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Biomedical subjects

R Gallassi

Publications and source records attributed to R Gallassi.

At least 19 recordsLinked to original sources
PubMed2002

Bilateral paramedian thalamic syndrome: abnormal circadian wake-sleep and autonomic functions.

OBJECTIVES: To describe wake-sleep and body core temperature (t degrees ) rhythm abnormalities in two patients with bilateral paramedian thalamic calcifications. METHODS: Patients underwent (18F)FDG PET scans and 24 hour polygraphic recordings of wake-sleep and t degrees. RESULTS: PET showed bilateral thalamic hypometabolism in both patients with additional basal ganglia or mesiolateral frontal and cingular hypometabolism. Wake-sleep studies showed abnormal sleep organisation and in the case with frontal and limbic PET hypometabolism, pre-sleep behaviour associated with "subwakefulness" EEG activities, lack of EEG spindles and K complexes, and features of status dissociatus. The t degrees rhythms showed increased mesor in both (37.4 degrees C and 37.75 degrees C) and inverted rhythm in one patient. CONCLUSIONS: Paramedian thalamic structures and interconnected, especially frontal and cingular, areas play a part in the organisation of the wake-sleep cycle and attendant autonomic functions.

Autonomic Nervous System Diseases↗
PubMed1998

Endozepine stupor. Recurring stupor linked to endozepine-4 accumulation.

Recurring stupor can be caused by repeated metabolic, toxic or structural brain disturbances. Recently, cases of recurring stupor, with fast EEG activity were shown to display increased endogenous benzodiazepine-like activity during the episodes of stupor. Patients with recurring stupor underwent extensive metabolic and toxicologic screening, EEG and brain imaging. Endozepines and exogenously administered benzodiazepines were assayed in plasma and CSF by means of mass spectrometry. Flumazenil, a benzodiazepine antagonist was administered and the behavioural and EEG responses monitored. Treatment with oral flumazenil was attempted in selected cases. Twenty patients were found with recurring stupor. Episodes had begun between ages 18 and 67 years, and in nine patients, had disappeared spontaneously after 4-6 years with symptoms. Stupor lasted hours or days. Onset of the episodes and frequency were unpredictable. Patients were normal between attacks. Stupor was characterized by initial drowsiness, staggering and behavioural changes, followed by deep sleep and spontaneous recovery with post-ictal amnesia. Biochemical screening and brain imaging were always normal. Ictal EEG showed fast background activity, and flumazenil transiently awoke the patients and normalized the EEG. In the nine cases examined, endozepine-4 levels were increased during the stupor. Oral flumazenil reduced the frequency of the attacks in three of these nine patients. Recurring episodes of stupor may be due to increased endozepine-4. We propose the term 'endozepine stupor' for such episodes. Endozepine-4 is an endogenous ligand for the benzodiazepine recognition site at the GABAA receptor, with unknown molecular structure.

Adult↗
PubMed1998

Clinical features of fatal familial insomnia: phenotypic variability in relation to a polymorphism at codon 129 of the prion protein gene.

Fatal Familial Insomnia is a hereditary prion disease characterized by a mutation at codon 178 of the prion protein gene cosegregating with the methionine polymorphism at codon 129 of the mutated allele. It is characterized by disturbances of the wake-sleep cycle, dysautonomia and somatomotor manifestations (myoclonus, ataxia, dysarthria, spasticity). PET studies disclose severe thalamic and additionally cortical hypometabolism. Neuropathology shows marked neuronal loss and gliosis in the thalamus, especially the medio-dorsal and anterior-ventral nuclei, olivary hypertrophy and some spongiosis of the cerebral cortex. Detailed analysis of 14 cases from 5 unrelated families showed that patients ran either a short (9.1 +/- 1.1 months) or a prolonged (30.8 +/- 21.3 months) clinical course according to whether they were homozygote met/met or heterozygote met/val at codon 129. Moreover, homozygotes had more prominent oneiric episodes, insomnia and dysautonomia at onset, whereas heterozygotes showed ataxia and dysarthria at onset, earlier sphincter loss and epileptic Grand Mal seizures; they also displayed more extensive cortical involvement on PET and at postmortem examination. Our data suggest that the phenotype expression of Fatal Familial Insomnia is related, at least partly, to the polymorphism at codon 129 of the prion protein-gene.

Adult↗
PubMed1996

Fatal familial insomnia: behavioral and cognitive features.

Fatal familial insomnia (FFI) is a familial prion disease linked to a mutation of the prion protein gene. Neuropsychological investigations in seven patients with FFI belonging to two different families showed that the main behavioral and neuropsychological features are (1) early impairment of attention and vigilance, (2) memory deficits, mainly of the working memory, (3) impairment of temporal ordering of events, and (4) a progressive dream-like state with neuropsychological and behavioral features of a confusional state. Neuropathologic examination of six patients showed prominent neuronal loss and gliosis involving the anterior ventral and mediodorsal thalamic nuclei, with additional cerebral cortical involvement in two cases. Clinicopathologic correlations indicate that FFI is associated with a neuropsychological and behavioral syndrome that is distinct from the cortical and subcortical dementias, and Wernicke-Korsakoff syndrome. These findings offer insights into the function of the thalamic nuclei and challenge the notion of thalamic dementia.

Adult↗
PubMed1993

Transient global amnesia: neuropsychological findings after single and multiple attacks.

We examined by neuropsychological tests 41 patients who had presented attacks of transient global amnesia (TGA; 31 had single and 10 multiple episodes), comparing them with 41 matched normal controls. Patients with single attacks showed only two impaired memory tasks with respect to controls (immediate and long-term verbal memory), while patients with multiple attacks showed more impaired tasks in memory and visuoperceptual ability. These data confirm that TGA is a benign syndrome, but could leave a few subclinical memory deficits probably exacerbated by repeated attacks.

Aged↗
PubMed1993

[18F]FDG PET in fatal familial insomnia: the functional effects of thalamic lesions.

We used [18F]2-fluoro-2-deoxy-D-glucose ([18F]FDG) and positron emission tomography (PET) to study regional cerebral glucose utilization (rCMRglc) in four patients with fatal familial insomnia (FFI), a prion disease with a mutation at codon 178 of the prion protein gene. Two patients, presenting only with insomnia and dysautonomia, had a prominent and, in one case, selective thalamic hypometabolism. The remaining two cases presented a more complex clinical picture with multiple neurologic deficits, with both thalamic and widespread brain hypometabolism involving the majority of cortical structures, basal ganglia, and the cerebellum. This widespread pattern was present in the early stage of the disease and showed significant worsening as the disease progressed in one patient examined twice. The thalamic hypometabolism, consistently found with PET in FFI patients, is in agreement with the neuropathologic findings and is a hallmark of the disease.

Adult↗
PubMed1992

Idiopathic recurring stupor: a case with possible involvement of the gamma-aminobutyric acid (GABA)ergic system.

A patient had recurrent spontaneous episodes of stupor or coma in the absence of toxic, metabolic, or structural brain damage. Ictal electroencephalography showed fast 14 Hz background activity; sleep studies excluded narcolepsy. Flumazenil (Anexate), a benzodiazepine antagonist, promptly resolved the episodes and normalized the electroencephalogram. Radioreceptor binding studies showed the presence of a ligand to the central benzodiazepine receptor in plasma and cerebrospinal fluid during the episodes, suggesting a gamma-aminobutyric acid (GABA)ergic system involvement in the origin of the attacks.

Benzodiazepines↗
PubMed1992

"Fatal familial insomnia": neuropsychological study of a disease with thalamic degeneration.

Fatal Familial Insomnia (FFI) is an inherited disease characterized clinically by sleep, autonomic and motor disturbances and pathologically by marked atrophy of the anterior and dorsomedial nuclei of the thalamus. The neuropsychological study of three cases of FFI showed: (1) a progressive disturbance of attention and vigilance, (2) a memory deficit with lability of mnesic traces and difficulty in manipulation and ordering of events, suggesting an alteration of working memory and (3) a deficit of frontal abilities with impairment in planning and prevision of events but preservation of general intelligence.

Adult↗
PubMed1992

Epileptic amnesic syndrome.

Thirteen patients with "epileptic amnesic syndrome" (EAS) presented with adult-senile onset of a severe memory complaint that started before or at the same time as seizures. All were diagnosed as temporal lobe epilepsy (TLE). The seizures were stereotyped, with only short loss of contact and oral automatisms, and because they were not obvious or disturbing, they remained underdiagnosed for a long time. Nine cases also presented attacks of transient anteroretrograde amnesia after the seizures--called "epileptic amnesic attacks" (EAA)--during which the patients were able to perform complex actions. EAA are similar to the attacks of transient global amnesia (TGA) but are more frequent, shorter, accompanied by clear-cut clinical and electroencephalographic epileptic manifestations, and respond favorably to antiepileptic therapy. Neuropsychological investigation ruled out global mental deterioration, showing only selective memory impairment in a few long-term tasks and dissociation between formal findings and the relevant memory complaint. These cases have uniform anamnestic, clinical, and neuropsychological characteristics and represent a particular clinical expression of TLE, namely EAS. We suggest that an epileptic origin be entertained in patients presenting repeated amnesic attacks resembling TGA or who complain of persistent memory disturbance, after more common etiologies have been excluded.

Adult↗
PubMed1992

Cognitive effects of antiepileptic drug discontinuation.

We studied the cognitive effects of antiepileptic drugs (AEDs), by investigating epileptic patients who were seizure-free for a long time and who were undergoing fixed monotherapy. Ninety patients [27 with phenobarbital (PB), 18 with carbamazepine (CBZ), 16 with phenytoin (PHT), and 29 with valproate (VPA)] were examined by a neuropsychological battery exploring intelligence, vigilance, attention, memory, and visuomotor performances at full AED dose (T1) and compared to 28 normal volunteers. We also evaluated the effects of AED discontinuation by retesting patients 3 months after reduction at half drug dose (T2) and 3 months (T3) and 1 year (T4) after complete discontinuation. Our findings showed that patients receiving CBZ did not differ from controls at any time of examination. Patients receiving PB had significant differences only at T1 (visuomotor performance and immediate spatial memory). Patients receiving VPA showed differences in attention, visuomotor performance, verbal span and sensory discrimination tasks at T1, in visuomotor performance at T2 and in spatial span at T3, whereas no differences were detected at T4. Patients receiving PHT had a difference in intelligence and visuomotor performance at T1, in intelligence at T2, and no differences at T3 or T4. This study model is useful for investigating the cognitive effects of AED because it allows selection of a uniform sample, eliminating variables such as type, frequency, and gravity of seizures that complicate this kind of study.

Adolescent↗
PubMed1991

Binswanger's disease and normal-pressure hydrocephalus. Clinical and neuropsychological comparison.

We investigated the clinical and cognitive aspects of patients with normal-pressure hydrocephalus and possible Binswanger's disease. We studied 19 patients with normal-pressure hydrocephalus and 19 patients with Binswanger's disease, comparing them with the same number of matched controls. The patients with normal-pressure hydrocephalus had a later age and more frequent gait disturbance at the onset, shorter duration of the illness, rare signs of vascular disturbances, and more frequent severe mental deterioration. Ventricular enlargement may play a role in determining the more rapid and worse clinical course of normal-pressure hydrocephalus.

Aged↗
PubMed1990

Cognitive effects of valproate.

The effects of valproate on cognition are usually considered to be minimal, but few formal neuropsychological studies are available. We studied the psychomotor performances of 20 seizure-free epileptics during fixed valproate monotherapy and after its withdrawal. Our findings suggest some adverse effects of valproate which appear to be completely reversible after withdrawal.

Adult↗
PubMed1990

Neurological examination in subjects over 65 years: an epidemiological survey.

The frequency of abnormal findings at neurological examination was analyzed in an unselected sample of elderly people aged 67-87 years. Absent deep tendon reflexes and impairment of proprioceptive sensation rarely occurred in the elderly. Limitation of upward gaze and convergence appear a common finding, especially in the very old. Overall, the presence of cortical disinhibition signs (primitive reflexes and paratonia) did not discriminate well between subjects without CNS disease and demented patients. Only the presence of a prominent and persistent response to the stimulus and the number of cortical disinhibition signs found in the same subject appear useful criteria to distinguish between normality and dementia.

Aged↗
PubMed1990

'Psychic akinesia' following carbon monoxide poisoning.

In 3 patients, carbon monoxide poisoning was followed by a modification of habits and personality without definite mental deterioration, but with loss of initiative, which led the patients to lose all their previous interests and to spend most of their time in bed. CT scans showed bilateral calcification of globi pallidi in one patient and pallidal hypodensities in another.

Adult↗