Günther Birbamer

European Pentoxifylline Multi-Infarct Dementia Study

A double-blind, placebo-controlled, parallel-group, multicentre study was conducted to evaluate the efficacy of pentoxifylline (Trental) in patients with multi-infarct dementia (MID) according to DSM-III-R criteria. Men and women aged 45 years or older, with a Hachinski Ischemia Scale score > or = 7 and a Mini Mental State Examination (MMSE) score of 10-25 at entry, and computed tomographic evidence of vascular disease were enrolled. A total of 289 patients were randomised to receive either oral pentoxifylline 400 mg t.i.d. or placebo for 9 months, and efficacy was assessed every 3 months. The primary outcome variable was the difference in scores between the two treatment groups, as measured on the Gottfries, Bråne, Steen (GBS) scale. Secondary outcome variables included the scores achieved on the Sandoz Clinical Assessment Geriatric (SCAG) scale and MMSE, and a battery of psychological and other tests. The intention-to-treat analysis for patients completing the study (n = 239) showed a statistically significant difference in the total GBS score in favour of pentoxifylline (improvement of 3.5 points, p = 0.028). A significant difference in the total GBS score in favour of pentoxifylline was even almost achieved in the intention-to-treat analysis for all evaluable patients (n = 269, improvement of 2.1 points, p = 0.065). It is concluded that treatment with pentoxifylline is beneficial for patients with MID, the global results of the GBS and SCAG scales being reinforced by significant improvements in those subscales specific for intellectual and cognitive function.

Magnetic resonance imaging and angiography in hemifacial spasm

SummaryWe 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 irriation 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.

Phenytoin Overdosage and Cerebellar Atrophy in Epileptic Patients: Clinical and MRI Findings

Mild overdosage of phenytoin produces reversible cerebellar symptoms (nystagmus, double vision, dysarthria and ataxia). Several case reports suggest that relatively mild and relatively short intoxication can lead to cerebellar degeneration. We observed 11 patients who had episodes of abnormally increased serum levels, most of which developed clinical signs of cerebellar dysfunction. All of these patients were examined with a 1.5-tesla whole-body system (Magnetom, Siemens). Five patients had normal cerebellar structures, although 3 of them had a history of clinical intoxication and all had at least one episode of increased serum level of diphenylhydantoin. The remaining 5 had moderate to severe cerebellar atrophy. Two of them never experienced signs of clinical intoxication. There was no correlation between degree of atrophy and severity of clinical symptoms and elevation of serum DPH levels. There was no correlation between cerebellar atrophy, duration of epilepsy and frequency of seizures.

Magnetic Resonance Volumetry of the Cerebellum in Epileptic Patients after Phenytoin Overdosages

The aim of this study was to evaluate the relationship between phenytoin medication and cerebellar atrophy in patients who had experienced clinical intoxication. Five females and 6 males, 21-59 years of age, were examined with a 1.5-T whole-body system using a circular polarized head coil. Conventional spin echo images were acquired in the sagittal and transverse orientation. In addition, we performed a high-resolution 3D gradient echo, T1-weighted sequences at a 1-mm slice thickness. The images were subsequently processed to obtain volumetric data for the cerebellum. Cerebellar volume for the patient group ranged between 67.66 and 131.08 ml (mean 108.9 ml). In addition 3D gradient echo data sets from 10 healthy male and 10 healthy female age-matched volunteers were used to compare cerebellar volumes. Using linear regression we found that no correlation exists between seizure duration, elevation of phenytoin serum levels and cerebellar volume. However, multiple regression for the daily dosage, duration of phenytoin treatment and cerebellar volume revealed a correlation of these parameters. 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. Quantitative morphometric studies of the cerebellum provide valuable insights into the pathogenesis of cerebellar disorders.

Magnetic Resonance Imaging and Magnetic Resonance Angiography of Vertebrobasilar Dolichoectasia

We performed magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) in 16 patients with vertebrobasilar dolichoectasia (VBD). Five patients had compressive cranial nerve deficits an

MRI of cerebral hypoxia

MRI findings are described in 24 cases of hypoxic coma. In this study hypoxic damage has occurred as a consequence of diverse conditions such as cardiac arrest, anaesthetic accidents, carbon monoxide poisoning, high altitude brain oedema, drowning, suicidal hanging, hypo-glycaemia and shock. The main forms of cerebral damage were watershed infarction and bilateral selective neuronal necrosis within the globus pallidus, putamen, nucleus cau-datus, thalamus, parahippocampal gyrus, hippocampus, cerebellum and brainstem nuclei. Whereas watershed infarction indicated failure of circulation, the pattern of damage within the basal ganglia, thalami, temporal lobe and brain stem could not be related to any of the underlying pathogenetic processes. No typical pattern of lesion could be found in regard to the cause of the disease. However, arterial boundary zone involvement indicates the underlying pathogenetic mechanism. The sensitivity of MRI in the detection of hypoxic lesions was greatly superior to that of CT, while specificity based on signal behaviour allowed differentiation of acute and chronic alterations. Based on serial MRI studies prediction of prognostic outcome will be improved.

Early detection of post-traumatic olivary hypertrophy by MRI

Two patients are described, in whom MRI detected unilateral signal abnormalities in the region of the inferior olivary nuclei, suggesting an early stage of olivary hypertrophy. MRI was performed 4 and 7 weeks respectively after traumatic brain-stem injury. Palatal myoclonus was concomitantly observed in one patient, while the other showed no evidence of segmental myoclonus at the time of examination. The authors conclude that MRI is highly sensitive in the detection of olivary hypertrophy and of traumatic lesions of the dentatorubro-olivary pathway.

Spontaneous collapse of posttraumatic syringomyelia : serial magnetic resonance imaging

The case of a 30-year-old man with posttraumatic syringomyelia involving the cervical and upper thoracic spine is reported. The patient was followed clinically and with magnetic resonance (MR) imaging over a 3-year period. Spontaneous complete remission of the syrinx-related symptoms correlated with a partial collapse of the syrinx, as proved by serial MR imaging.

Der zerebelläre Infarkt

ZusammenfassungGrundlagen:Es ist nicht klar, ob Patienten mit einem Kleinhirninfarkt von einem früheren chirurgischen Eingriff profitieren. Diese Studie untersucht 2 Patientengruppen mit Kleinhirninfarkt, die eine konservativ, die andere operativ behandelt.Methodik:64 Fälle mit ischämischem Kleinhiminfarkt wurden retrospektiv untersucht. Diagnose und Nachsorgeuntersuchungen wurden durch computer-tomographische Studien abgesichert. 12 Patienten wurden zusätzlich einer Magnetresonanzuntersuchung unterzogen. 53 Patienten, wurden konservativ behandelt, 11 Patienten wurden operiert. In 6 von 11 Patienten wurde ein Verschlußhydrozephalus durch eine externe Ventrikeldrainage behandelt. 8 Patienten entwickelten eine foraminelle Herniation und wurden durch eine Entlastungskraniotomie der hinteren Schädelgrube und Resektion des nekrotischen Gewebes behandelt. Das mittelfristige Ergebnis wurde 3 Monate nach der Entlassung untersucht.Ergebnisse: Nach 3 Monaten zeigten 34 der 53 konservativ behandelten Patienten (64%) eine komplette oder nahezu komplette Restitution, 14 (26%) waren schwer behindert, 5 (10%) starben. Keiner der Patienten, in denen nur eine externe Ventrikeldrainage angelegt wurde, überlebte. Von den 8 Patienten, die einer Kraniotomie unterzogen wurden, erholten sich 6 vollständig oder zeigten nur ein geringes neurologisches Defizit, 2 verblieben schwer behindert.Schlußfolgerungen:Unsere Studie scheint zu belegen, daß frühe neurochirurgische Intervention bei Patienten mit einem Kleinhirninfarkt und daraus resultierendem Verschlußhydrozephalus oder Hirnstammkompression eine Verbesserung im Outcome dieser Patienten erreicht.SummaryBackground:At present it is not clear whether patients with cerebellar infarction benefit from early surgical intervention. This study compares outcome in operated versus non operated patients with ischemic infarction of the cerebellum.Methods:64 cases of ischaemic infarction of the cerebellum were studied retrospectively. Computed tomography was used for diagnosis and follow-up in all cases: 12 patients underwent complementary MR imaging. 53 patients were treated conservatively, 11 patients were operated. In 6 of these 11 patients an occlusive hydrocephalus was treated with external ventricular drainage. 8 patients developed for-aminal herniation and underwent decompressive craniotomy of the posterior fossa and resection of necrotic tissue. Clinical outcome was evaluated 3 months after dismission.Results:After 3 months 34 of the 53 conservatively treated patients (64%) showed a complete or nearly complete restitution, 14 (26%) remained severely impaired, and 5 (10%) died. None of the 3 patients who underwent only external ventricular drainage survived. Of the 8 patients treated with craniotomy. 6 recovered totally or showed only minor neurologícal deficit. 2 remained severely impaired.Conclusions:The results of our study suggest that early neurosurgical intervention reduces mortality and improves clinical outcome in patients with cerebellar infarction and occlusive hydrocephalus or brain stem compression.

Nuclear Magnetic Resonance Spectroscopy of Low- and High-Grade Human Gliomas

Magnetic resonance imaging (MRI) is most sensitive in detecting intracranial tumors but lacks specificity concerning histopathology and the malignant versus benign nature of the lesion. Since in vivo magnetic resonance spectroscopy (MRS) became available, several experimental and clinical investigations have suggested that MRS provides useful information for biochemical tumor characterization (Tanaka et al. 1986; Heindel et al. 1988; Bruhn et al. 1989; Gill et al. 1990). Monitoring of therapy effects (Naruse et al. 1986; Segebarth et al. 1987) may become an even more important application of MRS. The purpose of this study was to evaluate the clinical value of MRS for the diagnosis of low- and high-grade gliomas.