The temporal relationship between premonitory urges and covert compulsions in patients with obsessive-compulsive disorder

Recent studies in patients with obsessive-compulsive disorder (OCD) have shown that many compulsions are associated with urges rather than obsessions. Premonitory urges are uncomfortable sensory feelings or a rising inner tension, often likened to the urge to scratch, yawn or blink. We studied premonitory urges preceding mental compulsions in 19 patients with OCD and preceding eye blinks in 16 healthy controls. Urge intensity was assessed continuously over 20 min using a real-time urge intensity monitor; compulsions and blinks were measured as discrete events in a free compulsion/blinking and a compulsion/blink suppression condition. Urge intensity showed an inverted U-shaped relationship (increase then decrease) around compulsions within a time-window of approximately 60 s in patients with OCD and within 13 s around blinks in healthy controls. Urge intensity was higher during compulsion / blink suppression and varied more independently of compulsion execution in patients with OCD. There is a close temporal relationship between premonitory sensations and compulsion execution that changes when compulsions are suppressed, indicating that urge intensity might drive the execution of and is then alleviated by compulsions. Suppression weakens the association between urge intensity and compulsion execution.

Prospective evaluation of Globus pallidus internus deep brain stimulation in Huntington's disease

INTRODUCTION

Pharmacological treatment of chorea in Huntington's disease (HD) is often limited by poor efficacy or side effects. Pallidal deep brain stimulation (DBS) has been considered in these patients but experience is so far limited.

METHODS

We prospectively evaluated the effects of bilateral DBS of the Globus pallidus internus (GPi) over one year in six severely affected HD patients with treatment refractory chorea in an advanced stage of the disease. Primary endpoint of the study was improvement in chorea. Additionally, we evaluated the effects of GPi DBS on the motor part of the Unified Huntington's Disease Rating Scale (UHDRS), bradykinesia, dystonia, functional impairment, psychiatric and cognitive symptoms. Side effects were systematically assessed.

RESULTS

The chorea subscore was significantly reduced postoperatively (-47% six months, -40% twelve months postoperatively). The UHDRS total motor score was significantly reduced at six months postoperatively (- 17%) but the effect was not sustained twelve months after the operation (- 5%). Pallidal DBS did not improve other motor symptoms or functional impairment. There was no effect on psychiatric symptoms or cognition. A number of side effects were noted, especially spasticity in three of the patients.

CONCLUSIONS

Pallidal DBS is a treatment option for HD patients with severe pharmacologically refractory chorea. Further studies are needed to define optimal candidates for this procedure.

White Matter Microstructure of the Human Mirror Neuron System is Related to Symptom Severity in Adults with Autism

Mirror neuron system (MNS) dysfunctions might underlie deficits in autism spectrum disorders (ASD). Diffusion tensor imaging based probabilistic tractography was conducted in 15 adult ASD patients and 13 matched, healthy controls. Fractional anisotropy (FA) was quantified to assess group differences in tract-related white matter microstructure of both the classical MNS route (mediating "emulation") and the alternative temporo-frontal route (mediating "mimicry"). Multiple linear regression was used to investigate structure-function relationships between MNS connections and ASD symptom severity. There were no significant group differences in tract-related FA indicating an intact classical MNS in ASD. Direct temporo-frontal connections could not be reconstructed challengeing the concept of multiple routes for imitation. Tract-related FA of right-hemispheric parieto-frontal connections was negatively related to autism symptom severity.

Alcohol improves cerebellar learning deficit in myoclonus-dystonia: A clinical and electrophysiological investigation

OBJECTIVE

To characterize neurophysiological subcortical abnormalities in myoclonus-dystonia and their modulation by alcohol administration.

METHODS

Cerebellar associative learning and basal ganglia-brainstem interaction were investigated in 17 myoclonus-dystonia patients with epsilon-sarcoglycan (SGCE) gene mutation and 21 age- and sex-matched healthy controls by means of classical eyeblink conditioning and blink reflex recovery cycle before and after alcohol intake resulting in a breath alcohol concentration of 0.08% (0.8g/l). The alcohol responsiveness of clinical symptoms was evaluated by 3 blinded raters with a standardized video protocol and clinical rating scales including the Unified Myoclonus Rating Scale and the Burke-Fahn-Marsden Dystonia Rating Scale.

RESULTS

Patients showed a significantly reduced number of conditioned eyeblink responses before alcohol administration compared to controls. Whereas the conditioning response rate decreased under alcohol intake in controls, it increased in patients (analysis of variance: alcohol state × group, p = 0.004). Blink reflex recovery cycle before and after alcohol intake did not differ between groups. Myoclonus improved significantly after alcohol intake (p = 0.016). The severity of action myoclonus at baseline correlated negatively with the conditioning response in classical eyeblink conditioning in patients.

INTERPRETATION

The combination of findings of reduced baseline acquisition of conditioned eyeblink responses and normal blink reflex recovery cycle in patients who improved significantly with alcohol intake suggests a crucial role of cerebellar networks in the generation of symptoms in these patients. Ann Neurol 2017;82:543-553.

Involvement of obliquus capitis inferior muscle in dystonic head tremor

INTRODUCTION

Head tremor is a common feature in cervical dystonia (CD) and often less responsive to botulinum neurotoxin (BoNT) treatment than dystonic posturing. Ultrasound allows accurate targeting of deeper neck muscles.

METHODS

In 35 CD patients with dystonic head tremor the depth and thickness of the splenius capitis (SPL), semispinalis capitis and obliquus capitis inferior muscles (OCI) were assessed using ultrasound. Ultrasound guided EMG recordings were performed from the SPL and OCI.

RESULTS

Burst-like tremor activity was present in both OCI in 25 and in one in 10 patients. In 18 patients, tremor activity was present in one SPL and in 2 in both SPL. Depth and thickness of OCI, SPL and semispinalis capitis muscles were very variable.

CONCLUSION

Muscular activity underlying tremulous CD is most commonly present in OCI. Due to the variability of muscle thickness, we suggest ultrasound guided BoNT injections into OCI.

Influence of L-dopa on subtle motor signs in heterozygous Parkin- and PINK1 mutation carriers

INTRODUCTION

A latent nigrostriatal deficit and its possible clinical consequences in asymptomatic heterozygous Parkin and PINK1 mutation carriers (AMC) have been a matter of investigation in recent years. Notably, mild Parkinsonian signs in heterozygous mutation carriers can be so subtle that they may be missed if not specifically investigated.

METHODS

We studied 15 heterozygous Parkin and PINK1 AMC and 18 age- and sex-matched mutation-negative controls using a standardized video, instructing the probands to perform relevant parts of the UPDRS III to investigate fine motor movements at baseline and after first-time L-Dopa administration. Additionally, available UPDRS III scores of mutation carriers from the past ten years were reviewed.

RESULTS

AMC showed a reduced number of fine motor movements per second compared to controls at baseline (p = 0.04). L-Dopa improved motor performance numerically but non-significantly in AMC (p = 0.2301), but significantly in healthy controls (p = 6.1·10-5). Although none of the AMC reported symptoms, nine showed rigidity, bradykinesia, tremor, and postural instability when the UPDRS III was applied. Mean UPDRSIII scores significantly decreased after L-Dopa administration (p = 0.005), but did not increase over the past ten years.

CONCLUSIONS

(i) Heterozygous AMC show subtle motor abnormalities when a detailed, specialized motor examination is applied and compared to mutation-negative matched control subjects. (ii) The mild motor deficit present in a subgroup of heterozygous Parkin and PINK1 AMC appears to be non-progressive and responsive to L-dopa administration. (iii) Evaluating motor changes, their progression, and treatment response in AMC can provide valuable insights into possible early disease stages and compensatory mechanisms.

Psychiatric associations of adult-onset focal dystonia phenotypes

BACKGROUND

Depression and anxiety frequently accompany the motor manifestations of isolated adult-onset focal dystonias. Whether the body region affected when this type of dystonia first presents is associated with the severity of these neuropsychiatric symptoms is unknown.

OBJECTIVES

The aim of this study was to determine whether depression, anxiety and social anxiety vary by dystonia onset site and evaluate whether pain and dystonia severity account for any differences.

METHODS

Patients with isolated focal dystonia evaluated within 5 years from symptom onset, enrolled in the Natural History Project of the Dystonia Coalition, were included in the analysis. Individual onset sites were grouped into five body regions: cervical, laryngeal, limb, lower cranial and upper cranial. Neuropsychiatric symptoms were rated using the Beck Depression Inventory, Hospital Anxiety and Depression Scale and Liebowitz Social Anxiety Scale. Pain was estimated using the 36-Item Short Form Survey.

RESULTS

Four hundred and seventy-eight subjects met our inclusion criteria. High levels of depression, anxiety and social anxiety occurred in all groups; however, the severity of anxiety and social anxiety symptoms varied by onset site group. The most pronounced differences were higher anxiety in cervical and laryngeal, lower anxiety in upper cranial and higher social anxiety in laryngeal. Increases in pain were associated with worse neuropsychiatric symptom scores within all groups. Higher anxiety and social anxiety in laryngeal and lower anxiety in upper cranial persisted after correcting for pain and dystonia severity.

CONCLUSION

Anxiety and social anxiety severity vary by onset site of focal dystonia, and this variation is not explained by differences in pain and dystonia severity.

Nerve ultrasound in clinical management of carpal tunnel syndrome in mucopolysaccharidosis

AIM

Mucopolysaccharidoses (MPS) are a group of diseases with an almost 100% lifetime incidence of carpal tunnel syndrome (CTS) in MPSsubtypes I, II, and VI. We compared nerve ultrasound with clinical signs and electrophysiology in a clinical setting to screen for CTSin MPS.

METHOD

Twenty-four patients (13 male, 11 female, mean age of 7y 11mo [SD8y 5mo], range 6mo-29y) were screened for CTS. Eight of these patients were re-examined post-operatively. Clinical signs, distal motor latency, compound muscle action potential, sensory nerve action potential amplitude and velocity, as well as echogenicity and the cross-sectional area (CSA) of the median nerve at the wrist and forearm determined with ultrasound were assessed and the wrist to forearm ratio (WFR) calculated. Eighteen healthy participants formed a comparison group, who were also investigated with nerve ultrasound.

RESULTS

In 26% of the patients' hands, clinical signs of CTSwere present; 77% fulfilled electrophysiological and 92% nerve ultrasound criteria for CTS. Post-operatively, electrophysiology improved significantly, whereas ultrasound results were unchanged. In the comparison group, age and height correlated with the CSA, but not with WFR.

INTERPRETATION

Nerve ultrasound is a useful and painless primary screening tool for CTSin MPS.

Abnormal premotor-motor interaction in heterozygous Parkin- and Pink1 mutation carriers

OBJECTIVES

Mutations in the Parkin and PINK1 gene account for the majority of autosomal recessive early-onset Parkinson cases. There is increasing evidence that clinically asymptomatic subjects with single heterozygous mutations have a latent nigrostriatal dopaminergic deficit and could be taken as in vivo model of pre-symptomatic phase of Parkinsonism.

METHODS

We charted premotor-motor excitability changes as compensatory mechanisms for subcortical dopamine depletions using transcranial magnetic stimulation by applying magnetic resonance-navigated premotor-motor cortex conditioning in 15 asymptomatic, heterozygous Parkin and PINK1 mutation carriers (2 female; mean age 53±8years) and 16 age- and sex-matched controls (5 female; mean age 57±9years). Participants were examined at baseline and after acute l-dopa challenge.

RESULTS

There were l-dopa and group specific effects during premotor-motor conditioning at an interstimulus interval of 6ms indicating a normalisation of premotor-motor interactions in heterozygous Parkin and PINK1 mutation carriers after l-dopa intake. Non-physiologically high conditioned MEP amplitudes at this interval in mutation carriers decreased after l-dopa intake but increased in controls.

CONCLUSION

Premotor-motor excitability changes are part of the cortical reorganization in asymptomatic heterozygous Parkin- and PINK1 mutation carriers.

SIGNIFICANCE

These subjects offer opportunities to delineate motor network adaptation in pre-symptomatic Parkinsonism.

Childhood-Onset Movement Disorders: A Clinical Series of 606 Cases

The aim of this work is to report the distribution of clinical phenomenology, demographic variables, and delay of diagnosis in a cohort of patients with childhood-onset movement disorders. Personally examined patients with childhood-onset movement disorders apart from those with cerebral palsy are reported. A total of 606 patients were included. The majority had tic disorders (346; 57%) followed by dystonia (72; 12%); other movement disorders were less frequent (<5%). Mean onset age of patients with tics was 7.4 years ± 3.8 standard deviation; mean delay of diagnosis was 9.9 ± 11 years. Mean onset age of other movement disorders was 8.6 ± 5.7 years; mean delay of diagnosis was 11.1 ± 12.5 years. Psychogenic movement disorders had a later onset than all other movement disorders (P < 0.01) apart from tremor and "other movement disorders." Dystonias had a longer delay of diagnosis than psychogenic movement disorders (P < 0.038). The diagnostic delay of childhood-onset movement disorders is considerable, indicating that they are probably under-recognized.

Motor cortex excitability and fatigue in multiple sclerosis: a transcranial magnetic stimulation study

We investigated electrophysiological correlates of fatigue in patients with multiple sclerosis (MS). Transcranial magnetic stimulation (TMS) was used to explore motor excitability in three groups of subjects: MS patients with fatigue (MS-F), MS patients without fatigue (MS-NF) and healthy control subjects. All participants had to perform a fatiguing hand-grip exercise. TMS was performed prior to and after the exercise. Prior to the motor task, MS-F patients had less inhibition in the primary motor cortex compared to both other groups. Postexercise, intracortical inhibition was still reduced in the MS-F patients compared to the MS-NF patients. In MS-F patients the postexercise time interval for normalization of the motor threshold was correlated with the fatigue severity. We conclude that MS patients with fatigue have an impairment of inhibitory circuits in their primary motor cortex. The results also indicate that fatigue severity is associated with an exercise-induced reduction of membrane excitability.

Relevance of sonography for botulinum toxin treatment of cervical dystonia: an expert statement

Botulinum neurotoxin A (BoNT A) is the first-line treatment for cervical dystonia. However, although BoNT A has a favorable safety profile and is effective in the majority of patients, in some cases the treatment outcome is disappointing or side effects occur when higher doses are used. It is likely that in such cases either the target muscles were not injected accurately or unintended weakness of non-target muscles occurred. It has been demonstrated in clinical trials for spastic movement disorders that sonography-guided BoNT A injections could improve treatment outcome. As the published evidence for a benefit of sonography-guided BoNT injection in patients with cervical dystonia is scarce, it is the aim of this review to discuss the relevance of sonography in this indication and provide a statement from clinical experts for its use. The clear advantage of sonography-guided injections is non-invasive, real-time visualization of the targeted muscle, thus improving the precision of injections and potentially the treatment outcomes as well as avoiding adverse effects. Other imaging techniques are of limited value due to high costs, radiation exposure or non-availability in clinical routine. In the hands of a trained injector, sonography is a quick and non-invasive imaging technique. Novel treatment concepts of cervical dystonia considering the differential contributions of distinct cranial and cervical muscles can reliably be implemented only by use of imaging-guided injection protocols.

46,XY Gonadal Dysgenesis due to a Homozygous Mutation in Desert Hedgehog (DHH) Identified by Exome Sequencing

BACKGROUND

46,XY disorders of sex development (DSD) comprise a heterogeneous group of congenital conditions. Mutations in a variety of genes can affect gonadal development or androgen biosynthesis/action and thereby influence the development of the internal and external genital organs.

OBJECTIVE

The objective of the study was to identify the genetic cause in two 46,XY sisters of a consanguineous family with DSD and gonadal tumor formation.

METHODS

We used a next-generation sequencing approach by exome sequencing. Electrophysiological and high-resolution ultrasound examination of peripheral nerves as well as histopathological examination of the gonads were performed.

RESULTS

We identified a novel homozygous R124Q mutation in the desert hedgehog gene (DHH), which alters a conserved residue among the three mammalian Hedgehog ligands sonic hedgehog, Indian hedgehog, and desert hedgehog. No other relevant mutations in DSD-related genes were encountered. The gonads of one patient showed partial gonadal dysgenesis with loss of Leydig cells in tubular areas with seminoma in situ and a hyperplasia of Leydig cell-like cells expressing CYP17A1 in more dysgenetic parts of the gonad. In addition, both patients suffer from a polyneuropathy. High-resolution ultrasound revealed a structural change of peripheral nerve structure that fits well to a minifascicle formation of peripheral nerves.

CONCLUSION

Mutations in DHH play a role in 46,XY gonadal dysgenesis and are associated with seminoma formation and a neuropathy with minifascicle formation. Gonadal dysgenesis in these cases may be due to impairment of Sertoli cell-Leydig cell interaction during gonadal development.