A variant of normal-pressure hydrocephalus simulating Pick's disease on computerized tomography. Report of two cases

Diagnostic criteria for the behavioral variant of frontotemporal dementia (bvFTD): current limitations and future directions

The most widely established diagnostic criteria for the behavioral variant of frontotemporal dementia have now been in use for almost a decade. Although consensus criteria have provided a much needed standard for frontotemporal dementia research, a growing body of evidence suggests that revisions are needed to improve their applicability. In this article, we discuss the limitations of current diagnostic criteria and propose the establishment of an international consortium to revise diagnostic and research criteria for the behavioral variant of frontotemporal dementia.

Chronic hydrocephalus in adults

Chronic hydrocephalus is a complex condition, the incidence of which increases with increasing age. It is characterised by the presence of ventricular enlargement in the absence of significant elevations of intracranial pressure. The clinical syndrome may develop either as a result of decompensation of a "compensated" congenital hydrocephalus, or it may arise de novo in adult life secondary to a known acquired disturbance of normal CSF dynamics. The latter may be due to late onset acqueductal stenosis or disruption of normal CSF absorptive pathways following subarachnoid hemorrhage or meningitis ("secondary" normal pressure hydrocephalus (NPH)). In some cases the cause of the hydrocephalus remains obscure ("idiopathic" NPH). In all forms of chronic hydrocephalus the clinical course of the disease is heavily influenced by changes in the brain associated with aging, in particular cerebrovascular disease. Recent research has challenged previously held tenets regarding the CSF circulatory system and this in turn has led to a radical rethinking of the pathophysiological basis of chronic hydrocephalus.

Normal pressure hydrocephalus manifesting as transient prosopagnosia, topographical disorientation, and visual objective agnosia

Usually, dementia, gait disturbance and urinary incontinence are an integral part of the clinical presentation of normal pressure hydrocephalus (NPH). However, NPH with transient visual cognitive disorders has not been reported previously. We herein describe an extremely rare case of NPH that presented with transient visual cognitive disorders and long lasting visual memory disturbances that subsided after CSF shunting. A 38-years-old man developed transient prosopagnosia, topographical disorientation, color vision disturbance, and visual objective agnosia that progressed over 5 years. Magnetic resonance images showed ventriculomegaly with ischemic lesions in the paraventricular deep white matter. ECD-SPECT showed a reduction of the cerebral blood flow (CBF) in the periventricular deep white matter. Three months after CSF shunting, the radiological findings normalized with dramatic improvement of the extremely rare symptoms.

Focal dilation and paradoxical collapse of cortical fissures and sulci in patients with normal-pressure hydrocephalus

OBJECT

The authors describe a subgroup of patients with shunt-proven normal-pressure hydrocephalus (NPH) who presented with focal fissural and sulcal dilation on imaging studies. The specific radiological features and methods of differentiating this condition from cortical atrophy are delineated.

METHODS

Normal-pressure hydrocephalus has been described as dilation of the ventricles that is out of proportion to the sulci. Sulcal dilation has been taken as evidence of cortical atrophy and has even been used as a criterion to exclude patients from undergoing a shunting procedure. The authors describe five cases of patients with shunt-proven NPH who presented with focal dilation of cortical fissures and sulci. In three of the cases, there was a paradoxical decrease in the size of the dilated fissures and sulci that paralleled the decrease in the size of the lateral ventricles following successful shunting.

CONCLUSIONS

This study demonstrates that focal fissural and sulcal dilation may represent reservoirs of cerebrospinal fluid analogous to the ventricular system. Patients should not be denied a shunting procedure solely on the basis of focally dilated fissures of sulci.

Classification of hydrocephalus and outcome of treatment

PURPOSE

Retrospective analysis in cooperative study of hydrocephalus at institutions of members of the Research Committee on Intractable Hydrocephalus sponsored by the Ministry of Health and Welfare of Japan was performed to determine the functional prognosis for all types of hydrocephalus and thus to clarify the outcome.

METHODS

In preparation of this study, we have proposed the definition, clinical classification and diagnostic criteria of hydrocephalus. We have classified non-tumoral hydrocephalus into eight types based on its etiology and the time of onset. To establish the diagnosis in each type of hydrocephalus, we have set up inclusion and exclusion criteria, as well as supplementary criteria which are useful for its diagnosis.

RESULTS

Analysis of the 1450 cases of hydrocephalus of various etiologies stored in the data base obtained from the study for each type of hydrocephalus revealed that following types and conditions were associated with a neurologic deficit: (1) early fetal hydrocephalus, (2) overt neonatal hydrocephalus, (3) hydrocephalus associated with such severe brain malformations as hydranencephaly, holoprosencephaly and lissencephaly, (4) hydrocephalus associated with severe brain damage, (5) hydrocephalus associated with epilepsy, (6) hydrocephalus shunted late after detection, and (7) hydrocephalus complicated by a shunting operation.

CONCLUSION

The postnatal functional outcome was significantly poor in fetal hydrocephalus diagnosed in the early gestation. Childhood onset hydrocephalus showed a poorer outcome than adult hydrocephalus.