Characteristics and therapeutic potential of sodium-dependent phosphate cotransporters in relation to idiopathic basal ganglia calcification.

Type-III sodium-dependent phosphate transporters 1 and 2 (PiT 1 and PiT 2, respectively) are proteins encoded by SLC20A1 and SLC20A2, respectively. The ubiquitous distribution of SLC20A1 and SLC20A2 mRNAs in mammalian tissues supports the housekeeping maintenance and homeostasis of intracellular inorganic phosphate (Pi), which is absorbed from interstitial fluid for normal cellular functions. SLC20A2 variants have been found in patients with idiopathic basal ganglia calcification (IBGC), also known as Fahr's disease or primary familial brain calcification (PFBC). Thus, disrupted Pi homeostasis is considered one of the major factors in the pathogenic mechanism of IBGC. In this paper, among the causative genes of IBGC, we focused specifically on PiT2, and its potential for a therapeutic target of IBGC.

Movement Disorders in Treatable Inborn Errors of Metabolism.

There are several hundred single-gene disorders that we classify as inborn errors of metabolism. Inborn errors of metabolism are often rare and highly heterogeneous multisystem diseases with non-neurological and neurological manifestations, commonly with onset during childhood. Movement disorders are among the most common neurological problems in inborn errors of metabolism, but, in many cases, remain poorly defined. Although movement disorders are usually not the only and often not the presenting symptom, their recognition can facilitate a diagnosis. Movement disorders contribute substantially to the morbidity in inborn errors of metabolism and can have a significant impact on quality of life. Common metabolic movement disorders include the monoamine neurotransmitter disorders, disorders of amino and organic acid metabolism, metal storage disorders, lysosomal storage disorders, congenital disorders of autophagy, disorders of creatine metabolism, vitamin-responsive disorders, and disorders of energy metabolism. Importantly, disease-modifying therapies exist for a number of inborn errors of metabolism, and early recognition and treatment can prevent irreversible CNS damage and reduce morbidity and mortality. A phenomenology-based approach, based on the predominant movement disorder, can facilitate a differential diagnosis and can guide biochemical, molecular, and imaging testing. The complexity of metabolic movement disorders demands an interdisciplinary approach and close collaboration of pediatric neurologists, neurologists, geneticists, and experts in metabolism. In this review, we develop a general framework for a phenomenology-based approach to movement disorders in inborn errors of metabolism and discuss an approach to identifying the "top ten" of treatable inborn errors of metabolism that present with movement disorders-diagnoses that should never be missed. © 2018 International Parkinson and Movement Disorder Society.

Subacute corticobasal syndrome following internal carotid endarterectomy.

The present report is of two patients who, immediately after internal carotid endarterectomy, presented with unexplained hemiplegia, despite normal findings on repeated MRI scans, which secondarily evolved into homolateral subacute corticobasal syndrome (CBS), with asymmetrical hemispheric hypometabolism and evidence of dopaminergic denervation. This prompted us to propose an hypothesis of transient cerebral hypoxia arising during the surgical clamping period that might have provoked a prolonged or permanent functional lesion of the left hemisphere and basal ganglia, with no visible infarction on MRI but only synaptic rearrangement of the neural networks, thereby revealing or exacerbating a potentially preexisting silent impairment.

High intensity focused ultrasound (HIFU) in tumor therapy.

HIFU (high intensity focused ultrasound) is a method in which high-frequency ultrasound is focused on a tissue in order to achieve a thermal effect and the subsequent percutaneously ablation, or tissue modulation. HIFU is non-invasive and results in an immediate tissue destruction effect corresponding to surgery, either percutaneously or through body cavities. HIFU can be utilized in the treatment of both benign and malignant tumors. In neurological diseases, focused HIFU can be used in the treatment of disorders of the basal ganglia.

Progressive supranuclear palsy and corticobasal degeneration: Diagnostic challenges and clinicopathological considerations.

Progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) are two atypical parkinsonian syndromes first described half a century ago. The spectrum of these conditions as well as, more generally, the concept of tauopathy have dramatically changed over the past decade and especially in recent years. In particular, clinicopathological correlations have led to the description of several subtypes of these diseases and the features they share with other neurodegenerative diseases. The present paper is a review of how the concepts of PSP and CBD have evolved over time. In particular, it focuses on the different presentations of the disease and the overlapping syndromes that can complicate the differential diagnoses. Also discussed are some of the tools that may prove useful in making a diagnosis. Indeed, differential diagnosis issues are of particular importance in light of the likely emergence of pathology-specific disease-modifying therapies in the near future.

Balancing the basal ganglia circuitry: a possible new role for dopamine D2 receptors in health and disease.

Current therapies for treating movement disorders such as Parkinson's disease are effective but limited by undesirable and intractable side effects. Developing more effective therapies will require better understanding of what causes basal ganglia dysregulation and why medication-induced side effects develop. Although basal ganglia have been extensively studied in the last decades, its circuit anatomy is very complex, and significant controversy exists as to how the interplay of different basal ganglia nuclei process motor information and output. We have recently identified the importance of an underappreciated collateral projection that bridges the striatal output direct pathway with the indirect pathway. These bridging collaterals are extremely plastic in the adult brain and are involved in the regulation of motor balance. Our findings add a new angle to the classical model of basal ganglia circuitry that could be exploited for the development of new therapies against movement disorders. In this Scientific Perspective, we describe the function of bridging collaterals and other recent discoveries that challenge the simplicity of the classical basal ganglia circuit model. We then discuss the potential implication of bridging collaterals in the pathophysiology of Parkinson's disease and schizophrenia. Because dopamine D2 receptors and striatal neuron excitability have been found to regulate the density of bridging collaterals, we propose that targeting these projections downstream of D2 receptors could be a possible strategy for the treatment of basal ganglia disorders. © 2015 International Parkinson and Movement Disorder Society.

Supranuclear eye movement disorders.

PURPOSE OF REVIEW: This work reviews supranuclear ocular motor disorders, highlighting new data published during the past year. RECENT FINDINGS: Perceptional adaptative mechanisms may explain recent research concerning the discrepancy between objective measurement of saccade abnormalities and their putative functional visual impairment. Eye movement classes seem to be selectively disrupted by different neurodegenerative disorders. Deep brain stimulation in Parkinson's disease patients may improve pursuit deficits, highlighting the role of basal ganglia in the control of smooth pursuit. Subcortical optokinetic pathways seem to play an important role in maintaining the monocular nasotemporal optokinetic asymmetry seen in patients with infantile esotropia. Vergence-vestibular interaction has been further delineated in patients with idiopathic bilateral vestibular failure. Pharmacological treatment of central vestibular disorders with 4-aminopyridine has been extended to patients with ataxia-telangiectasia in whom it seems to reduce slow-phase velocity of nystagmus. SUMMARY: Recent data derived from anatomic and functional imaging studies are providing new insights into supranuclear ocular motor circuitry. Novel pharmacological and surgical therapies may have future implications in visual and vestibular rehabilitation of patients with supranuclear eye movement disorders.

[Satellite systems of the basal ganglia--anatomic position, clinical relevance]. / Satellitensysteme der Basalganglien--Anatomische Einordnung, klinische Relevanz.

The interaction of basal ganglia and other brain regions is more complex regarding anatomic and functional perspectives than previously assumed. Hence, the classical basal ganglia model has to be extended to at least four satellite systems modulating motor-executive, associative and limbic-motivational brain regions: (i) an indirect projection system, (ii) a striato-nigro-striatal loop, (iii) a "hyperdirect" projection system as well as additional projections to the subthalamic nucleus and (iv) multisynaptic connections from the cerebellum exerting influence on the indirect projection system. The investigation of these satellite systems would be invaluable to foster our understanding of basal ganglia circuitries and may yield a better appreciation of largely opaque symptoms like resting tremor in Parkinson's disease; analysis of these anatomic pathways and functional implications may facilitate explanatory model approaches to side effects due to dopaminergic therapy and deep brain stimulation in humans and thereby offer the possibility for new therapeutic approaches in movement disorders.

Symptomatic Treatment of Extrapyramidal Hyperkinetic Movement Disorders.

Extrapyramidal hyperkinetic movement disorders comprise a broad range of phenotypic phenomena, including chorea, dystonia, and tics. Treatment is generally challenging and individualized, given the overlapping phenomenology, limited evidence regarding efficacy, and concerns regarding the tolerability and safety of most treatments. Over the past decade, the treatment has become even more intricate due to advancements in the field of deep brain stimulation as well as optimized dopamine- depleting agents. Here, we review the current evidence for treatment modalities of extrapyramidal hyperkinetic movement disorders and provide a comprehensive and practical overview to aid the choice of therapy. Mechanism of action and practical intricacies of each treatment modality are discussed, focusing on dosing and adverse effect management. Finally, future therapeutic developments are also discussed.

Bilateral deep brain stimulation of the subthalamic nucleus effectively relieves dystonia secondary to Fahr's disease: a case report.

Fahr's disease (FD) is a rare movement disorder characterized by bilateral intracranial calcifications that is refractory to most treatments. We present the case of a 26-year-old male with FD who was unable to walk independently and could not eat solid food because of poor swallowing capability and severe cervical dystonia. Injections of botulin toxin into the neck muscles, as well as biperiden, tiapride, amantadine, L-dopa and clonazepam were ineffective. Deep brain stimulation (DBS) was performed with two permanent electrodes containing four contact sites implanted bilaterally into the subthalamic nucleus (STN). The antidystonic effect was evident immediately after STN stimulation, and it was sustained during a 24-month follow-up period. There was a marked reduction of cervical dystonia, and he could eat solid food and was able to walk independently. This case demonstrates that DBS of the STN can be effective for the treatment of dystonia associated with FD.

Apathy: a pathology of goal-directed behaviour: a new concept of the clinic and pathophysiology of apathy.

We propose to defined apathy as a quantitative reduction of goal-directed behaviour. As such, the neural bases of apathy rely on lesions or dysfunctions of the brain structures that generate and control goal-directed behaviour: the frontal lobes, the basal ganglia and the frontal-basal ganglia circuits. Lesions or dysfunctions of the limbic territories of the frontal lobes (the orbital-mesial prefrontal cortex) and the basal ganglia (e.g., the ventral striatum) lead to apathy through difficulties to provide the affective value of a given behavioural context. We also suggest that lesions or dysfunctions of the associative ("cognitive") territories of the frontal lobes (the dorsal prefrontal cortex) and the basal ganglia (e.g., the dorsal caudate) contribute to apathy via a "cognitive inertia" - an inability to generate or activate strategies required to successfully complete a given program of actions. The most severe forms of apathy ("auto-activation deficit" syndrome), due to bilateral lesions in the prefrontal-basal ganglia circuits can be explained either by the addition of lesions in the cognitive and limbic territories or by a more general and elementary impairment that mirrored the presumed normal functions of the prefrontal-basal ganglia circuits, that is to selectively amplified the behaviour that one considers as the most adapted to one's personal needs or environmental demands. These lesions may limit the selective amplification of the signal that represents relevant thoughts and actions, leading to difficulties to disambiguate decision-making at the level of the prefrontal cortex.

[Atypical Parkinson syndromes--recent advances in diagnosis and therapy]. / Atypische Parkinson-Syndrome - Aktuelles aus Diagnostik und Therapie.

The term "atypical Parkinson syndromes" usually encompasses the following diseases: multiple system atrophy (MSA), progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS). The differential diagnosis is still a challenge even for a movement disorders specialist, not least because of the distinct therapeutic approaches and disease prognosis. The aim of this review is to provide an overview of current diagnostic criteria and therapeutic approaches and to cite recent findings from clinical and experimental studies.

[Deep brain stimulation for Parkinson's disease and camptocormia? A case report]. / Tiefe Hirnstimulation bei Morbus Parkinson mit Kamptokormie? Ein Fallbericht.

Camptocormia is recognised as a severe postural movement disorder complicating neurodegenerative diseases like Parkinson's disease (PD) and multisystem atrophy. Pathophysiologically two main hypotheses are discussed: (i) a disorder of the basal ganglia resulting in axial dystonia and rigidity on the one hand and (ii) an extensor truncal myopathy on the other hand. Therapeutic efforts often result in limited success. Therefore, reports on improvements by deep brain stimulation (DBS) are of great interest. However, the role of DBS in the treatment of camptocormia remains unclear. Here, we report a female PD patient who responded well to DBS of the subthalamic nucleus for severe dyskinesias and fluctuations. However, after 6 months she started to develop a rapidly progressing camptocormia which did not respond to DBS. The clinical and electrophysiological examination suggested a truncal erector myopathy. The inconsistent reports on the effects of DBS on camptocormia in PD patients suggest heterogeneous pathogenetic pathways. A pathophysiological subtype with predominant basal ganglia dysfunction and responsivity to DBS, however, seems to be rather rare. A myopathy, in contrast, seems to be more frequent and DBS is not effective in this condition. Therefore, camptocormia in PD patients is not an established indication for DBS.

Recurrent macroglossia requiring tracheostomy after haemorrhagic basal ganglia stroke.

A 50-year-old African American woman with hypertension, congestive heart failure, chronic kidney disease and prior cerebral vascular accident was transferred from an outside hospital after being found unresponsive and subsequently intubated for severe orolingual swelling. Imaging showed left thalamic haemorrhagic stroke, and the lingual swelling was clinically concerning for angio-oedema, with which a lingual biopsy was consistent. Work-up was negative for hereditary or acquired angio-oedema, and imaging was negative for structural causes. Of note, the patient had an episode of severe orolingual swelling 3 months prior to this presentation after suffering left thalamic haemorrhage which self-resolved after approximately 2 months. In both episodes lingual swelling predated receipt of tissue plasminogen activator and she had discontinued ACE inhibitor therapy since her first episode of tongue swelling. Despite medical and supportive management, tongue swelling progressed during admission and the decision was made to allow the patient's tongue swelling to self-resolve.

Germinomas in the basal ganglia: magnetic resonance imaging classification and the prognosis.

Germinoma in the basal ganglia (BG) is notorious for its diagnostic difficulty. Clinical and radiological features of this disease are quite diverse, but have not been well characterized with respect to prognosis. We retrospectively reviewed the clinical course and treatment outcomes of 17 patients with a BG germinoma. The initial magnetic resonance imaging (MRI) features were classified. Clinical features and treatment outcomes were then analyzed with this classification scheme. A Type 1 lesion was defined as a subtle lesion with faint or no contrast enhancement (six patients). Type 2, 3, and 4 lesions were defined as contrast-enhancing lesions and were differentiated by the lesion size and the presence of subependymal seeding (11 patients). Type 1 lesions were distinct from the other lesions. Patients with a Type 1 lesion had a significantly longer time from the initial MRI to diagnosis than patients with Type 2, 3, and 4 lesions (P = 0.012). The actuarial progression-free survival and overall survival of patients 5 years after diagnosis were 66 and 77%, respectively. The presence of a Type 1 lesion (P = 0.004), a longer time delay in the diagnosis (P = 0.038), and radiation therapy without complete ventricular coverage (P = 0.010) were significantly associated with tumor progression. Profound motor deficits at diagnosis were associated with deterioration in motor function after tumor remission (P = 0.035). Early diagnosis of BG germinomas could affect the ability to control a tumor and neurological outcomes. In particular, high clinical suspicion and active diagnostic procedures are recommended. For optimal treatment, radiation fields should include entire ventricles even if there is no subependymal seeding.

Germinoma in the basal ganglia with an abnormal karyotype: case report and review of the literature.

INTRODUCTION: Germ cell tumor of basal ganglia with abnormal constitutional karyotype has been rarely reported. CASE REPORT: A 9-year-old boy presented with precocious puberty and right hemiparesis. Magnetic resonance imaging showed high intensity on T1-weighted, T2-weighted, and contrast-enhanced T1-weighted images in the left basal ganglia and ipsilateral cerebral hemiatrophy predominantly in the basal ganglia and midbrain. Germinoma in the left basal ganglia was confirmed by stereotactic biopsy and immunochemical examination. His constitutional karyotype was 46, XY, t (8; 19), (p23.1; p13.1), a novel chromosomal abnormality. DISCUSSION: Intracranial germinoma, a potentially curable tumor, should be considered in children with nonspecific neurological symptoms, endocrinologic changes, and ipsilateral cerebral hemiatrophy on computed tomography or magnetic resonance. Investigation of chromosomal aberrations in those patients would clarify the tumorigenesis and lead to possibilities for novel disease-specific therapies.

[Fahr's syndrome: two case report]. / Syndrome de Fahr: à propos de deux cas.

INTRODUCTION: Fahr's syndrome is characterized by symmetrical and bilateral intracerebral calcifications, located in the basal ganglia and mostly associated with a phosphorus calcium metabolism disorder. It must be distinguished from genetic or sporadic Fahr's disease. OBSERVATIONS: We report two cases of this syndrome, the first was revealed by psychotic and cognitive disorders and the other by epilepsy. In both cases, brain imaging and biology resulted in the diagnosis of Fahr's syndrome. The outcome was favorable after treatment in both cases. CONCLUSION: These two observations illustrate various clinical signs of Fahr's syndrome.

[Deep brain stimulation for neurological and psychiatric diseases: animal experiments on effect and mechanisms]. / Tiefe Hirnstimulation bei neurologischen und psychiatrischen Erkrankungen: Tierexperimentelle Untersuchungen zu Wirkung und Wirkmechanismen.

Deep brain stimulation at high frequencies has emerged as a powerful therapeutic strategy in the treatment of basal ganglia-related movement disorders. Attempts have also been made to establish this for the treatment of therapy-resistant psychiatric disorders. To date the mechanisms underlying the clinical efficacy of high frequency stimulation remain largely unknown. Their detailed description, however, is essential for promoting the extended application of high frequency stimulation as a therapeutic alternative and may simultaneously allow conclusions to be drawn on the pathophysiological mechanisms underlying the diseases benefiting from deep brain stimulation. This review demonstrates how animal models contribute to i) further understand the mechanisms underlying deep brain stimulation at high frequencies and ii) promote the establishment of high frequency stimulation for the treatment of therapy-resistant psychiatric disorders.