- Postgrad Med 2000 Oct;108(5):175-6,
179-82
- Is it a tic or tourette's? Clues for
differentiating simple from more complex tic
disorders
- Evidente VG
Parkinson's Disease and Movement Disorders
Center, Mayo Clinic Scottsdale, AZ 85359,
USA.
- Tics are characterized by sterotyped,
purposeless, and irregularly repetitive
movements and usually can be classified as
chronic motor or vocal tic disorders, transient
tic disorders, or Tourette's syndrome. The
latter is a complex disorder associated with
multiple tics and often accompanied by other
conditions, such as ADHD and
obsessive-compulsive disorder. Treatment can be
difficult, and drug therapy should begin with
agents least likely to cause problems for the
patient. Education of the patient and family and
support from the physician and other care
providers are essential elements of effective
management.
-
- Arch Gen Psychiatry 2000
Aug;57(8):741-8
- A functional neuroanatomy of tics in
Tourette syndrome.
- Stern E,
Silbersweig DA, Chee KY, Holmes A, Robertson MM,
Trimble M, Frith CD, Frackowiak RS, Dolan RJ
Functional Neuroimaging Laboratory,
Department of Psychiatry, Box 140, Room 1304,
Weill Medical College of Cornell University, 525
E 68th St, New York, NY 10021, USA.
- Tics are involuntary, brief, stereotyped
motor and vocal behaviors often associated with
irresistible urges. They are a defining symptom
of the classic neuropsychiatric disorder,
Tourette syndrome (TS), and constitute an
example of disordered human volition. The neural
correlates of tics are not well understood and
have not been imaged selectively. METHODS:
Event-related [(15)O]H(2)O positron
emission tomography techniques combined with
time-synchronized audio and videotaping were
used to determine the duration of, frequency of,
and radiotracer input during tics in each of 72
scans from 6 patients with TS. This permitted a
voxel-by-voxel correlational analysis within
Statistical Parametric Mapping of patterns of
neural activity associated with the tics.
RESULTS: Brain regions in which activity was
significantly correlated with tic occurrence in
the group included medial and lateral premotor
cortices, anterior cingulate cortex,
dorsolateral-rostral prefrontal cortex, inferior
parietal cortex, putamen, and caudate, as well
as primary motor cortex, the Broca's area,
superior temporal gyrus, insula, and claustrum.
In an individual patient with prominent
coprolalia, such vocal tics were associated with
activity in prerolandic and postrolandic
language regions, insula, caudate, thalamus, and
cerebellum, while activity in sensorimotor
cortex was noted with motor tics. CONCLUSIONS:
Aberrant activity in the interrelated
sensorimotor, language, executive, and
paralimbic circuits identified in this study may
account for the initiation and execution of
diverse motor and vocal behaviors that
characterize tics in TS, as well as for the
urges that often accompany them.
-
- Int J Neurosci 1995
Mar;81(1-2):95-100
- Cholinergic mechanisms in Gilles de la
Tourette's syndrome.
- Sandyk R
NeuroCommunication Research Laboratories,
Danbury, CT 06811, USA.
- Gilles de la Tourette syndrome (GTS), a
chronic, familial, neuropsychiatric disorder of
unknown etiology, is characterized clinically by
the presence of motor and vocal tics that wax
and wane in severity over time and by the
occurrence of a variety of neurobehavioral
disturbances including hyperactivity,
self-mutilatory behavior, obsessive compulsive
behavior, learning disabilities, and conduct
disorder. Pharmacological studies suggest that
the tics of GTS result from dysfunction of
monoaminergic systems, more specifically from
increased dopaminergic activity due to
postsynaptic dopamine receptor supersensitivity.
However, given that striatal dopaminergic and
cholinergic systems exhibit reciprocal
antagonism in other movement disorders such as
Parkinsonism and chorea, it is conceivable that
the cholinergic system is implicated in the
disease. In the present communication it is
proposed that: (a) the emergence of motor and
vocal tics in GTS is associated with increased
central cholinergic activity; (b) cholinergic
overactivity is involved in the manifestation of
other symptoms in GTS including depression,
sleep disorders, motion sickness, pain, sensory
tics, and the waxing and waning course of the
disease; (c) abnormalities of the cholinergic
system support previous evidence linking GTS
with delayed cerebral maturation in a subset of
young patients; and (d) drugs which stimulate
cholinergic receptors may exacerbate symptoms of
GTS, and as with dopamine agonists, should be
avoided in patients with GTS.
-
- Int J Neurosci 1996
Feb;84(1-4):187-94
- Effects of
picotesla flux electromagnetic fields on
dopaminergic transmission in Tourette's
syndrome.
- Sandyk R NeuroCommunication Research
Laboratories, Danbury, CT 06811, USA.
- Tourette's syndrome (TS), a chronic familial
neuropsychiatric disorder ofunknown etiology, is
characterized clinically by the presence of
motor and vocal tics that wax and wane in
severity over the time and by the occurrence of
a variety of neurobehavioral disorders. It is
believed that the tics of TS result from
increased dopamine (DA) activity caused by
postsynaptic DA receptor supersensitivity. The
synthesis and release of DA is regulated
presynaptically by a specific class of DA D2
receptors, termed autoreceptors activation of
which causes inhibition of DA synthesis and
release. In experimental animals and humans
administration of small doses of apomorphine, a
DA D2 autoreceptor agonist, produces yawning.
Recurrent episodes of yawning followed by
increased motor tic activity was observed in two
patients with TS during exposure to brief,
extracranial applications of picotesla flux
electromagnetic fields(EMFs). On the basis of
these observations it is suggested that
recurrent episodes of yawning in response to
application of EMFs was induced by activation of
presynaptic DA D2 autoreceptors while further
exposure to these EMFs caused excessive
stimulation of postsynaptic DA D2 receptors
resulting in exacerbation of the tics. Thus, the
dual effects of picotesla flux EMFs on the DA D2
autoreceptor and the postsynaptic receptor
resemble the biphasic pharmacological and
behavioral properties of apomorphine, a DA
agonist which activates the autoreceptors in low
doses while in higher doses causes stimulation
of the postsynaptic receptors producing
exacerbation of symptoms of TS. These findings
demonstrate that picotesla flux EMFs applied
extracerebrally may influence nigrostriatal DA
transmission at pre- and postsynaptic DA D2
receptor sites.
-
-
- Panminerva Med 2000
Mar;42(1):61-7
- Tourette's syndrome in children:
neurobiological issues in pathophysiology.
- Masi G,
Brovedani PDivision of Child Neurology and
Psychiatry, University of Pisa, IRCCS Stella
Maris, Calambrone, Italy.
- In recent decades significant advances in
the understanding of neurobiological substrates
of Tourette's Syndrome (TS) have led to the
formulation of hypotheses regarding the ways in
which the most salient features of the syndrome
may occur. Pathophysiology of TS involves
multiple intertwined neurobiological issues in
different areas of the Central Nervous System.
This review considers neuroimaging studies (MRI,
PET, SPECT) in patients with TS. Neurochemical
neurophysiological and electrophysiological
studies are also reviewed. The role of the
neuroendocrine and neuroimmunologic mechanism on
pathogenesis of the disease is discussed.
Advances in diagnostic techniques (fMRI, mMRI,
PET, SPECT) and in neurophysiological research
on neurotransmitter systems will allow us to
better understand the pathophysiology of TS and
to use more specific treatments.
-
- Eur Child Adolesc Psychiatry 2000;9
Suppl 1:I60-75
- Gilles de la Tourette syndrome: symptomatic
treatment based on evidence.
- Robertson MM, Stern
JS Department of Psychiatry and Behavioural
Sciences, Royal Free and UniversityCollege
Medical School, University College, London,
UK.
- The treatment of the Gilles de la Tourette
syndrome has evolved from case reports, clinical
experience and more recently blinded trials
usually in small numbers of patients. We have
reviewed the evidence available to clinicians.
The oldest and still most widely prescribed
drug, haloperidol, should now not be considered
the first-line agent in children as other agents
have superior adverse effects profiles.
Symptomatic treatment should be targeted to the
specific additional psychopathologies seen in
the syndrome. For the treatment of tics,
sulpiride, tiapride, possibly pimozide and in
some cases clonidine may be considered
first-line agents. Although a body of data
supports pimozide, caution has to be exercised
in relation to possible cardiac effects.
Antidepressants and stimulants have an important
place in the management of depression,
obsessionality and attention deficit
hyperactivity disorder. The latter also responds
to clonidine making it a rational first choice
where ADHD coexists with GTS. There are a
multitude of other drugs advocated in the
literature in addition to reports of
neurosurgery and the novel use of immune
modulation. Therapeutic trials for GTS are
challenging. However, further data from blinded
trials are required before many of these
treatments can be considered to be mainstream
treatment options.
-
- Addict
Dis 1975;2(1-2):187-99
- A study of factors that influence the
severity of neonatal narcotic withdrawal.
- Ostrea EM Jr, Chavez CJ, Strauss
ME
- 1. History is unreliable in assessing
maternal drug habit. Morphine was detected in
significant amounts in maternal and fetal urine
regardless of whether the mother was on a
methadone program or whether she denied any use
of heroin during the last trimester of
pregnancy. 2. Infants born to drug-addicted
mothers were, in general, of birthweight normal
and appropriate for gestational age (i.e.,
greater that 10th percentile). The infants born
to mothers on a methadone clinic program had a
higher birthweight compared to those whose
mothers were not on any methadone program. 3. In
order of frequency, the signs and symptoms of
withdrawal were: central nervous system
manifestations-fist sucking, irritability,
tremors, sneezing, high-pitch cry, hypertonia;
vasomotor in the form of stuffy nose; and
gastrointestinal in the form of sweating,
diarrhea, vomiting and yawning. Convulsions were
not noted. No death occurred. 4. The severity of
neonatal narcotic withdrawal did not correlate
with the infant's gestational age, APGAR, sex or
race; nor with maternal age, parity, duration of
heroin addiction or duration of methadone
intake. Also, it did not correlate with the
total morphine level measured either in infant's
or mother's urine or in cord blood. The serum
levels of calcium and glucose were normal and
identical in either mild or severe withdrawal.
5. The severity of neonatal withdrawal
correlated significantly with the methadone dose
per day of the mother (in initial, final or
average dose). A maternal methadone dose of more
than 20 mg per day was associated with a higher
incidence of moderate to severe withdrawal in
their babies. As a corollary, it was also noted
that infants whose mothers were on a high
methadone dose (i.e., greater than 20 mg per
day) had a greater postnatal weight loss despite
a significantly higher birthweight initially,
and stayed in the hospital longer. 6. Finally,
the modification of the environment to reduce
external stimuli to the infant born to a
drug-dependent mother, does not prevent or
diminish the severity of neonatal narcotic
withdrawal. Thus, there is no need to manage
these infants in a special nursery.
-
- Rev
Neurol (Paris) 1985;141(6-7):429-39
- Role of alpha-MSH and related peptides in
the central nervous system
- Delbende C, Jegou S, Tranchand-Bunel D,
Leroux P, Tonon MC, Mocaer E, Pelletier G,
Vaudry H
- Alpha-melanocyte stimulating hormone
(alpha-MSH) is a tridecapeptide secreted by
intermediate lobe cells and synthesized in the
brain as well. As a hormonal peptide, the
physiological function of alpha-MSH consists
mainly in the control of pigment movements
within dermal melanophores.At the pituitary
level, alpha-MSH secretion is under
multifactorial control: it is inhibited by
dopamine and GABA and stimulated by
corticoliberin (CRF), thyroliberin (TRH),
beta-adrenergic agonists and (or) serotonin.
Identification of alpha-MSH containing neurons
in the hypothalamus and other brain regions
(septum, thalamus, mid-brain, striatum,
hippocampus, cerebral cortex and spinal cord)
has been carried out by means of immunological
and biochemical techniques combined with
bioassays. In the central nervous system (CNS)
as in the hypophysis, alpha-MSH is synthesized
from a high molecular weight precursor,
pro-opiomelanocortin (POMC). Maturation of this
protein yield similar end products in the
hypothalamus and the intermediate lobe. Several
peptides chemically related to alpha-MSH are
generated including the desacetyl and monoacetyl
(authentic alpha-MSH) forms; the latter has the
greatest behavioral activity. The demonstration
that alpha-MSH has numerous central nervous
system effects has raised the possibility that
this neuropeptide acts as a neuromodulator or a
neurotransmitter. In the rat,
intra-cerebroventricular administration of
ACTH/MSH peptides induces the
stretching-yawning syndrome (SYS) which
is frequently preceded by excessive grooming.
This excessive grooming is blocked by
neuroleptics indicating that the central
dopaminergic neurons are implicated in this
behavioral effect of the peptide. alpha-MSH is
involved in memory, arousal and attention; in
hypophysectomized animals, the learning ability
is restored after administration of MSH or
related peptides. Injection of alpha-MSH delays
also extinction of passive avoidance behavior
and affects performances motivated by hunger as
well as aggressive behavior. Recent studies
concerning the role of alpha-MSH have been
undertaken in human beings. The effects of
MSH-related peptides favour a role of these
peptides in arousal: they maintain a high level
of vigilance and improve visual discrimination.
These behavioral changes were accompanied by
marked changes in CNS electrophysiology. Current
studies, which aim at establishing a
neurotransmitter function for alpha-MSH, concern
the distribution and characterization of
alpha-MSH receptors in the central nervous
system and the mechanism controlling the release
of neuronal alpha-MSH.
-
- Rinsho
Shinkeigaku 1982 Feb;22(2):112-9
- Ide M, Kataoka A, Koriyama T, Osame M,
Igata A
- New accompaning signs and symptoms of
adrenoleukodystrophy. Adrenoleukomyeloneuropathy
with hypoparathyroidism, cerebral calcification,
and frequent yawning
-
- Pharmacol Biochem Behav 1976;5(Suppl
1):159-63
- Neurologically active peptides
- Barbeau A, Gonce
M, Kastin AJ
- This paper reviews recent evidence that a
number of small peptides found in the brain are
active in the central nervous system and
behaviorally. Attention is focused on MSH/ACTH
4-10, alpha- and beta-MSH, and the prohormone
beta-LPH, as they produce a syndrome of yawning
and stretching. Studies with substance P and
mainly with MIF-I are also reviewed. It is shown
that substance P is an excitatory transmitter or
modulator in the dorsal spinal cord with that
MIF-I has antiparkinson properties. It is
concluded that many polypeptides have direct
actions on the central nervous system
independent of their neuroendocrine
properties
-
- Eur
J Pharmacol 1999 Jun
30;375(1-3):1-11
- Behavioral pharmacology of neuropeptides
related to melanocortins and the
neurohypophyseal hormones.
- de Wied D Rudolf Magnus Institute for
Neurosciences, Department of Medical
Pharmacology, Utrecht University, The
Netherlands.
- Neuropeptides are peptides which affect the
nervous system. They are derived from large
precursor molecules. These are converted to
neurohormones, neuropeptides of the "first
generation", which can be further converted to
neuropeptides of the "second generation". This
review is a brief survey of the nervous system
effects of neuropeptides derived from
pro-opiomelanocortin (POMC) and the
neurohypophyseal hormones. Processing of these
molecules results in neuropeptides of the first
and second generation which have similar,
different, more selective or even opposite
effects. Among those are effects on learning and
memory processes, grooming, stretching and
yawning, social, sexual and rewarded behavior,
aging and nerve regeneration, thermoregulation,
pain, sensitivity to seizures, and
cardiovascular control. Results of animal
studies as well as those of clinical studies
suggest that these neuropeptides may be
beneficial in aging, neuropathy, memory
disturbances and schizophrenia. Most of these
nervous system effects in animal studies were
found before receptors in the nervous system for
the various neuropeptides were detected.
G-protein-coupled receptors for the
neuropeptides of the "first generation", i.e.,
melanocortin receptors, opioid receptors, and
neurohypophyseal hormone receptors have been
found, in contrast to the receptors for
neuropeptides of the "second generation",
although there are indications that G-protein
coupled receptors for these may be present in
the brain.
-
-
- Biol
Rev Camb Philos Soc 1999
Aug;74(3):347-74
- Miklosi A. Department of Ethology,
Eotvos University, Budapest, Hungary.
- The ethological analysis of imitation.
- Theorists and experimental researchers have
long debated whether animals are able to
imitate. A variety of definitions of imitation
have been proposed to describe this complex form
of social learning. Experimental research on
imitation has often been hampered by either a
too loose 'anthropomorphic' approach or by too
narrow 'behaviourist' definitions. At present
neither associative nor cognitive theories are
able to offer an exhaustive explanation of
imitation in animals. An ethological approach to
imitation offers a different perspective. By
integrating questions on function, mechanism,
development and evolution one can identify
possible directions for future research. At
present, however, we are still far from
developing a comprehensive theory of imitation.
A functional approach to imitation shows that,
despite some evidence for imitative learning in
food processing in apes, such learning has not
been shown to be involved in the social
transmission of either tool-use skills or
communicative signals. Recently developed
procedures offer possible ways of clarifying the
role of imitation in tool use and visual
communication. The role of imitation in
explorative play in apes is also investigated
and the available data suggest that copying
during play might represent a behavioural
homologue of human imitation. It is proposed
that the ability to copy the behaviour of a
companion is under a strong genetic influence in
many social species. Many important factors have
not been examined experimentally, e.g. the
effect of the demonstrator, the influence of
attention and memory and the ability to
generalize. The potential importance of
reinforcement raises the possibility that
copying abilities serving divergent functions
might be partly under the control of different
mechanisms.
-
- Child Dev 1983
Jun;54(3):702-9
- Newborn infants imitate adult facial
gestures.
- Meltzoff AN,
Moore MK.
- Newborn infants ranging in age from 0.7 to
71 hours old were tested for their ability to
imitate 2 adult facial gestures: mouth opening
and tongue protrusion. Each subject acted as his
or her own control in a repeated-measures design
counterbalanced for order of stimulus
presentation. The subjects were tested in low
illumination using infrared-sensitive video
equipment. The videotaped records were scored by
an observer who was uninformed about the gesture
shown to the infants. Both frequency and
duration of neonatal mouth openings and tongue
protrusions were tallied. The results showed
that newborn infants can imitate both adult
displays. 3 possible mechanisms underlying this
early imitative behavior are suggested:
instrumental or associative learning, innate
releasing mechanisms, and active intermodal
matching. It is argued that the data favor the
third account.
-
- Revue du praticien 1991, 41, 1
p7-15
- G. Couly
Development of the face in the embryo
- The facial complex and the brain develop
separately from a common embryonic structure
called ectoblast. The neural crest cells which
migrate early on from the neural groove
differentiate into facial parenchyma, so that
the embryological origin of the face is a neural
one. The cephalic pole bas a primitive
encephalofacial and encephalocervical
segmentation with strict topographical
correspondence : the nasofrontral and
premaxillary structures are related to the
anterior brain, whereas the maxi! Io-mandi bular
and anterior cervical structures are related to
the brainstem and its nerves. Thus the face is a
qualitative, quantitative and topographical
marker of the central nervous system. At the
beginning of the third month the embryo becomes
a fœtus due to the appearance of the first
oral and pharyngeal motor sequences which are
dependent upon the neurological development of
the brainstent. This sum of embryological
knowledge has clinical semiological applications
: the face and its functions play the predictive
role in the search for associated malformations
of the same neural origin (brain, eye, neck,
thorax). Such malformations are
neurocristopathies.
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