Contingent negative variation in adults with Gilles de la Tourette syndrome

Three deflections or waves of the Contingent Negative Variation (CNV): the Slow Negative Wave (SNW), the Terminal CNV (TCNV) and the Post Imperative Negative Variation (PINV) were studied in 18 adults with Gilles de la Tourette syndrome and in 15 controls. The patients showed a reduced SNW, a normal TCNV and an increased PINV. Moreover, at the right parietal region the patients demonstrated a decreased SNW, TCNV and PINV. The results are discussed in relation to behavioral and neuropsychological disturbances found in Gilles de la Tourette syndrome.

Sensory evoked responses in Tourette syndrome

Based on an earlier study of EEGs and the present article on sensory evoked responses, with a total of 32 patients, it appears that routine electrophysiologic studies do not provide a good biological marker in Tourette Syndrome.

Opioid modulation of gonadotrophin release in Tourette's syndrome

Currently the most prevailing hypothesis attempting to explain the pathophysiology of Tourette's syndrome (TS) suggests that the disease results from dopaminergic (DA) hyperactivity (Golden, 1986). Evidence for this hypothesis is indirect and includes the favorable response of these patients to haloperidol, exacerbation of symptoms with dopaminergic drugs (e.g., methylphenidate) and the findings of reduced DA metabolites in the CSF of some TS patients (Singer et al., 1982). We have recently suggested that deranged opioid functions may also be important in the pathophysiology of TS (Sandyk, 1985). Our hypothesis was based on the favorable response of a subgroup of patients to administration of opiate antagonists (e.g., naloxone, naltrexone) (Sandyk et al., 1986), and is also supported by a recent finding demonstrating depletion of striatal dynorphins in a subject with TS (Haber et al., 1986). Furthermore, based on several clinical features of the disease, we have recently suggested that the hypothalamus could be a site of dysfunction in the disease (Sandyk et al., 1986). To investigate the possible role of deranged opioid-mediated hypothalamic functions in TS further, we tested the effects of acute naloxone (Nx) challenge on plasma FSH and LH levels in 5 male TS patients (aged 11-16 years) and in 4 non-TS-diseased controls (narcoleptics). The plasma FSH and LH levels were drawn prior to and 30 min following the intramuscular administration of 1.2 mg of naloxone.

Opioid-serotoninergic dysregulation in the pathophysiology of Tourette's syndrome

In the following communication the major neurotransmitter systems postulated to be involved in the pathophysiology of Tourette's syndrome are discussed. Malfunctions of the opioid and serotoninergic systems are discussed regarding their role in the pathophysiology of the neuropsychological, behavioural and other manifestations of the disease.

Tourette's syndrome in Monroe County school children

We examined children from Monroe County, New York, to establish the prevalence of Gilles de la Tourette's syndrome (TS) in the county's schools. Patients were recruited for free evaluations from physicians, other health professionals, school personnel, and through extensive coverage in the local news media. Forty-one TS patients were detected among the 142,636 pupils enrolled in the county's public and private schools at the time of the study (estimated prevalence, 28.7 per 100,000). Twenty patients had obsessive-compulsive symptoms, but only three had an impairing, diagnosable disorder. Fifty-six percent had a positive family history for TS or tics. Eighteen needed pharmacotherapy, although, for most, TS was a mild disorder requiring no drug treatment.

A controlled study of Tourette syndrome. VI. Early development, sleep problems, allergies, and handedness

Developmental milestones, problems with bladder and bowel control, sleep disturbances, allergies, and handedness were compared in 247 consecutive Tourette syndrome (TS) patients, 17 patients with attention-deficit disorder (ADD), 15 patients with ADD secondary to TS (ADD 2(0) TS), and 47 random controls. There were no significant differences in age of first talking or walking. By contrast, there were significant differences in problems with bladder and bowel control between TS patients and controls, as measured by age of first toilet training, age of last bed-wetting, frequency of enuresis, and age that bowel control was achieved. Sleep problems were pervasive in TS patients, with a significantly increased frequency of sleepwalking, night terrors, trouble getting to sleep, early awakening, and inability to take afternoon naps as a young child. In all diagnostic categories, including mild (grade 1) TS patients, a total sleep-problem score was significantly greater than that in controls. The sleep disorders and other TS symptoms are consistent with TS as a disorder of disinhibition of the limbic system. Allergies and left-handedness have been evoked as contributing to or being associated with ADD and learning disorders. There were no significant differences in the frequency of allergies or left-handedness in TS patients compared with that in controls. We conclude that when there is a clearly defined genetic cause of ADD and learning disorders, it is not associated with an increased frequency of allergies or left-handedness.

A controlled study of Tourette syndrome. VII. Summary: a common genetic disorder causing disinhibition of the limbic system

Tourette syndrome (TS) is one of the most common genetic disorders affecting man. Approximately one in 100 individuals manifests one or more of the aspects of the TS gene. This series of papers has emphasized that although motor and vocal tics are the hallmark of TS, the complete range of behavioral problems is much broader. This spectrum of behavior can be explained on the basis of the TS gene causing an imbalance of the mesencephalic-mesolimbic dopamine pathways, resulting in disinhibition of the limbic system.

Sleep disorders in Tourette's syndrome

Sleep disorders have been reported in approximately 80% of Tourette's syndrome (TS) patients. Sleep studies in TS patients have demonstrated a 30% reduction in delta-sleep (slow-wave sleep) in nontreated subjects, decreased percentage of REM-sleep and the presence of tics during sleep. A subgroup of young TS patients was reported to have an increased percentage of delta sleep. Although these findings were initially thought to result from deranged dopaminergic and serotoninergic functions in TS, we suggest that abnormalities of hypothalamic-mediated control mechanisms involving the intrinsic opioids may also account for the observed derangements in sleep-wave patterns in TS patients. Evidence for impaired hypothalamic regulation in TS patients includes our preliminary observations of abnormal growth-hormone release to administration of the opiate antagonist naloxone in TS. These data further suggest an interrelationship of neurochemical mechanisms involving opioid-mediated hyperactivity, slow-wave sleep and growth hormone at the level of the hypothalamus.

A rating scale for Gilles de la Tourette's syndrome: description, reliability, and validity data

We developed a rating scale for tic disorders that uses only objective criteria and accommodates the variety of tic manifestations. Using short videotaped recordings with the examiner out of the taping room, we measured five tic variables: number of body areas affected, frequency of motor tics and vocalizations, and severity of motor tics and vocalizations. The rating scale fulfilled tests for inter-rater reliability and temporal stability, and correlated well with scales used to assess global changes over prolonged periods. It objectively detected improvement in tics with neuroleptics, the one pharmacotherapy accepted to abate tics in most patients.

Motor, behavioral and pharmacologic findings in Tourette's syndrome

We studied 112 patients with Tourette's syndrome (TS); the male-to-female ratio was 3.8, the mean age of onset was 7.3 years, and the average duration of symptoms prior to the initial evaluation was 15.2 years. Seventy-nine percent of the patients had at least one family member with motor or vocal tics, and an additional 10 percent had a family member with marked obsessive-compulsive behavior. Simple motor tics occurred as the presenting symptom in about one-third of patients; one-third had multiple motor tics at the onset, and another third started with vocal tics. During the course of the illness all patients developed multifocal motor tics and 86 percent had vocal tics. Verbal and mental coprolalia was present in 44 percent of the patients. Copropraxia was seen in 19 percent of patients, and both coprolalia and copropraxia were more frequent among the males than expected. Attentional deficit disorder was diagnosed in 36 percent of the patients and 32 percent had obsessive-compulsive personality. Sleep disturbances were reported by 62 percent of the patients and polysomnographs in 34 patients showed motor and vocal tics during all stage of sleep, sleep apnea, abnormal arousal pattern, and other sleep disturbances. Patients with mild symptoms improved with clonidine or clonazepam, but those with more advanced disorder required fluphenazine, pimozide, haloperidol or tetrabenazine.

Opioid neuronal denervation in Gilles de la Tourette syndrome

Increased striatal dopaminergic functions with heightened postsynaptic receptor sensitivity has been proposed to underlie the major clinical symptoms of Tourette's syndrome (TS). The beneficial response of the majority of TS patients to haloperidol supports the hyperdopaminergic pathophysiological concept of TS. However, in 5 recently encountered TS patients, haloperidol failed to ameliorate self-injurious behavior (SIB) while the opiate antagonist, naloxone, attenuated SIB, implicating deranged endorphinergic mechanisms in the pathophysiology of this disorder. Brain damage is commonly associated with partial neuronal denervation, denervation supersensitivity and neuronal habituation (Cannon's Law). While the motor tics of TS possibly reflect neuronal denervation of striatal dopaminergic neurons. SIB may represent opioid denervation with alterations in opioid receptor sensitivity possibly involving striato-limbic-hypothalamic circuits. The effect of naloxone on SIB in TS could thus be explained on the basis of a modulatory effect of this drug on opioid receptor sensitivity.

The hypothalamus in Tourette's syndrome

Although a recent report by Devinsky (1983) has suggested that dysfunction at a midbrain levels is most likely to underlie the major symptoms of Tourette's syndrome, several features of the disease including alterations in the severity of the disease during puberty and premenstrually, disorders of appetite, amelioration of tics with rise in body temperature, and sleep point to hypothalamic involvement in the pathophysiology of the disease.

The autonomic nervous system in Gilles de la Tourette's syndrome

Twenty-three patients with Gilles de la Tourette's syndrome (GTS) underwent noninvasive investigation of autonomic nervous system (ANS) function, as did 23 age-matched controls. ANS function in GTS patients was no different from that of controls, and patients receiving neuroleptic drugs had the same ANS function as untreated patients. All 23 patients later received clonidine and were retested. The ANS values before administration of clonidine were compared with those while patients were taking clonidine. The only significant change (p less than 0.01) with clonidine was a reduced resting pulse rate. The combination of clonidine and neuroleptic drugs did not induce significant autonomic changes compared with neuroleptic therapy alone. These results indicate that the ANS in GTS patients is normal and that the drugs used to abate tics do not produce clinically significant changes in ANS when chronically given. The findings suggest that the pathophysiology and treatment of GTS do not directly involve the nuclei or tracts of autonomic regulation.

Rebound phenomena in Tourette's syndrome after abrupt withdrawal of clonidine. Behavioral, cardiovascular, and neurochemical effects

Following an open trial of clonidine hydrochloride (3 to 8 micrograms/kg/day for 12 weeks), we studied the behavioral, cardiovascular, and neurochemical effects of abrupt clonidine withdrawal in seven patients with Tourette's syndrome aged 9 to 13 years. Five patients showed marked worsening of tics. After reinitiation of clonidine therapy, the time required for patients to return to prewithdrawal levels of tic symptoms ranged from two weeks to four months. Increases in motor restlessness, blood pressure, and pulse rate were also observed over the 72-hour period following abrupt withdrawal of clonidine. Plasma levels of free 3-methoxy-4-hydroxyphenylglycol, homovanillic acid, and urinary excretion of norepinephrine and epinephrine increased during the withdrawal period. Clonidine's effectiveness in Tourette's syndrome may be dependent on changes in dopaminergic as well as adrenergic mechanisms.

Electroencephalographic findings in unmedicated, neurologically and intellectually intact Tourette syndrome patients

Electroencephalograms were obtained in 30 unmedicated, neurologically and intellectually intact Tourette syndrome (TS) patients, none having a history of clinically apparent seizure disorder. Six (20%) of initial 30 EEGs were judged to be abnormal, 2 (6.6%) on account of slowing of intrinsic rhythms and/or excess of slow frequencies and 4 (13.3%) on account of epileptiform alterations. Two of the latter 4 patients continued to show similar abnormalities in EEGs done 4 and 8 months later. Five of 6 patients with abnormal EEGs had history of migraine or migraine equivalents compared to 8 of 24 with normal EEGs (chi 2 = 4.88, P less than 0.05). It is concluded that in the population of Tourette patients studied, EEG abnormalities occurred in one-fifth of all patients despite an absence of medication effect, brain damage or seizure disorder and may, in part at least, be related to associated migrainous equivalents.

Familial Tourette's syndrome: report of a large pedigree and potential for linkage analysis

We studied a large Mennonite kindred affected by chronic motor tics (CMTs) and vocal tics in a probable autosomal dominant pattern. We administered a standardized questionnaire to 69 family members and reviewed our videotapes of 47. Using DSM III criteria and independent ratings, we diagnosed 10 subjects as having definite Tourette's syndrome (TS), 3 with definite CMTs, 15 with probable TS, and 1 with probable CMT. The clinical features of this family are presented. This is the largest known kindred with TS. Permanent lymphoblastoid cell lines have been established from 67 family members for genetic linkage analysis.

The endogenous opioid system in Gilles de la Tourette syndrome

The various neurotransmitter systems postulated to be involved in the pathogenesis of Gilles de la Tourette syndrome(GTS) are described with special reference to the endogenous opioid system(EOS). Malfunction of the opioid system is proposed as the underlying disturbance in this disease causing secondary dysfunction of the other systems. Furthermore, the various symptoms of the illness are examined also in terms of dysfunction of the endogenous opioid system.

Gilles de la Tourette's syndrome and schizophrenia

A Gilles de la Tourette's syndrome (TS) patient is described who experienced a schizophrenic episode 11 years after TS onset. Analogies and differences between the two syndromes are reviewed, leading to the conclusion that TS is a definite entity independent from schizophrenia, but that they share some common features of symptomatology and pathophysiology and have closely related anatomical lesions.

Tics in a patient with Parkinson's disease

A patient with Gilles de la Tourette syndrome later developed Parkinson's disease in middle age. This was accompanied by a marked reduction in the frequency of tics but levodopa toxicity exacerbated the tics. The dopamine hypothesis of tic disorders is supported by this observation.

The endogenous opioid system in neurological disorders of the basal ganglia

The endogenous opioid peptides have for some time been implicated in the regulation of motor behavior in animals. Recently, however, there is increased evidence to suggest a role for these peptides in the control of human motor functions as well as in the pathophysiology of abnormal movement disorders. Degeneration of opioid peptide-containing neurons in the basal ganglia has been demonstrated in Parkinson's disease and Huntington's chorea, but the clinical significance of these findings is largely unknown. On the other hand, there is evidence that excessive opioid activity may be important in the pathophysiology of some movement disorders such as tardive dyskinesia, progressive supra-nuclear palsy, and a subgroup of Tourette's patients. These findings indicate that diseases of the basal ganglia are possibly associated with alterations in opioid peptide activity, and that these alterations may be useful in designing experimental therapeutic strategies in these conditions.

Gilles de la Tourette syndrome and the neurological basis of obsessions and compulsions

Gilles de la Tourette syndrome (GTS) is a chronic neurological disorder manifested by involuntary motor tics and vocalizations. Many GTS patients also suffer from obsessions and compulsions. The clinical similarities between GTS and obsessive-compulsive disorder (OCD), their occurrence among members of the same families, and the fact that both can be observed as symptoms of known basal ganglia disturbances suggest that GTS and OCD share common neurological mechanisms. It is hypothesized that the tics and vocalizations of GTS are aberrant manifestations of simple motor programs that are spontaneously generated by the basal ganglia and that obsessions and compulsions represent more complex motor plans initiated by similar anomalous activities.

Relationship of age to neuropsychological deficit in Tourette's syndrome

A previous study suggested that neuropsychological deficit in patients with Gilles de la Tourette's syndrome (TS) may increase with age. This question was studied by examining the relationship between age and neuropsychological deficit in 21 TS patients. It was found that increased age was related to greater neuropsychological deficit on a pattern of measures consistent with previous reports. The use of age corrected t-scores ruled out the general relationship of age with test performance as an explanation of these results. In addition, when the subjects were grouped on the basis of age, older patients were significantly worse than younger patients on several measures.

Eye-blink rate in Tourette's syndrome

Gilles de la Tourette's syndrome is a hyperkinetic movement disorder in which an etiological role for dopaminergic hyperactivity has been proposed. Blink rate, a putative correlate of central dopamine activity, is commonly held to be elevated in Tourette's syndrome, a finding that would be consistent with the "dopamine" hypothesis of this disorder. In 19 patients who had Tourette's syndrome, however, blink rates during placebo treatment were identical with those of 49 index controls during reading and quiet sitting. Blink rate did correlate, however, with both the number and severity of tics. Pimozide treatment did not reduce blinking in the patients. It should be noted that nine of the patients were adolescents for whom there were not adequate age-matched controls, a fact which could obscure a blink rate elevation in this group. Insofar as blink rate is a putative correlate of central dopamine activity, these results are not consistent with elevated brain dopamine activity in adult patients who have Tourette's syndrome.

Tonic, phasic and cortical arousal in Gilles de la Tourette's syndrome

This study explored the hypothesis that Gilles de la Tourette's syndrome involves a disturbance in arousal modulation. The experimental group consisted of 20 unmedicated subjects with the Gilles de la Tourette's syndrome, and the control group of 20 subjects with chronic medical illnesses (haemophilia, von Willebrandt's disease and diabetes). There were differences between groups in the manner in which log conductance level changed over time during sound and light habituation experiments involving mild levels of stimulation with the Gilles de la Tourette group showing less change in arousal level over trials than the control group. No group differences were found in measures of phasic arousal, rate of spontaneous fluctuations and performance on two tasks that have been related to cortical arousal. It is suggested that the slower change in log conductance level in the Gilles de la Tourette group during the sound and light habituation experiments indicates that reticular activity is more persistent in these patients.

Gilles de la Tourette's syndrome. A review of clinical and research studies and consideration of future directions for investigation

Tourette syndrome (TS) is a complex neurobehavioral disorder that has recently become a topic for clinical, genetic, neurochemical, and therapeutic research. Substantial progress has been made defining the clinical features of the disorder, establishing its familial nature, and documenting its response to pharmacotherapeutic intervention. Despite these advances, significant problems remain. The separation between TS and other syndromes is imprecise, and there are no uniformly accepted criteria for measuring response to treatment. Although family studies are promising, no mechanism of genetic transmission has been defined and the number of available revealing kindred for future DNA linkage studies is small. Clinical neurochemical investigations have been hampered by poor design and small subject samples; detailed postmortem neurochemical and pathological studies of brains from patients with TS have not been undertaken thus far. Careful application of newer research technologies combined with appropriately chosen subjects with TS may add to our understanding of the physiologic, anatomic, and genetic factors that contribute to this intriguing disorder. Future postmortem central nervous system studies will be essential.

Late components of the auditory evoked potentials in Gilles de la Tourette syndrome

Late components (N1, P2, N2, P3) of the event-related potential (ERP) elicited by simple auditory discrimination tasks were investigated in 6 patients with Gilles de la Tourette syndrome. The ERP's were registrated in the patients before and during drug treatment as well as in 16 healthy controls. It appeared that in Tourette syndrome the N2 and P2 waveforms (target response) at Cz and Pz were remarkably less well identifiable. The results did not reveal P3 abnormalities in the patients. However, the patients demonstrated definite changes in the N1 and P2 components as compared to the controls. The N1 amplitudes were decreased in the patients. During drug treatment the N1 amplitudes increased although they remained smaller than in the controls. It is concluded that Tourette patients have no abnormalities in early and late components, but that specifically the components between 90-280 ms are affected. These abnormalities may reflect specific attention deficits which often occur in Tourette syndrome.

Homogeneous clinical subgroups in children with Tourette syndrome

The existence of two clinically homogeneous subgroups in Tourette syndrome, depending upon the presence or absence of migraine or a family history of migraine, is suggested. Patients with Tourette syndrome who have migraine (n = 18) were found to have a significantly higher prevalence of disorders of arousal--particularly sleepwalking and night terrors--as well as a higher prevalence of motion sickness than patients without migraine (n = 27). They were also significantly more likely to exhibit a co-occurrence of associated features (two or more) than the patients without migraine. Patients with Tourette syndrome who have not had migraine headaches but in whom there is a family history for migraine (n = 20) were shown to have an intermediate prevalence of associated symptoms. It is suggested that the differential association for these symptoms in patients with Tourette syndrome may reflect an underlying abnormality in function of two different neurotransmitter systems.

The pathophysiology of movement disorders

This review concentrated on the more recent findings of investigations into the functional anatomy and pathophysiology of movement disorders. Attempts were made to provide explanations for rigidity, bradykinesia, and tremor. What little is known of the pathophysiology of chorea, tics, and dystonia is discussed. Greater information is available to allow pathophysiologic classification of different types of myoclonus.