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Biomedical subjects

M M Robertson

Publications and source records attributed to M M Robertson.

At least 73 records · Page 4Linked to original sources
PubMed1994

Genomic cloning and localization by FISH and linkage analysis of the human gene encoding the primary subunit NMDAR1 (GRIN1) of the NMDA receptor channel.

A cDNA clone of the NMDAR1 (isoform E) has been used to screen both lambda and cosmid genomic libraries. A genomic phage clone was identified and sequenced and was found to contain some of the 3' coding regions of the GRIN1 gene. This clone was used to localize the gene using fluorescent in situ hybridization (FISH) to normal chromosomes, and also to a lymphoblastoid cell line containing a translocation involving chromosomes 9 and 15. FISH localized the gene to chromosome 9q34.3. The clone was used to screen a panel of genomic DNAs cut with 20 restriction enzymes. A VNTR sequence 5' to the gene, which was polymorphic for a number of restriction enzymes, was detected. A PvuII fragment of the genomic clone was found to detect the VNTR on Southern hybridization. The polymorphic VNTR marker was mapped against chromosome 9q34 markers using linkage analysis in the CEPH families. The GRIN1 gene was linked to D9S7 with a maximum lod score of 20.09 at zero recombination fraction in males and 0.03% recombination in females.

Alleles↗
PubMed1994

Stimulus induced behaviours in Tourette's syndrome.

Three cases of Gilles de la Tourette's syndrome (GTS) who experienced different tic related behaviours in response to both external and internal stimuli are described. Such behaviours might represent sensory tics, reflex motor tics, exaggerated startle responses, or obsessive compulsive behaviours. It is suggested that there is a continuum of stimulus induced behaviours, and that, in some cases, separations into individual descriptive entities may be difficult. There also seems to be a continuum between internal and external phenomena that induce the behaviours. Implications for the relation between GTS and obsessive compulsive disorder are also discussed.

Acoustic Stimulation↗
PubMed1994

Tourette's syndrome in New Zealand. A postal survey.

It has become increasingly evident that Tourette's syndrome (TS) is not as rare as was once thought and substantial cohorts from various parts of the world have been reported. The clinical characteristics seem independent of culture as they appear to occur with some degree of uniformity irrespective of the country of origin. We investigated the point prevalence and report the clinical characteristics of TS in New Zealand. Forty probable cases were identified and the symptoms were similar to those described in cohorts from other parts of the world.

Adolescent↗
PubMed1994

Bilineal transmission in Tourette's syndrome families.

We assessed the frequency of bilineal (from maternal and paternal sides) transmission of Tourette's syndrome (TS) in two groups of pedigrees: (1) 39 high-density families in which five or more relatives were reported to have TS, and (2) the families of 39 consecutively ascertained probands referred for evaluation of TS. We used two designations for the TS phenotype (tics, tics or obsessive-compulsive behavior [OCB]), and we attempted to verify bilineal transmission with direct examinations. For the high-density pedigrees, bilineal transmission was evident in 33% (considering tics) and 41% (considering tics or OCB) of families, which was confirmed by examination in 77% of the kindreds. For the consecutive pedigrees, bilineal transmission was seen in 15% (tics) and 26% (tics or OCB) of families, which was verified by examination in 66% of the kindreds. Both parents of the proband were affected (tics or OCB) in 38% of the high-density pedigrees and 10% of the consecutive pedigrees. For the high-density families only, the frequency of bilineal transmission appeared to be related to the proband's severity of TS, and for both pedigree groups, the frequency of both parents being affected was higher in families in which the proband's symptoms were most severe. Our findings support the contention that bilineal transmission and homozygosity are common in TS. These genetic phenomena might play a role in determining severity of illness and may explain current difficulties in localizing the gene defect by linkage analysis.

Fathers↗
PubMed1993

An idiot savant calendrical calculator with Gilles de la Tourette syndrome: implications for an understanding of the savant syndrome.

We describe the existence of the savant syndrome in association with Gilles de la Tourette's Syndrome (GTS). The presentation of savant abilities is typical of that previously described. Similarities between autism, the disorder most characteristically associated with savants, and GTS in terms of obsessionality are noted. Previously reported psychological studies of autistic savants are briefly reviewed and, together with evidence from neuroimaging in GTS, obsessive compulsive disorder (OCD), and autism, used to support a model of the underpinnings of savant skills.

Adolescent↗
PubMed1993

Working memory in clinical depression: an experimental study.

This study compared clinically depressed subjects with normal controls on a range of working memory tasks. The findings suggested the articulatory loop and visuospatial sketch pad components of working memory to be unimpaired in depression. On a range of clinical tasks likely to involve central executive function, depressed subjects showed impairment only on some tasks.

Adult↗
PubMed1993

Effects of structure and clustering on recall and recognition memory in clinical depression.

The present study compared retrieval of high, medium, and low structured material, using word lists consisting of uncategorized words and categorized words presented in randomized and clustered order. Clinically depressed subjects were found to be significantly impaired relative to controls only on the medium level of structure and the randomized categories list when measured by free recall. There were no effects of group nor any interactions for recognition memory, although there was a main effect for group on d' when signal detection analysis was applied. The implications of the findings for models of memory deficits in depression are discussed.

Adult↗
PubMed1993

Obsessions in obsessive-compulsive disorder with and without Gilles de la Tourette's syndrome.

OBJECTIVE AND METHOD: Although obsessive-compulsive disorder commonly occurs in many patients with Gilles de la Tourette's syndrome, little is known about the obsessions and compulsions of Tourette's syndrome and whether they differ from those seen in pure obsessive-compulsive disorder. The authors prospectively studied 10 subjects with obsessive-compulsive disorder and 15 subjects with obsessive-compulsive disorder and comorbid Tourette's syndrome by using the Yale-Brown Obsessive Compulsive Scale, the Leyton Obsessional Inventory, and a new questionnaire designed to emphasize the differences in symptoms between these two groups. RESULTS: Subjects with comorbid obsessive-compulsive disorder and Tourette's syndrome had significantly more violent, sexual, and symmetrical obsessions and more touching, blinking, counting, and self-damaging compulsions. The group with obsessive-compulsive disorder alone had more obsessions concerning dirt or germs and more cleaning compulsions. The subjects who had both disorders reported that their compulsions arose spontaneously, whereas the subjects with obsessive-compulsive disorder alone reported that their compulsions were frequently preceded by cognitions. CONCLUSIONS: There are phenomenologic differences between obsessive-compulsive disorder and obsessive-compulsive disorder with comorbid Tourette's syndrome that may reflect differential involvement of neurochemical and neuroanatomic pathways.

Adult↗
PubMed1993

The psychopathology of Gilles de la Tourette's syndrome. A controlled study.

The present study compares adults with Gilles de la Tourette's syndrome (GTS) with depressed adults and normal controls on questionnaires measuring obsessionality, depression, and anxiety. The GTS and depressed groups scored significantly higher than the normal controls on all measures. The GTS subjects had similar scores on measures of obsessionality to those of the depressed subjects, but significantly lower scores on measures of depression and anxiety. This suggests that obsessionality is a prominent feature of GTS, and that the psychopathological profile is different to that of patients with major depressive disorder.

Adult↗
PubMed1993

Evidence for autosomal dominant transmission in Tourette's syndrome. United Kingdom cohort study.

Complex segregation analyses were performed on families ascertained through 40 unselected consecutive patients with Tourette's syndrome to examine the hypothesis that its transmission is consistent with genetic inheritance. Analyses were done using several diagnostic classifications. All results were consistent with an autosomal dominant gene with high penetrance. The penetrances ranged from 0.882 to 1.000 for males and 0.452 to 0.980 for females, depending upon the specific classification scheme incorporated into the analyses.

Adolescent↗
PubMed1992

Elevated frontal cerebral blood flow in Gilles de la Tourette syndrome: a 99Tcm-HMPAO SPECT study.

Case reports, numerous brain imaging studies, and certain disease states suggest that the orbital frontal cortex and the striatum are dysfunctional in obsessive-compulsive disorder (OCD). Interest has also grown recently concerning the genetic, neuroanatomic, and clinical links between OCD, chronic motor tics, and Gilles de la Tourette Syndrome (GTS). To test the hypothesis of possible orbito-frontal/basal ganglia dysfunction in GTS, similar to OCD, we studied 20 unmedicated GTS subjects, 10 of whom also had comorbid OCD (GTS/OCD), and 8 control subjects. The subjects were examined with high-resolution single photon emission computed tomography (SPECT) and the labeled regional cerebral blood flow (rCBF) ligand technetium-99m-d,l-hexamethyl-propylene amine oxime (99Tcm-HMPAO). As a group, GTS subjects showed significantly elevated right frontal/visual cortex activity (mean = 0.879, SD = 0.107) compared with control subjects (mean = 0.798, SD = 0.049). A subanalysis comparing simple GTS versus GTS with comorbid OCD failed to reveal significant differences in regional flow.

Adult↗
PubMed1992

Pharmacologic controversy of CNS stimulants in Gilles de la Tourette's syndrome.

The controversy of the use of stimulants in Gilles de la Tourette's syndrome (GTS) can only be understood by examining the relationship between GTS and attention deficit-hyperactivity disorder (ADHD), because the relationship between the two disorders is complex, and stimulants are used in the one (ADHD) and may be contraindicated in the other (GTS). This relationship therefore has to be viewed from several perspectives, including clinical, genetic, neurobiochemical, neurophysiological, and treatment strategies, to highlight the complexities involved, and reasons for controversy. The present review will examine these relationships, and thus the evidence for and against the treatment of GTS with stimulants.

Adolescent↗