[Epidural abscess and encephalocele following tegmen defect due to mastoidectomy: a case report]

In chronic otitis media surgery, especially in cases with cholesteatoma, different complications can occur in the course of the operation or postoperatively. In our clinic, in one of the cases who had staged canal-wall down operation for otitis media with cholesteatoma, an iatrogenic 0.5x0.5 cm dural plate defect had occurred in tegmen tympani during the operation. In this article, we present an uncommon case who had encephalocele with epidural abscess because of unrepaired dural plate defect superimposed with early postoperative infection at the first month after the operation and we discuss it in the light of the literature.

Frontal-lobe syndrome and psychosis after damage to the brainstem dopaminergic nuclei

A patient developed frontal-lobe syndrome and psychotic symptoms after infarction in the pontomesencephalic junction. Stereotaxic lesion localization on magnetic resonance imaging and statistical analyses of regional cerebral blood flow (rCBF) disclosed an involvement of the rostral brainstem dopaminergic nuclei and hypoperfusion in the frontal-subcortical circuit components. We suggest that the patient's cognitive and behavioral disturbances were associated with disruption of ascending dopaminergic projections to the frontal-subcortical circuits.

The metabolic topography of posthypoxic myoclonus

Posthypoxic myoclonus (PHM) is a syndrome of action and intention myoclonus that occurs in some patients who survive a cardiac arrest. Using PET and statistical parametric mapping, the authors observed a significant bilateral increase in glucose metabolism in the ventrolateral thalamus and pontine tegmentum in patients relative to controls. Interventions such as deep brain stimulation that interrupt networks that involve these structures may be useful in patients with severe PHM.

Regional cerebral blood flow in fibromyalgia: single-photon-emission computed tomography evidence of reduction in the pontine tegmentum and thalami

OBJECTIVE

To determine whether regional cerebral blood flow (rCBF) is abnormal in any cerebral structure of women with fibromyalgia (FM), following a report that rCBF is reduced in the thalami and heads of caudate nuclei in FM.

METHODS

Seventeen women with FM and 22 healthy women had a resting single-photon-emission computed tomography (SPECT) brain scan to assess rCBF and a T1-weighted magnetic resonance imaging (MRI) scan to enable precise anatomic localization. Additionally, all participants underwent 2 manual tender point examinations and completed a set of questionnaires evaluating clinical features. SPECT scans were analyzed for differences in rCBF between groups using statistical parametric mapping (SPM) and regions of interest (ROIs) manually drawn on coregistered MRI.

RESULTS

Compared with control subjects, the rCBF in FM patients was significantly reduced in the right thalamus (P = 0.006), but not in the left thalamus or head of either caudate nucleus. SPM analysis indicated a statistically significant reduction in rCBF in the inferior pontine tegmentum (corrected P = 0.006 at the cluster level and corrected P = 0.023 for voxel of maximal significance), with consistent findings from ROI analysis (P = 0.003). SPM also detected a reduction in rCBF on the perimeter of the right lentiform nucleus. No correlations were found with clinical features or indices of pain threshold.

CONCLUSION

Our finding of a reduction in thalamic rCBF is consistent with findings of functional brain imaging studies of other chronic clinical pain syndromes, while our finding of reduced pontine tegmental rCBF is new. The pathophysiologic significance of these changes in FM remains to be elucidated.

Comparison of impaired subcortico-frontal metabolic networks in normal aging, subcortico-frontal dementia, and cortical frontal dementia

Normal aging, progressive supranuclear palsy (PSP), and frontotemporal dementia (FTD) are characterized by different degrees of decline in frontal lobe functions. We used (18)FDG-PET and statistical parametric mapping (SPM96) to compare relative subcorticofrontal metabolic impairment at rest in 21 healthy elderly subjects (HES), 20 PSP patients, and 6 FTD patients. When HES were compared to 22 healthy young subjects, widespread decrease in metabolism was observed in bilateral medial prefrontal areas including anterior cingulate cortices, in dorsolateral prefrontal areas, in left lateral premotor area, in Broca's area, and in left insula. In PSP compared to the 43 healthy subjects (HS), we observed subcorticofrontal metabolic impairment including both motor and cognitive neural networks. Impairment of functional connections between midbrain tegmentum and cerebellar, temporal and pallidal regions was demonstrated in PSP as compared to HS. When comparing FTD to HS, glucose uptake was primarily reduced in dorsolateral and ventrolateral prefrontal cortices and in frontopolar and anterior cingulate regions. There was also bilateral anterior temporal, right inferior parietal, and bilateral striatal hypometabolism. Finally, FTD showed more severe striatofrontal metabolic impairment than PSP, while mesencephalothalamic involvement was only observed in PSP. Our data suggest that subcorticofrontal metabolic impairment is distributed in distinct subcorticocortical networks in normal aging, PSP, and FTD. Subcorticofrontal dementia in PSP is related to hypometabolism in discrete frontal areas, which are probably disconnected from certain subcortical structures. The concept of subcortical dementia is reinforced by our data, which show disrupted functional connections between mesencephalon and cerebellar cortex, inferior and medial temporal regions, and pallidum.

MR vs CT in progressive supranuclear palsy

Nine progressive supranuclear palsy (PSP) patients were studied with computerized tomography (CT) and magnetic resonance (MR) in order to determine the efficacy of each in detecting atrophy of the brainstem. Three additional PSP patients were evaluated with MRI for quantitative (electronic) measurements of the colliculi, pons and midbrain tegmentum. Both CT and MRI were equally effective in demonstrating midbrain atrophy. The MR was able to utilize the sagittal view to visualize thinning of the collicular (quadrigeminal) plate, a useful sign in PSP. Atrophy of the thinned collicular plate is more pronounced in the superior colliculus, one of the most common sites of pathology in PSP. The MR is able to make quantitative measurements of the degree of atrophy of the colliculi, pons and midbrain tegmentum.

Dilatation of pupils in a 'top of the basilar' stroke. Case report

A case is presented of a 'top of the basilar' stroke followed by a well circumscribed midbrain lesion mainly involving the parenchyma around both third nerve nuclear complexes. Prominent clinical features were: third nerve paralysis including huge pupils unresponsive to light, transient unconsciousness, and slight cerebellar dyscoordination.

The clinical manifestations of pontine hemorrhage

The survival rate was 40% in 10 patients suffering hemorrhage into the pons who were admitted to an acute care facility. This rate is higher than previously reported. In addition to the "classic" pontine hematoma syndrome characterized by coma, quadriparesis, and eventual demise, two more benign syndromes arising from hemorrhage confined to one side of the pons were also recognized. In one of these hemipontine syndromes, hematoma involved both the basis pontis and tegmentum and was associated with hemiparesis, brainstem signs, and preserved consciousness. In the other, hemorrhage was confined to the tegmentum and was associated with gaze paresis, motor sparing, and preserved consciousness. All patients suffering hemipontine hemorrhage survived. An impressive degree of functional recovery occurred in these survivors.

Ophthalmoplegia, ataxia and hyporeflexia (Fisher's syndrome). With a midbrain lesion demonstrated by CT scanning

This report concerns a patient with ophthalmoplegia, ataxia and hyporeflexia (Fisher's syndrome) with a lesion in the midbrain tegmentum demonstrated by computerized-tomography (CT) scanning. Spontaneous recovery was almost complete 1 month after the onset. Based upon its strategic location, it is suggested that the lesion can explain the findings in the patient. The CT finding, if confirmed, will necessitate a reconsideration of our current pathogenetic views about Landry-Guillain-Barré syndrome in general and Fisher's syndrome in particular.