Diagnosis and management of acute movement disorders

A novel termination site in a case of Stüve-Wiedemann syndrome: case report and review of literature

Stüve-Wiedemann syndrome (SWS) is a rare autosomal recessive disorder that is characterized by bowing of long bones, dysautonomia, temperature dysregulation, swallowing and feeding difficulties, and frequent respiratory infections. Respiratory distress and hyperthermic events are the leading causes of early neonatal death, and most patients are not expected to survive past infancy. Here, we report on the survival of a 5-year-old male with SWS, discussing his case presentation, providing a brief clinical course, and discussing the outcome. This case adds to the literature surrounding rare instances of childhood survivors of SWS and raises awareness for this syndrome to facilitate an earlier recognition, intervention, and genetic counseling for the families, thereby improving understanding of this disease and the health outcomes for the children affected by this condition.

Episodic Ataxias: Faux or Real?

The term Episodic Ataxias (EA) was originally used for a few autosomal dominant diseases, characterized by attacks of cerebellar dysfunction of variable duration and frequency, often accompanied by other ictal and interictal signs. The original group subsequently grew to include other very rare EAs, frequently reported in single families, for some of which no responsible gene was found. The clinical spectrum of these diseases has been enormously amplified over time. In addition, episodes of ataxia have been described as phenotypic variants in the context of several different disorders. The whole group is somewhat confused, since a strong evidence linking the mutation to a given phenotype has not always been established. In this review we will collect and examine all instances of ataxia episodes reported so far, emphasizing those for which the pathophysiology and the clinical spectrum is best defined.

Ziprasidone-Induced Oculogyric Crisis in a 74-Year-Old Female

Oculogyric crisis is a rare ocular dystonia first appearing at the turn of the last century in postencephalitic patients. In the modern era, they were most frequently associated with first-generation D1 dopaminergic receptor blocking antipsychotic medication.

We present an unusual case of acute oculogyric crisis in a 74-year-old woman with long-standing Parkinson disease following exposure to the second-generation neuroleptic ziprasidone, which has dopaminergic (D2) and serotoninergic (5-HT2A) receptor blocking effects and is used for severe delusions and psychosis. To the best of our knowledge, there are no other published reports.

Caregiver burden and health-related quality of life in idiopathic dystonia patients under botulinum toxin treatment: a cross-sectional study

Dystonia is a chronic movement disorder that is associated with a reduction in health-related quality of life (HR-QoL) and restriction of activities of daily living. Botulinum neurotoxin (BT) improves disease-specific HR-QoL by reducing abnormal movements, postures, and pain. We examined the burden of the corresponding primary caregiver as a potential important factor for disease management and HR-QoL of dystonia patients under treatment with BT. 114 patients with focal, segmental, or generalized dystonia were recruited, together with 93 corresponding caregivers, whose burden was investigated using the Caregiver Burden Inventory. In addition, all participants were assessed for cognitive impairment, depression, anxiety, alexithymia, and HR-QoL. Only a small proportion of caregivers suffered from caregiver burden. Despite BT therapy, patients' HR-QoL was decreased compared to the age-matched general German population. Psychological symptoms, notably anxiety, and depression correlated significantly with reduced HR-QoL. Our data imply that caregiver burden emerged to be an issue in subgroups of dystonia patients. Furthermore, HR-QoL of dystonia patients is reduced even under optimized BT treatment in a specialized center.

Acute Focal Dystonia After a Single Dose of Oral Cetirizine in a 9-Year-Old Boy

Common cold is an acute illness affecting pediatric population in particular. The use of antihistamines is a common practice, with cetirizine being a frequently used drug with a good safety profile. However, adverse events due to the use of antihistamines have been rarely reported, such as drug-induced dystonia with the use of cetirizine. In our present case, dystonia due to the intake of cetirizine was observed, which the patient responded well to the use of benzodiazapines, namely, clonazepam. We report this case to highlight the occurrence of this adverse event with the use of cetirizine.

An unusual cause of cervical kyphosis

BACKGROUND CONTEXT

Acute fixed cervical kyphosis may be a rare presentation of conversion disorder, psychogenic dystonia, and potentially as a side effect from typical antipsychotic drugs. Haldol has been associated with acute dystonic reactions. In some cases, rigid deformities ensue. We are reporting a case of a fixed cervical kyphosis after the use of Haldol.

PURPOSE

To present a case of a potential acute dystonic reaction temporally associated with Haldol ingestion leading to fixed cervical kyphosis.

STUDY DESIGN

This is a case report.

METHODS

A patient diagnosed with bipolar disorder presented to the emergency room several times with severe neck pain and stiffness. The neck appeared fixed in flexion with extensive osteophyte formation over a 3-month period.

RESULTS

The patient's condition was resolved by a posterior-anterior-posterior surgical approach. It corrected the patient's cervical curvature from 88° to 5°.

CONCLUSIONS

Acute dystonic reactions have the potential to apply enough pressure on bone to cause rapid osteophyte formation.

Stroke-like onset of brain stem degeneration presents with unique MRI sign and heterozygous NMNAT2 variant: a case report

Background

Acute-onset neurodegenerative diseases in older patients are rare clinical cases, especially when the degeneration only affects specific regions of the nervous system. Several neurological disorders have been described in which the degeneration of brain parenchyma originates from and/or primarily affects the brain stem. Clinical diagnosis in these patients, however, is often complicated due to a poor understanding of these diseases and their underlying mechanisms.

Case presentation

In this manuscript we report on a 73-year-old female who had experienced a sudden onset of complex neurological symptoms that progressively worsened over a period of 2 years. Original evaluation had suggested a MRI-negative stroke as underlying pathogenesis. The combination of patient’s medical history, clinical examination and exceptional pattern of brain stem degeneration presenting as “kissing swan sign” in MR imaging was strongly suggestive of acute onset of Alexander’s disease. This leukoencephalopathy is caused by GFAP (glial fibrilary acidic protein) gene mutations and may present with brain stem atrophy and stroke-like onset of symptoms in elderly individuals. However, a pathognomonic GFAP gene mutation could not be identified by Sanger sequencing.

Conclusions

After an extended differential diagnosis and exclusion of other diseases, a definite diagnosis of the patient’s condition presently remains elusive. However, whole-exome sequencing performed from patient’s blood revealed 12 potentially disease-causative heterozygous variants, amongst which several have been associated with neurological disorders in vitro and in vivo – in particular the axon degeneration-related NMNAT2 gene.

Abnormal movements in critical care patients with brain injury: a diagnostic approach

Abnormal movements are frequently encountered in patients with brain injury hospitalized in intensive care units (ICUs), yet characterization of these movements and their underlying pathophysiology is difficult due to the comatose or uncooperative state of the patient. In addition, the available diagnostic approaches are largely derived from outpatients with neurodegenerative or developmental disorders frequently encountered in the outpatient setting, thereby limiting the applicability to inpatients with acute brain injuries. Thus, we reviewed the available literature regarding abnormal movements encountered in acutely ill patients with brain injuries. We classified the brain injury into the following categories: anoxic, vascular, infectious, inflammatory, traumatic, toxic-metabolic, tumor-related and seizures. Then, we identified the abnormal movements seen in each category as well as their epidemiologic, semiologic and clinicopathologic correlates. We propose a practical paradigm that can be applied at the bedside for diagnosing abnormal movements in the ICU. This model seeks to classify observed abnormal movements in light of various patient-specific factors. It begins with classifying the patient’s level of consciousness. Then, it integrates the frequency and type of each movement with the availability of ancillary diagnostic tests and the specific etiology of brain injury.

Childhood dystonias

OPINION STATEMENT

Dystonia is a movement disorder caused by diverse etiologies. Its treatment in children is particularly challenging due to the complexity of the development of the nervous system from birth to young adulthood. The treatment options of childhood dystonia include several oral pharmaceutical agents, botulinum toxin injections, and deep brain stimulation (DBS) therapy. The choice of drug therapy relies on the suspected etiology of the dystonia and the adverse effect profile of the drugs. Dystonic syndromes with known etiologies may require specific interventions, but most dystonias are treated by trying serially a handful of medications starting with those with the best risk/benefit profile. In conjunction to drug therapy, botulinum toxin injections may be used to target a problematic group dystonic muscles. The maximal botulinum toxin dose is limited by the weight of the child, therefore limiting the number of the muscles amenable to such treatment. When drugs and botulinum toxin injections fail to control the child's disabling dystonia, DBS therapy may be offered as a last remedy. Delivering optimal DBS therapy to children with dystonia requires a multidisciplinary team of experienced pediatric neurosurgeons, neurologists, and nurses to select adequate candidates, perform this delicate stereotactic procedure, and optimize DBS delivery. Even in the best hands, the response of childhood dystonia to DBS therapy varies greatly. Future therapy of childhood dystonia will parallel the advancement of knowledge of the pathophysiology of dystonic syndromes and the development of clinical and research tools for their study.

Acute cervical dystonia after the first dose of butamirate citrate

Butamirate citrate is a central-acting antitussive drug and is widely used in clinical practice in childhood. It is thought that to be centrally active antitussive drugs act through receptors in the brainstem to inhibit cough, and these findings were based on the evidence of animal models. Central nervous system adverse effects of cough suppressants are rare and include irritability, lethargy, hallucinations, and dystonic reactions. In this report, we present the first patient who developed cervical dystonia shortly after the first dose of butamirate citrate, and the patient's symptoms improved immediately after a single intramuscular dosage of biperiden.

Effect of acetazolamide for long-lasting paroxysmal dystonia in a patient with multiple sclerosis: a case report and review of literature

Dystonia is a rare manifestation of multiple sclerosis (MS), but it always interferes with the functional performance and quality of life. We report a rare case of long-lasting paroxysmal dystonia associated with MS. The patient was a 40-year-old woman with relapsing- remitting MS for 6 years. During the latest attack of MS, she suffered from long-lasting paroxysmal dystonia in her left hand. Despite treatment with pulse high-dose intravenous methylprednisolone, interferon, and baclofen, along with occupational therapy, the dystonia persisted and significantly bothered her daily activities. Finally, she was treated with oral acetazolamide (250 mg, three times a day for 4 days), which was very effective for the control of her dystonia. The dystonic movement subsided without recurrence in a follow-up of 17 months. We advocate this effective and safe treatment for patients with paroxysmal dystonia associated with MS.

Neuroleptic malignant syndrome-an 11-year longitudinal case-control study

OBJECTIVE

To describe patients with neuroleptic malignant syndrome (NMS), to establish occurrence of NMS, to investigate risk factors of NMS, and to investigate mortality associated with NMS.

METHOD

We conducted a longitudinal register linkage case-control study of NMS.

RESULT

In health care registers covering the period from 1996 to 2007, we identified, among 224 372 patients with organic, psychotic, affective, or neurotic diagnosis, 83 patients with NMS, equivalent to an occurrence of 0.04%. Treatment with second-generation antipsychotics (SGAs) in the 3 months preceding admission increased the NMS risk (OR 4.66; 95% CI 1.96 to 11.10) and also first-generation antipsychotics (FGAs) of high potency (OR 23.41; 95% CI 5.29 to 103.61) and mid potency (OR 4.81; 95% CI 1.96 to 11.79), and depot antipsychotics (OR 4.53; 95% CI 1.60 to 12.80). Benzodiazepines (BDZs) also increased the risk of NMS (OR 3.43; 95% CI 1.68 to 12.80). NMS was associated with an increased mortality (HR 1.88; 95% CI 1.19 to 2.98) in patients, compared with sex-, age-, and diagnosis-matched control subjects, but no significant difference in mortality between patients and control subjects was observed after the initial 30 days (P = 0.27).

CONCLUSIONS

The occurrence of NMS is low, and the prediction of NMS is difficult. Previous treatment with FGAs, SGAs, and BDZs was identified as a risk factor for developing NMS. NMS increased mortality within 30 days after NMS.

Cefixime-induced oculogyric crisis

Oculogyric crisis is a neurologic adverse event characterized by bilateral dystonic, usually upward, conjugate eye deviations. Cefixime is a third-generation cephalosporin and is widely used in clinical practice in childhood. Confusion, encephalopathy, coma, myoclonus, nonconvulsive status epilepticus, and seizures have been described with the use of cephalosporins. We presented a cefixime-induced oculogyric crisis in a 7-year-old boy during the treatment of urinary tract infection, and this is the first case of cefixime-induced oculogyric crisis whose ocular symptoms gradually disappeared within 48 hours after the drug was discontinued.

Treatment of paroxysmal dyskinesias

IMPORTANCE OF THE FIELD

Paroxysmal dyskinesias represent a heterogeneous group of rare diseases sharing characteristics with two important groups of neurological disorders, the movement disorders and the epilepsies. Their common hallmark is the paroxysmal occurrence of dyskinesias including athetosis, ballism, chorea and dystonia. During the last two decades, various genetic abnormalities have been identified thereby providing insight into the underlying pathophysiology and offering therapeutic opportunities for many of these conditions.

AREAS COVERED IN THIS REVIEW

We summarize the diagnostic criteria of idiopathic and symptomatic paroxysmal dyskinesias and describe their therapeutic options. For the preparation of this review article, an extensive literature search was undertaken using PubMed.

WHAT THE READER WILL GAIN

This review provides a practical guide to the diagnosis and treatment of paroxysmal dyskinesias.

TAKE HOME MESSAGE

The mainstay of therapy is carbamazepine for paroxysmal kinesigenic dyskinesias and clonazepam for the nonkinesigenic dyskinesias. In symptomatic paroxysmal dyskinesias, the treatment of the underlying disease will provide best results. The ketogenic diet for patients with paroxysmal exertion-induced dyskinesias is a promising new therapeutic strategy and may not only prevent attacks but also lead to improvement of developmental delay in affected children.

A prospective study of acute movement disorders in children

AIM

The purpose of this study was to report a prospective cohort of children with acute-onset movement disorders.

METHOD

We report on 52 individuals (31 females, 21 males; mean age 6y 5mo, range 2mo-15y) with acute-onset movement disorders managed at a busy tertiary paediatric referral hospital over a 40-month period.

RESULTS

In descending order of frequency, the movement disorders reported were chorea, dystonia, tremor, myoclonus, and parkinsonism. It was possible to divide the participants into three groups: (1) those with inflammatory or autoimmune disorders (n=22), (2) those with non-inflammatory disorders (n=18), and (3) those with psychogenic disorders (n=12). The inflammatory or autoimmune aetiologies included N-methyl-D-aspartate receptor encephalitis (n=5), opsoclonus-myoclonus syndrome (n=4), Sydenham chorea (n=3), systemic lupus erythematosus (n=3), acute necrotizing encephalopathy (n=3), and other types of encephalitis (n=4). Other important non-inflammatory movement disorder aetiologies included drug-induced movement disorder (n=6), post-pump chorea (n=5), metabolic (n=3) and vascular (n=2) disease. The participants with psychogenic movement disorders (n=12) were all over 10 years of age and were more likely to be female. Tremor and myoclonus were significantly over-represented in the psychogenic movement disorder subgroup. The outcomes of the total cohort were variable, and included full recovery, severe morbidity, and death.

INTERPRETATION

Acute-onset movement disorders in children are important and may be treatable. Management should focus upon identifying the cause and treating the underlying disease process, as symptomatic treatment of the abnormal movements is variably effective.

Evaluation of akathisia in patients with schizophrenia, schizoaffective disorder, or bipolar I disorder: a post hoc analysis of pooled data from short- and long-term aripiprazole trials

The objective of this article is to assess the clinical characteristics of akathisia in patients with schizophrenia, schizoaffective disorder, or bipolar I disorder receiving aripiprazole, haloperidol, olanzapine, or placebo. We conducted post hoc analyses of pooled safety data from trials in patients with schizophrenia, schizoaffective disorder, and bipolar I disorder. Outcome measures included the incidence of akathisia, time to onset, duration, severity, and discontinuation due to akathisia, concomitant use of benzodiazepines and/or anticholinergics, Barnes Akathisia Rating Scale (BARS) scores, and the correlation between antipsychotic efficacy and akathisia. The results for schizophrenia and schizoaffective disorder were as follows: akathisia in 9% of aripiprazole- and 6% of placebo-treated patients; 12.5% of aripiprazole- versus 24% of haloperidol-treated patients; 11% of aripiprazole- versus 6% of olanzapine-treated patients. Bipolar I disorder: akathisia in 18% of aripiprazole- and 5% of placebo-treated patients. The clinical characteristics of akathisia were similar between each data set, regardless of disease. Akathisia was generally mild-to-moderate in severity. Discontinuation due to akathisia was low in both the schizophrenia trials (aripiprazole 0.3%; placebo 0%; aripiprazole 0.9%; haloperidol 2.3%; aripiprazole 1.2%; olanzapine 0.2%) and the bipolar trials (aripiprazole 2.3%; placebo 0%). Treatment-emergent akathisia was not associated with a poorer clinical response. In conclusion, akathisia with aripiprazole occurred early in treatment, was mild-to-moderate in severity, led to few study discontinuations, and did not compromise therapeutic efficacy.

Barking vocalizations and shaking movements in a 13-year old girl

Erica is a 13-year old female who was hospitalized for a 4-week history of "barking" noises and 2 weeks of generalized shaking episodes. Four weeks prior to admission, she had a viral upper respiratory infection (URI) with cough which was treated with over-the-counter cough syrup. After resolution of the URI, she developed a persistent cough that turned into a "bark"-like vocalization. Both the mother and patient demonstrated the bark as an "arf" sound like that of a small dog at times, a large dog at others. These vocalizations were unrelenting, occurring 3-10 times per minute only while awake. They were not precipitated by any known factors nor were there alleviating factors. She could not voluntarily suppress the sound. In addition to the vocalizations, episodes of generalized shaking of the extremities began 2 weeks prior to admission. According to Erica's mother, each episode lasted about 10-60 seconds and occurred 30-40 times a day only when she was awake. These episodes were not rhythmic or symmetric, and they were not associated with bowel or bladder incontinence. There was no alteration of consciousness following the episodes. Erica denied any recollection of the barking or shaking. The medical evaluation did not reveal an etiology. It included a complete physical examination, a neurological examination, biochemical laboratory studies, and a negative video EEG study that captured 10 episodes of shaking. Child psychiatry was consulted. Erica was a pleasant, quiet female with slightly constricted affect and a normal speech pattern. She reported that she was a straight-A honors student who had difficulty trusting others; she said that she had no friends, only "associates." She said that she had periods of feeling "sad" and crying easily, but could not identify any recent stressful event. Episodes of barking and shaking diminished during the hospitalization. Erica was discharged home with outpatient psychiatric follow-up.

Past, present and future therapeutics for cerebellar ataxias

Cerebellar ataxias are a group of disabling neurological disorders. Patients exhibit a cerebellar syndrome and can also present with extra-cerebellar deficits, namely pigmentary retinopathy, extrapyramidal movement disorders, pyramidal signs, cortical symptoms (seizures, cognitive impairment/behavioural symptoms), and peripheral neuropathy. Recently, deficits in cognitive operations have been unraveled. Cerebellar ataxias are heterogeneous both at the phenotypic and genotypic point of view. Therapeutical trials performed during these last 4 decades have failed in most cases, in particular because drugs were not targeting a deleterious pathway, but were given to counteract putative defects in neurotransmission. The identification of the causative mutations of many hereditary ataxias, the development of relevant animal models and the recent identifications of the molecular mechanisms underlying ataxias are impacting on the development of new drugs. We provide an overview of the pharmacological treatments currently used in the clinical practice and we discuss the drugs under development.

Increased c-fos expression in the central nucleus of the amygdala and enhancement of cued fear memory in Dyt1 DeltaGAG knock-in mice

DYT1 dystonia is caused by a trinucleotide deletion of GAG (DeltaGAG) in DYT1, which codes for torsinA. A previous epidemiologic study suggested an association of DYT1 DeltaGAG mutation with early-onset recurrent major depression. However, another study reported no significant association with depression, but instead showed an association with anxiety and dystonia. In this study, we analyzed these related behaviors in Dyt1 DeltaGAG heterozygous knock-in mice. The knock-in mice showed a subtle anxiety-like behavior but did not show depression-like behaviors. The mutant mice also displayed normal sensorimotor gating function in a prepulse inhibition test. While normal hippocampus-dependent contextual fear memory and hippocampal CA1 long-term potentiation (LTP) were observed, the knock-in mice exhibited an enhancement in the formation of cued fear memories. Anatomical analysis indicated that the number of c-fos positive cells was significantly increased while the size of the central nucleus of the amygdala (CE) was significantly reduced in the knock-in mice. These results suggest that the Dyt1 DeltaGAG mutation increased the activity of the CE and enhanced the acquisition of the cued fear memory.

The differential diagnosis of epilepsy: a critical review

The wrong diagnosis of epilepsy is common. At referral epilepsy centers, psychogenic non-epileptic attacks are by far the most common condition found to have been misdiagnosed as epilepsy, with an average delay of 7-10 years. There are many "red flags" that can raise the suspicion of psychogenic non-epileptic attacks. Syncope is the second most common condition misdiagnosed as epilepsy, and it is probably more common in outpatient populations. Other conditions more rarely misdiagnosed as epilepsy include hypoglycemia, panic attacks, paroxysmal movement disorders, paroxysmal sleep disorders, TIAs, migraines, and TGA. Conditions specific to children include nonepileptic staring spells, breath-holding spells, and shudder attacks. At all ages, the over-interpretation of EEGs plays an important part in the misdiagnosis of epilepsy.

Psychogenic movement disorders in children

Psychogenic movement disorders (PMDs) are well characterized in adults, but childhood-onset PMDs have not been extensively studied. We reviewed the medical records of children who were diagnosed in our clinic with PMDs since 1988 and identified 54 patients with PMDs, representing 3.1% of our pediatric movement disorder population and 5.7% of all PMD cases. The mean age at symptom onset was 14.2 years (+/-2.11, range 7.6-17.7). Similar to published data in adults, two-thirds of children exhibited multiple PMD phenotypes, the most common being tremor followed by dystonia and myoclonus. Most PMDs were abrupt in onset, paroxysmal and triggered by identifiable physical or psychological trauma. As in adults, childhood PMDs were more likely to affect females, but there was no female predominance in children less than 13 years old. Although prior studies suggest that medically unexplained symptoms beginning in childhood often follow a benign course, this cohort of children experienced marked disability and morbidity related to PMDs, including prolonged school absences and unnecessary surgical procedures in more than one-fifth of patients.

Movement disorders

Abnormal involuntary movements are major features of a large group of neurologic disorders, some of which are neurodegenerative and pose a significant diagnostic and treatment challenge to treating physicians. This article presents a concise review of clinical features, pathogenesis, epidemiology, and management of seven of the most common movement disorders encountered in a primary care clinic routinely. The disorders discussed are Parkinson disease, essential tremor, restless legs syndrome, Huntington disease, drug-induced movement disorder, Wilson disease, and Tourette syndrome.

A case of respiratory akathisia in a cancer patient: a case report

OBJECTIVE

It has been reported that akathisia is a neurological side effect induced by antiemetic drugs and/or antipsychotics. Akathisia can occur in any area of the body, but respiratory akathisia is an unusual type of akathisia. Cases of respiratory akathisia in cancer patients taking antiemetic drugs have not previously been reported.

METHODS

We report on a case of a cancer patient taking prochlorperazine as an antiemetic drug who experienced dyspnea accompanied by severe restlessness associated with respiration. By administration of biperiden, his restlessness in respiration and dyspnea promptly disappeared.

RESULTS

This finding led us to conclude that this cancer patient was experiencing respiratory akathisia.

SIGNIFICANCE OF RESULTS

Respiratory akathisia is uncommon. It is important for cancer patients that dyspnea induced by disease progression be ruled out as a cause of the respiratory restlessness. It is necessary to consider the possibility of akathisia in patients that complain of vague anxiety, chest discomfort, or dyspnea following antipsychotic medication.

Barking vocalizations and shaking movements in a 13-year old girl

Erica is a 13-year old female who was hospitalized for a 4-week history of "barking" noises and 2 weeks of generalized shaking episodes. Four weeks prior to admission, she had a viral upper respiratory infection (URI) with cough which was treated with over-the-counter cough syrup. After resolution of the URI, she developed a persistent cough that turned into a "bark"-like vocalization. Both the mother and patient demonstrated the bark as an "arf" sound like that of a small dog at times, a large dog at others. These vocalizations were unrelenting, occurring 3-10 times per minute only while awake. They were not precipitated by any known factors nor were there alleviating factors. She could not voluntarily suppress the sound. In addition to the vocalizations, episodes of generalized shaking of the extremities began 2 weeks prior to admission. According to Erica's mother, each episode lasted about 10-60 seconds and occurred 30-40 times a day only when she was awake. These episodes were not rhythmic or symmetric, and they were not associated with bowel or bladder incontinence. There was no alteration of consciousness following the episodes. Erica denied any recollection of the barking or shaking.The medical evaluation did not reveal an etiology. It included a complete physical examination, a neurological examination, biochemical laboratory studies, and a negative video EEG study that captured 10 episodes of shaking. Child psychiatry was consulted. Erica was a pleasant, quiet female with slightly constricted affect and a normal speech pattern. She reported that she was a straight-A honors student who had difficulty trusting others; she said that she had no friends, only "associates." She said that she had periods of feeling "sad" and crying easily, but could not identify any recent stressful event. Episodes of barking and shaking diminished during the hospitalization. Erica was discharged home with outpatient psychiatric follow-up.

Enhanced excitation-coupled calcium entry in myotubes expressing malignant hyperthermia mutation R163C is attenuated by dantrolene

Dantrolene is the drug of choice for the treatment of malignant hyperthermia (MH) and is also useful for treatment of spasticity or muscle spasms associated with several clinical conditions. The current study examines the mechanisms of dantrolene's action on skeletal muscle and shows that one of dantrolene's mechanisms of action is to block excitation-coupled calcium entry (ECCE) in both adult mouse flexor digitorum brevis fibers and primary myotubes. A second important new finding is that myotubes isolated from mice heterozygous and homozygous for the ryanodine receptor type 1 R163C MH susceptibility mutation show significantly enhanced ECCE rates that could be restored to those measured in wild-type cells after exposure to clinical concentrations of dantrolene. We propose that this gain of ECCE function is an important etiological component of MH susceptibility and possibly contributes to the fulminant MH episode. The inhibitory potency of dantrolene on ECCE found in wild-type and MH-susceptible muscle is consistent with the drug's clinical potency for reversing the MH syndrome and is incomplete as predicted by its efficacy as a muscle relaxant.

Mouvements anormaux paroxystiques non épileptiques de l'enfant

Paroxysmal movement disorders are not uncommon in childhood, but are probably under-recognised. Paroxysmal movement disorders are a distinctive group of disorders that represents various clinical situations, characterised by intermittent and episodic disturbances of movement. Diagnosis relies on semiological analysis, mainly based on parental description of the manifestations; video recording (during an EEG-video monitoring or home made video) are often helpful to establish the correct diagnosis. In the large majority of the cases, paroxysmal movement disorders are benign situations. Some of them are transient, as they spontaneously stop over time (benign torticolis of infancy, paroxysmal tonic upgaze). Being familiar with these disorders will lead to accurate diagnosis, so avoiding useless investigations. Most of the time, no treatment will be required, and the families will be informed of the good prognosis.