Hemiballismus

Catching the Culprit: How Chorea May Signal an Inborn Error of Metabolism

Background

Movement disorders, particularly chorea, are uncommon in inborn errors of metabolism, but their identification is essential for improved clinical outcomes. In this context, comprehensive descriptions of movement disorders are limited and primarily derived from single cases or small patient series, highlighting the need for increased awareness and additional research in this field.

Methods

A systematic review was conducted using the MEDLINE database and GeneReviews. The search included studies on inborn errors of metabolism associated with chorea, athetosis, or ballismus. The review adhered to PRISMA guidelines.

Results

The systematic review analyzed 76 studies out of 2350 records, encompassing the period from 1964 to 2022. Chorea was observed in 90.1% of the 173 patients, followed by athetosis in 5.7%. Various inborn errors of metabolism showed an association with chorea, with trace elements and metals being the most frequent. Cognitive and developmental abnormalities were common in the cohort. Frequent neurological features included seizures, dysarthria, and optic atrophy, whereas non-neurological features included, among others, facial dysmorphia and failure to thrive. Neuroimaging and biochemical testing played crucial roles in aiding diagnosis, revealing abnormal findings in 34.1% and 47.9% of patients, respectively. However, symptomatic treatment efficacy for movement disorders was limited.

Discussion

This study emphasizes the complexities of chorea in inborn errors of metabolism. A systematic approach with red flags, biochemical testing, and neuroimaging is required for diagnosis. Collaboration between neurologists, geneticists, and metabolic specialists is crucial for improving early detection and individualized treatment. Utilizing genetic testing technologies and potential therapeutic avenues can aid in the improvement of patient outcomes.

Clozapine's multiple cellular mechanisms: What do we know after more than fifty years? A systematic review and critical assessment of translational mechanisms relevant for innovative strategies in treatment-resistant schizophrenia

Almost fifty years after its first introduction into clinical care, clozapine remains the only evidence-based pharmacological option for treatment-resistant schizophrenia (TRS), which affects approximately 30% of patients with schizophrenia. Despite the long-time experience with clozapine, the specific mechanism of action (MOA) responsible for its superior efficacy among antipsychotics is still elusive, both at the receptor and intracellular signaling level. This systematic review is aimed at critically assessing the role and specific relevance of clozapine's multimodal actions, dissecting those mechanisms that under a translational perspective could shed light on molecular targets worth to be considered for further innovative antipsychotic development. In vivo and in vitro preclinical findings, supported by innovative techniques and methods, together with pharmacogenomic and in vivo functional studies, point to multiple and possibly overlapping MOAs. To better explore this crucial issue, the specific affinity for 5-HT₂R, D1R, α_2c, and muscarinic receptors, the relatively low occupancy at dopamine D2R, the interaction with receptor dimers, as well as the potential confounder effects resulting in biased ligand action, and lastly, the role of the moiety responsible for lipophilic and alkaline features of clozapine are highlighted. Finally, the role of transcription and protein changes at the synaptic level, and the possibility that clozapine can directly impact synaptic architecture are addressed. Although clozapine's exact MOAs that contribute to its unique efficacy and some of its severe adverse effects have not been fully understood, relevant information can be gleaned from recent mechanistic understandings that may help design much needed additional therapeutic strategies for TRS.

Dystonia, chorea, hemiballismus and other dyskinesias

Hyperkinesias are heterogeneous involuntary movements that significantly differ in terms of clinical and semeiological manifestations, including rhythm, regularity, speed, duration, and other factors that determine their appearance or suppression. Hyperkinesias are due to complex, variable, and largely undefined pathophysiological mechanisms that may involve different brain areas. In this chapter, we specifically focus on dystonia, chorea and hemiballismus, and other dyskinesias, specifically, levodopa-induced, tardive, and cranial dyskinesia. We address the role of neurophysiological studies aimed at explaining the pathophysiology of these conditions. We mainly refer to human studies using surface and invasive in-depth recordings, as well as spinal, brainstem, and transcortical reflexology and non-invasive brain stimulation techniques. We discuss the extent to which the neurophysiological abnormalities observed in hyperkinesias may be explained by pathophysiological models. We highlight the most relevant issues that deserve future research efforts. The potential role of neurophysiological assessment in the clinical context of hyperkinesia is also discussed.

Acute Hemiballismus as the Initial Manifestation of Ischemic Stroke: A Case Report

Introduction

Cerebrovascular disease often presents with “negative” symptoms such as weakness with reduced movement of body parts or sensory loss. Rarely do “positive” symptoms such as abnormal movements manifest in acute stroke, with hemichorea being a very rare manifestation.

Case Report

This is a case report of a 62-year-old chronic smoker with no known past medical history who presented with choreatic movements of his arm and leg. Magnetic resonance imaging of the brain showed changes consistent with an infarct in the right centrum semiovale. He was treated with dual antiplatelets and was noted to have subsequent improvement in symptoms.

Conclusion

Recognition and awareness of stroke presenting as movement disorders in the emergency department can help prevent delays in diagnosis and treatment.

Focal Ballismus (Right Arm) in a Boy with Wilson's Disease

Ballismus is defined as rapid, forceful, shaking or throwing involuntary movement of the extremities, mainly proximal parts. When it affects half of the body (upper and lower limbs on one side), it is called hemiballismus. If it affects one limb, it could be labeled as focal or one limb ballismus. Any lesion (vascular, trauma, tumor, deposition, and demyelination) in the subthalamic nucleus of the basal ganglia results in ballismus. A rare entity such as copper deposition in Wilson's disease can manifest as ballismus. In this case report, we described a boy with Wilson's disease with focal ballismus of the right arm.

Treatment of Persistent Hemiballism with Deep Brain Stimulation of the Globus Pallidus Internus: Case Report and Literature Review

BACKGROUND

Hemiballism is a rare hyperkinetic movement disorder characterized by involuntary, high-amplitude, unilateral flailing of upper or lower extremities or both. In the case of hemiballism refractory to pharmaceutical interventions, deep brain stimulation (DBS) is an effective primary neurosurgical treatment. DBS targets for hemiballism include the thalamus, subthalamic nucleus, and globus pallidus internus (GPi).

CASE DESCRIPTION

We present a case of a patient who sustained a posterior cerebral artery ischemic stroke that eventually led to uncontrolled hemiballism, which was then successfully treated by unilateral GPi stimulation. We include a video depicting the patient preoperatively, intraoperatively with stimulation off, and intraoperatively with stimulation on. We also review published cases of hemiballism treated by GPi-DBS, which support the claim that GPi-DBS is an effective method for treating hemiballism.

CONCLUSIONS

Evidence gathered from the literature indicates that GPi-DBS is an effective treatment for hemiballism, especially after neuroleptics have failed. Results from various case studies of GPi-DBS used to treat hemiballism reveal improved motor ability and decreased dyskinesia, although degree of improvement may vary. More studies are required to establish which DBS target requires the least amount of stimulation to treat hemiballism.

Post-stroke dyskinesias

Strokes, whether ischemic or hemorrhagic, are among the most common causes of secondary movement disorders in elderly patients. Stroke-related (vascular) movement disorders, however, are uncommon complications of this relatively common disease. The spectrum of post-stroke movement disorders is broad and includes both hypo- and hyperkinetic syndromes. Post-stroke dyskinesias are involuntary hyperkinetic movements arising from cerebrovascular insults and often present with mixed phenotypes of hyperkinesia which can sometimes be difficult to classify. Nevertheless, identification of the most relevant motor phenotype, whenever possible, allows for a more specific phenomenological categorization of the dyskinesia and thus helps guide its treatment. Fortunately, post-stroke dyskinesias are usually self-limiting and resolve within 6 to 12 months of onset, but a short-term pharmacotherapy might sometimes be required for symptom control. Functional neurosurgical interventions targeting the motor thalamus or globus pallidus interna might be considered for patients with severe, disabling, and persistent dyskinesias (arbitrarily defined as duration longer than 12 months).

Hyperkinetic Movement Disorder Secondary to Punctate Hemorrhage in Lateral Ventricle Lining

We present the case of an elderly male with hyperkinetic movements of the right arm and leg due to a small hemorrhage in the lateral aspect of the left lateral ventricle atrium. As per our database search, this is a unique presentation of a stroke in this particular location.

Movement disorders in cerebrovascular disease

Movement disorders can occur as primary (idiopathic) or genetic disease, as a manifestation of an underlying neurodegenerative disorder, or secondary to a wide range of neurological or systemic diseases. Cerebrovascular diseases represent up to 22% of secondary movement disorders, and involuntary movements develop after 1-4% of strokes. Post-stroke movement disorders can manifest in parkinsonism or a wide range of hyperkinetic movement disorders including chorea, ballism, athetosis, dystonia, tremor, myoclonus, stereotypies, and akathisia. Some of these disorders occur immediately after acute stroke, whereas others can develop later, and yet others represent delayed-onset progressive movement disorders. These movement disorders have been encountered in patients with ischaemic and haemorrhagic strokes, subarachnoid haemorrhage, cerebrovascular malformations, and dural arteriovenous fistula affecting the basal ganglia, their connections, or both.

Ballismus as a sign of transitional ischemic attack

A 70-year-old woman presented to our emergency center with a complaint of jerking and twisting movements in her left upper limb and left ankle with deviation of her mouth toward the left. The movements had lasted two minutes and the deviation resolved spontaneously after 30 minutes. She had a history of similar movements five days earlier. During her stay in the emergency center, she experienced the same movements three times. A CT scan without contrast showed a small lesion in the left putamen. Four vessel color Doppler sonography showed a small atheroma plaque in the proximal part of the left internal carotid artery with stenosis less than ten percent. The repeated CT scans revealed progression of the hypodense lesion and the patient developed hemiparesis. In this case, ballismus movements were a cardinal sign for a future stroke and her problem can be considered a recurrent transient ischemic attack or a stroke in evolution.

Confirmation of functional zones within the human subthalamic nucleus: patterns of connectivity and sub-parcellation using diffusion weighted imaging

The subthalamic nucleus (STN) is a small, glutamatergic nucleus situated in the diencephalon. A critical component of normal motor function, it has become a key target for deep brain stimulation in the treatment of Parkinson's disease. Animal studies have demonstrated the existence of three functional sub-zones but these have never been shown conclusively in humans. In this work, a data driven method with diffusion weighted imaging demonstrated that three distinct clusters exist within the human STN based on brain connectivity profiles. The STN was successfully sub-parcellated into these regions, demonstrating good correspondence with that described in the animal literature. The local connectivity of each sub-region supported the hypothesis of bilateral limbic, associative and motor regions occupying the anterior, mid and posterior portions of the nucleus respectively. This study is the first to achieve in-vivo, non-invasive anatomical parcellation of the human STN into three anatomical zones within normal diagnostic scan times, which has important future implications for deep brain stimulation surgery.

Dopamine, affordance and active inference

The role of dopamine in behaviour and decision-making is often cast in terms of reinforcement learning and optimal decision theory. Here, we present an alternative view that frames the physiology of dopamine in terms of Bayes-optimal behaviour. In this account, dopamine controls the precision or salience of (external or internal) cues that engender action. In other words, dopamine balances bottom-up sensory information and top-down prior beliefs when making hierarchical inferences (predictions) about cues that have affordance. In this paper, we focus on the consequences of changing tonic levels of dopamine firing using simulations of cued sequential movements. Crucially, the predictions driving movements are based upon a hierarchical generative model that infers the context in which movements are made. This means that we can confuse agents by changing the context (order) in which cues are presented. These simulations provide a (Bayes-optimal) model of contextual uncertainty and set switching that can be quantified in terms of behavioural and electrophysiological responses. Furthermore, one can simulate dopaminergic lesions (by changing the precision of prediction errors) to produce pathological behaviours that are reminiscent of those seen in neurological disorders such as Parkinson's disease. We use these simulations to demonstrate how a single functional role for dopamine at the synaptic level can manifest in different ways at the behavioural level.

[Nonketotic hyperglycemia-induced hemiballism]

Nonketotic hyperglycemia-induced hemichorea or hemiballism is a well-recognized entity that is rarely encountered. Particular computed tomography and magnetic resonance imaging findings have been described. The pathophysiological mechanism of this disease remains uncertain. We report here on two female patients that presented with hemiballism secondary to nonketotic hyperglycemia and underwent brain computed tomography and magnetic resonance imaging.

[Vascular hemiballismus due to extraluysian lesions]

INTRODUCTION

Hemiballismus is a very rare disorder; less than 7% of all hyperkinetic disorders. Classically, a lesion of the contralateral corpus Luysii is involved. We report a case of hemiballismus due to an extraluysian lesions and discuss the underlying pathophysiology.

CASE REPORT

A 74-year-old women, with a history of diabetes and hypertension, developed left-sided hemiballismus one week before admission. The brain MRI showed a right lenticular nucleus hematoma with vascular leucoencephalopathy. The patient was given haloperidol and recovered well. The brain MRI showed the integrity of both corpus Luysii.

CONCLUSION

Hemiballismus has been classically characterized as pathognomonic of a lesion in the contralateral corpus Luysii. However, many cases due to an extraluysian lesion of the striatum, caudate or thalamus have been reported recently. Prognosis is benign in most cases.