V. Di Piero

Chronic pain: a PET study of the central effects of percutaneous high cervical cordotomy

&NA; We have studied 5 patients with unilateral, severe chronic pain due to cancer before and after percutaneous, ventrolateral cervical cordotomy to investigate the central effects of the procedure. The aim was to identify the functional anatomical correlates of abolishing unilateral nociceptive input to the brain. Patients were investigated by positron emission tomography using C15O2 to evaluate cerebral blood flow. Comparisons were made between the patients with unilateral pain before cordotomy and normal volunteers. These demonstrated significantly less blood flow in 3 out of 4 of the individual quadrants of the hemithalamus contralateral to the side of pain (P < 0.01–0.05). These differences were abolished by cordotomy. Comparison of the patients before and after cordotomy showed a significant decrease in blood flow in the dorsal anterior quadrant of the thalamus contralateral to the side of pain (P < 0.05) which was normalised after cordotomy. There were no significant changes in the prefrontal or primary somatosensory cortex. We conclude that chronic pain results in a decrease of synaptic activity at thalamic level either from decreased activity in neurones projecting to that region and/or attenuated local neuronal firing. We have demonstrated no secondary remote effects in cortex, indicating the importance of subcortical mechanisms in central responses to chronic pain.

Predictive value of brain perfusion single-photon emission computed tomography in acute ischemic stroke.

We investigated 32 patients with completed ischemic stroke less than or equal to 6 hours after the onset of symptoms by means of computed tomography, cerebral angiography, and technetium-99m-labeled hexamethylpropyleneamine oxime single-photon emission computed tomography to study cerebral blood flow. Follow-up computed tomography and cerebral blood flow studies were performed 1 week and 1 month after admission. Poor outcome at 1 month was evident in 18 (78%) of the 23 patients with severe neurologic deficit on admission and in 11 (92%) of the 12 patients with severe hypoperfusion in the affected hemisphere on admission. All 10 patients with severe impairment of both neurologic status and cerebral blood flow had a poor outcome at 1 month. We detected severe hypoperfusion in patients with large lesions on computed tomograms or cerebral artery occlusions on angiograms. Cerebral blood flow had increased at the 1-week follow-up despite different clinical outcomes. Our data provide evidence that early evaluation of cerebral blood flow with single-photon emission computed tomography is useful to detect subgroups of patients with different clinical outcomes during the acute phase of ischemic stroke.

Contrast Carotid Ultrasound for the Detection of Unstable Plaques with Neoangiogenesis: A Pilot Study

OBJECTIVES To evaluate whether contrast ultrasonography can be used to distinguish asymptomatic from symptomatic carotid plaques and provide insight into underlying pathophysiological differences. DESIGN Contrast carotid ultrasound was performed in both symptomatic and asymptomatic patients referred for carotid endarterectomy. MATERIALS AND METHODS Of 77 consecutive patients referred for carotid artery evaluation, 64 underwent carotid endarterectomy for asymptomatic cerebrovascular disease and 9 underwent urgent surgery for acute neurological deficits with hemiparesis. The endarterectomy specimens were assessed immunohistologically. RESULTS In all 9 patients undergoing urgent surgery, contrast ultrasonography showed the accumulation of diffuse microbubble contrast at the base of the carotid plaque. This pattern was observed only in 1/64 of the patients undergoing surgery for asymptomatic carotid disease. Immunohistologically staining of the endarterectomy specimens showed that the area of microbubble contrast at the base of the symptomatic plaques was associated with an increased number of small diameter (20-30 microm) microvessels staining for vascular endothelial growth factor (VEGF). CONCLUSIONS Contrast carotid ultrasonography may allow the identification of microvessels with neoangiogenesis at the base of carotid plaques, and differentiate symptomatic from asymptomatic plaques.

Cerebrovascular Reactivity in Degenerative and Vascular Dementia: A Transcranial Doppler Study

Background: An impairment of cerebral microvessels is reported both in normal ageing and in senescence-associated processes, as well as in Alzheimer’s disease (AD) and vascular dementia (VaD). The aim of this study was to explore cerebral hemodynamics by transcranial Doppler in VaD and AD, compared with age-matched control subjects. Methods: Transcranial Doppler was investigated in all patients in the basal condition. Cerebral vasoreactivity to hyper- and hypocapnia was evaluated with CO2 mixture inhalation followed by hyperventilation. Results: We studied 60 AD and 58 VaD patients and 62 nondemented controls. Both AD and VaD subjects showed lower flow velocities (FV) and higher pulsatility indices (PI) as compared with controls. Lower total vasomotor reactivity and lower response to hypercapnia were observed in the AD and VaD groups as compared with controls. AD and VaD patients did not show significant differences in FV, PI values or cerebral vasoreactivity. Conclusions: Reduced FV and increased PI with a significant vasoreactivity reduction in VaD and AD patients are indicators of impairment of cerebral microvasculature circulation in both diseases. The identification of vascular function impairment in all kinds of dementia could be of help in identifying patients who would thus benefit more from specific therapeutic approaches.

Motor recovery after acute ischaemic stroke: a metabolic study.

The metabolic changes occurring after ischaemic stroke were measured to investigate the functional anatomy of clinical motor recovery. Positron emission tomography (PET) and the steady-state 15O technique was used to compare resting relative metabolic distributions at the onset of functional deficit with those following recovery. Ten patients were studied with repeat scans. Motor recovery was associated in some patients with an increase of relative oxygen metabolism in anatomical structures normally involved in motor function in the affected hemisphere, particularly in the cortical motor areas. In those patients without such metabolic changes in the cortex of the diseased hemisphere, relative increases in cortical metabolism in the contralateral hemisphere were associated with better motor recovery than in patients with no relative cortical metabolic increase in either hemisphere. There was no correlation between the degree of improvement in motor function and the severity of motor deficit at onset, the size and site of the lesion and the metabolic changes in the infarcted zone. No particular pattern of global metabolic changes was observed after recovery. Thus different relative patterns of metabolic recovery were seen in patients with different lesions and evidence was found for the participation of contralateral structures in the recovery process in some patients.

Patterns of neuropsychological impairment in mild dementia: a comparison between Alzheimer's disease and multi-infarct dementia

The objective was to investigate the clinical and psychometric differences between patients with dementia of Alzheimer type (DAT) and patients with multi‐infarct dementia (MID), matched for age, sex, education, and severity. Sixteen patients with DAT, 16 patients with MID, and 30 healthy individuals, were drawn from a longitudinal study on aging and dementia. Subjects with medical or previous mental disorders were excluded. DAT and controls with focal brain abnormalities on magnetic resonance imaging (MRI) were excluded. Diagnosis of dementia was carried out according to DSM‐III‐R criteria. Dementia severity was staged using the Clinical Dementia Rating (CDR) scale, and only patients with a score of 0.5‐1 on CDR were studied. The main outcome measures were quantitative clinical scales of the assessment of global mental status, depression and anxiety, as well as a wide battery of neuropsychological tests for the evaluation of executive/conceptual functions and memory, as well as attention verbal ability, and visuospatial skill functions. The performance of demented patients compared to normal controls was affected on all measurements except for depression and anxiety. DAT patients showed compared to MID patients a greater extent of impairment on tasks assessing verbal comprehension and memory while MID patients were more significantly impaired on measures of frontal lobe functioning. Clinically matched DAT and MID patients show a differential pattern of neuropsychological impairment when studied in an early stage of dementia and with a mild degree of severity. Such patterns might be of value for the development of clinical diagnostic criteria.

Depression after minor stroke: prevalence and predictors.

Background and purpose:  Post‐stroke depression (PSD) is one of the most frequent complications of stroke, with a prevalence ranging 20–60%. As PSD seems to be related to stroke severity, we hypothesized that the prevalence of PSD would be lower in patients with minor stroke.

Depression in the early phase of MS : influence of functional disability, cognitive impairment and brain abnormalities

This study investigated the relationship between depression, physical disability, cognitive deficit and brain abnormalities on magnetic resonance imaging (MRI) in patients with early MS. Eighteen relapsing‐remitting MS patients were evaluated: depression was diagnosed according to DSM‐III R and measured by the MMPI depression subscale, physical disability was assessed by using the Kurtzke Expanded Disability Status Scale (EDSS) and cognitive functions by means of an extensive neuropsychological test battery. A neuroradiologist blinded to clinical findings quantified cerebral lesion on MRI. Weighted brain area lesion score were developed according to number and size of cerebral lesions. On the basis of DSM‐III criteria, six patients were classified as having major depression, seven patients had minor depression and five patients were without depressive symptoms. No significant differences were found among the three groups on both neuropsychological performances and weighted MRI lesion scores. However patients with major depression exhibit greater physical disability than the other MS subgroups. A significant correlation was found between MMPI depression subscale and physical disability. This study suggests that at least in the early phase of MS, depression appears more related to the physical disability than to the severity of pathological brain involvement.

Aminergic tone correlates of migraine and tension-type headache : A study using the Tridimensional Personality Questionnaire

Background.—Aminergic neurotransmitter activity has been studied in many neuropsychiatric diseases by means of a self‐administered questionnaire proposed by Cloninger. Given that central aminergic modulation plays a major role in the pathophysiology of primary headaches, we investigated the personality dimensions related to aminergic neurotransmitter activity in patients with migraine and tension‐type headache.

Sjögren's syndrome presenting as ischemic stroke.

We describe a young woman who presented with minor stroke as a first clinical symptom of Sjögrens syndrome (SS) in the absence of well-known risk factors for cerebrovascular disease. Case Description The medical history included recurrent miscarriages and sun rashes, which directed the diagnosis toward inununologic disorders such as systemic lupus erythematosus and antiphospholipid antibody syndrome, which are often associated with stroke. Only complete laboratory testing, including SSB antibody studies, and ophthalmologic and salivary gland evaluation revealed the correct diagnosis. Conclusions Sjögrens syndrome should be considered among the causes of stroke, especially in a young female patient.