Neuroradiology 0028-3940

Reijneveld, J.; Grond, J.; Ramos, L.; Bromberg, J.; Taphoorn, M.

doi: 10.1007/s00234-005-1435-zpmid: 16133483

We compared the value of changes in proton magnetic resonance spectroscopic imaging (1H-MRSI) with changes in clinical status and/or contrast-enhanced magnetic resonance imaging (MRI) in the monitoring of patients with suspected low-grade glioma (LGG). From June 1, 1999 till May 31, 2002, we included consecutive, neurologically intact adult patients suspected of having an LGG, demonstrating non-enhancing supratentorial lesions without edema or mass effect on MRI, and in whom all treatment (including a diagnostic biopsy) was deferred. Till January 1, 2003, patients were surveyed clinically and radiologically (contrast-enhanced MRI and 1H-MRSI). Patients who showed progression on clinical examination and/or MRI were denoted as progressive disease. Other patients were denoted as stable disease. A decrease in NAA/CHO ratio of ≥20% compared to the baseline value was considered as indicative for progression on 1H-MRSI. We included 14 patients with suspected LGG. Seven patients demonstrated progressive disease during the follow-up period, preceded or accompanied by concomitant 1H-MRSI changes in five patients. Four of these five patients were operated on within the follow-up interval. The histological diagnosis demonstrated high-grade glioma in three and LGG in one patient. In the other two patients with progressive disease, no progression was found on 1H-MRSI. The other seven patients demonstrated stable disease, but four of them showed progression on 1H-MRSI. Our data do not show convincing evidence that 1H-MRSI contributes to adequate monitoring and follow-up of patients with suspected LGG. Future research should preferably include pathological data at the time of 1H-MRSI changes.

Yang, C.; Yang, B.

doi: 10.1007/s00234-005-1437-xpmid: 16142478

Microscopic cerebral arterial air embolism (CAAE) has been described in many patients undergoing cardiac surgery as well as other invasive diagnostic and therapeutic procedures. However, massive CAAE is rare. We report a 42-year-old woman who initially presented with thalamic and basal ganglia hemorrhages. Shortly after a radial arterial catheter was inserted, the patient suffered a generalized seizure and CT demonstrated intra-arterial air in bilateral cerebral hemispheres.

Salamon, N.; Sicotte, N.; Alger, J.; Shattuck, D.; Perlman, S.; Sinha, U.; Schultze-Haakh, H.; Salamon, G.

doi: 10.1007/s00234-005-1439-8pmid: 16158279

The authors have reviewed the diffusion tensor imaging (DTI) of the brain stem in 19 subjects, consisting of 15 normal volunteers and four multi-system atrophy patients. The study was performed with 1.5 T MRI scanners. DTI was correlated with an automated program allowing superposition of the structural anatomy. Axial, sagittal, and coronal images demonstrated major white-matter fibers within the brain stem, including cortico-spinal tracts, transverse pontine fibers, and medial lemniscus. Smaller fibers, such as medial longitudinal fascicles and central tegmental tracts are difficult to visualize. To identify the anatomical orientation of the brain stem, white-matter fibers will help us understand the different functional disease processes, and DTI will play an important role for the evaluation of the different white matter fibers in the brain stem.

Kalina, Peter; Decker, Andrew; Kornel, Ezriel; Halperin, John

doi: 10.1007/s00234-005-1440-2pmid: 16158278

Lyme disease is a multisystem infectious disease caused by the tick-borne spirochete, Borrelia burgdorferi. Central nervous system (CNS) involvement typically causes local inflammation, most commonly meningitis, but rarely parenchymal brain involvement. We describe a patient who presented with clinical findings suggesting a brainstem process. Magnetic resonance imaging (MRI) and positron emission tomography (PET) suggested a brainstem neoplasm. Prior to biopsy, laboratory evaluation led to the diagnosis of Lyme disease. Clinical and imaging abnormalities improved markedly following antimicrobial therapy. We describe Lyme disease involvement of the cerebellar peduncles with hypermetabolism on PET. Although MRI is the primary imaging modality for most suspected CNS pathology, the practical applications of PET continue to expand.

Watanabe, A.; Kobashi, T.

doi: 10.1007/s00234-005-1441-1pmid: 16142477

A 72-year-old man who was attending the outpatients clinic in our hospital because of multiple lacunar cerebral infarctions and mild mental disturbance developed an inability to gaze to the left side voluntarily. MR imaging revealed a new cerebral microbleed in the medial lemniscus of the right side in the mid-pontine region. The finding in this case suggests that the pathways from the frontal eye field descend at least to the level of the mid-pontine region ipsilaterally, and that the pathways then contralaterally decussate and terminate in the paramedian pontine reticular formation. Cerebral microbleeds can be symptomatic depending on the neuro-anatomical structures involved.

No, Young; Lee, Eun; Lee, Deok; Kim, Jong

doi: 10.1007/s00234-005-1445-xpmid: 16133479

Transient ischemic attacks (TIAs) or ischemic stroke may complicate thromboangiitis obliterans (TAO). However, there has been debate regarding the mechanism of ischemic stroke in TAO. We report the case of a patient with TAO who developed repeated TIAs. An angiogram showed multiple alternative areas of arterial occlusions in the distal segments of both middle cerebral arteries. Extensive collateral vessels around the occluded segment were also observed, which resembled the “tree root” or “corkscrew” vessels described in the peripheral arteries in TAO. Our patient illustrates that cerebral manifestations of TAO may occur with vascular changes that are identical with those encountered in the limb arteries in TAO.

Lee, S.; Kim, D.; Kim, K.; Chung, C.; Song, I.; Chang, K.

doi: 10.1007/s00234-005-1447-8pmid: 16158277

This study was performed to evaluate the effect of seizures on the bilateral hippocampus in mesial temporal lobe epilepsy (mTLE) and neocortical epilepsy by single voxel proton magnetic resonance spectroscopy (MRS). Forty-one patients with mTLE having unilateral hippocampal sclerosis and 43 patients with a neocortical epilepsy who underwent subsequent epilepsy surgery were recruited. Ninety-five percent confidence intervals of N-acetyl aspartate/choline (NAA/Cho) and NAA/creatine (NAA/Cr) ratios in 20 healthy control subjects were used as threshold values to determine abnormal NAA/Cho and NAA/Cr. NAA/Cho and NAA/Cr were significantly lower in the ipsilateral hippocampus of mTLE and neocortical epilepsy. Using asymmetry indices for patients with bilaterally abnormal ratios of NAA/Cho and NAA/Cr in addition to using unilateral abnormal ratio, the seizure focus was correctly lateralized in 65.9% of patients with mTLE and 48.8% of neocortical epilepsy patients. Bilateral NAA/Cho abnormality was significantly related to a poor surgical outcome in mTLE. No significant relationship was found between the results of NAA/Cho or NAA/Cr and surgical outcome in neocortical epilepsy. The mean contralateral NAA/Cr ratio of the hippocampus in mTLE was significantly lower in patients with a history of secondary generalized tonic-clonic seizure (SGTCS) than in those without. Our results demonstrate effects of seizures on the hippocampi in neocortical epilepsy and the relation between SGTCS and NAA/Cr of the contralateral hippocampus in mTLE. This proves the presence of a seizure effect on the hippocampus in neocortical epilepsy as well as in mTLE.

Ahn, Y.; Lee, S.; Chung, S.; Park, H.; Shin, S.

doi: 10.1007/s00234-005-1436-ypmid: 16133482

A discogenic cervical headache is a subtype of cervicogenic headache (CEH) that arises from a degenerative cervical disc abnormality. The purpose of this study was to evaluate the clinical outcome of percutaneous endoscopic cervical discectomy (PECD) for patients with chronic cervical headache due to soft cervical disc herniation. Seventeen patients underwent PECD for intractable headache. The inclusion criteria were soft disc herniation without segmental instability, proven by both local anesthesia and provocative discography for headache unresponsive to conservative treatment. The mean follow-up period was 37.6 months. Fifteen of the 17 patients (88.2%) showed successful outcomes based on the Macnab criteria. Pain scores on a visual analog scale (VAS) improved from a preoperative mean of 8.35±0.79 to 2.12±1.17, postoperatively (P<0.01). The mean disc height decreased from 6.81±1.08 to 5.98±1.07 mm (P<0.01). There was no newly developed segmental instability or spontaneous fusion on follow-up radiography. In conclusion, PECD appears to be effective for chronic severe discogenic cervical headache under strict inclusion criteria.

Krings, Timo; Piske, Ronie; Lasjaunias, Pierre

doi: 10.1007/s00234-005-1438-9pmid: 16136262

The pathogenesis of intracranial arterial aneurysms (AA) remains unclear, despite their clinical importance. An improved understanding of this disease is important in choosing therapeutic options. In addition to the “classical” berry-type aneurysm, there are various other types of intracranial AA such as infectious, dissecting or giant, partially-thrombosed aneurysms. From the clinician’s perspective, the hypothesis that some of these intracranial AA might be due to abluminal factors has been proposed for several years. Indeed, this hypothesis and the empirical use of anti-inflammatory drugs in giant intracranial aneurysms have been confirmed by recent studies reporting that an enzyme involved in the inflammatory cascade (5-lipoxygenase or 5-LO) promotes the pathogenesis of specific aneurysms in humans. 5-LO generates different forms of leukotrienes which are potent mediators of inflammation. Adventitial inflammation leads to a weakening of the media from the abluminal part of the vessel wall due to the release of proinflammatory factors that invade the media, thereby degrading the extracellular matrix, the elastic lamina of the vascular wall, and, finally, the integrity of the vessel lumen. This in turn results in a dilation of the vessel and aneurysm formation. Moreover, neoangiogenesis of vasa vasorum is found in close proximity to 5-LO activated macrophages. In addition to this biological cascade, we argue that repeated subadventitial haemorrhages from the new vasa vasorum play an important role in aneurysm pathogenesis, due to a progressive increase in size mediated by the apposition of new layers of intramural haematoma within the vessel wall. Intracranial giant AA can therefore be regarded as a proliferative disease of the vessel wall induced by extravascular activity. Considering certain aneurysmal vasculopathies as an abluminal disease might alter current therapeutic strategies. Therapy should not only be aimed at the intraluminal repair of the artery, but also cross the vessel wall to reach the vasa vasorum. Drug-eluting stents placed proximal to the lesion and targeted to the origin of the vasa vasorum could be considered as a potential future option. “Intelligent” MRI contrast agents (i.e., macrophage marking) could be used to detect vasa vasorum proliferation and weakening of the vessel wall in vivo.

Bradač, G.B.; Bergui, M.; Fontanella, M.

doi: 10.1007/s00234-005-1444-ypmid: 16133480

We report our experience in the endovascular treatment with detachable platinum coils of ruptured or symptomatic unruptured cerebral aneurysms in 61 patients aged 70–82 years. Complete occlusion was achieved in 38, subtotal in 17 and partial in one. The treatment failed in five patients. Clinical follow-up was performed in all patients for 8 months to 8 years. No bleeding occurred during the follow-up period. Outcome was favourable in 63% of the patients. When we compared the outcome of elderly patients with those of younger age endovascularly treated in the same period of time, we found a significantly higher frequency of poorer outcome in the elderly group (χ2=9.084; P=0.011). The frequency of favourable outcome in the elderly was significantly lower than in the younger group for H–H IV–V (χ2=9.299; P=0.010). The most important factor influencing the outcome was not age itself, but primary clinical condition on admission. The therapy of symptomatic aneurysms in elderly patients should not be purely conservative—a direct approach of the aneurysm should be considered. Endovascular treatment whenever possible seems to be a good alternative to surgery.