Hidetoshi Takei

Cognitive deterioration associated with focal cortical dysplasia

Surgery for an area of focal cortical dysplasia in a critical region is reported in a right-handed female manifesting intractable focal epilepsy and verbal cognitive deterioration. She developed the first seizure at 2 years of age and was treated with phenytoin and zonisamide, with good control until 10 years of age. Although seizures did not occur at 9 years of age, she manifested dyscalculia, right-left disorientation, and finger agnosia, and N-isopropyl-p-iodoamphetamine single-photon emission computed tomography (SPECT) revealed focal hypoperfusion in the left parietal lobe. At 11 years of age, she developed regular nocturnal seizures and gradually lost the ability to understand the meaning of sentences. Verbal IQ declined from 94 to 63, and the area of hypoperfusion detected by interictal N-isopropyl-p-iodoamphetamine SPECT spread over the left parietotemporal lobes. Magnetic resonance imaging revealed focal cortical dysplasia mainly in the left parietal lobe, and ictal technetium-99m-ethyl cysteinate dimer SPECT images demonstrated an area of hyperperfusion around the focal cortical dysplasia, including the left precentral gyrus. Because of the overlap between the epileptogenic and functional cortex, the authors concluded that cortical resection, including focal cortical dysplasia, was inappropriate in this patient.

Pediatric Brain Stem Infarction Caused by a Basilar and Vertebral Artery Occlusion

Basilar and right vertebral artery occlusion, which caused a brain stem infarction, occurred in an 11-year-old boy. There have been nine previous cases of basilar artery occlusion with steno-occlusive lesion in the vertebral artery. It is suspected that dissection of the vertebral artery at the atlantoaxial level and a gradual progression of arterial dissection to the basilar artery were the major causes of this infarction.

Primary position upbeat nystagmus localizing value.

Primary position upbeat nystagmus has been associated predominantly with lesions of the midbrain, midline cerebellum, and lower brainstem. However, the precise localization still remains unclear. We report one case of primary position upbeat nystagmus in which magnetic resonance imaging showed probable bilateral lesions of the prepositus hypoglossi nuclei. Morphological and physiological studies have shown that this nucleus plays important roles in vertical eye movements. We conclude that the dysfunction of bilateral prepositus hypoglossi nuclei causes the upbeat nystagmus in our patient.

Brain perfusion SPECT in neuro-Behçet’s disease: Discordance between Tc-99m-HMPAO and Tc-99m-ECD

A patient with neuro-Behçet’s disease was studied with both Tc-99m-HMPAO and Tc-99m-ECD brain perfusion SPECT during the same time period. In Tc-99m-HMPAO SPECT, focal high uptake was observed in the left basal ganglia where MRI depicted abnormal signal intensity. Conversely, Tc-99m-ECD SPECT did not show corresponding high uptake, but demonstrated rather low uptake in contrast to the Tc-99m-HMPAO SPECT. This case suggests that Tc-99m-HMPAO and Tc-99m-ECD may show discordant distribution in inflammatory brain disease such as neuro-Behçet’s disease.

MYELOPATHY DUE TO OSSIFICATION OR CALCIFICATION OF THE LIGAMENTUM FLAVUM: RADIOLOGIC AND HISTOLOGIC EVALUATIONS

The clinical, radiologic, and histologic features of ossification and calcification of the ligamentum flavum were studied in 18 patients. Ossification (15 patients) usually occurred in the lower thoracic spine in men of various ages, while calcification (three patients) was found exclusively in the cervical region of older women. Histologic examinations of ossification showed mature lamellar bone associated with proliferated cartilage replacing the ligamentum flavum (endochondral ossification). This corresponded well with radiographic and computed tomographic (CT) appearances. In the cases with calcification of the ligamentum flavum, calcification within the degenerated ligamentous fibers was observed on histologic examination, and correlated well with an oval nodular density on radiographs and CT. The two conditions differ in clinical, radiologic, and histologic considerations. Pathomechanisms in the development of these lesions and clinical significance are also discussed.