High-Resolution Magnetic Resonance Imaging Reveals Symmetric Bitemporal Cortical Necrosis After Carbon Monoxide Intoxication

High-resolution magnetic resonance images obtained in a patient several months after carbon monoxide (CO) intoxication revealed nearly symmetric regional atrophy of both lateral temporal lobes. This pattern of cortical lesions after CO exposure has not been reported before. The patient suffered from severe cognitive deficits including a transient Klüver-Bucy-like behavior. This report underlines the value of high-resolution magnetic resonance imaging in chronic stages of CO intoxication in the attempt to understand the neuroanatomical bases of the observed behavior.     

Magnetic Resonance Imaging Findings in Japanese Encephalitis

Ten patients with Japanese encephalitis diagnosed by serological criteria underwent magnetic resonance imaging (MRI) in axial and coronal sections. In 6, a second MRI study was done. The MRI findings were compared with the clinical outcome. Four patients died within several months of onset, 2 had sequelae such as hemiparesis and dementia, and the remaining 4 had no sequelae. In 9 of 10 patients, either diffuse or patchy white matter lesions were observed bilaterally, together with abnormalities in areas such as the thalamus, basal ganglia, and brainstem. For 3 patients who died or remained demented, the second MRI revealed extensive, diffuse white matter abnormalities. This study indicates that Japanese encephalitis can produce white matter involvement, although gray matter structures such as the thalamus, basal ganglia, and brainstem are more severely affected. The severity of these MRI lesions correlated with the clinical outcome.     

Carbon Monoxide Brain Toxicity: Clinical, Magnetic Resonance Imaging, Magnetic Resonance Spectroscopy, and Neuropsychological Effects in 9 People

Carbon monoxide (CO) exposure is a common cause of toxic brain damage, whereby effects range from transient neurological dysfunction to coma and death. A spectrum of severity of magnetic resonance imaging (MRI) findings after CO brain toxicity, including globus pallidus and white matter lesions, is well documented. Reports of MR spectroscopy (MRS) findings re main sparse. This article reports 9 people exposed to CO because of an apartment house's faulty gas heater. Four, with transient loss of consciousness after chronic moderate level CO exposure, suffered intellectual impairment without MRI abnormalities. The MRS of 1 individual demonstrated decreased n-acetyl aspartase in the basal ganglia, bilaterally. Of 5 exposed to high levels for about 12 hours, 1 died prior to clinical and/or MRI evaluation. One who suffered coma recovered but was lost to evaluation. Three, who were unconscious for hours to days, exhibited T2 MRI white matter signal abnormalities. MRS showed decreased basal ganglia n-acetyl aspartase in 2. One of these suffers a Parkinsonian syndrome. All 3 are intellectually impaired. This study demonstrates that although MRI and MRS are useful markers of CO-induced brain damage, they are not always sensitive to resultant intellectual dysfunction.     

Interpreting Magnetic Resonance Imaging Findings in Bipolar Disorder

The episodic nature of bipolar disorder together with the ostensibly polar extremes of mania and depression have favored the acceptance of a functional model postulating regionally disturbed brain activity returning to normal with time or treatment. Seemingly contrary to that view, anatomical imaging studies have demonstrated abnormalities in brain structure which could reflect neurodegeneration or represent disturbed neuronal development. Resolution may come from an appreciation of adult neurogenesis, especially given the neuroprotective properties of drugs, such as lithium and their effects on brain volume. The brain regions vulnerable to structural changes also show evidence of dysfunction, giving rise to corticolimbic dysregulation interpretations of bipolar disorder. This article reviews the structural and functional magnetic resonance imaging data in bipolar disorder. Its focus is on the interpretation of findings in light of recent developments in the fields of neurobiology and image analysis, with particular attention paid to both the confounding effects of medication and the baseline energy state of the brain.     

Neoplastic Meningitis with Normal Neurological Findings Magnetic Resonance Imaging Results

Neoplastic meningitis, an unusual complication of systemic cancer, is becoming more common as cancer patients live longer. Although leptomeningeal metastases from solid tumors are usually associated with multifocal neurological signs, the authors report on 4 patients who presented with normal findings on neurological exammation. One man had severe headache and complex partial seizures. Magnetic resonance imaging (MRI) of the bram revealed gadolmium enhancement of multiple cranial nerves. Cerebrospinal fluid (CSF) cytology was positive for melanoma. One woman presented with severe migratory retroorbital headaches. MRIs of the brain with and without gadolinium appeared normal CSF cytology was positive for pulmonary adenocarcinoma. One man presented with morning headache, and a woman presented with back pain. Both had CSF cytologies positive for lymphoma. Neoplastic meningitis can occur without abnormalities on neurological or MRI examinations. Lumbar punctures should be performed on cancer patients with severe, unusual, or prolonged headaches.     

Magnetic Resonance Imaging and Spectroscopy Findings After Focal Status Epilepticus

Summary: The etiology of cerebral abnormalities after focal status epilepticus (SE) is unknown. Possible causes include hypoxia and the excessive release of excitatory amino acids. Magnetic resonance imaging (MRI) of a 21–year-old patient with "cryptogenic" continuous motor seizures showed swelling and signal hyperintensity of the contralateral panetotemporal cortex, the thalamus, and the ipsilateral cerebellum on T₂-weighted images. These regions are connected by glutamatergic pathways. Proton magnetic resonance spectroscopy (MRS) of the cortical lesion yielded a signal peak at the resonance frequency of 2.29 ppm, suggesting a focal increase of glutamate or its degradation product glutamine. At 3–month follow-up, structural alterations had disappeared, but the N-acetylaspartatelcholine ratio was still reduced in the previously abnormal area. These findings are the first to demonstrate the contribution of MRS to pathophysiologic studies of focal SE in humans and, in combination with the pattern of imaging abnormalities, support a major role of glutamate for seizure-related brain damage.     

Cognitive Disturbances and Magnetic Resonance Imaging Findings in Multiple Sclerosis

Twenty patients (mean age ± standard deviation, 42 ± 14 yr) with multiple sclerosis were studied to define a possible relation between cognitive decline and pathology seen on magnetic resonance images (MRis). In all, a battery of psychometric tests and MRis were conducted. MRI results were classified according to cerebral lesions and different ventricle indexes. A rating scale graded the severity of cerebral lesions. MRI and psychometric data from the patients were compared with the results of an age- and sex-matched control group. The results suggest that evidence of cognitive decline shows a stronger relation to substance loss, defined by ventricle indexes, than to the lesion score.     

Proton Magnetic Resonance Spectroscopy and Magnetic Resonance Imaging Findings in a Patient with Central Nervous System Paracoccidioidomycosis

The authors describe a patient with brain paracoccidioidomycosis whose magnetic resonance image (MRI) showed multiple hypointense lesions on T2-weighted images with peripheral enhancement after gadolinium injection. Single-voxel proton magnetic resonance spectroscopy (1H-MRS) of one of the lesions showed 2 peaks at 0.9 and 1.32 ppm, corresponding to lipid signals, indicating intense necrosis. The other characteristic peaks of 1H-MRS were undifferentiated from baseline. These findings, although not specific, may help to differentiate fungal abscess from tumoral lesions and other types of abscess.     

Sturge-Weber Syndrome: Brain Magnetic Resonance Imaging and Neuropathology Findings

BackgroundWe describe the brain magnetic resonance imaging (MRI) abnormalities and neuropathologic findings of patients with Sturge-Weber syndrome and medically refractory epilepsy.MethodsWe reviewed the clinical features, preoperative MRI studies, and pathologic findings of all patients with Sturge-Weber syndrome who underwent excisional surgery for intractable epilepsy at Boston Children's Hospital between 1993 and 2011.ResultsEleven patients (male/female = 4/7) with Sturge-Weber syndrome were identified who underwent surgery for intractable epilepsy (mean age 13 ± 6.2 months), including hemispherectomy (n = 10) and focal cortical resection (n = 1). Mean age at seizure onset was 15 ± 11 weeks. Fifty-five percent (n = 6) of patients exhibited two different types of seizures, and 18% (n = 2) had three types of seizures. Focal clonic seizures were the most common type, occurring in nine patients; apnea was the second most common, occurring in four patients. Brain MRIs were reviewed in five patients. Histopathologic examination revealed varied degrees of cortical morphologic anomaly in seven of 11 patients. Overall, there were no abnormalities in the MRIs that corresponded directly with the pathologic findings except in one patient with polymicrogyria.ConclusionsIn spite of pathologic findings of cortical anomalies in varied degrees, these findings could not be readily detected on brain MRIs. The failure to detect focal cortical dysplasia on MRIs may be attributable to the subtle microscopic nature of the abnormalities; in some of the older individuals, the imaging studies available for review were done during an advanced stage of the disease.     

Continuous Arterial Spin Labeling Perfusion Magnetic Resonance Imaging Findings in Postpartum Vasculopathy

Postpartum vasculopathy (PPV) is a rare heterogeneous nonatherosclerotic vasculopathy that occurs in the puerperium. It occurs spontaneously but may be triggered by vasoconstrictor substances. The angiographic findings vary and include narrowing of the intracranial arteries and vasospasm. The angiographic findings and the occurrence of ischemic infarcts suggest that cerebral blood flow (CBF) is impaired in PPV. The purpose of this study is to determine CBF in patients with PPV. The authors conducted a case study of 3 patients with clinical and laboratory criteria for PPV examined during a 2-year period. Clinical examination, computed tomography imaging, structural magnetic resonance imaging (MRI), cerebral angiography, and continuous arterial spin labeling perfusion (CASL-PI) MRI were performed in all patients. Mean global CBF was determined, and perfusion maps were visually inspected. The CBF values and perfusion maps were correlated with the clinical symptoms and the neuroimaging findings. Three women were studied (22, 34, and 36 years old). The median time of presentation was 4 days postpartum. One presented with intracranial hemorrhage and diffuse arterial narrowing, the other 2 with stroke-like lesions, encephalopathy, and segmental narrowing mainly in the posterior circulation. CASL-PI was performed within 1 week of symptom onset in all 3 patients. Global mean CBF values were 51.8, 39.3, and 41.8 cc/100 g/min. Although global CBF was mildly diminished, it was above ischemic levels. Visual inspection of the CASL-PI perfusion maps did not reveal areas of focal hypoperfusion or hyperperfusion. In this series of patients with PPV, CBF was close to normal. Although angiography often reveals diffuse arterial narrowing, the CBF values encountered in this study do not support a state of generalized or focal oligoemia. Vasomotor tone may change intermittently in patients with PPV.     

Acute Wernicke's Encephalopathy Associated with Hyperemesis Gravidarum: Magnetic Resonance Imaging Findings

A 25-year-old woman with hyperemesis gravidarum developed acute Wernicke 's encephalopathy during prolonged mt ravenous fluid therapy without vitamin supplements. Delay in diagnosis led to a persistent severe neurological deficit, including coma. Gadolinium-diethylenetriaminepentaacetic acid-enhanced magnetic resonance imaging revealed symmetrical lesions around the aqueduct and fourth ventpathy Which resolved after treatment with thiamine. She did not regain consciousness. This report demonstrates the diagnostic value of enhanced magnetic resonance Imaging in acute Wernicke's encephalopathy.     

Magnetic Resonance Imaging,Computed Tomography,and Autopsy Findings after Cardiorespiratory Arrest

A 29-year-old man had temporary cardiorespiratory arrest. Eight hours later, magnetic resonance imaging (MRI) of the brain revealed scattered hyperintense gyri and a marked high signal intensity of the caudate nuclei and the putamen. Computed tomography (CT) displayed no focal abnormalities but only diffuse brain swelling and blood in the subarachnoid space. The patient died 17 hours after the arrest. Histopathological findings were consistent with early ischemic brain damage. Perivascular infiltrates, probably inflammatory, involved the entire brainstem. Neither MRI nor CT demonstrated brainstem encephalitis, the presumed cause for the arrest. This observation suggests a high sensitivity of MRI for cerebral damage caused by global hypoxemia, yielding valuable diagnostic and prognostic information after resuscitation.