Successful treatment of monomorphic primary central nervous system post-transplantation lymphoproliferative disorder 5 years after kidney transplantation.

A 31-year-old man underwent living-related kidney transplantation in 2004 as a consequence of primary focal segmental glomerulosclerosis (FSGS). Four years after the transplantation, we confirmed nephrotic syndrome caused by recurrent FSGS. We performed plasmapheresis and low-density lipoprotein adsorption. We also combined steroid therapy with a reduction in the dose of tacrolimus and an increased dose of mycophenolate mofetil. The nephrotic syndrome improved dramatically with this combined therapeutic approach. However, 10 months after these treatments, he revisited our hospital because of altered consciousness. We detected multiple tumor masses in his brain that were ring enhanced on contrast magnetic resonance imaging. Consequently, we suspected primary central nervous system post-transplantation lymphoproliferative disorder (CNS-PTLD). We performed a craniotomy to biopsy the brain tumors. The biopsy specimen showed Epstein-Barr virus-associated diffuse large B-cell lymphoma. There is no definitive treatment for CNS-PTLD. Therefore, we treated the primary CNS-PTLD successfully with whole-brain radiation and discontinuation of immunosuppression therapy.

Interictal hyperperfusion observed in infants with cortical dysgenesis.

We investigated increases of interictal regional cerebral blood flow (rCBF) in patients with intractable epilepsy caused by cortical dysgenesis. Using single photon emission computed tomography, we measured interictal rCBF of epileptic foci in 24 patients with cortical dysgenesis who achieved Engel Class I or II outcomes at least 1 year after surgical intervention. The patients included 14 males and ten females, ranging in age from 2 months to 34 years (mean 6 years and 5 months). In the interictal period, dysplastic areas showed hyperperfusion in four patients (17%), hypoperfusion in 15 (62%), and isoperfusion patterns in five (21%). Interictal hyperperfusion was found in four infants aged 3-4 months; three with focal cortical dysplasia and one with hemimegalencephaly. Our results suggest that interictal hyperperfusion may indicate the presence of an active epileptic focus in infants with cortical dysgenesis, but not in older children or adults with the same disorder. Given the risk of misinterpreting the normal side as hypoperfused, the phenomenon of interictal hyperperfusion in the epileptogenic area should be taken into account when diagnosing pediatric epilepsy caused by cortical dysgenesis.

[Chondroblastoma of the temporal bone: a case report].

A 30-year-old male had been suffering from left temporalgia of six months duration and then developed left hearing disturbance. Craniogram and bone window CT revealed a well defined osteolytic lesion in the left temporal bone. CT scan showed an expansile heterogenous mass with calcification. Both T1 and T2 weighted MRI demonstrated a well lobulated mixed intensity mass, but no evidence of dural or intracranial invasion. The tumor exhibited homogenous enhancement on CT and MRI. Angiogram revealed a well marked staining supplied by the left middle meningeal and deep temporal arteries. Subtotal removal of the tumor was carried out with cranioplasty. Histologically, this tumor was composed of round or polygonal chondroblasts, scattered osteoclast-like giant cells with a foci of cartilage in the stroma. Many reports describe giant cell tumor can be differentiated by immunohistochemical demonstration of S100 protein. Although in our case, histological findings simulated those of eosinophilic granuloma, it was diagnosed as chondroblastoma because of the foci of cartilage in the stroma. Because this tumor is usually benign, recurrence of the tumor is rare after surgical resection. Post-operative irradiation has been reported to be effective in decreasing the recurrence of the tumor. But it should be carefully observed because of possible sarcomatous change in such tumors.

Altered reactivity of human cerebral arteries after subarachnoid hemorrhage.

To investigate the effects of subarachnoid hemorrhage (SAH) on the responsiveness of human cerebral arteries to vasoactive substances, the authors measured the isometric tension generated in helical strips of basilar and middle cerebral arteries isolated from human cadavers. Contractions caused by KCl, prostaglandin F2 alpha, noradrenaline, and serotonin were reduced in arteries obtained from cadavers with aneurysmal SAH damage and compared to those obtained from cadavers with no indication of intracranial diseases. Endothelium-dependent relaxation elicited by substance P and bradykinin, and endothelium-independent relaxation induced by prostaglandin I2 and nitroglycerin were also markedly decreased in arteries affected by SAH. However, the reduction in relaxation response to prostaglandin I2 was significantly less than that to the other vasodilator agents. These results indicate that human cerebral artery functions are severely impaired after SAH and that poor responses to vasoactive agents may result primarily from dysfunction of smooth-muscle cells.

Cytokine production in cerebrospinal fluid after subarachnoid haemorrhage.

Pathophysiological mechanisms for vasospasm after subarachnoid haemorrhage (SAH) remain unclear and, so far, roles of cytokines in vasospasm have not been known. In the present study, we measured interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumour necrosis factor-alpha (TNF-alpha) concentrations in the cerebrospinal fluid (CSF) of patients with subarachnoid haemorrhage (SAH). ELISA assay were performed on 21 CSF samples from 7 patients with SAH and on 4 sera samples. Both IL-6 and IL-8 were detected in all CSF samples, but IL-1 alpha, IL-1 beta, and TNF-alpha were not detected. IL-6 and IL-8 were also detected in sera, but at much lower concentrations. This study indicates that IL-6 and IL-8 may play roles as immunomodulators in patients with SAH. In addition, it has been reported that IL-6 inhibits prostaglandin I2 production and increases the mRNA level of c-sis gene, suggesting that IL-6 may play an important role in vasospasm as vasoconstrictor.

Suppression of cerebral vasodilation with endothelin-1.

We investigated the effect of endothelin-1 on relaxation responses induced by vasodilator substances in canine middle cerebral arteries to better understand regulation of cerebrovascular tone and its potential impact on mechanism of cerebral vasospasm. Endothelin-1 elicited concentration-dependent contractions in helical strips of canine cerebral arteries (EC50; 4.62 x 10(-9) M). Pretreatment with 10(-9) M endothelin-1 significantly reduced endothelium-dependent relaxation elicited by substance P and endothelium-independent relaxations by nitroglycerin, prostaglandin I2, and KCl. Although endothelin-1 in a lower concentration (10(-10) M) did not affect these endothelium-independent relaxations, it did inhibit endothelium-dependent relaxation caused by substance P. A low concentration (10(-10) M) of endothelin-1 also significantly reduced endothelium-dependent relaxation of canine mesenteric arteries induced by acetylcholine. Other vasoconstrictor peptides such as angiotensin-II and vasopressin did not inhibit endothelium-dependent and -independent relaxations. These results indicate that endothelin-1 not only produces cerebral vasoconstriction but also interferes with vasodilator mechanisms and that endothelium-dependent vasodilation is more sensitive to the inhibitory effect of endothelin-1 than endothelium-independent vasodiltion.

Human basilar and middle cerebral arteries exhibit endothelium-dependent responses to peptides.

We examined the activities of bradykinin, substance P, and vasopressin in isolated human cerebral arteries to better understand humoral control of cerebrovascular tone. Basilar and middle cerebral arteries were isolated from human cadavers during autopsy, and isometric tension was measured in helical strips of the arteries. Both bradykinin and substance P relaxed strips of both arteries precontracted with prostaglandin F2 alpha to similar extents. The relaxations induced by both peptides were abolished by removal of the vascular endothelium and were markedly reduced by pretreatment with NG-nitro-L-arginine, an inhibitor of endothelium-derived relaxing factor. Treatment with indomethacin, a cyclooxygenase inhibitor, did not attenuate the relaxations. These results indicate that the responses of human cerebral arteries to bradykinin and substance P are mediated by endothelium-derived relaxing factor. In contrast, vasopressin primarily produced endothelium-independent contractions in human cerebral arteries. Contractions of basilar arteries induced by vasopressin were much less than those of middle cerebral arteries. Two of eighteen basilar arteries, but none of the middle cerebral arteries, responded to vasopressin with endothelium-dependent relaxation. This suggests that the function of vasopressin receptors differs in basilar and middle cerebral arteries.

Investigation of postmortem functional changes in human cerebral arteries.

This study demonstrated the time-dependent changes in postmortem responses of isolated human middle cerebral artery strips to vasodilators. The relaxation induced by prostaglandin (PG) I2 or nitroglycerin remained stable for 24 h postmortem. In arterial strips precontracted with PGF2 alpha, substance P and bradykinin both elicited relaxation that was almost completely abolished by removal of the endothelium. The endothelium-dependent response to both peptides was significantly degraded in strips obtained > 12 h postmortem. These results indicate a selective functional or anatomical vulnerability of the vascular endothelium compared with that of the vasodilator mechanisms of the smooth muscle in the postmortem period. However, cerebral arteries isolated from human cadavers within 12 h postmortem should be adequate for studies of both smooth muscle and endothelial reactivity to vasodilators.

The potentiating effect of KC-404 on prostacyclin-induced vasodilation in isolated human cerebral artery.

1. KC-404 (10(-9)-10(-6) g/ml) produced concentration-dependent relaxations in human middle cerebral arteries contracted with prostaglandin F2 alpha. 2. KC-404 (10(-8) and 10(-7) g/ml) has the ability to significantly potentiate prostaglandin I2-induced relaxations in human middle cerebral arteries. 3. KC-404, at least in low concentrations, may elicit human cerebral vasodilation predominantly by potentiating relaxant responses to prostaglandin I2 produced spontaneously in vascular wall. 4. KC-404 is expected to increase cerebral blood flow at least by dilation of major cerebral arteries, and this agent may be beneficial for the treatment of cerebrovascular disorders.

[A case of visual allesthesia].

A case of visual allesthesia is reported. A thirty-year-old right-handed man with a right temporo-occipital arteriovenous malformation underwent the surgery for extirpation of the lesion. Postoperatively he had left homonymous hemianopsia. Approximately 6 months after the surgery, he experienced the initial spell of generalized convulsion, followed by the episodes of visual allesthesia. He experienced illusory left hemonymous transpositions of objects viewed in the right homonymous field. The transposition occurred from normal to the defective visual field. The illusory image was palinoptic, persisting for up to several minutes after the real object was no longer in view. It was equal in shape with the original, and caused monocular diplopia. MRI showed a large area of postoperative changes. The lesion was located from the posterior half of the middle and inferior gyri of the right temporal lobe to the occipital and a part of the parietal cortex. And it extended into the right fusiform and lingual gyri. The right lateral geniculate body and the posterior part of thalamus were also involved. We speculated that this phenomenon may result from irritation of the affected brain and its surrounding areas, since the episode took place following the seizure.