Methodologic considerations in neuropsychologic testing of ataxic patients.
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Humans↗
Biomedical subjects
M I Botez
Publications and source records attributed to M I Botez.
Visual memory deficits after damage to the anterior commissure and right fornix.
A 47-year-old right-handed woman suffered an accidental dural perforation in the course of intranasal drainage of a right-sided sphenoid mucocele. Radiological examination revealed a small hematoma involving the anterior commissure, the right foramen of Monro, and the right fornix, resulting in severe anterograde amnesia for visual stimuli. Visual retention disturbances were manifested by a loss of the ability to conjure up new visual images, loss of topographical memory, and the cessation of dreaming. Dissociation was striking between severe deficits on tests exploring anterograde visual memory, revisualization, visuospatial organization, construction abilities, and normal or mildly impaired performance on tests implying verbal material and verbal memory. In agreement with experimental findings, it is postulated that combined damage to the anterior commissure and fornix on the right side could cause severe deficits in visual retention in humans.
Cerebral Ventricles↗
The neuropsychology of the cerebellum: an emerging concept.
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Cerebellar Diseases↗
Motor abnormalities in lurcher mutant mice.
Lurcher mutants had deficits in equilibrium in the coat-hanger and grid tests but not the wooden beam test. Although the mutants had less hole-pokes when confronted with small holes in most conditions, they had more hole-pokes with larger holes, demonstrating perseverative behavior. There was no decrease in rearing responses. These results indicate that in spite of cerebellar degeneration and ataxia, lurcher mutants are not impaired in all tests measuring motor function.
Animals↗
Thiamine status in inherited degenerative ataxias.
Blood thiamine levels in ataxia patients were studied. No significant differences were found between 30 patients with Friedreich's ataxia and 29 patients with olivopontocerebellar atrophy (OPCA) compared with control subjects. Both OPCA and Friedreich's ataxia patients presented significantly lower cerebrospinal fluid thiamine levels than their controls (p less than 0.001 and p less than 0.04 respectively). These results, discussed in terms of the high degree of cerebellar atrophy on CT scans in OPCA v Friedreich's ataxia patients, seem to correlate with cerebellar thiamine turnover and content.
Adult↗
Death from bulbar involvement in Friedreich's ataxia.
Cheyne-Stokes breathing occurs in patients with Friedreich's ataxia. In some cases, this form of periodic breathing may be caused by degenerative changes at the bulbar level. In view of decreased levels of glycine in the spinal cord in patients with Friedreich's ataxia, though medullary levels have not been measured, it is hypothesized that glycine (and perhaps other inhibitory amino acids) reverses Cheyne-Stokes breathing and could perhaps prolong life expectancy in patients with Friedreich's ataxia.
Animals↗
Treatment of heredo-degenerative ataxias with amantadine hydrochloride.
Amantadine hydrochloride (AH) was administered (200 mg/day) for more than three months to 17 patients with Friedreich's ataxia (FA) and to 12 patients with olivopontocerebellar atrophies (OPCA) in an open clinical trial. Reaction time (RT) and movement time (MT) with the right and left hand were measured before and after treatment. A striking improvement on both RT and MT was observed in the OPCA group (on seven out of eight measures), whereas in the FA patients improvement was seen only in two out of four MT measures with no improvement in RT. Both groups had low levels of homovanillic acid (HVA) in their cerebrospinal fluid before treatment, relative to their controls. However, improvement with AH was not related to HVA levels.
Adult↗
Single photon emission computed tomography (SPECT) in cerebellar disease: cerebello-cerebral diaschisis.
Single photon emission computed tomography assessments were conducted in normal controls (n = 25), patients with unilateral cerebellar infarctions (n = 4), patients with olivopontocerebellar atrophy (OPCA; n = 15) and patients with Friedreich's ataxia (FA; n = 6). In subjects with unilateral cerebellar infarctions, crossed cerebellar-cortical diaschisis was observed: reduced cerebellar hexamethylpropyleneamine oxime (HMPAO) uptake was invariably accompanied by a diminution of HMPAO in the contralateral basal ganglia and frontoparietal cortex. OPCA and FA patients had various degrees of decreased HMPAO uptake in both the cerebellum and cerebral hemispheres.
Adult↗
Effects of anticonvulsant treatment and low levels of folate and thiamine on amine metabolites in cerebrospinal fluid.
A total of 157 epileptic patients were studied with respect to (1) biogenic amine precursors and metabolites in the CSF, (2) levels of folate and thiamine in the blood and CSF, (3) length of treatment with phenytoin (PHT), (4) PHT intoxication, (5) CNS atrophy. Alterations in CSF amine metabolite levels were related primarily to PHT intoxication, and low CSF folate and thiamine levels, but not to length of treatment or CNS atrophy. PHT intoxication increased CSF 5-hydroxyindoleacetic acid (5HIAA). Low folate levels were associated with decreased CSF 5HIAA and homovanillic acid, while low thiamine levels were associated with decreased CSF 5HIAA and 3-methyoxy-4-hydroxyphenylethylene glycol. It remains to be seen to what extent these alterations in biogenic amine metabolism, mediated by low CNS vitamin levels, also lead to deficits in cerebral function.
Adult↗
[Cerebral crossed diaschisis caused by cerebellar lesion: role of the cerebellum in mental functions].
In 3 patients with a stroke limited to the posterior fossa, regional cerebral blood Flows were measured by the 133 Xe inhalation method (the first two cases) or by the SPECT with HMPAO method (the third case). The first patient had a median and paramedian hematoma of the left cerebellar hemisphere and the left dorsolateral portion of the pons. Remote cerebral hypoperfusion, measured 3 months later, was observed in both frontal premotor regions (but more marked in the right hemisphere) and in a circumscribed area of the right temporal region. The second patient had a right-sided ischaemic lesion of the anterior cerebellar lobe and the mesencephalic tectum. Contralateral parietal and rolandic hypoperfusion, measured 7 weeks after the stroke, was observed. The third patient had on old infarct of the right cerebellar hemisphere. The SPECT, measured 17 years later, showed a left fronto-parieto-temporal hypoperfusion and the absence of perfusion in the right cerebellar hemisphere. Preliminary data of neuropsychological assessment in our patients disclosed impairment in visuo-spatial and constructive organization, memory and learning compatible with the published findings in some patients and animals with predominantly cerebellar damage. These interesting findings should be confirmed in a large number of patients with age, sex, and sociocultural matched controls. In the absence of supratentorial insult, and during the hemodynamical stable phase, crossed cerebello-cerebral diaschisis is suggested in our 3 patients. Although it is too early to draw definite conclusions, our findings may: (1) confirm the functional interconnections between the cerebellum and the cerebrum in man and (2) provide functional basis for the behavioral function impairment reported in patients with cerebellar insult. Further rCBF, metabolism, and pathologic studies on this subject are required to elucidate this issue.
Cerebellar Diseases↗
Exploration and habituation in Purkinje cell degeneration mutant mice.
Purkinje cell degeneration (pcd) mutant mice lose virtually all Purkinje cells. It was found that the pcd mutants did not show within-sessions habituation in terms of hole-poking responses. This type of perseverative responding has been found in rats with limbic system damage and implies a role for the cerebellum in behavioral inhibition.
Animals↗
Role of the cerebellum in complex human behavior.
Thirty-three outpatient epileptics with normal CT scans (group 1) and 31 patients with cerebellar and brain stem (CBS) atrophy (group 2) were randomly included in this study. There were no significant statistical differences between the groups with regard to age, education, and number of grand mal and other seizures. Statistical analyses showed that group 2 had a longer history of epilepsy with a consequently longer duration of phenytoin (PHT) consumption. Neuropsychological assessment revealed lower performance by this group on the following measures: full I.Q. scale, verbal I.Q. scale, performance I.Q. scale, information, arithmetic, block design, object assembly, digit symbol, Stroop test forms I and II, the B-M dexterity test, and the simple visual and auditory reaction time. No significant differences were observed between the two groups for the remaining 5 subtests from the WAIS scale, for the immediate recall and the delayed recall subtests belonging to Wechsler memory scale as well as for visual and auditory movement time. Analysis of the composite scores of neuropsychological performance showed that the cerebellum interferes with the following complex behavioral functions: (i) visuo-spatial organization for a concrete task, a function related to the cerebello-parietal loops' (ii) planning and programming of daily activities, a function related to the cerebello-frontal loops; and (iii) the speed of information processing, a mainly subcortical function.
Adult↗
Acute effect of protein or carbohydrate breakfasts on human cerebrospinal fluid monoamine precursor and metabolite levels.
Patients with normal pressure hydrocephalus who had three lumbar punctures during 1 week ingested either water, a protein breakfast, or a carbohydrate breakfast 2.5 h before each of the lumbar punctures. The CSF was analyzed for biogenic amine precursors and metabolites. The protein meal raised CSF tyrosine levels, a finding consistent with animal data, but did not alter those of tryptophan or any of the biogenic amine metabolites. The carbohydrate meal increased CSF 3-methoxy-4-hydroxyphenylethylene glycol, an unexplained finding. The carbohydrate meal did not affect CSF tryptophan, tyrosine, 5-hydroxyindoleacetic acid, or homovanillic acid. Our results support the idea that in humans protein or carbohydrate meals do not alter plasma amino acid levels sufficiently to cause appreciable changes in CNS tryptophan levels or 5-hydroxytryptamine synthesis.
Dietary Carbohydrates↗
Treatment of Friedreich's ataxia with amantadine.
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Adolescent↗
Spontaneous alternation and exploration in weaver mutant mice.
Weaver mutant mice engaged less in motor activity and hole poking. Weaver mice alternated spontaneously in a 4-trial but not a 2-trial test. These results are similar to those of a previous study with staggerer mutants, in that both are less active. However, weaver mutants are less affected in the spontaneous alternation measure.
Animals↗
Spontaneous alternation and exploration in staggerer mutant mice.
Staggerer mutant mice were found to be less active in terms of motor activity in a maze, hole poking and rearing. Staggerer mutant mice also showed a lack of spontaneous alternation in both 2-trial and 4-trial tests. A lack of spontaneous alternation in this mutant may be due to a deficit in response inhibition or in spatial orientation, similar to that of animals with limbic lesions.
Animals↗
Cerebellar atrophy in epileptic patients.
High-resolution CT scans of the brain and posterior fossa were performed on 106 phenytoin (PHT)-treated epileptics, 28 de novo epileptics and 43 control subjects. A higher incidence of cerebellar and brainstem (CBS) atrophy was observed in chronic PHT- or PHT+ phenobarbital-treated epileptics compared to the two other groups. Some control subjects and de novo epileptics presented mild CBS atrophy, whereas moderate to severe atrophy was noted exclusively in chronically-treated patients. In attempting to delineate the etiology of CBS atrophy, epileptic patients were divided in three groups: 55 subjects with normal CT scans, 30 with both cerebral and CBS atrophy, and 49 with pure CBS atrophy. Their ages, length of illness, number of generalized seizures, number of other seizures, and amount of PHT received during their lifetime were assessed. Statistical analysis revealed that posterior fossa atrophy in epileptics was significantly correlated with both the length of the illness and the amount of PHT ingested during the patient's lifetime. The number of seizures appears to not be related to CBS atrophy.
Adolescent↗
Delayed spontaneous alternation in Purkinje cell degeneration mutant mice.
Purkinje cell degeneration (pcd) mutant mice lose cerebellar Purkinje cells. It was found that pcd mice, contrary to normal mice, did not alternate spontaneously at any of 3 inter-trial intervals (15 s, 3 or 6 min). Deficits in spontaneous alternation are typical of animals with brain damage in areas important in spatial learning. Results are discussed in terms of a role for the cerebellum in spatially mediated behavior and behavioral inhibition.
Animals↗