Until the introduction of microsurgery, the surgical treatment of pineal region tumors had very poor results with high mortality and morbidity. However, there have been remarkable improvements with modern surgical technology and advanced knowledge. Now the main surgical approaches to pineal region tumors are the occipital transtentorial approach and the infratentorial supracerebellar approach. Recently the neuroendoscopic approach has been added. The surgical approach and any supplementary treatment should be selected in each case according to the nature of the individual tumor. The forms of treatment practiced by ourselves, including neuroendoscopic surgery, are presented, and the surgical treatments now applied are discussed.

Adolescent↗

PubMedDate not supplied

Origin and distribution of thalamic somatosensory evoked potentials in humans.

The distribution and generator sources of somatosensory evoked potentials (SEPs) in the thalamus and subthalamic area were studied, using a 'semi-microelectrode' during stereotaxic surgery on 34 patients with involuntary movements or intractable pain. Electrical stimulation was given to the median nerve at the wrist. Two distinct SEPs were evoked by contralateral stimulation. A high voltage (160 microV) positive SEP with a peak latency of 15.5 msec was strictly confined to the ventral part of the sensory relay nucleus (nucleus ventro-caudalis, V.c). A much lower voltage, positive-negative-positive triphasic SEP showed peak latencies of the initial positivity and the major negativity of 13.3 msec and 16.0 msec, respectively, and had maximal voltage (16 microV) in the ventralmost parts of the nucleus ventro-intermedius (V.im) and radiatio praelemniscalis (Ra.prl), and substantial potentials in the lemniscus medialis (L.m) and nucleus ventro-oralis posterior (V.o.p). The potential field of the triphasic SEP spread farther across the different thalamic nuclei and subthalamic region with identical configurations and peak latencies, but with decreasing amplitude. These findings suggest that the high voltage positive SEP reflects a postsynaptic potential generated by the V.c neurons, and the smaller triphasic SEP a presynaptic axonal potential generated in the rostral part of the lemniscal pathway, extending by means of volume conduction.

Adolescent↗

PubMedDate not supplied

Direct recording of somatosensory evoked potentials in the vicinity of the dorsal column nuclei in man: their generator mechanisms and contribution to the scalp far-field potentials.

Somatosensory evoked potentials (SEPs) in the vicinity of the dorsal column nuclei in response to electrical stimulation of the median nerve (MN) and posterior tibial nerve (PTN) were studied by analyzing the wave forms, topographical distribution, effects of higher rates of stimulation and correlation with components of the scalp-recorded SEPs. Recordings were done on 4 patients with spasmodic torticollis during neurosurgical operations for microvascular decompression of the eleventh nerve. The dorsal column SEPs to MN stimulation (MN-SEPs) were characterized by a major negative wave (N1; 13 msec in mean latency), preceded by a small positivity (P1) and followed by a large positive wave (P2). Similar wave forms (P1'-N1'-P2') were obtained with stimulation of PTN (PTN-SEPs), with a mean latency of N1' being 28 msec. Maximal potentials of MN-SEPs and PTN-SEPs were located in the vicinity of the ipsilateral cuneate and gracile nuclei, respectively, at a level slightly caudal to the nuclei. The latencies of P1 and N1 increased progressively at more rostral cervical cord segments and medulla, but that of P2 did not. A higher rate of stimulation (16 Hz) caused no effects on P1 and N1, while it markedly attenuated the P2 component. These findings suggest that P1 and N1 of MN-SEPs, as well as P1' and N1' of PTN-SEPs, are generated by the dorsal column fibers, and P2 and P2' are possibly of postsynaptic origin in the respective dorsal column nuclei.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMedDate not supplied

Origin and distribution of brain-stem somatosensory evoked potentials in humans.

The distribution of somatosensory evoked potentials (SEPs) recorded from the brain-stem surface was studied to investigate their generator sources in 14 patients during surgical exploration of the posterior fossa. Two distinct SEPs of different morphologies and electrical orientation were obtained by median nerve stimulation. A small positive-large negative-late prolonged positive wave was recorded from the cuneate nucleus and its vicinity. There was a phase-reversal between the cuneate nucleus and the ventral surface of the medulla, depicting a dipole for dorso-ventral organization. From the pons and midbrain, triphasic waves with predominant negativity were obtained. This type of SEP had identical wave forms between the dorsal, lateral and ventral surface of the pons and midbrain. It showed an increase in negative peak latency as the recording sites moved rostrally, suggesting an ascending axial orientation. In a patient with pontine hemorrhage, the killed end potential, a large monophasic positive potential was obtained from the lesion. This potential occurs when an impulse approaches but never passes beyond the recording electrode. Therefore, the triphasic SEP from the pons and midbrain reflects an axonal potential generated in the medial lemniscal pathway.

Adolescent↗

PubMedDate not supplied

Discrepancy between SEPs directly recorded from the dorsal column nuclei following upper and lower limb stimulation in patients with syringomyelia.

Somatosensory evoked potentials (SEPs) in response to electrical stimulation of the median nerve (MN) and posterior tibial nerve (PTN) were studied in 2 patients with syringomyelia. Intraoperative recordings were made from the surface of the dorsal column nuclei as well as from the scalp. Following MN stimulation, there was a preservation of scalp-recorded P9, P11, P13, and N20, however, there was an absence of spinal N13-P13. The dorsal column SEPs to MN stimulation were normal, characterized by a major negativity (N1), preceded by a small positivity (P1) and followed by a large positivity (P2). On the other hand, there was little or no cortical response (P37) to PTN stimulation. The dorsal column SEPs to PTN stimulation showed a disappearance of the normal P1'-N1'-P2' configuration, being replaced by a series of small spiky waves. The syringomyelic cavity may have thus compressed the gracile dorsal column which courses more medially than the cuneate pathway, causing desynchronization of the dorsal column SEPs. These findings suggest that dorsal column pathway arising from the lower limb is more vulnerable than that from the upper limb when a cervical syrinx is present.

Adult↗

PubMedDate not supplied

MRI of intradural-extramedullary spinal neurinomas and meningiomas.

The magnetic resonance images of 16 patients with intradural-extramedullary spinal tumors, consisting of 11 neurinomas and five meningiomas were reviewed. The neurinomas appeared hypointense compared to the spinal cord on unenhanced T1-weighted images (T1WI) in nine of 11 patients, and hyperintense on T2-weighted images (T2WI) in nine of 11 patients. Neural foraminal extension was present in two cases. All 10 neurinomas were markedly enhanced; six of them exhibited ring-like enhancement on Gadolinium-DTPA (Gd-DTPA)-enhanced T1WI. The meningiomas appeared isointense on unenhanced T1WI in four of five patients and on T2WI in three of four patients. Three meningiomas showed moderate homogeneous contrast enhancement after the intravenous administration of Gd-DTPA. It is concluded that careful scrutiny of magnetic resonance images facilitates the differential diagnosis of spinal neurinomas and meningiomas.

Adult↗

PubMedDate not supplied

Cerebral venous angiomas associated with hemorrhagic lesions. Their MRI manifestations.

Using two 1.5-T magnetic resonance (MR) scanners, 82 venous angiomas (VAs) were imaged. There were 13 (16%) VAs associated with hemorrhagic lesions. Ten of the 13 hemorrhagic lesions were considered hematomas in the subacute or chronic stage, caused by VAs or coexisting cavernous hemangiomas. Two of the 13 were subacute intracerebral hematomas; the remaining one was a sequela of a hemorrhagic venous infarct. After analysis of our data, it was concluded that infratentorial VAs and deeply draining supratentorial VAs in relatively young adults, especially females, are relatively frequently associated with intracerebral hemorrhagic lesions. MR imaging proved useful for diagnosing VAs and associated hemorrhagic lesions.

Adolescent↗

PubMedDate not supplied

Spontaneous regression of a pituitary cyst: report of two cases.

Two unusual cases of pituitary cysts are described. Both patients presented with sudden onset of severe headache, and magnetic resonance imaging (MRI) demonstrated pituitary cysts, which regressed over months. Although the precise etiology of the cysts was unproven, the cystic lesions in our patients are thought to have shrunken after "pituitary apoplexy."

Adolescent↗

PubMedDate not supplied

Determination of bromvalerylurea and its metabolites in biological samples by frit-fast atom bombardment liquid chromatography-mass spectrometry.

A simple, rapid, and sensitive method which allows us to simultaneously determine bromvalerylurea (BVU) and its three metabolites (3-methylbutyrylurea [MVU], alpha-(cystein-S-yl)isovalerylurea [CVU], and alpha-(N-acetylcystein-S-yl)isovalerylurea [AcCVU]) was investigated by frit-fast atom bombardment liquid chromatography-mass spectrometry (frit-FAB LC-MS). The LC-MS analysis was performed after the solid-phase extraction from tissue and urine samples with a Sep-Pak C18 cartridge. Tissue homogenates and urine were adjusted to pH 4.0 and applied to the cartridges. The retained BVU and its metabolites were eluted from the cartridge with 2 mL of acetonitrile/10 mM ammonium acetate buffer (pH 3.5, 50:50, v/v). The eluate was analyzed by LC-MS, which employs a semimicro type L-column ODS column. The proposed conditions are as follows: mobile phase A, 0.4% glycerol in acetonitrile/10 mM ammonium acetate buffer (pH 3.5) (5:95, v/v); mobile phase B, 0.4% glycerol in acetonitrile; elution mode, linear gradient, 100% A (5 min) to 100% B in 15 min; flow rate, 0.2 mL/min; split ratio, 1:40. Extraction recoveries of BVU and its metabolites were 91.90-97.79% from the spiked liver homogenate and 89.68-96.13% from the spiked urine. The detection limits ranged from 10 to 25 ng/g in selected ion monitoring mode.

Animals↗

PubMedDate not supplied

Surgical treatment of intractable seizures due to hypothalamic hamartoma.

A 6.5-year-old boy developed seizures at age 2.8 years consisting of episodes of unconsciousness and laughing attacks. By age 6 years, multiple seizure types, including generalized tonic-clonic (GTC), complex partial (CPS) and akinetic seizures, and drop attacks were occurring several times daily. EEG showed multifocal epileptic discharges. Antiepileptic drugs (AEDs) did not control the seizures. With progression of the epilepsy, cognitive deterioration developed. There were no manifestations of precocious puberty. Neuroimaging disclosed a suprasellar mass in continuity with the hypothalamus, and a diagnosis of hypothalamic hamartoma was made. After surgical resection of the hamartoma, the seizures were completely alleviated, and the epileptic EEG discharges disappeared. Improvement of mental function was also noted.

Anticonvulsants↗

PubMedDate not supplied

Renal expression of mRNAs for endothelin-1, endothelin-3 and endothelin receptors in NZB/W F1 mice.

Endothelin (ET)-1, ET-3, and ET receptors are widely distributed in the vascular system and the kidney. The present study was designed to measure the renal concentrations of ET-1, ET-3, and ET receptor mRNAs in NZB/W F1 mice at 8, 24, and 48 weeks of age. The renal concentration of ET-1 mRNA increased significantly in NZB/W F1 mice as their nephritis progressed, reaching, by 48 weeks, a 10-fold higher concentration than in control NZW mice. Renal ET-3 mRNA concentrations, however, remained unchanged. The renal concentrations of ET receptor A and B mRNAs in NZB/W F1 mice increased gradually with the progression of nephritis, reaching 5- and 3-fold higher concentrations, respectively, at 48 weeks of age than found in control mice. Transforming growth factor-beta (TGF-beta) and tumor necrosis factor-alpha (TNF-alpha) have been shown to stimulate ET-1 mRNA expression in cultured mesangial cells. We therefore also examined the concentrations of TGF-beta and TNF-alpha mRNAs in the renal tissues of NZB/W F1 mice, and found that, at 48 weeks of age, they were 10- and 8-fold higher, respectively, than in control NZW mice. At 24 weeks, NZB/W F1 mice were divided into two groups receiving either methylprednisolone (MPSL) or saline injections for the following 24 weeks. The development of the histologic lesions characteristic of lupus nephritis and the increased renal concentrations of ET-1, ET receptors, TGF-beta and TNF-alpha mRNAs were suppressed by MPSL treatment. These data suggest that ET and ET receptor gene transcription is upregulated in the renal tissues of NZB/W F1 mice and that the beneficial treatment of lupus nephritis with MPSL is accompanied by a reduction in the elevated concentrations of ET-1, ET receptors, TGF-beta and TNF-alpha mRNAs.

Aging↗

PubMedDate not supplied

Abnormal gene expression of matrix metalloproteinases and their inhibitor in glomeruli from diabetic rats.

The steady state levels of mRNA encoding for metalloproteinase (MMP)-1, -2, -3, and -9 and tissue inhibitor of metalloproteinase (TIMP)-1 were examined in glomeruli at 4, 12, and 24 weeks after the injection of streptozocin (STZ) in rats. The mRNA levels for MMP-1 and MMP-3 decreased with age in STZ-induced diabetes. At 24 weeks after STZ injection, mRNA levels for MMP-1 and MMP-3 fell to 40% (p < 0.01) and 20% (p < 0.01), respectively, in the glomeruli of diabetic rats when compared with control rats. In contrast, mRNA levels for TIMP-1 increased significantly with age in the diabetic glomeruli and reached an 8-fold (p < 0.01) increased at 24 weeks after STZ injection. mRNA levels for MMP-2 were not altered in glomeruli from diabetic and control rats throughout the experimental period, whereas those for MMP-9 were not detected in glomeruli from either group of rats. Insulin treatment partially ameliorated the decrease in mRNA levels for MMP-1 and MMP-3 and the increase in those for TIMP-1 in the glomeruli of diabetic rats. These data indicate that abnormal gene regulation of MMPs and TIMP-1 in the glomeruli of diabetic rats may contribute to the progression of glomerular lesions and that hyperglycemia or insulin deficiency may be associated with abnormal MMPs and TIMP-1 gene regulation.

Animals↗

PubMedDate not supplied

Effects of enalapril treatment on gene expression of smooth muscle myosin heavy chain isoforms in glomeruli of diabetic rats.

We have previously shown that smooth muscle contains three types of myosin heavy chains: SM1, SM2, and SMemb. The present study was designed to assess how glomerular expression of mRNA for these isoforms is regulated and whether their expression is affected by enalapril treatment in diabetic rats. Animals were divided into 4 groups: (1) untreated diabetic rats; (2) enalapril-treated diabetic rats; (3) untreated control rats, and (4) enalapril-treated control rats. Enalapril treatment was continued for 24 weeks. The glomerular mRNA levels for SM1 and SM2 showed little change in all groups throughout the experimental period. In contrast, SMemb mRNA in group 1 increased significantly with age compared to levels found in untreated controls (4.6-fold higher at 4 weeks, p < 0.01; 6.8-fold higher at 12 weeks, p < 0.01, and 10.6-fold higher at 24 weeks, p < 0.001). Enalapril reduced both creatinine clearance (p < 0.01) and urinary protein excretion (p < 0.01) in diabetic rats. Moreover, enalapril significantly attenuated the increase in the glomerular SMemb mRNA level in diabetic rats (the difference between treated and untreated rats was significant at p < 0.01 from week 4 to 24). However, enalapril had no effect on SMemb mRNA levels in controls. These data suggest that SMemb is a molecular marker for phenotypic alteration and that the beneficial effect of enalapril on proteinuria and renal function may be, at least in part, associated with reducing SMemb mRNA expression in diabetic glomeruli.

Angiotensin-Converting Enzyme Inhibitors↗

PubMedDate not supplied

The development of personal computer-based medical consultation system for diagnosis of congenital malformation syndromes using MUMPS.

This paper describes a medical consultation system for diagnosis of congenital malformation syndromes. The system consists of a personal computer, NEC PC-98XL (MS-DOS), using SP-MUMPS for the retrieval of knowledge data, and BASIC for the input/output of image data. This system displays pictorial knowledge and is designed so users can build up the knowledge base, as needed, by adding knowledge from medical literature and records of patients actually treated.

Congenital Abnormalities↗