Nonlocal neurology: beyond localization to holonomy.

The concept of local pathology has long served neurology admirably. Relevant models include self-organizing nonlinear brain dynamics, global workspace and dynamic core theories. However such models are inconsistent with certain clinical phenomena found in Charles Bonnet syndrome, disjunctive agnosia and schizophrenia, where there is disunity of content within the unity of consciousness. This is contrasted with the split-brain case where there is disunity of content and disunity of consciousnesses. The development of quantum brain theory with it nonlocal mechanisms under the law of the whole ("holonomy") offers new possibilities for explaining disintegration within unity. Dissipative quantum brain dynamics and its approach to the binding problem, memory and consciousness are presented. A nonlocal neurology armed with a holonomic understanding might see more deeply into what clinical neurology has always aspired to: the patient as a whole.

The syndrome of spontaneous intracranial hypotension.

The authors report four cases of headache and other symptomatology related to the syndrome of intracranial hypotension. They were seen in a routine clinical practice over the past 3 years. The clinical features, magnetic resonance imaging (MRI) findings, and follow-up of these patients are described. Review of the prior literature on the topic is also included. All four patients presented with orthostatic headache syndrome. Three of the four demonstrated diffuse leptomeningeal thickening and enhancement on MRI studies. One subsequently developed a subdural effusion. One patient demonstrated downward displacement of the posterior fossa initially, which resolved on follow-up MRI scanning. Possible pathophysiologies of the syndrome are discussed.

Aspergillosis of the nervous system.

Cerebral aspergillosis currently occurs most frequently with disseminated aspergillosis in immunocompromised hosts. Twelve patients with cerebral aspergillosis in this setting were seen over 10 years. Underlying illnesses were renal transplantation in six cases and one case each of subacute hepatic necrosis, head trauma, glioblastoma, microglioma, and esthesioneuroblastoma. All patients were receiving high dose steroid therapy except one who had ectopic ACTH syndrome. Eleven patients were receiving broad spectrum antibiotics. All patients were febrile and developed progressive pulmonary infiltrates preceding or coincident with neurologic symptoms. Sudden onset of neurologic deficits or seizures occurred in nine of 11 clinically analyzable cases. Brainstem or cerebellar signs and symptoms were a presenting feature in three cases and were eventually seen in five cases. Cranial computerized tomography in four cases showed low absorption areas with minimal enhancement and little mass effect. Neurologic deterioration was rapid with nine of 11 patients dying within 6 days of onset. Neuropathologic examination showed multiple abscess formation in 11 cases and prominent blood vessel invasion in all cases. The sudden onset of stroke-like deficits and brainstem findings in a febrile immunocompromised host with pulmonary infiltrates suggests the diagnosis of cerebral aspergillosis. Two cases of aspergillus meningitis were also seen, one postoperatively.

Malignant meningiomas: CT and histologic criteria, including a new CT sign.

Histologic features that could be correlated with malignancy were assessed by reviewing the microscopic slides of 167 meningiomas. Six tumors had shown two or more recurrences. In three having three or more recurrences, the number of mitoses counted under high power was higher than in those meningiomas showing clinically benign behavior. The radiologic and histologic features of seven meningiomas showing malignant clinical behavior and/or malignant histologic features were also evaluated and correlated. On computed tomography (CT), most of the malignant meningiomas were moderately hyperdense before contrast enhancement, but showed no or minimal calcification. Marked perifocal edema was common. Indistinct tumor margins or, occasionally, deeply extending fringes of tumor interdigitating with brain substance, marked bone destruction, or prominent pannus or tumor, extending well away from the globoid mass, termed "mushrooming," is described for the first time and seems to be the most useful correlate of histologic or clinical malignancy. This sign occurred in five of the seven cases and was absent in about 250 benign meningiomas reviewed. It was visible only at surgery in one additional case.

Computed tomography of intracranial aspergillosis.

Cranial computed tomography (CT) scans were analyzed in five patients with autopsy documented intracranial aspergillosis. All infections occurred in immunocompromised hosts. Our findings included subtle low attenuation abnormalities, minimal mass effect, and poor contrast enhancement without ring configuration, in the clinical setting of lethargy, fever, and pulmonary infection. The benign CT picture did not clearly depict the aggressive intracranial parenchymal destruction.