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Biomedical subjects

G Birbamer

Publications and source records attributed to G Birbamer.

At least 37 records · Page 2Linked to original sources

[Cerebellar atrophy and phenytoin poisoning. An MR study].

Phenytoin has been considered a possible cause of cerebellar degeneration, especially after clinical intoxication. Magnetic resonance provides the diagnosis of anatomical structures in the posterior fossa without the limitation of beam hardening artefacts. The aim of this study was to evaluate the relationship of phenytoin medication and cerebellar atrophy in 11 patients with increased serum levels (21.4 micrograms/ml-95.6 micrograms/ml). Five patients had normal cerebellar structures, although three of them had a history of clinical intoxication and all had at least one episode of increased serum level of DPH. The remaining six patients had moderate severe cerebellar atrophy (n = 4) and atrophy of the vermis cerebelli (n = 5). Two of them had never experienced clinical intoxication. There was no correlation between the degree of atrophy and severity of clinical symptoms and evaluation of serum DPH levels (up to four times normal values). There was also no correlation between cerebellar atrophy, duration of epilepsy and frequency of seizures. We conclude that phenytoin overdosage does not necessarily result in cerebellar atrophy and it is unlikely that phenytoin medication was the only cause of cerebellar atrophy in the remaining patients.

Adult↗

Magnetic resonance: a noninvasive approach to metabolism, circulation, and morphology in human brain death.

Phosphorus (31P) magnetic resonance spectroscopy and magnetic resonance imaging were used to study the intracellular metabolism, circulation, and morphology in the brains of 3 patients with clinical brain death syndrome due to traumatic brain damage, subarachnoid hemorrhage, and acute occlusive hydrocephalus caused by a colloid cyst. Magnetic resonance spectra were characterized by a complete absence of ATP and were dominated by an intense inorganic phosphate signal. Magnetic resonance imaging revealed a uniform pattern of diffuse brain swelling and tentorial and foraminal herniation. Intracranial blood flow was absent on the magnetic resonance angiography projections. These preliminary findings suggest an important impact of magnetic resonance in the determination of human brain death.

Adenosine Triphosphate↗

Magnetic resonance imaging and angiography in hemifacial spasm.

We used magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) to investigate 14 patients with unilateral hemifacial spasm (HS) and 20 controls. The relationship of the seventh and eighth cranial nerves to adjacent vessels was best visualized on the contiguous flow sensitive 3D-FISP images. Reconstruction of projectional MRA was helpful to assess the complex architecture of the vertebrobasilar system. Neurovascular contact in the facial nerve root exit zone was present in 4 of 20 controls and in 12 of 14 patients, in whom it predicted the affected side. These results support previous findings of surgical and electrophysiological investigations that local irritation of the facial nerve is the most possible explanation for HS. MRI and MRA provide vascular and brain tissue diagnosis in a single non-invasive examination and should be recommended as primary neuroradiological procedure in HS.

Aged↗

[Wilson's disease with primary CNS manifestation--current status in diagnosis and therapy].

Five cases studied at our clinic are discussed and the literature reviewed with the aim of assessing the diagnostic value of various examination methods used for Wilson's disease and a modified diagnostic approach is suggested. CT and MRI are compared with regard to sensitivity, specificity and prognostic value. Almost regularly, MRI showed bilateral lesions in the basal ganglia in combination with structural changes in the brain stem. A pattern consisting of symmetrical lesions of the red nuclei, the periaqueductal grey region and, facultatively, the substantia nigra and the dentate nuclei was discovered and appeared almost pathognomonic. Follow-up studies revealed excellent reversibility of MRI changes by both penicillamine and trientine. Auditory evoked potentials showed the highest sensitivity and the best correlation with structural findings. Kayser-Fleischer corneal rings--a diagnostic requirement in the literature--were not found in all patients. The current state of therapy and therapy management is discussed on the basis of pathophysiological considerations. As possible complications of penicillamine administration the deterioration of the clinical condition after initiating therapy, and the risks associated with an abrupt termination of therapy are discussed in detail.

Adolescent↗

Carpal tunnel syndrome: diagnosis with high-resolution sonography.

OBJECTIVE: Carpal tunnel syndrome is characterized by typical anatomic changes that can be shown with high-resolution sonography. To determine whether these findings are reliable and can be used to establish the diagnosis, sonograms of patients with the disease were compared with sonograms obtained in patients with normal wrists. Also compared were sonograms and MR images obtained in the patients with carpal tunnel syndrome. SUBJECTS AND METHODS: Twenty wrists in 18 consecutive patients with clinical symptoms of carpal tunnel syndrome and with abnormal nerve conduction studies were examined with real-time sonography and MR imaging. The sonograms and MR images were evaluated quantitatively by two unbiased observers with regard to the size and shape of the median nerve and the palmar bowing of the flexor retinaculum. A t test was used to compare these data with those from previous sonographic studies of 28 normal wrists. Correlation coefficients for the measurements obtained with sonography and with MR were calculated. The relative accuracies of different diagnostic criteria for the diagnosis of carpal tunnel syndrome were assessed by using receiver-operating-characteristic analytical techniques. RESULTS: Characteristic findings on both MR and CT scans of the 20 wrists with carpal tunnel syndrome included swelling of the median nerve in the proximal part of the carpal tunnel in 16 wrists, flattening of the median nerve in the distal part of the carpal tunnel in 13 wrists, and increased palmar bowing of the flexor retinaculum in nine wrists. Comparison with the data of 28 normal wrists proved that these findings were significant (p less than .01 to p less than .001). Receiver-operating-characteristic analysis showed that the discrimination between wrists in normal subjects and in patients with carpal tunnel syndrome achieved with each of the three diagnostic criteria was not significantly different. Measurements of the size and flattening of the median nerve obtained from sonograms were similar to those on MR images, whereas sonography was less accurate for measuring the palmar bowing of the flexor retinaculum. CONCLUSION: We conclude that the results of sonography are reliable, and that the diagnosis of carpal tunnel syndrome can be established on the basis of sonographic findings.

Carpal Tunnel Syndrome↗

[MR tomographic aspects of olivary pseudohypertrophy].

MRI aspects of olivary pseudohypertrophy (OH) following pontocerebellar lesions of different etiology and localization are reviewed. OH is characterized by unilateral or bilateral enlargement of the inferior olivary nucleus and increased signal intensity in T2- and, especially, in proton-density (PD)-weighted images. Correlations between the extent and the uni- or bilateral presence of olivary hypertrophy and the localization of the primary pontocerebellar lesions are discussed.

Adolescent↗

Laminar heterotopic grey matter (double cortex) in a patient with late onset Lennox-Gastaut syndrome.

The Lennox-Gastaut syndrome (LGS) is a severe epileptic disorder, characterized by developmental delay, typical electroencephalographic pattern and poor control of seizures. This epileptic syndrome generally presents in early childhood but exceptionally starts at the age of 5 years or later. We describe a patient who was classified as late-onset LGS, with evidence of mild hydrocephalus on CT. MRI added new diagnostic information by demonstrating laminar heterotopic grey matter.

Adult↗

[Cerebral and spinal nocardia infection. A case report].

We report a case of multiple cerebral and spinal abscesses due to Nocardia asteroides in a non-immunocompromised patient. The initial central nervous system manifestation was a sterile meningitis, with secondary development of multiple cerebral and spinal abscesses. Since the location of the abscesses did not allow neurosurgical exploration and the cultures remained negative, the diagnosis was finally established by raised antibody titres to Nocardia asteroides. After specific antibiotic therapy, resolution of the spinal and cerebral abscesses was documented on the basis of serial magnetic resonance tomography and computed tomography controls.

Abscess↗

Agenesis of the corpus callosum and epilepsy in two brothers. Neurophysiological and MRI features.

We report on two brothers with partial agenesis of the corpus callosum and seizure disorder presumably related to ectopic grey matter. Development of both patients was characterized by psychomotor retardation and focal epileptic seizures. Genetic examination revealed normal karyotypes. One brother showed a remarkable focal miniature spike and wave periodicity constantly observed on sequential EEG records. Magnetic resonance imaging revealed partial agenesis of the corpus callosum and ectopic grey matter. Prior computerized tomography failed to visualize ectopic grey matter and overestimated corpus callosum agenesis. The heterotopic grey matter, isolated from the surrounding inhibiting influences, is the most probable source of focal seizures and the partial connection of both hemispheres may explain secondary generalization of seizures.

Adult↗

Neuropsychological outcome after traumatic temporal lobe damage.

The most frequent sequelae after severe brain injury include changes in personality traits, disturbances of emotional behaviour and impairment of cognitive functions. In particular, emotional changes and/or verbal and non verbal dysfunctions were found in patients with bilateral or unilateral temporal lobe lesions. The aim of our study is to correlate the localization of the brain damage after severe brain injury, in particular of the temporal lobe, with the cognitive impairment and the emotional and behavioural changes resulting from these lesions. The patients with right temporal lobe lesions showed significantly better scores in verbal intelligence and verbal memory in comparison with patients with left temporal lobe lesions and those with other focal brain lesions or diffuse brain damage. In contradistinction, study of the personality and the emotional changes (MMPI and FAF) failed to demonstrate pathological scores in the 3 groups with different CT lesions, without any significant difference being found between the groups with temporal lesions and those with other focal brain lesions or diffuse brain damage. The severity of the brain injury and the prolongation of the disturbance of consciousness could, in our patients, account for prevalence of congnitive impairment on personality and emotional changes.

Adolescent↗

[Determination of tuberculostearic acid--progress in early diagnosis of tuberculous meningitis].

Rapid diagnosis of cerebral tuberculous meningitis is of the greatest importance in determining the outcome of therapy. Since tubercle bacilli are often not seen on microscopy of the cerebrospinal fluid, and culture of Mycobacterium tuberculosis takes many weeks, there is a need for more rapid and sensitive confirmatory tests. The importance of the detection of tuberculostearic acid in the cerebrospinal fluid in combination with magnet resonance imaging will be shown in this case report.

Aged↗

Principal advantages of CNS diagnostics by magnetic resonance imaging.

In this paper the authors present the principal advantages and values of CNS diagnostics by magnetic resonance imaging (MRI), on the basis of the data from the available literature as well as on the 3-year experience of the MRI Institute in Innsbruck. Also, qualitative advantages of MR 1.5 T over other, less powerful machines, have been emphasized. So far, the experience has proved that, for the moment, the 1.5 MR machine offers optimal characteristics for the diagnostics of the CNS diseases.

Adult↗

Association of ganglioneuroblastoma with syringomyelia. Case report.

The association of a syndrome of a degenerative nature such as syringomyelia and a neuroblastoma can be of clinical interest. We will describe the case of a young female suffering from a retroperitoneal neuroblastoma and secondary development of syringomyelia. The possible pathogenetic link between these two pathologies will be discussed. Firstly, the dysontogenetic interpretation will be underlined. Other hypotheses will concentrate on the presence of tumors within the cord, which tend to cavitate, and furthermore, on the association between the edema and some diseases such as neoplasma, traumas, and on arachnoiditis as a major pathogenetic factor in syringomyelia. The existence of a possible link between arachnoiditis and the radiotherapy received by the patient after the surgical excision of the retroperitoneal neuroblastoma, will be discussed. Lastly a further pathogenetic hypothesis will be pointed out: an intramedullary softening due to disturbed blood supply, caused by the extramedullary neoplasm.

Adolescent↗

[Motor speech disorder after removal of a glioblastoma in the left hemisphere: Cortical disorder or apraxia?].

A 38-year-old male patient with a deep central parietal lesion in the left hemisphere reveals a motor speech disorder but no aphasia as evidenced by linguistic testing with the Aachener Aphasietest. Nuclear magnetic resonance tomography of the brain shows no lesion of the brainstem. Whether the speech disorder can be termed cortical dysarthria or apraxia of speech is left open to discussion.

Adult↗