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Biomedical subjects

H Lanfermann

Publications and source records attributed to H Lanfermann.

At least 19 recordsLinked to original sources
PubMed2007

[Neurosyphilis: important differential diagnosis of herpes simplex encephalitis].

Diagnosis of herpes simplex encephalitis in the acute stage is based on clinical symptoms (nonspecific prodromi, neuropsychological deficits, epileptic seizures) in combination with typical CSF abnormalities (lymphomonozytic pleocytosis) and MR imaging abnormalities assumed to be typical for herpes simplex encephalitis (increased fluid-attenuated inversion recovery and T2 hyperintensities in the mesiotemporal lobe region). Definite diagnosis of herpes simplex encephalitis is based on positive polymerase chain reaction in the CSF, usually available some days after hospital admission. Suspected herpes simplex encephalitis requires immediate treatment with acyclovir. Bacterial encephalitis caused by spirochetes may present with similar features but requires different treatment. This should therefore be considered in the differential diagnosis of herpes simplex encephalitis. We report a young patient with neurosyphilis whose correct diagnosis could be made only several days after beginning specific treatment.

Adult↗
PubMed2007

[Primary central nervous system degeneration in elderly patients. Characteristic imaging features].

Despite further development of new magnetic resonance imaging techniques, e.g., diffusion tensor imaging and 1H magnetic resonance spectroscopy, structural imaging will continue to play a major role in the diagnosis of primary central nervous system degeneration in ageing. Characteristic imaging patterns of multisystem atrophies and primary dementias as well as differential diagnostic features are demonstrated. While such features may have high specificity, their sensitivity is low especially in cross-sectional studies. Longitudinal studies are the optimal method to characterize the dynamic neuroanatomical correlates of the disease. However, according to disease duration and progression, neuroimaging will show increased overlapping and convergence of pathological changes in multisystem atrophy as well as in dementia.

Aged↗
PubMed2006

Proton magnetic resonance spectroscopy in childhood brainstem lesions.

BACKGROUND: Diagnosis of brainstem lesions in children based on magnetic resonance imaging alone is a challenging problem. Magnetic resonance spectroscopy (MRS) is a noninvasive technique for spatial characterization of biochemical markers in tissues and gives information regarding cell membrane proliferation, neuronal damage, and energy metabolism. METHODS: We measured the concentrations of biochemical markers in five children with brainstem lesions and evaluated their potential diagnostic significance. Images and spectra were acquired on a 1.5-T imager. The concentrations of N-acetylaspartate, tetramethylamines (e.g., choline), creatine, phosphocreatine, lactate, and lipids were measured within lesions located at the brainstem using Point-resolved spectroscopy sequences. RESULTS: Diagnosis based on localized proton spectroscopy included brainstem glioma, brainstem encephalitis, demyelination, dysmyelination secondary to neurofibromatosis type 1 (NF 1), and possible infection or radiation necrosis. In all but one patient, diagnosis was confirmed by biopsy or by clinical follow-up. CONCLUSIONS: This small sample of patients suggests that MRS is important in the differential diagnosis between proliferative and nonproliferative lesions in patients without neurofibromatosis. Unfortunately, in cases of NF 1, MRS can have a rather misdiagnosis role.

Adolescent↗
PubMed2005

Accelerated myelination associated with venous congestion.

Magnetic resonance imaging is currently the gold standard in the assessment of brain myelination. The normal pattern of brain myelination conforms to a fixed chronological sequence. Focal accelerated myelination is a usual pathological state and previously has only been associated with Sturge-Weber syndrome. The purpose of our study is to describe alternate causes for accelerated myelination. We retrospectively reviewed serial MR scans, MR angiography, conventional angiography and the clinical progress of three children with accelerated myelination. Two patients with accelerated myelination had an underlying cerebral sinovenous thrombosis. The third patient had Sturge-Weber syndrome. Our study strongly suggests that cerebral venous thrombosis with the consequent restriction of venous outflow could be a key factor in the induction of accelerated myelination. We recommend that in patients with accelerated myelination, the search for an underlying etiology should include careful evaluation of the intracranial vascular pathology, especially cerebral venous thrombosis.

Brain↗
PubMed2005

Importance of diffusion-weighted imaging in the diagnosis of cystic brain tumors and intracerebral abscesses.

OBJECTIVE: It is often difficult to decide whether a cystic brain lesion is a tumor or an abscess by means of conventional MRI techniques. The immediate diagnosis of a brain abscess is important for the patient's outcome. Our goal was to study the ability of diffusion-weighted imaging and calculation of the apparent diffusion coefficient (ADC) to differentiate between these two pathologies. PATIENTS AND METHODS: Ten patients (five men, five women) with cystic brain lesions were examined with MRI. The ADC maps were calculated for each subject and the ADC value of each lesion was measured. Histology revealed glioblastoma multiforme in six patients and abscess in four patients. RESULTS: All brain abscesses showed markedly hyperintense signal changes on diffusion-weighted imaging, whereas the appearance of glioblastoma varied from slightly hyperintense to hypointense signal conversion. The mean ADC value calculated in the six patients with cystic brain tumor was: 2.05 x 10 (-3) mm(2)/s (1.38-2.88 x 10 (-3) mm(2)/s). The mean ADC value of the four patients with brain abscess was: 0.57 x 10 (-3) mm(2)/s (0.38-0.77 x 10 (-3) mm(2)/s). CONCLUSION: Diffusion-weighted imaging and calculation of ADC maps constitute a helpful tool to differentiate between cystic brain tumors and brain abscesses.

Adult↗
PubMed2005

Isolated CNS relapse in neuroblastoma.

We report three patients with primary extracerebral neuroblastoma and central nervous system (CNS) relapse. As the survival of children with metastatic neuroblastoma improves with recent advances in treatment, CNS involvement becomes more frequently detected. MR imaging of the brain and spine are strongly indicated in the follow-up of patients with increased risk of developing CNS disease.

Central Nervous System Neoplasms↗
PubMed2004

Granulocytic sarcoma in children.

We report three children with leukaemia (two acute myeloid and one acute lymphoblastic) and granulocytic sarcoma in the skull, orbit and sinuses. Lesions in these sites in children, with or without bone changes, are suggestive of systemic diseases such as lymphoproliferative conditions. Although involvement by granulocytic sarcoma, with or without acute myeloid leukaemia, is described, an association with acute lymphoblastic leukaemia is rare. Recognition of this rare entity is important, because early aggressive chemotherapy can bring about regression of the tumour and improve survival.

Child, Preschool↗
PubMed2004

Central nervous system imaging in childhood leukaemia.

The aim of this study was to document the imaging abnormalities seen in the central nervous system (CNS) in cases of childhood leukaemia or as complications of its treatment. Magnetic Resonance (MR) images and Computed Tomographic (CT) scans were reviewed retrospectively in 22 children and adolescents with neurological manifestations/complications of leukaemia or its treatment. Among the 22 patients, nine had two or more different CNS abnormalities. The imaging abnormalities seen in 15 patients before or during treatment included sinus thrombosis, cortical vein thrombosis, cerebral haemorrhage, meningeal leukaemia, infections, skull leukaemic infiltration and treatment-related neurotoxicity. After therapy, seven patients had CNS abnormalities, including secondary brain tumours, skull tumour, mineralising microangiopathy, leucoencephalopathy, transient white matter abnormalities, spinal intradural haematoma, chronic subdural haematoma, radiation necrosis, meningeal leukaemia and leukaemic infiltration at the vertebral body. CNS complications are related to the inherent risk of leukaemia itself, to the treatment method and to the duration of survival.

Adolescent↗
PubMed2004

Comparison of intracranial 3D-ToF-MRA with and without parallel acquisition techniques at 1.5T and 3.0T: preliminary results.

PURPOSE: To evaluate the performance of four 3D-ToF magnetic resonance angiography (MRA) sequences with and without integrated parallel acquisition techniques (iPAT) at 1.5T and 3.0T in imaging intracranial vessels. MATERIAL AND METHODS: Seven volunteers and 5 patients (4 aneurysms, 1 AVM) underwent 3D-ToF-MRA at 1.5T (Magnetom Sonata) and 3.0T (Magnetom Trio) with and without parallel acquisition techniques (iPAT) using similarly designed 8-channel phased-array head coils. Imaging time of the pulse sequences was set to 7.15 and 7.35 min, respectively. Images were analyzed quantitatively by calculating signal-to-noise (SNR) and contrast-to-noise (CNR) ratios of proximal M2 segments and qualitatively by using a 5-point scale. RESULTS: SNR and CNR were significantly higher for both 3D-ToF sequences at 3.0T compared with both pulse sequences at 1.5T. The highest SNR and CNR were obtained at 3.0T without iPAT. However, because of a higher spatial resolution (matrix 512 x 640) visualization of small vessel details was best at 3.0T with iPAT. CONCLUSION: Intracranial 3D-ToF-MRA at 3.0T offers superior image quality compared with 1.5T, particular in the delineation of smaller vessels. In contrast to 1.5T, implementation of iPAT at 3.0T is of additional benefit since the high SNR available at 3.0T allows for higher spatial resolution without prolongation of measurement time.

Artifacts↗
PubMed2004

Cerebral venous sinus thrombosis manifesting as bilateral subdural effusion.

Three patients with bilateral subdural effusion, an exclusive manifestation of cerebral venous sinus thrombosis (CVST), are presented. A possible explanation of this rare occurrence is provided, and the differential therapeutic strategies are discussed. We propose to consider CVST in cases of subdural effusions of obscure origin. Appropriate imaging studies should not be delayed if there is suspicion of sinus thrombosis to enable adequate therapy to be started as soon as possible.

Aged↗
PubMed2004

Tissue at risk concept for endovascular treatment of severe vasospasm after aneurysmal subarachnoid haemorrhage.

OBJECTIVE: To report a case of severe vasospasm after subarachnoid haemorrhage (SAH) where "tissue at risk" was identified by magnetic resonance imaging (MRI), and to demonstrate the haemodynamic consequences with either resolution of the perfusion-diffusion mismatch by balloon angioplasty or evolution of an infarct. METHODS: A 45 year old women with SAH underwent surgical treatment of a ruptured middle cerebral artery (MCA) aneurysm. On day 3 she became obtunded and developed a right hemiparesis. Diffusion weighted (DWI) and perfusion weighted (PWI) imaging were done before and after transluminal balloon angioplasty (TBA) of multifocal proximal vasospasm. RESULTS: The initial MRI revealed no DWI lesion but PWI showed a severe perfusion deficit of 6.7 to 16.4 seconds in the complete left MCA territory. Digital subtraction angiography confirmed severe segmental narrowing of left C1 and M1. The spastic segments were successfully dilated by TBA. Follow up MRI showed that the PWI-DWI mismatch resolved in the anterior and middle MCA territory with no tissue infarction, whereas in the terminal dorsal MCA territory a severe mismatch remained and cerebral infarction evolved. CONCLUSIONS: PWI/DWI can identify tissue at risk for infarction in severe vasospasm following SAH. This may allow selection of patients for angioplasty and the monitoring of treatment effects.

Angioplasty, Balloon↗
PubMed2003

Functional imbalance of visual pathways indicates alternative face processing strategies in autism.

OBJECTIVE: To investigate whether autistic subjects show a different pattern of neural activity than healthy individuals during processing of faces and complex patterns. METHODS: Blood oxygen level-dependent (BOLD) signal changes accompanying visual processing of faces and complex patterns were analyzed in an autistic group (n = 7; 25.3 [6.9] years) and a control group (n = 7; 27.7 [7.8] years). RESULTS: Compared with unaffected subjects, autistic subjects demonstrated lower BOLD signals in the fusiform gyrus, most prominently during face processing, and higher signals in the more object-related medial occipital gyrus. Further signal increases in autistic subjects vs controls were found in regions highly important for visual search: the superior parietal lobule and the medial frontal gyrus, where the frontal eye fields are located. CONCLUSIONS: The cortical activation pattern during face processing indicates deficits in the face-specific regions, with higher activations in regions involved in visual search. These findings reflect different strategies for visual processing, supporting models that propose a predisposition to local rather than global modes of information processing in autism.

Adolescent↗
PubMed2003

Posterior encephalopathy with vasospasm: MRI and angiography.

Posterior encephalopathy is characterised by headache, impairment of consciousness, seizures and progressive visual loss. MRI shows bilateral, predominantly posterior, cortical and subcortical lesions with a distribution. Our aim was to analyse the MRI lesion pattern and angiographic findings because the pathophysiology of posterior encephalopathy is incompletely understood. We report three patients with clinical and imaging findings consistent with posterior encephalopathy who underwent serial MRI including diffusion-weighted imaging (DWI) and construction of apparent diffusion coefficient (ADC) maps, and four-vessel digital subtraction angiography (DSA). DWI revealed symmetrical subcortical and cortical parieto-occipital high signal. High and also low ADCs indicated probable vasogenic and cytotoxic oedema. On follow-up there was focal cortical laminar necrosis, while the white-matter lesions resolved almost completely, except in the arterial border zones. DSA revealed diffuse arterial narrowing, slightly more marked in the posterior circulation. These findings suggest that posterior encephalopathy may in some cases be due to diffuse, severe vasospasm affecting especially in the parieto-occipital grey matter, with its higher vulnerability to ischemia. Cerebral vasospasm due to digitoxin intoxication, resulting in posterior encephalopathy, has not yet been described previously.

Adult↗
PubMed2003

Vasogenic edema in Bickerstaff's brainstem encephalitis: a serial MRI study.

The authors report serial MRI of a patient with Bickerstaff's brainstem encephalitis (BBE), disclosing caudal migration of an initial upper midbrain lesion. High apparent diffusion coefficient values imply a vasogenic rather than cytotoxic edema as the cause of the hyperintense signal changes on T2-weighted images.

Brain Edema↗
PubMed2003

Striatal activation during blepharospasm revealed by fMRI.

OBJECTIVE: To investigate brain areas involved in the initiation and execution of eyelid spasm in patients with benign essential blepharospasm. METHODS: The authors used fMRI and correlated the blood oxygenation level-dependent (BOLD) signal with epochs of frequent eyelid spasm in six patients and with epochs of voluntary eye blinks in four healthy subjects. RESULTS: Spasm epochs were accompanied by activation in a subregion of the putamen in all patients, whereas voluntary blinking in healthy subjects was not. Other areas of activation common to patients and healthy subjects included frontal and parietal operculum, supplementary motor area, primary sensorimotor cortex, various visual areas, and the cerebellum. CONCLUSIONS: The striatum may be involved in the initiation or execution of eyelid spasm. Future studies, possibly including electromyography (EMG) during fMRI, are needed to detect the sequence and role of other concomitantly activated areas.

Adult↗
PubMed2003

An unusual intraventricular haemangiopericytoma: MRI and spectroscopy.

We present a 43-year-old woman with a tumour within the left lateral ventricle with the typical appearances of meningioma on MRI. (1)H MR spectroscopy demonstrated an increased choline peak, suggesting a malignant form of meningioma. Histologically a haemangiopericytoma was found, an exceptionally rare tumour at this site.

Adult↗