained when she had GEN only showed a lesion involving the medullary tegmentum, and follow-up MRIs revealed additional lesions in the pontine and midbrain tegmentum along with development of rightward gaze palsy, and finally bilateral medial thalamus lesions in association with upbeat nystagmus. The evolution of abnormal ocular motor findings and serial MRI changes in our patient with WE provide imaging evidence on relative vulnerability of the neural structures, and on the progression of lesions and ocular motor findings in thiamine deficiency.

[NeuroBehcet disease with corpus callosum involvement]. / Neuro-Behçet avec atteinte du corps calleux.

INTRODUCTION: Behçet's disease is a multi-system vascular-inflammatory disease with possible involvement of the central nervous system. Lesions of the corpus callosum on MRI have been rarely reported in this disease. CASE REPORT: A 47-year-old woman was admitted for a sudden right hemiplegia and confusion revealing a Behcet's disease. MRI showed a pedonculo-thalamic lesion and a white matter hypersignals, which was suggestive of the disease. Besides, involvement of the corpus callosum was observed. CONCLUSION: This case demonstrates that Behcet's disease should be considered among diseases with corpus callosum involvement.

Minimally conscious state after ruptured giant basilar aneurysm.

OBJECTIVE: To report the clinical and radiologic findings in a case of transient minimally conscious state after rupture and coiling of a giant basilar aneurysm. DESIGN: Case report. SETTING: Neuroscience intensive care unit. PATIENT: A 44-year-old man who developed a transient minimally conscious state in association with perianeurysmal edema in the rostral brainstem and thalamus after rupture and coiling of a giant basilar artery aneurysm. MAIN OUTCOME MEASURE: Correlation of clinical and magnetic resonance imaging findings. RESULTS: A minimally conscious state and bilaterally symmetric vasogenic edema of the rostral brainstem and thalamus developed 2 days after endovascular aneurysm coiling. The clinical and radiologic abnormalities improved significantly and in parallel during the following 4 weeks. CONCLUSIONS: Perianeurysmal vasogenic edema in the brainstem and thalamus can develop after rupture and coiling of a giant basilar artery aneurysm. This process can be transient and can produce dramatic alterations in consciousness that later resolve.

Dystonia associated with pontomesencephalic lesions.

Secondary dystonia is well known subsequent to lesions of the basal ganglia or the thalamus. There is evidence that brainstem lesions may also be associated with dystonia, but little is known about pathoanatomical correlations. Here, we report on a series of four patients with acquired dystonia following brainstem lesions. There were no basal ganglia or thalamic lesions. Three patients suffered tegmental pontomesencephalic hemorrhage and one patient diffuse axonal injury secondary to severe craniocerebral trauma. Dystonia developed with a delay of 1 to 14 months, at a mean delay of 6 months. The patients' mean age at onset was 33 years (range 4-56 years). All patients presented with hemidystonia combined with cervical dystonia, and two patients had craniofacial dystonia in addition. Three patients had postural or kinetic tremors. Dystonia was persistent in three patients, and improved gradually in one. There was little response to medical treatment. One patient with hemidystonia combined with cervical dystonia improved after thalamotomy. Overall, the phenomenology of secondary dystonia due to pontomesencephalic lesions is similar to that caused by basal ganglia or thalamic lesions. Structures involved include the pontomesencephalic tegmentum and the superior cerebellar peduncles. Such lesions are often associated with fatal outcome. While delayed occurrence of severe brainstem dystonia appears to be rare, it is possible that mild manifestations of dystonia might be ignored or not be emphasized in the presence of other disabling deficits.

Bimedial rectus hypermetabolism in convergence spasm as observed on positron emission tomography.

A 52-year-old man developed vertical gaze palsy, convergence spasm, and convergence-retraction nystagmus due to glioblastoma of the right thalamus. 18F-fluorodeoxyglucose positron emission tomography (PET) inadvertently demonstrated markedly increased metabolism in the medial rectus muscles. The hypermetabolism indicates active contraction of these extraocular muscles due to excessive convergence drive attributed to inappropriate activation or disrupted inhibition of convergence neurons by the diencephalic lesion.

Transcerebellar stereotactic biopsy for lesions of the brainstem and peduncles under local anesthesia.

OBJECTIVE: For certain brainstem lesions, a diagnostic biopsy is required for treatment planning. We reviewed the indications, safety, and diagnostic effectiveness of a transcerebellar stereotactic biopsy using local anesthesia and sedation. METHODS: We retrospectively reviewed hospital records for all adult patients with symptomatic lesions of the pons and/or cerebellar peduncle who underwent an awake transcerebellar stereotactic biopsy at our institution over a 7-year period. Our technique features several modifications from the standard method and was performed under local anesthesia with patients in the semi-sitting position. RESULTS: Our rate of diagnostic success (92%) was comparable to those in other published reports. However, only 5 (42%) of 12 biopsy-derived diagnoses were consistent with those predicted from preoperative magnetic resonance imaging. There were no deaths, and the only neurological complication was a cranial nerve palsy. Diagnoses in the 13 cases included infiltrative glioma (), metastases (), lymphoma (), encephalitis (), and reactive astrogliosis (). CONCLUSION: Tissue diagnosis of lesions in the brainstem and cerebellar peduncles continues to be a significant challenge, with the potential for major morbidity. With appropriate patient selection, however, awake transcerebellar biopsy is a safe and effective procedure that can change clinical management and provide important prognostic information.

Brainstem tuberculoma in the immunocompetent: case report and literature review.

Brainstem tuberculoma is an uncommon entity especially in the immunocompetent adult. The authors describe the case of a 32-year-old immunocompetent woman with no systemic signs or symptoms of tuberculosis, presenting with sudden-onset hemiparesis and diplopia. MRI of brain revealed an enhancing lesion in the midbrain and thalamus. Cerebrospinal fluid examination was normal. Chest imaging was consistent with miliary tuberculosis; however initial expectorated sputum was culture negative. Bronchosopy sputum culture was positive for Mycobacterium tuberculosis. Her PPD was negative. Patient became asymptomatic with treatment for tuberculosis and follow-up MRI showed complete resolution of the lesion a year later. We conclude that a high index of suspicion is essential to make an early diagnosis of intracranial tuberculoma, since often, traditional TB tests like PPD and sputum examinations can be negative.

A history of human-like dieting alters serotonergic control of feeding and neurochemical balance in a rat model of binge-eating.

OBJECTIVE: This study replicated a model of stress-induced binge-eating in rats with a history of caloric restriction (HCR), tested their response to SSRI (fluoxetine) treatment, and explored changes in brain monoamine levels. METHOD: Young female rats with no-HCR/no-Stress, no-HCR/Stress, HCR/no-Stress, and HCR+Stress (binge-eating) were treated with fluoxetine. Post-mortem levels of serotonin, dopamine, and metabolites were assessed from brain regions key to feeding and reward. RESULTS: A 3 mg/kg dose of fluoxetine without effect in the no-HCR groups suppressed intake of HCR groups, normalizing the binge-eating of HCR/Stress rats. No differences in monoamines were detected in the hypothalamus or tegmentum but a strong positive relationship between accumbens serotonin and dopamine turnover in no-HCR rats was absent in rats with HCR. CONCLUSION: Despite lack of hunger, a history of human-like dieting alters serotonin function in ways suggesting consequences not only to feeding but also control of reward and mood that are dependent on dopamine/serotonin interactions.

The metabolic topography of posthypoxic myoclonus.

Posthypoxic myoclonus (PHM) is a syndrome of action and intention myoclonus that occurs in some patients who survive a cardiac arrest. Using PET and statistical parametric mapping, the authors observed a significant bilateral increase in glucose metabolism in the ventrolateral thalamus and pontine tegmentum in patients relative to controls. Interventions such as deep brain stimulation that interrupt networks that involve these structures may be useful in patients with severe PHM.

Neuropathology of early-infantile epileptic encephalopathy with suppression-bursts; comparison with those of early myoclonic encephalopathy and West syndrome.

For the critical lesions and pathomechanism of early-infantile epileptic encephalopathy (EIEE) with suppression-bursts, we investigated the brains of EIEE, early myoclonic encephalopathy (EME), and West syndrome (WS) patients using immunohistochemical technique and neuropathological examination. We could compare with the results of these diseases. The EIEE patients had the most severe lesions, which were in the putamen, thalamus, hippocampus as well as the tegmentum of the brainstem. Among the syndromes, EIEE brains showed the most expanded lesions. Tyrosine hydroxylase-immunopositive cells and fibers were not demonstrated in EIEE, but were detected in WS. Reduced tyrosine hydroxylase immunoexpression in the EIEE brains was in the putamen, globus pallidus, and substantia nigra. Tryptophan hydroxylase immunoreactivity was reduced in the three epileptic syndromes, but especially in EIEE. Reduced expression of tyrosine hydroxylase and tryptophan hydroxylase may demonstrate dysfunction of the catecholaminergic and serotonergic neurons. From this study, the lesions in EIEE were widespread, including in the lower brainstem and cerebellum, compared with in EME and WS. Dysfunction of the catecholaminergic and serotonergic systems could be suggested. These characteristic changes may lead to the pathophysiology of EIEE.

Combined mesencephalic and hypothalamic transplants reverse lesion-induced sexual behavior deficits in the male rat.

Studies of sexual behavior in rodent animal models have provided evidence about the relevant role played by the medial preoptic area of the anterior hypothalamus and the central tegmental field within the mesencephalon in the control of this behavior. Bilateral lesions of the anterior hypothalamus or central tegmental field as well as combined unilateral lesions of both these regions result in sexual behavior deficits. Studies using fetal hypothalamic transplants have been shown to reverse sexual behavior deficits induced either by lesions or aging. However, no previous study has evaluated the effect of combined homotopic transplants into both the anterior hypothalamus and the mesencephalon. In the present study male Wistar animals received two electrolytic lesions, one aimed at the ipsilateral medial preoptic area of the anterior hypothalamus and the other at the contralateral central tegmental field. Following these lesions, unilateral homotopic fetal hypothalamic and mesencephalic transplants were placed into the lesioned areas. Sexual behavior recovered gradually and by weeks 14-15 after transplantation, above 90% of animals with bilateral transplants showed mounts, intromissions, and ejaculations. Only animals with viable transplants located within both lesioned areas showed recovery. These results indicate that the behavioral deficits induced by combined unilateral lesions of hypothalamic and mesencephalic regions can be reversed by homotopic fetal transplants and that this recovery could be the result of the restoration of a behavioral relevant circuit between transplants and host brain nuclei separated by as much as 5 mm, which makes this an excellent model to study mechanisms underlying behavioral recovery after transplantation.

Acute encephalopathy with bilateral thalamotegmental involvement in infants and children: imaging and pathology findings.

PURPOSE: To investigate the imaging and pathologic characteristics of acute encephalopathy with bilateral thalamotegmental involvement in infants and children. METHODS: Five Japanese children ranging in age from 11 to 29 months were studied. We performed CT imaging in all patients, 10 MR examinations in four patients, and an autopsy in one patient. RESULTS: The encephalopathy affected the thalami, brain stem tegmenta, and cerebral and cerebellar white matter. The brain of the autopsied case showed fresh necrosis and brain edema without inflammatory cell infiltration. Petechiae and congestion were demonstrated mainly in the thalamus. CT and MR images showed symmetric focal lesions in the same areas in the early phase. These lesions became more demarcated and smaller in the intermediate phase. The ventricles and cortical sulci enlarged. MR images demonstrated T1 shortening in the thalami. The prognosis was generally poor; one patient died, three patients were left with severe sequelae, and only one patient improved. CONCLUSIONS: The encephalopathy might be a postviral or postinfectious brain disorder. T1 shortening in the thalami indicated the presence of petechiae.

Magnetic resonance imaging of patients with intention tremor.

We evaluated the magnetic resonance images of the patients with intention tremor. Five patients out of seven had some atrophic structures or changes in signal intensity in the cerebello-rubral thalamic tract. Moreover, the T2-weighted images of the patients group detected the dentate and red nuclei more poorly than those of our control group. From these results, the etiological significance of the tract was confirmed and the mechanism of the intention tremor onset was discussed.

Experimental tremor produced by ventromedial tegmental lesion in monkeys. Neuroanatomical study.

Destruction of the ventromedial tegmentum (VMT) of the midbrain in the monkey has been known to produce tremor similar to that seen in Parkinson's disease. A neuroanatomical study by a silver impregnation method was conducted on 5 monkeys, demonstrating the characteristic flexed posture with hypokinesia of the contralateral upper limb (reliable premonitory sign of tremor) following destruction of VMT with a histologically proven lesion site. The results are summarized as follows: (1) the tractus nigrostriatus, (2) tractus tegmentalis centralis, (3) ascending fiber bundles going to the thalamus (particularly VL.X and VPLo) and (4) descending fibers leading to the bilateral substantia nigra constitute the bulk, if not all, of those neural tracts which pass through the VMT. This, along with the proven existence of fibers projecting to the thalamic nuclei, is thought to account for the rhythmic burst discharges recorded from the VL or Vim nucleus in the monkey and in Parkinson's disease patients. The present experimental study also seems to provide an additional anatomical basis for the concept that the tractus tectonigralis is involved in the mechanism of development of kinésie paradoxale.