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PubMed1994

Trichothiodystrophy: clinical spectrum, central nervous system imaging, and biochemical characterization of two siblings.

Trichothiodystrophy (TTD), an autosomal recessive disorder characterized by sulfur-deficient brittle hair, identifies a group of genetic disorders with an altered synthesis of high-sulfur matrix proteins and a defect in excision repair of ultraviolet damage in fibroblasts of most TTD patients. In contrast to patients with xeroderma pigmentosum (XP), TTD patients do not have an increased frequency of skin cancers. TTD patients may be grouped into four categories: 1) those without photosensitivity and without a defect in excision repair of UV damage; 2) those without photosensitivity and with an excision-repair defect in the same gene as in XP-D (complementation group D); 3) those with photosensitivity and with the XP-D repair defect; 4) those with photosensitivity and with a repair defect distinct from that in XP-D. We present a brother and sister in the third category of TTD. Clinically, the patients have brittle hair, short stature, ichthyosis, photosensitivity, nail and dental dysplasias, cataracts, mental retardation, and pyramidal tract abnormalities. Diagnosis was made by hair mount, which shows the characteristic banding pattern with polarizing microscopy, and by hair amino acid analysis, which demonstrated decreased high-sulfur matrix proteins. Fibroblasts cultured from skin biopsies had a marked DNA excision repair defect similar to the repair defect seen in XP-D. We have documented a unique dysmyelinating disorder on magnetic resonance imaging of the brain that might explain their mental retardation, marked hyperactivity, and neurologic deficits. Following the discovery that the human excision repair cross complementing rodent ultraviolet group 2 (ERCC2) gene is able to correct the ultraviolet sensitivity of XP-D cell strains, the ERCC2 cDNA from previous TTD patients was sequenced and shows frameshifts, deletions and point mutations in the ERCC2 gene. Molecular analysis of our patients is in progress. Molecular analysis of the defects in ERCC2 in clinically distinct patients with XP,XP/Cockayne's syndrome, and TTD may provide insight into the molecular mechanisms of these genetically related but clinically distinct disorders.

Brain↗
PubMed1979

Adrenoleukodystrophy: report of a familial case.

Adrenoleukodystrophy is an unusual disorder in which progressive diffuse demyelination of the cerebrum is associated with adrenal insufficiency, and which is transmitted as a sex-linked recessive trait. This report describes a 36-year-old-male, who first presented 12 years previously with hypogonadothrophic hypogonadism. It is only more recently that he has developed primary adrenal insufficiency, as well as a neurological disorder characterized by cerebellar, pyramidal tract and cerebral cortical abnormalities. One brother died at age 7 with Schilder's disease, while another brother suffered adrenal insufficiency, progressive mental and neurological deterioration and death at age 38 with post-mortem evidence of adrenoleukodystrophy. Histological studies have revealed cytoplasmic striated inclusions, which proved to be lipid in nature, but the precise defect in lipid metabolism has yet to be clarified.

Adrenal Insufficiency↗
PubMed2006

An autopsy case of frontotemporal dementia with severe dysarthria and motor neuron disease showing numerous basophilic inclusions.

We report a clinicopathological study of a patient suffering from frontotemporal dementia (FLD) with severe dysarthria and concomitant motor neuron disease (MND). The patient was a 52-year-old woman with almost simultaneous emergence of severe dysarthria and FTD. The severe dysarthria subsequently evolved into anterior opercular syndrome. Motor neuron signs then emerged, and the patient developed akinetic mutism approximately 2 years after the onset of the disease. The patient died of pneumonia after a 7-year clinical illness. Pathologically, severe and widespread degeneration in the frontal and temporal lobes, including the anterior opercular area, limbic system, basal ganglia, spinal cord and cerebellum, and frequent ubiquitin- and tau-negative basophilic inclusions were observed. The pyramidal tracts and anterior horns of the cervical cord also showed marked degeneration. Cases showing basophilic inclusions reported so far have been divided into two groups: early onset FTD and MND with basophilic inclusions. Our case presented clinicopathological features of both FTD and MND, which suggests that cases showing basophilic inclusions may constitute a clinicopathological entity of FTD/MND.

Autopsy↗
PubMed1976

Familial unusual encephalopathy of Binswanger's type without hypertension.

Clinical and pathological studies have been conducted on two brothers with unusual encephalopathy of Binswanger's type. The disease started in the third decade with steady progressive course leading to death in eight or nine years. The clinical picture was summarized as a combination of organic dementia, extrapyramidal disorders associated with pseudobulbar symptoms and marked pyramidal tract signs. The blood pressure remained always normal during the course. Pathologically, there were diffuse and focal demyelination with sparing of U-fibers, multiple small foci of perivascular softening in the cerebral white matter and in the basal ganglia and severe arteriosclerotic changes of memingeal small arteries and long arteries with 100 to 400 micron caliber in the cerebral white matter. Vessel changes consisted of fibrous intimal proliferation, severe hyalinosis and splitting of intima and/or internal elastic membrane. The histopathological process belonged to the category of subcortical arteriosclerotic encephalopathy of Binswanger's type. There has been some discussion as to differential diagnosis among various forms of vasculitis such as cerebral endangiitis obliterans, periarteritis nodosa, systemic lupus erythematosus, rheumatic vascular disease and giant cell arteritis.

Adult↗
PubMed1986

Treatment of amyotrophic lateral sclerosis with thyrotropin-releasing hormone (TRH).

Despite the efforts of many workers, the cause and therapy has not been clarified. We carried out the therapeutic trial of thyrotropin releasing hormone (TRH) for amyotrophic lateral sclerosis (ALS) from January, 1979 to January, 1983. There were 16 subjects. The patients were given a low dose (0.5-2 mg) of TRH intravenously or intramusculary. Mild to moderate improvement was found in 9 (56%) of 16 patients. TRH has been reported to have the activating effects on the pyramidal tract, brainstem motor nuclei, and motoneuron in the spinal cord as a neurotransmitter or neuromodulator. We thought such action of TRH to be useful to the therapy of ALS.

Adult↗
PubMed1997

Suspected acute encephalopathy with symmetrical abnormal signal areas in the basal ganglia, thalamus, midbrain and pons diagnosed by magnetic resonance imaging.

A 4-year-old boy was admitted with disturbed consciousness following a convulsion. He developed bilateral pyramidal tract signs and showed a decerebrate posture. Laboratory findings revealed severe liver dysfunction and disseminated intravascular coagulation. On the eighth day eight in hospital he developed parkinsonism. However, 5 months from onset he had recovered almost completely. Brain CT on admission showed low density areas in the basal ganglia, thalamus, midbrain and pons. A T2-weighted scan in magnetic resonance imaging (MRI) showed almost symmetrical high signal intensities in both basal ganglia (including putamen, caudate nucleus, globus pallidus), external capsule, internal capsule thalamus, midbrain, pons and white matter of the peribasal ganglia; but a T1-weighted scan showed low signal intensities in the same regions during all phases. Therefore hemorrhagic lesions or the presence of thalamic methemoglobin were excluded. It was considered that the pathogenesis may be cytotoxic cellular edema due to cytotoxic agents or acute metabolic factors. Clinical presentation, laboratory findings and radiological findings were most suggestive of acute necrotizing encephalopathy. As differential diagnoses, acute disseminated encephalomyelitis and brainstem encephalitis were considered.

Acute Disease↗
PubMed1998

Encephalopathy and cytomegalovirus colitis in an AIDS child.

A 2-year-old girl, who had prolonged thrush and spastic diplegia, was found to have a mother-to-child vertical transmission of human immunodeficiency virus type-1 (HIV). A brain computed tomography scan revealed a symmetrical calcification on the bilateral basal ganglia and periventricular white matter. She had an acquired immune deficiency syndrome (AIDS) encephalopathy of pure dominant pyramidal tract disorder without an intellectual deficit. Helper cell lymphocyte count (CD4) increased with the beginning of zidovudine (ZDV, also known as AZT) monotherapy but began to decrease after the 4th week to reach the baseline at 20th week. Zidovudine plus didanosine combination therapy was started at the 68th week, but because of intolerance, the combination was changed to ZDV plus lamivudine at the 98th week. By the 80th week, neither severe opportunistic infection nor deterioration of the neurological status was recognized, but chronic diarrhea appeared. The diarrhea advanced to the wasting syndrome at the age of 4 years and cytomegalovirus genome was confirmed in a biopsied specimen of the colon. Ganciclovir treatment was effective in stopping the diarrhea and increasing her bodyweight, but after the age of 5, resumption of diarrhea was followed by progressive emaciation and weakness. This work may provide some clues in treating children's AIDS.

AIDS Dementia Complex↗
PubMed2006

Relationship between intracerebral gamma oscillations and slow potentials in the human sensorimotor cortex.

Changes in sensorimotor rhythms (mu, beta and gamma) and movement-related cortical potentials (MRCPs) are both generated principally by the contralateral sensorimotor areas during the execution of self-paced movement. They appear to reflect movement control mechanisms, which remain partially unclear. With the aim of better understanding their sources and significance, we recorded MRCPs and sensorimotor rhythms during and after self-paced movement using intracerebral electrodes in eight epileptic subjects investigated by stereoelectroencephalography. The results showed that: (i) there is a strong spatial relationship between the late components of movement--the so-called motor potential (MP) and post-movement complex (PMc)--and gamma event-related synchronization (ERS) within the 40-60 Hz band, as the MP/PMc always occurred in contacts displaying gamma ERS (the primary sensorimotor areas), whereas mu and beta reactivities were more diffuse; and (ii) MPs and PMc are both generated by the primary motor and somatosensory areas, but with distinct sources. Hence, this could mean that kinesthesic sensory afferences project to neurons other than those firing during the pyramidal tract volley. The PMc and low gamma ERS represent two electrophysiological facets of kinesthesic feedback from the joints and muscles involved in the movement to the sensorimotor cortex. It could be suggested that gamma oscillations within the 40-60 Hz band could serve to synchronize the activities of the various neuronal populations involved in control of the ongoing movement.

Action Potentials↗
PubMed1999

Central regulation of motor cortex neuronal responses to forelimb nerve inputs during precision walking in the cat.

1. The responses of neurones in forelimb motor cortex to impulse volleys evoked by single pulse electrical stimulation (at 1.5 or 2 times the threshold for most excitable nerve fibres) of the superficial radial (SR) and ulnar (UL) nerves of the contralateral forelimb were studied in awake cats both resting quietly and walking on a horizontal ladder. Nerve volley amplitude was monitored by recording the compound action potential elicited by the stimulus. 2. In the resting animal 34/82 (41%) cells yielded statistically significant responses to SR stimulation, and 20/72 (28%) responded to UL stimulation. Some responses were confined to or began with an increase in firing probability ('excitatory' responses) and others with a decrease in firing ('inhibitory' responses), typically including a brief interruption of the spike train (zero rate). Cells responding to both nerves usually yielded responses similar in type. Most (78%) response onset latencies were less than 30 ms. Responses involved the addition or subtraction of from 3.4 to 0.1 impulses stimulus-1 (most <1 impulse stimulus-1). The distribution of response sizes was continuous down to the smallest values, i.e. there was no 'gap' which would represent a clear separation into 'responsive' and 'unresponsive' categories. Responses were commonest in the lateral part of the pericruciate cortex, and commoner among pyramidal tract neurones (PTNs) than non-PTNs. 3. During ladder walking most cells generated a rhythmic step-related discharge; in assessing the size of responses to nerve stimulation (20 studied, from 13 cells) this activity was first subtracted. Response onset latencies (90% <30 ms) and durations showed little or no change. Although most cells were overall more active than during rest both 'excitatory' and 'inhibitory' responses in both PTNs and non-PTNs were often markedly reduced in large parts of the step cycle; over some (usually brief) parts responses approached or exceeded their size during rest, i.e. response size was step phase dependent. Such variations occurred without parallel change in the nerve compound action potential, nor were they correlated with the level of background firing at the time that the response was evoked. When responses to both nerves were studied in the same neurone they differed in their patterns of phase dependence. 4. The findings are interpreted as evidence for central mechanisms that, during 'skilled', cortically controlled walking, powerfully regulate the excitability of the somatic afferent paths from forelimb mechanoreceptors (including low threshold cutaneous receptors) to motor cortex. Retention (or enhancement) of responsiveness often occurred (especially for ulnar nerve) around footfall, perhaps reflecting a behavioural requirement for sensory input signalling the quality of the contact established with the restricted surface available for support.

Animals↗
PubMed1999

Rhythmic neuronal activity in the lateral cerebellum of the cat during visually guided stepping.

1. The discharge patterns of 117 lateral cerebellar neurones were studied in cats during visually guided stepping on a horizontal circular ladder. Ninety per cent of both nuclear cells (53/59) and Purkinje cells (53/58) showed step-related rhythmic modulations of their discharge frequency (one or more periods of 'raised activity' per step cycle of the ipsilateral forelimb). 2. For 31% of nuclear cells (18/59) and 34% of Purkinje cells (20/58) the difference between the highest and lowest discharge rates in different parts of the step cycle was > 50 impulses s-1. 3. Individual neurones differed widely in the phasing of their discharges relative to the step cycle. Nevertheless, for both Purkinje cells and nuclear cells population activity was significantly greater in swing than in stance; the difference was more marked for the nuclear population. 4. Some cells exhibited both step-related rhythmicity and visual responsiveness (28 of 67 tested, 42%), whilst others were rhythmically active during locomotion and increased their discharge rate ahead of saccadic eye movements (11 of 54 tested, 20%). The rhythmicity of cells that were visually responsive was typical of the rhythmicity seen in the whole locomotor-related population. The step-related rhythmicity of cells that also discharged in relation to saccades was generally below average strength compared with the cortical and nuclear populations as a whole. 5. The possibility is discussed that the rhythmicity of dentate neurones acts as a powerful source of excitatory locomotor drive to motor cortex, and may thereby contribute to establishing the step-related rhythmicity of motor cortical (including pyramidal tract) neurones. More generally, the activity patterns of lateral cerebellar neurones provide for a role in the production of visually guided, co-ordinated eye and body movements.

Animals↗
PubMed1991

Central nervous system involvement of children with HIV infection.

The neurological findings in 41 HIV-seropositive children are described. 23 children were symptomatic, eight seropositive but without symptoms and 10 seropositive children less than 15 months of age had no other evidence of immunodeficiency. Acquired microcephaly, developmental regression and progressive motor deterioration indicated HIV encephalopathy, as did developmental delay, mental retardation, cerebellar symptoms and behavioural changes. Three children with progressive encephalopathy improved after treatment with azidothymidine (AZT). In eight children treated with prophylactic intravenous immunoglobulin therapy (IVIG) and seven treated with both IVIG and AZT, no mental deterioration has been observed since the beginning of therapy. One child with advanced encephalopathy and severe pyramidal tract involvement did not improve.

Adolescent↗
PubMed1986

Regional cerebral glucose utilization during insulin-induced hypoglycemia in unanesthetized rats.

Regional cerebral glucose utilization (rCMRgl) was studied during insulin-induced hypoglycemia in unanesthetized rats. Rats were surgically prepared using halothane and nitrous oxide anesthesia and allowed 5 h to recover from the anesthesia before rCMRgl was measured. The rCMRgl was measured using [6-14C]glucose in a normoglycemic control group and two hypoglycemic groups, A (30 min after insulin injection) and B (2 h after insulin injection). The mean plasma glucose level was 7.03 mumol/ml in the normoglycemic group, 1.96 mumol/ml in hypoglycemic group A, and 1.40 mumol/ml in hypoglycemic group B. The rCMRgl in hypoglycemic group A decreased 8-18% in 17 brain regions measured; five changes were statistically significant. The rCMRgl in hypoglycemic group B decreased significantly in all but one of the brain regions measured; the decrease ranged from 15% in the pyramidal tract to 36% in the motor and auditory cortices. The rCMRgl in every brain region decreased when the plasma glucose level fell below 1.5-2.5 mumol/ml. No brain region could maintain rCMRgl at plasma glucose concentrations lower than predicted by regional glucose influx described in previous studies. Glucose utilization in all brain regions appears to be limited by the influx of glucose.

Animals↗
PubMed1991

Creatine kinase activity in postnatal rat brain development and in cultured neurons, astrocytes, and oligodendrocytes.

The development and distribution of cytosolic creatine kinase (CK) activity was studied in rat brain and in cell culture. The activity of CK in whole brain increased almost fivefold during the period from birth to day 40 when adult levels of 18-19 U/mg of protein were attained. The distribution of CK activity was examined in dissected regions of the adult brain and was nonuniform; the cerebellum, the striatum, and the pyramidal tracts contained significantly higher CK activity than did whole brain. The cellular compartmentation of CK was investigated using primary cultures of purified neurons, astrocytes, and oligodendrocytes. The CK activity in neurons increased fourfold greater than that measured at the time of isolation to 4 U/mg of protein. The CK activity in astrocytes cultured for 20 days was 3.5 U/mg of protein and was 1.5-fold greater than that measured at the time of isolation. In contrast, the CK activity in cultured oligodendrocytes (day 20) was three- to fourfold higher than that determined in astrocytes and almost sevenfold higher than the activity measured at the time the cells were isolated. The high levels of CK in cultured oligodendrocytes suggest a role for this enzyme in oligodendrocyte function and/or myelinogenesis.

Animals↗
PubMed1976

Responses of neurones in the cerebral cortex and caudate nucleus to amantadine, amphetamine and dopamine.

1. Dopamine amantadine and amphetamine have been applied directly by microiontophoresis to single neurones in the caudate nucleus and cerebral cortex of rats anaesthetized with urethane. 2. The predominant response to all three agents was a depression of neuronal firing rate. The responses to dopamine and amantadine could be antagonized by the dopamine receptor blocking agent, chlorpromazine. 3. Amantadine did not cause any potentiation of dopamine responses, suggesting that inhibition of amine uptake was not responsible for its effects. 4. The responses of pyramidal tract cells in the cerebral cortex to dopamine, amphetamine and amantadine were compared in control groups of rats and rats pretreated with reserpine (10 mg/kg i.p.) or alpha-methyl-p-tyrosine methyl ester (200 mg/kg i.p.). The reduction of cortical catecholamine concentrations was confirmed by a direct fluorimetric assay method. 5. Responses to dopamine were unaltered in the amine-depleted animals compared with controls. Responses to amantadine and amphetamine were reduced but not abolished. 6. It is concluded that amantadine acts partly by releasing catecholamines from neuronal stores. The residual responses to amantadine and amphetamine may be the result of a direct postsynaptic receptor stimulation.

Amantadine↗
PubMed1978

Comparison of the actions of octopamine and catecholamines on single neurones of the rat cerebral cortex.

1. The technique of microelectrophoresis was used to compare the actions of octopamine, noradrenaline and dopamine on single cortical neurones of the rat. 2. Octopamine both excited and depressed neurones of the cortex. Frequently cells depressed by noradrenaline were excited by octopamine; occasionally the converse was true. The time courses of action of the two amines also differed. Dopamine-elicited excitations were observed, but also were not correlated with octopamine-elicited effects. 3. When octopamine and noradrenaline both caused depressant effects, octopamine frequently was of less apparent potency than noradrenaline. When these amines were excitatory, octopamine appeared at least as and sometimes more potent than noradrenaline. 4. Octopamine was only weakly effective on cortical neurones identified by antidromic stimulation of the pyramidal tract, or synaptically excited by stimulation of the ventrobasal thalamus. 5. alpha-Flupenthixol and propranolol were without effect on octopamine-elicited changes in firing rate at doses which were effective in blocking the actions of dopamine and noradrenaline respectively. Metoclopramide did not block the actions of any of the three agonists, but had strong effects of its own. 6. The results suggest that receptors sensitive to octopamine, and which appear to be pharmacologically distinct from those previously categorized as noradrenaline and dopamine receptors, may exist on central neurones of the rat.

Animals↗
PubMed1979

Amino acids as neurotransmitters of corticofugal neurones in the rat: a comparison of glutamate and aspartate.

1 The relative sensitivities to aspartate and glutamate of neurones receiving a corticofugal innervation were examined by microiontophoresis, and compared with the relative sensitivities of neurones not appearing to receive such an input.2 On all the cells tested, glutamate appeared to be a more potent excitant than aspartate in terms of neuronal response size or effective dose.3 DL-alpha-Aminoadipate (alphaAA) reduced the excitatory amino acid responses on all the neurones tested. On many of these cells a control excitation could be produced, by acetylcholine or hydrogen ions, which was in most cases unaffected by doses of alphaAA producing antagonism of amino acid excitation.4 On 70% of the cells, aminoadipate showed no selectivity for aspartate compared with glutamate but a differential action, involving blockade of aspartate but not glutamate, was apparent on the other 30%.5 Doses of alphaAA which selectively reduced responses to aspartate had no effect on short latency evoked spikes, but doses which also reduced responses to glutamate reduced the short-latency synaptic excitation induced by electrical stimulation of either the surface of the cerebral cortex, or of the pyramidal tracts in the medulla.6 These findings suggest that corticofugal neurones having an excitatory action on cells in various parts of the brain may use an amino acid, probably glutamate, as a common neurotransmitter.7 As no significant difference could be demonstrated in the potency ratios of glutamate:aspartate on monosynaptically activated cells compared with other cells, doubt is cast on the validity of drawing conclusions about transmitter identity from potency ratios alone, without the support of antagonist studies.

2-Aminoadipic Acid↗
PubMed1989

Sjögren-Larsson syndrome associated with the Dandy-Walker malformation: report of a case.

The Sjögren-Larsson syndrome is defined as the association of ichthyosis, spastic diplegia or tetraplegia, and mental retardation. Although most cases described have come from the Swedish county of Vasterbotten, isolated reports from the United States and elsewhere do exist. Numerous neurologic abnormalities have been reported with this syndrome, including speech defects, seizures, and pyramidal tract disorders. Abnormal ophthalmologic findings are not rare. Previous studies with computerized tomographic (CT) scans have revealed no abnormalities of cranial anatomy. We report a 6-year-old boy with Sjögren-Larsson syndrome who had a Dandy-Walker malformation as demonstrated by diagnostic imaging by CT and magnetic resonance imaging scans. This case illustrates that developmental defects of the central nervous system can also occur in association with Sjögren-Larsson syndrome.

Child↗
PubMed1977

Anticonvulsant action of diazepam: increase of cortical postsynaptic inhibition.

The action of intravenously administered diazepam (Valium) on postsynaptic inhibition was studied in cat motor cortex. The efficacy of postsynaptic inhibition of pyramidal tract cells was measured as the ability to suppress action potential generation. Diazepam increased the suppression of action potentials by inhibition. This effect may explain the anticonvulsant action of diazepam.

Action Potentials↗