Calbindin-D28k in cerebrovascular extrinsic innervation system of the rat.

Calbindin-D28k, one of the calcium-binding proteins, belongs to the EF hand family and is commonly found in neurons. It serves as a representative neuronal marker for neuroanatomical investigations. The authors' knowledge of its precise function, however, is yet very limited. In this study, we examined the existence of nerve fibers with calbindin-D28k immunoreactivity in the cerebral blood vessels and ganglia that innervate the cerebral blood vessels in the rat. Numerous nerve fibers with calbindin-D28k immunoreactivity were observed on the walls of the major extracerebral arteries forming the circle of Willis and its branches. Calbindin-D28k immunoreactivity was seen in many neurons of the trigeminal, dorsal root and jugular ganglia. A small number of neurons showed calbindin-D28k immunoreactivity in the otic and superior cervical ganglia. Calbindin-D28k immunoreactivity was not detected in the sphenopalatine or internal carotid ganglia. Pericellular basket-like formations of nerve terminals with calbindin-D28k immunoreactivity were observed in the sphenopalatine, otic, internal carotid and superior cervical ganglia. The present study demonstrated calbindin-D28k immunoreactivity in the cerebrovascular nerve fibers as well as in their origins--the cranial ganglia. These findings are significant in understanding the calcium-mediated mechanism of the neural control of the cerebral blood vessels.

Portal systemic encephalopathy presenting with dressing and constructional apraxia.

We report a case with portal systemic encephalopathy who presented with dressing and constructional apraxia and subtle weakness of the left hand. We initially suspected a cerebrovascular attack in the right cerebral hemisphere, but brain T1-weighted magnetic resonance (MR) imaging revealed high intensity in the basal ganglia and hyperammonemia was detected. We performed abdominal MR angiography, which visualized an intrahepatic portal systemic shunt. Cerebral blood flow, measured by xenon-enhanced computed tomography, was decreased in the bilateral, but more dominantly right-sided, parietal watershed regions. We speculate that these boundary territories might be susceptible to damage by toxic metabolites of hepatic encephalopathy.

Pathologic findings of silent hyperintense white matter lesions on MRI.

The pathologic features of silent hyperintense white matter lesions in T2-weighted images on MRI were studied in patients with no neurologic signs or symptoms. The small patchy hyperintense white matter lesions represented myelin pallor associated with vessels showing hypertension and arteriosclerotic changes. 'Caps' also showed myelin pallor with dilated perivascular spaces. There were no lacunar infarcts in these lesions. Some of 'caps' was shown to be elongated normal lateral ventricle. 'Rims' of early stage revealed subependymal gliosis that was a part of normal aging processes.

Occurrence and distribution of substance P receptors in the cerebral blood vessels of the rat.

The distribution of immunoreactivity to the receptor for substance P was examined in the cerebral blood vessels of the rat. Substance P immunoreactivity has been demonstrated in the nerve fibers of the cerebral blood vessels. Recently, the production of substance P receptor specific antibody has enabled the detection of localization of the substance P receptor in the central nervous system. In this study, we examined the existence of nerve fibers with substance P receptor immunoreactivity in the cerebral blood vessels and the cranial ganglia innervating the cerebral blood vessels. Sprague-Dawley rats were perfused with fixative and the pial arteries and the cranial ganglia known to innervate the cerebral blood vessels, i.e., trigeminal, sphenopalatine, internal carotid, otic and superior cervical ganglia, were dissected. All specimens were incubated with anti-substance P receptor IgG, then stained by the avidin-biotin-peroxidase complex method. Numerous nerve fibers with varicosities forming plexuses, with substance P receptor immunoreactivity were observed on the walls of the major extracerebral arteries forming the circle of Willis and its branches. Substance P receptor immunoreactivity was also detected in the endothelium of the cerebral arteries. Substance P receptor immunoreactivity was positive in many neurons of the sphenopalatine ganglion, otic ganglion, trigeminal ganglion, superior cervical ganglion and internal carotid ganglion. The present study demonstrated the existence of nerve fibers with substance P receptor immunoreactivity in the cerebral blood vessels and the cranial ganglia that innervate the cerebral blood vessels. These findings are important in understanding the responsiveness of the cerebral blood vessels to substance P.

Pathologic findings of silent, small hyperintense foci in the basal ganglia and thalamus on MRI.

We analyzed the pathologic features of silent, small hyperintense foci in the basal ganglia and thalamus on MRI T2-weighted images (T2WI). Eight foci were histologically lacunar infarcts (LI), and 21 were dilated perivascular spaces (DPS). The foci with smooth margins were mostly DPS, whereas those with irregular margins were mostly LI (p = 0.018). Most putaminal foci were DPS, whereas most thalamic foci were LI (p = 0.001). The mean areas of LI and DPS overlapped below 19.6 mm2. The shape and site of hyperintense foci on T2WI are important for differentiating LI from DPS.

Localized hypertrophic mononeuropathy involving the femoral nerve.

The authors report a case of localized hypertrophic mononeuropathy involving the femoral nerve in a 20-year-old woman referred because of progressive weakness and atrophy of the left thigh. MRI showed an enlarged femoral nerve and biopsies of fascicles displayed a concentric pattern of cells resembling an onion bulb. These cells were positive for epithelial membrane antigen immunostaining and had an incomplete basal lamina.

Characteristic form of standing up from squatting in Miyoshi's distal muscular dystrophy.

A 27-year-old woman with Miyoshi's distal muscular dystrophy devised a unique form of standing up from a squatting position; She held her ankles with her hands to support the weight transfer, fixed the heels, extended the knees to elevate the hips, raised the upper half of the body, and finally stood up. This strategy illustrates the characteristic and specific distribution of the wasted muscle in this disease.

[Giant cell arteritis with bilateral obstruction of the internal carotid artery--report of an autopsy case].

Internal carotid artery involvement and dementia occur infrequently in patients with giant cell (temporal) arteritis. A 75-year-old woman admitted with progressive cognitive decline, drowsiness and headache was diagnosed as having giant cell arteritis by temporal artery biopsy (TAB). High dose corticosteroid improved inflammatory reaction but did not improve his cognitive function. Cerebral angiograms showed obstruction of both internal carotid arteries at the siphon. Brain MRI showed only small cerebral infarcts in the basal ganglia and corona radiata bilaterally. However, brain SPECT disclosed reduced cerebral blood flow in the frontal lobe bilaterally. A postmortem examination revealed bilateral parietal infarcts and isolated giant cell arteritis involving the both internal carotid arteries at the siphon. We speculated that perfusion insufficiency and multiple cerebral infarction due to bilateral internal carotid artery occlusion had caused this neurologic deterioration.

[Progressive multifocal leukoencephalopathy (PML). Report of a case diagnosed by amplification of JC virus DNA from cerebrospinal fluid (CSF)].

We report a 54-year-old Japanese man who was diagnosed as progressive multifocal leukoencephalopathy (PML). He had been maintained on regular hemodialysis for 10 years. He was admitted to our hospital with chief complaints of visual disturbance and disorientation. On neurological examination, he was somnolent, and showed mild weakness in the right upper and lower limbs. Deep tendon reflexes were brisk on the right upper and bilateral lower limbs. Sensory examination revealed no abnormal findings. The cerebrospinal fluid (CSF) showed five mononuclear cells/mm3, protein 39 mg/dl and glucose 38 mg/dl. Brain MRI revealed multiple hyperintense lesions in T2-images, which were confined to the white matter of bilateral occipital and the left frontal lobes without an enhancement after gadolinium administration. Using polymerase chain reaction, we amplified the JCV regulatory region from the CSF of the patient. The amplified product contained a rearranged regulatory region that could have been generated from the archetype by deletion and amplification. PML was diagnosed on the basis of these findings. The patient died 7 months after onset of the symptoms. The diagnosis of PML was confirmed by the postmortem findings. The present case indicates that PCR of JCV from CSF is very useful for definitive diagnosis of PML.

Rapid changes in pial arterial diameter and cerebral blood flow caused by ipsilateral carotid artery occlusion in rats.

We investigated rapid changes in pial arterial diameter and in cerebral blood flow (CBF) caused by transient ipsilateral common carotid artery occlusion (CCA-O) in anesthetized rats in order to elucidate how the cerebral circulation reacts to acute stem artery occlusion. In separate groups of rats, pial arterial diameter was recorded through a closed cranial window and CBF was recorded by laser-Doppler flowmetry. CCA-O was performed for 5 minutes under normotension and normocapnia (control) and under graded hypotension, hypercapnia and hypocapnia. In the control condition, pial arterial diameter increased rapidly, triggered by CCA-O. It took 12 +/- 3 s to reach the maximum of 204 +/- 42% of the value before CCA-O, and 60 +/- 24 s to become stable at 131 +/- 11%. CBF decreased rapidly to 66 +/- 11%, then increased reactively to 135 +/- 9%, and again decreased to 91 +/- 3%. The reactive increase in CBF caused by CCA-O decreased in parallel with the degree of hypotension, and also became barely detectable under hypercapnia. Our data suggest that active vascular dilation in the territory of the occluded artery is important for inducing collateral circulation.

[A patient with spontaneous intracranial hypotension--comparison between MRI findings and meningeal pathology].

We report a 44-year-old woman with spontaneous intracranial hypotension (SIH) who developed an acute, severe, nonthrobbing headache. The headache remained more severe in the occipital region and was markedly worse with upright posture. Cerebrospinal fluid (CSF) examination revealed an opening pressure of 55 mmH2O, and the CSF contained 38 cells/mm3 and 57 mg/dl of protein. The results of other laboratory examinations were unremarkable. T1-weighted MR images (MRI) of the head revealed an extensive diffuse pachymeningeal gadolinium enhancement and bilateral subdural fluid accumulation. On the 21st hospital day, a meningeal biopsy was performed through a right parietal craniotomy. On histologic examination, the dural border cell layer demonstrated nonspecific granulation tissue with mild inflammatory changes. The remaining layers of the dura mater and the arachnoid membrane showed no obvious pathological changes. We speculated that the inflammatory changes of the dural border cell layer correspond to the zone of pachymeningeal gadolinium enhancement of the MRI. The granulation tissue of the dural border cell layer and subdural fluid accumulation may represent secondary reactive phenomena, and were suspected to have been caused by downward displacement of the brain due to decreased intracranial pressure.

[Ruptured fusiform aneurysm of the basilar artery with minimal atherosclerosis--report of a case].

We reported a case of ruptured fusiform aneurysm of the basilar artery with minimal atherosclerosis. A 51-year-old man was admitted because of subarachnoid hemorrhage (SAH). He had no previous illness and family history. Computed tomographic scan revealed subarachnoid hemorrhage and a fusiform aneurysm in the basilar artery. Cerebral angiography confirmed the presence of the basilar fusiform aneurysm. After four days, the consciousness level worsened and a respiratory support was initiated. The patient died on the fifth hospital day. Autopsy was permitted only to the brain. The brain weighed 1,700 g. Massive subarachnoid hemorrhage was noted at the base of the brain and in the sylvian fissures. A large fusiform aneurysm (30 x 20 x 17 mm) was located in the proximal portion of the basilar artery. Atherosclerotic changes were minimal in the aneurysmal wall and the major extracerebral arteries. SAH was most severe around the aneurysm. The pons showed focal necrosis due to compression by the aneurysm. Microscopically, the aneurysmal wall revealed diffuse attenuation of the muscularis. The elastica also showed a focal defect. We suggest that in the present case of fusiform aneurysm, the pathogenesis is not atherosclerosis but a congenital defect of the muscularis and elastic lamina.

Detrimental effects of exogenous glutamate on spinal cord neurons during brief ischemia in vivo.

BACKGROUND: Paraplegia remains a serious complication of thoracoabdominal aortic operations. However, despite growing in vitro evidence, it has been difficult to demonstrate glutamate neurotoxicity in vivo because of the reuptake activity that occurs. We hypothesized that glutamate can be toxic to the spinal cord under metabolic stress. METHODS: Infrarenal aortic isolation was performed in New Zealand white rabbits. Group A animals (n = 7) then received a segmental infusion of glutamate (50 mmol/L) for 5 minutes. Group B animals (n = 7) received saline as a negative control. Group C animals (n = 6) were pretreated with a segmental infusion of 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(f)-quinoxaline (4 mg/kg), a competitive alpha-amino-3-hydroxy-5-methylisoazole-4-propionic acid/kainate antagonist, followed by the segmental infusion of glutamate (30 mmol/L) for 4 minutes. Group D animals (n = 6) received the vehicle agents only, followed by the same glutamate infusion (30 mmol/L) as in group C as a control for group C. Neurologic status was assessed at 12, 24, and 48 hours after operation and scored using the Tarlov system. RESULTS: Group A animals exhibited paraplegia or paraparesis with marked neuronal necrosis. Group B animals recovered fully. Group C animals had better neurologic function than group D animals (p = 0.0039). CONCLUSIONS: Exogenous glutamate can have detrimental effects on spinal cord neurons during a brief period of ischemia. This model may be useful for the purpose of assaying a glutamate receptor antagonist in vivo.

[Clinical features of 5 cases of tuberculous meningitis--with special reference to brain CT and MRI findings].

We evaluated the clinical features of 5 cases of tuberculous meningitis who had been admitted to our department from 1987 to 1994. Three patients were male and two were female. Their age ranged from 17 to 74 years old. All cases were examined by both CT and MRI before and during antituberculous treatment. Before the treatment, CT scan revealed abnormal findings such as nodular lesion suggesting tuberculoma, subarachnoid contrast enhancement or cerebral infarction in 2 cases, while MRI revealed abnormal findings such as inflammatory lesions with Gd-enhancement in 4 out of 5 patients. During the treatment, all abnormal findings except cerebral infarction disappeared. No abnormal findings were detected by CT. MRI and SPECT in one case who showed right hemiparesis and motor aphasia. In summary, CT scan could demonstrate abnormal findings in only a small portion of patients with tuberculous meningitis. One the other hand, MRI revealed various abnormal findings in most patients, and could reveal some lesions which could be responsible for the symptoms of patients. In a few patients, however, MRI could not show any lesion in spite of obvious focal neurological signs. MRI is considered to be useful for detecting the lesions in most patients with tuberculous meningitis, although its findings are not always specific for the disease.

[Diagnosis of silent cerebral infarction].

High intensity lesions are frequently encountered in the basal ganglia, thalamus and cerebral white matter in T2-weighted images of MRI. Most of them are generally assumed to represent cerebral infarction without pathologic verification. Studies were performed on the brain showing such lesions with particular emphasis on the differential diagnosis of lacunar infarcts and dilated perivascular spaces. As a result, it was shown that irregularly shaped, lesions or those in the thalamus more frequently represent lacunar infarcts, while those with smooth rims or in the putamen likely represent dilated perivascular spaces. Neither proton density nor the size of the lesions on the MRI helps to differentiate the two conditions. Small patchy high intensity areas of the white matter in the T2-weighted images showed myelin pallor with mild gliosis. Periventricular "rims" of high intensity revealed only subependymal gliosis.

[Two cases of primary low spinal fluid pressure syndrome with pachymeningeal gadolinium enhancement].

We report two patients with primary low spinal fluid pressure syndrome with pachymeningeal gadolinium enhancement. Case 1 was a 36-year-old man and case 2 was a 29-year-old man. Each case developed postural headache and had no histories of head trauma, craniotomy or lumbar puncture. The spinal fluid pressures were 20 mmH2O in case 1 and 0 mmH2O in case 2 at decubitus position. Cranial MRIs revealed diffuse pachymeningeal enhancement after gadolinium infusion, flattening of the pons, and tight posterior fossa in each case. Their headache spontaneously resolved within a couple of weeks by bed rest and intravenous hydration. Follow-up MRIs which were examined 3 or 4 months later, revealed a remarkable reduction in the degree of pachymeningeal enhancement, flattening of the pons and tight posterior fossa. Primary low spinal fluid pressure syndrome should be included in the differential diagnosis of pachymeningeal enhancement on MRI.