We studied 36 patients with MRI-proven isolated acute pontine infarct. Corresponding to the constant territories of intrinsic pontine vessels, infarcts followed a predictable distribution, enabling us to delineate three main syndromes. Twenty-one patients had a ventral pontine infarct. Motor involvement varied from mild hemiparesis (ventrolateral pontine syndrome) to severe hemiparesis with bilateral ataxia and dysarthria (ventromedial pontine syndrome). In addition, three-fourths of the patients had clinical evidence for usually mild tegmental dysfunction. Eleven patients had a tegmental pontine infarct, presenting tegmental signs (eye movement disorders, cranial nerve palsies, sensory disturbances), and mostly mild motor deficits (tegmental pontine syndrome). Only four patients had alternating deficits, and these never corresponded to any of the so-called classic pontine syndromes. Infarcts in the medial and the extreme lateral tegmental territory were never observed in isolation, being always associated with cerebellar or larger (and multiple) infarctions in the posterior circulation. Four patients with a bilateral ventrotegmental pontine infarct presented with acute pseudobulbar palsy, bilateral motor deficits, and tegmental signs. The results of etiologic work-up emphasize the concept of basilar artery branch disease, which was the most common presumed cause of stroke (16/36, 44%). Basilar artery branch disease was particularly associated with large ventral infarcts, severe clinical symptomatology, progressive or fluctuating course, and local recurrence. Presumed small-artery disease (9/36, 25%) was usually associated with small ventral or tegmental infarcts and rapidly improving lacunar syndromes. Large-artery stenosis (8/36, 22%) and cardioembolism (1/36, 3%) were less common than in series of posterior circulation infarcts that include simultaneous pontine and extrapontine lesions. Recovery was good in two-thirds of the patients, the worse outcome being associated with large ventral infarcts.

In vitro ischemia models have utilized oxygen, or oxygen and glucose deprivation to simulate ischemic neuronal injury. Combined oxygen and glucose deprivation can induce neuronal damage which is in part mediated through NMDA receptors. Severe oxygen deprivation alone however can cause neuronal injury which is not NMDA mediated. We tested the hypothesis that NMDA, or non-NMDA receptor mediated mechanisms may predominate, to induce neuronal injury following severe oxygen deprivation depending on the presence of glucose. We found that NMDA receptor blockade using dizocilpine (MK-801), DL-2-amino-5- phosphonovaleric acid (APV), or CGS 19755, was highly effective in reducing CA1 injury in organotypic hippocampal cultures, caused by complete oxygen and glucose deprivation. Complete oxygen deprivation alone however, caused CA1 neuronal injury which was not diminished using NMDA receptor blockade alone with MK-801 or APV, or in combination with AMPA/kainate receptor blockade using 6-cyano-7- dinitroquinoxalone-2,3-dione (CNQX). Neuronal protective strategies which act primarily through non-glutamate dependent mechanisms, including hypothermia, low chloride and calcium, and the free radical scavenger, alpha-phenyl-tert-butyl nitrone (PBN), provided neuronal protection against complete oxygen, as well as combined oxygen/glucose deprivation. Raising the pH using Hepes buffer during complete oxygen deprivation did not result in neuronal protection by NMDA receptor blockade. Partial oxygen deprivation alone, partial oxygen deprivation combined with glucose deprivation, glucose deprivation alone, and also glutamate exposure, all produced neuronal damage that was reduced by NMDA receptor blockade. The presence of glucose during complete oxygen deprivation appears to prevent glutamate receptor blockade from reducing neuronal injury in organotypic hippocampal cultures.

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Object The need for interbody fusion or stabilization after anterior cervical microdiscectomy is still debated. The objectives of this prospective randomized study were 1) to examine whether combined interbody fusion and stabilization is more beneficial than microdiscectomy only (MDO) and 2) if fusion is found to be more beneficial than MDO, to determine which is the best method of fusion by comparing the results achieved using autologous bone graft (ABG), polymethylmethacrylate (PMMA) interposition, and threaded titanium cage (TTC). Methods A total of 125 patients with a single-level cervical disc disease were included in this prospective study. All patients were randomized and assigned to one of the four following groups: Group 1 (33 patients), MDO; Group 2 (30 patients), microdiscectomy followed by ABG; Group 3 (26 patients), microdiscectomy followed by injection of PMMA; and Group 4 (36 patients), microdiscectomy followed by placement of a TTC. Clinical outcome according to Odom criteria was summarized as 1) excellent and good or 2) satisfactory and poor. One-year follow-up examination was performed in 123 patients. Patients in the TTC group experienced a significantly better outcome 6 months after surgery (92% excellent and good results) compared with those in the MDO and ABG groups (72.7 and 66.6% excellent and good results, respectively). Twelve months after surgery there was still a significant difference in outcomes between the TTC group (94.4% excellent and good results) and the MDO group (75.5% excellent and good results). Outcome in patients treated with PMMA was comparable with that in those treated with TCC after 6 (91.6%) and 12 months (87.5%), but no segmental fusion was achieved. Differences compared with MDO and ABG were, however, not significant, which may be related to the smaller number of patients in the PMMA group. Conclusions Interbody cage-assisted fusion yields a significantly better short- and intermediate-term outcome than MDO in terms of return to work, radicular pain, Odom criteria, and earlier fusion. In addition, the advantages of interbody cages over ABG fusion included better results in terms of return to work, Odom criteria, and earlier fusion after 6 months. These results suggest that interbody cage–assisted fusion is a promising therapeutic option in patients with single-level disc disease. Polymethylmethacrylate seems to be a good alternative to interbody cage fusion but is hindered by the absence of immediate fusion.