Takayuki Kuroyanagi

Parasympathetic Cerebrovascular Innervation

To elucidate parasympathetic cerebrovascular innervation of the rat sphenopalatine ganglion (SPG), we injected wheat germ agglutinin-conjugated horseradish peroxidase into the SPG of one side and traced anterogradely labeled nerve fibers. Three days after the injection, the animals were killed and tissues including the SPG, major cerebral arteries, and ethmoidal arteries were reacted by the tetramethylbenzidine method. A number of cells and nerve fibers labeled with wheat germ agglutinin-conjugated horseradish peroxidase were observed in the SPG. The nasal mucous membrane, the periorbital soft tissue, and the lacrimal gland of the injected side contained numerous labeled nerve fibers. In cerebral vessels, anterogradely labeled nerve fibers were observed around the internal ethmoidal, anterior cerebral, middle cerebral, internal carotid, and posterior cerebral arteries of both sides. A few labeled nerve fibers were seen on the wall of the basilar arteries of the distal portion, and the vertebral arteries contained no labeled nerve fiber. In animals of which the ethmoidal nerve and the external ethmoidal artery were cut together with the surrounding periorbital soft tissues just before entering the ethmoidal foramen, no labeled nerve fiber was identified on the wall of the major cerebral arteries. Although labeled gangliocytes were found in the trigeminal and superior cervical ganglia after the tracer injection to the ipsilateral SPG, the chronic maxillary neurotomy and superior cervical ganglionectomy did not alter the distribution of the labeled nerve fibers on the wall of the cerebral arteries.(ABSTRACT TRUNCATED AT 250 WORDS)

Parkinsonism and midbrain dysfunction after shunt placement for obstructive hydrocephalus.

We report a patient in whom placement of a ventriculoperitoneal shunt for obstructive hydrocephalus secondary to non-neoplastic aqueductal stenosis was complicated by progressive parkinsonism and midbrain dysfunction. These sequelae were refractory to treatment, including shunt revision and levodopa therapy. These findings contradict the opinion from the literature that this type of parkinsonism is a reversible condition and levodopa therapy is effective for managing the symptoms. We discuss the pathophysiological mechanism of this complication.

Odontoid compression of the brainstem without basilar impression – “ odontoid invagination”

We report five patients with odontoid invagination, in which the odontoid process bulges upward into the foramen magnum and compresses the brainstem without deformity of the occipital bone. Two patients had a craniovertebral abnormality associated with Chiari malformation without instability of the craniovertebral junction (stable odontoid invagination). The other three patients had dislocation of the craniovertebral junction due to iatrogenic destruction of the occipital condyle, rheumatoid arthritis or an anomaly of C2 (unstable odontoid invagination). Patients with stable odontoid invagination underwent a transoral odontoidectomy followed by occipitocervical fixation. Those with unstable odontoid invagination underwent cervical traction followed by posterior fixation in reducible cases, while in irreducible cases odontoidectomy with subsequent occipitocervical fixation was performed. Decompression of the neuraxis together with symptomatic improvement was achieved in all patients and none became unstable or developed new symptoms during follow-up ranging from 3 to 15 years.

Subarachnoid hemorrhage, midbrain hemorrhage and thalamic infarction following transsphenoidal removal of a pituitary adenoma. A case report

We report a rare case of complication following transsphenoidal resection of a nonfunctioning pituitary adenoma in which subarachnoid hemorrhage, midbrain hemorrhage and thalamic infarction occurred. Possible pathologic mechanisms are discussed and the need for clinical awareness of this rare complication is stressed.

Angiographic differentiation of carotid cave aneurysms from ventral paraclinoid carotid aneurysms of Nutik type.

Although it appears that carotid cave and ventral paraclinoid carotid aneurysms are different types of internal carotid artery (ICA) aneurysms, it can be difficult to differentiate the two on the basis of angiograms, because their locations are very close. The purpose of this study was to review the angiographic findings in 21 cases with carotid cave aneurysms and 7 cases with ventral paraclinoid carotid aneurysms of less than 15 mm in diameter (Nutik aneurysm) operated upon in our unit during the last 14 years, and to discuss the difference between the two groups. The results showed that in the anteroposterior view of the angiogram, all carotid cave aneurysms projected medially in semicircular, or berry shape, while only slight medial projection was noted in 3 cases with Nutik aneurysm, the remainder being super-imposed on the ICA. In the lateral view of the angiogram, we found that in 6 of the 7 Nutik aneurysms there was a space between the axilla (area inside the genu of the ICA) and the anterior or anteroinferior wall of the aneurysm. This space was absent in all carotid cave aneurysms since these aneurysms projected inferoposteriorly from the genu of the ICA. It is concluded that predominant medial projection in the anteroposterior view and absence of space in the lateral view are two characteristic features of carotid cave aneurysms which can be used to differentiate them from most Nutik aneurysms.

Catecholamine histofluorescence depletion in the infarcted brain parenchyma but not in the adventitia of the occluded cerebral arteries in rats

The effect of acute cerebral ischemia on the catecholamine-containing nerve fibers in the brain parenchyma and in the adventitia of the cerebral arteries was studied in the rat. Unilateral cerebral ischemia was produced with an intraluminal thread technique which does not damage the adventitia of cerebral arteries. One to three days after surgery the ischemic damage of the brain was consistently observed in the territory of the middle cerebral artery of the operated side. Depletion of catecholamine histofluorescence was observed in the infarcted brain parenchyma. However, in the adventitia of the middle cerebral arteries of the operated side, catecholamine histofluorescence remained intact. No detectable changes in fluorescence were observed in the brain parenchyma or adventitia of the cerebral arteries in the contralateral side. The results indicate that the perivascular catecholamine-containing nerve fibers are not impaired by the intraluminal occlusion of the cerebral artery in the early stage of ischemia.