Subacute diencephalic angioencephalopathy: biopsy diagnosis and radiological features of a rare entity

A method for measuring brain partial pressure of oxygen in unanesthetized unrestrained subjects: the effect of acute and chronic hypoxia on brain tissue PO(2)

The level of tissue oxygenation provides information related to the balance between oxygen delivery, oxygen utilization, tissue reactivity and morphology during physiological conditions. Tissue partial pressure of oxygen (PtO(2)) is influenced by the use of anesthesia or restraint. These factors may impact the absolute level of PtO(2). In this study we present a novel fiber optic method to measure brain PtO(2). This method can be used in unanesthetized, unrestrained animals, provides absolute values for PO(2), has a stable calibration, does not consume oxygen and is MRI compatible. Brain PtO(2) was studied during acute hypoxia, as well as before and after 28 days of high altitude acclimatization. A sensor was chronically implanted in the frontal cortex of eight Wistar rats. It is comprised of a fiber optic probe with a tip containing material that fluoresces with an oxygen dependent lifetime. Brain PtO(2) declines by 80% and 76% pre- and post-acclimatization, respectively, when the fraction of inspired oxygen declines from 0.21 to 0.08. In addition, a linear relationship between brain PtO(2) and inspired O(2) levels was demonstrated r(2)=0.98 and r(2)=0.99 (pre- and post-acclimatization). Hypoxia acclimatization resulted in an increase in the overall brain PtO(2) by approximately 35%. This paper demonstrates the use of a novel chronically implanted fiber optic based sensor for measuring absolute PtO(2). It shows a very strong linear relationship in awake animals between inspired O(2) and tissue O(2), and shows that there is a proportional increase in PtO(2) over a range of inspired values after exposure to chronic hypoxia.

Subacute brainstem angioencephalopathy: favorable outcome with anticoagulation therapy

We present a patient who developed progressive neurological disease caused by lesions histologically compatible with those observed in subacute brainstem angioencephalopathy. The patient was treated with low-molecular weight heparin, and treatment response was monitored clinically and with MRI. Anticoagulation therapy stopped progression of the neurological deficit and led to improvement of MRI findings. This report further supports the existence of subacute brainstem angioencephalopathy as a characteristic disease entity and gives insight into possible therapeutic approach with anticoagulation treatment.

Subacute brainstem angioencephalopathy: a case report and review of the literature

A previously healthy 69-year-old man developed a progressive neurological illness with bulbar signs and ataxic paraparesis. Repeated MRI examinations revealed a large space occupying lesion in the lower brain stem with patchy contrast enhancement. MRI angiography was unremarkable and CSF had normal cell count but raised protein content. A brainstem tumor was suspected and a course of intravenous glucocorticosteroids was started. No improvement occurred and the patient died of pneumonia 11 weeks after onset. Neuropathology revealed confluent areas of complete or incomplete necrosis with marked edema in the lower brainstem. Predominantly venous meningeal vessels of the brainstem showed extensive fibromuscular thickening of all layers with luminal narrowing. In addition, intramural mononuclear infiltration was found. With the exception of localisation, this case exhibits all pathologic features of subacute diencephalic angioencephalopathy (SDAE), a rare fatal disease of unknown aetiology. In addition, the clinical features of typical age, male sex, disease duration and raised CSF proteins are shared. A common disease entity is suggested and the pathogenetic relevance of inflammation and venous outflow obstruction is discussed.

Distinct neuropsychological characteristics in Creutzfeldt-Jakob disease

OBJECTIVES

To characterise the nature of cognitive change in Creutzfeldt-Jakob disease (CJD).

METHODS

Case histories are reported of four patients with sporadic (sCJD) and two with familial CJD (fCJD), with postmortem pathological findings in four cases. The data derived from cognitive examination are examined with respect to the presence or absence of a variety of characteristics to elicit performance profiles across cognitive domains.

RESULTS

Three patients with sCJD exhibited clear focal cortical deficits. One patient had visual impairment leading to cortical blindness, associated with posterior hemisphere abnormalities on single photon emission computed tomography (SPECT) imaging; two others had impairments in language, mirrored by left hemisphere SPECT abnormalities. The remaining three patients showed no specific cortical symptomatology. Despite these differences all six patients shared common qualitative characteristics: episodic unresponsiveness, interference effects, and profound verbal and motor perseveration. These common features are interpreted in terms of impaired activation and regulation of neocortex from subcortical structures. Findings from postmortem pathological examination and from the published literature provide converging evidence to implicate a critical role of the thalamus.

CONCLUSION

These preliminary findings suggest that sCJD and fCJD may be associated with distinct neuropsychological characteristics.