Unilateral Myoclonus as an initial manifestation in Moyamoya disease with asymmetric vasculature.

Movement disorders have been identified as a rare early manifestation of the Moyamoya disease. Herein, we present a case of a 34-year-old man with a genetically confirmed Moyamoya disease who showed unilateral myoclonus as an initial manifestation. Neuroimaging studies showed prominent asymmetrically developed Moyamoya disease on the right hemisphere with near-complete loss of normal vessels while the left hemisphere was adjunctively fed with extension of posterior cerebral artery: uneven progression of vasculature. 99mTc-hexamethylpropylene amine oxime single-photon emission computed tomography demonstrated impaired vascular reserve. Electroencephalography showed occasional sharp waves on right temporal area. The phenomenon of this patient could be explained in the context of excitable cortex and hypoactive subcortical substrate that might imply putative contradictory neurobiology in Moyamoya disease.

Expanding the Spectrum of Diabetic Striatopathy: Insights from a Case of Hyperglycemia-Induced Propriospinal Myoclonus.

This video abstract delves into the expanded definition of diabetic striatopathy, linked initially to hyperglycemia-induced choreoballism and striatal hyperintensity on magnetic resonance imaging, but now recognized to encompass a broader range of acute onset, non-choreoballistic movement disorders in diabetes mellitus, including tremors, hemifacial spasm, parkinsonism, different types of myoclonus, dystonia, restless leg syndrome, ataxia, and dyskinesias. We report the case of a 45-year-old female patient with type-2 diabetes mellitus who developed propriospinal myoclonus, characterized by painless, involuntary jerky movements of the bilateral lower limbs in a supine position after admission for suspected rhino-orbital mucormycosis. The abnormal movements resolved entirely following the control of her blood glucose levels, suggesting a direct correlation between hyperglycemia and the clinical picture. This case highlights the importance of considering a wide range of differential diagnoses for abnormal lower limb movements in diabetic patients, emphasizing the need for accurate identification of movement semiology, routine bedside capillary blood glucose checks, and prompt hyperglycemia management to resolve such movement disorders effectively.

Surgical Treatment of Upper Extremity Segmental Myoclonus in an Adolescent with Chiari Malformation and Cervicothoracic Syrinx.

BACKGROUND: Myoclonus is an involuntary movement disorder characterized by semirhythmic jerking movements of muscle groups but is rarely seen in association with Chiari malformation type I (CM-1). CM-1 is a frequently encountered clinical entity in pediatric neurosurgery characterized by caudal displacement of the cerebellar tonsils with or without syringomyelia. We report a pediatric patient who presented with upper extremity myoclonus and was found to have CM-1 and a complex septated cervicothoracic syrinx eccentric to the left. CASE PRESENTATION: A 12-year-old female presented with 6 months of headaches and upper extremity paresthesias who subsequently developed a left upper extremity segmental myoclonus after a fall. MRI demonstrated a CM-1 and a large complex cervicothoracic syrinx with a midline and left paracentral cavities. Her myoclonus was nonepileptic and refractory to clonazepam, cyclobenzaprine, and gabapentin. She underwent an intradural Chiari decompression and duraplasty. Postoperatively, she had complete resolution of her segmental myoclonus. DISCUSSION: This case demonstrates a durable resolution of posttraumatic upper extremity segmental myoclonus after surgical decompression of a CM-1 with syringomyelia. Thus, Chiari decompression should be considered in cases of myoclonus with CM-1 and syringomyelia.

Isolated generalized myoclonus immune-mediated by SARS-CoV-2: an illustrative videotaped case.

Myoclonus in the context of COVID-19 is an increasingly recognized condition. The occurrence in an ICU context in hypoxic patients, with metabolic disorders, taking several types of medication, makes difficult to establish a precise cause. Also, the implication of SARS-CoV-2 by direct invasion of the CNS or by immune-mediated phenomena is not yet clear. Currently, a dozen of cases of myoclonus as a predominant clinical manifestation, immune-mediated by SARS-Cov-2 are published. In all these cases, myoclonus was preceded by respiratory or other suggestive symptoms (e.g., anosmia) for this infection making straightforward the causal link. We describe a case of an isolated generalized myoclonus without other clinical complaints nor chest CT scan abnormalities nor SARS-CoV-2 RNA detection on nasopharyngeal swabs and on the CSF, as a para-infectious phenomenon of COVID-19 infection with excellent response to steroids perfusion. This challenging diagnosis was made upon confirmation of seroconversion (serology was negative at admission, then positive for IgM at day 6, then for both IgM and IgG at day 10) underlying that repeating serology is a diagnostic key to capture a similar findings.

Objective bilateral tinnitus from palatal nystagmus. Audio and video features of a rare case of palatal myoclonus.

Tinnitus is one of the most represented otological symptom, affecting 15% of adults, worldwide. Literature describes subjective tinnitus when it's perceived by the patient only, and objective tinnitus when it's heard both, by patient and examiner. An objective tinnitus can be caused by a large variety of anomalies and diseases; one of them is Palatal Myoclonus, characterized by rhytmic movements of soft palatal muscles and, only occasionally, involving other near districts. Case presentation. We observed a rare case of essential palatal myoclonus in a 54 y.o. female, suffering from chronic objective bilateral tinnitus, since 35 years, who underwent a wide number of clinical evaluations over the years, without receiving any conclusive diagnosis. In this video, we illustrate all the districts involved in clonic movements: soft palate, larynx and nasal wings. At the same time, we report the spectrographic analysis of tinnitus, recorded in esternal ear canal, taken together with the muscle movements. Palatal Myoclonus has to be considered in the etiological diagnosis of each objective tinnitus and should always be investigated properly.

Clinical Outcome and Intraoperative Neurophysiology of the Lance-Adams Syndrome Treated with Bilateral Deep Brain Stimulation of the Globus Pallidus Internus: A Case Report and Review of the Literature.

BACKGROUND: The Lance-Adams syndrome (LAS) is a myoclonus syndrome caused by hypoxic-ischemic encephalopathy. LAS cases could be refractory to first-line medications, and the neuronal mechanism underlying LAS pathology remains unknown. OBJECTIVES: To describe a patient with LAS who underwent bilateral globus pallidus internus (GPi) stimulation and discuss the pathophysiology of LAS with intraoperative electrophysiological findings. PATIENTS: A 79-year-old woman presented with a history of cardiopulmonary arrest due to internal carotid artery rupture following carotid endarterectomy after successful cardiopulmonary resuscitation. However, within 1 month, the patient developed sensory stimulation-induced myoclonus in her face and extremities. Because her myoclonic symptoms were refractory to pharmacotherapy, deep brain stimulation of the GPi was performed 1 year after the hypoxic attack. RESULTS: Continuous bilateral GPi stimulation with optimal parameter settings remarkably improved the patient's myoclonic symptoms. At the 2-year follow-up, her Unified Myoclonus Rating Scale score decreased from 90 to 24. In addition, we observed burst firing and interburst pause patterns on intraoperative microelectrode recordings of the bilateral GPi and stimulated this area as the therapeutic target. CONCLUSION: Our results show that impairment in the basal ganglion circuitry might be involved in the pathogenesis of myoclonus in patients with LAS.

COVID-19-related encephalopathy: a case series with brain FDG-positron-emission tomography/computed tomography findings.

AIM: The aim of this paper is to describe the clinical features of COVID-19-related encephalopathy and their metabolic correlates using brain 2-desoxy-2-fluoro-D-glucose (FDG)-positron-emission tomography (PET)/computed tomography (CT) imaging. BACKGROUND AND PURPOSE: A variety of neurological manifestations have been reported in association with COVID-19. COVID-19-related encephalopathy has seldom been reported and studied. METHODS: We report four cases of COVID-19-related encephalopathy. The diagnosis was made in patients with confirmed COVID-19 who presented with new-onset cognitive disturbances, central focal neurological signs, or seizures. All patients underwent cognitive screening, brain magnetic resonance imaging (MRI), lumbar puncture, and brain 2-desoxy-2-fluoro-D-glucose (FDG)-positron-emission tomography (PET)/computed tomography (CT) (FDG-PET/CT). RESULTS: The four patients were aged 60 years or older, and presented with various degrees of cognitive impairment, with predominant frontal lobe impairment. Two patients presented with cerebellar syndrome, one patient had myoclonus, one had psychiatric manifestations, and one had status epilepticus. The delay between first COVID-19 symptoms and onset of neurological symptoms was between 0 and 12 days. None of the patients had MRI features of encephalitis nor significant cerebrospinal fluid (CSF) abnormalities. SARS-CoV-2 RT-PCR in the CSF was negative for all patients. All patients presented with a consistent brain FDG-PET/CT pattern of abnormalities, namely frontal hypometabolism and cerebellar hypermetabolism. All patients improved after immunotherapy. CONCLUSIONS: Despite varied clinical presentations, all patients presented with a consistent FDG-PET pattern, which may reflect an immune mechanism.

MRI-EEG correlation for outcome prediction in postanoxic myoclonus: A multicenter study.

OBJECTIVE: To examine the prognostic ability of the combination of EEG and MRI in identifying patients with good outcome in postanoxic myoclonus (PAM) after cardiac arrest (CA). METHODS: Adults with PAM who had an MRI within 20 days after CA were identified in 4 prospective CA registries. The primary outcome measure was coma recovery to command following by hospital discharge. Clinical examination included brainstem reflexes and motor activity. EEG was assessed for best background continuity, reactivity, presence of epileptiform activity, and burst suppression with identical bursts (BSIB). MRI was examined for presence of diffusion restriction or fluid-attenuated inversion recovery changes consistent with anoxic brain injury. A prediction model was developed using optimal combination of variables. RESULTS: Among 78 patients, 11 (14.1%) recovered at discharge and 6 (7.7%) had good outcome (Cerebral Performance Category < 3) at 3 months. Patients who followed commands were more likely to have pupillary and corneal reflexes, flexion or better motor response, EEG continuity and reactivity, no BSIB, and no anoxic injury on MRI. The combined EEG/MRI variable of continuous background and no anoxic changes on MRI was associated with coma recovery at hospital discharge with sensitivity 91% (95% confidence interval [CI], 0.59-1.00), specificity 99% (95% CI, 0.92-1.00), positive predictive value 91% (95% CI, 0.59-1.00), and negative predictive value 99% (95% CI, 0.92-1.00). CONCLUSIONS: EEG and MRI are complementary and identify both good and poor outcome in patients with PAM with high accuracy. An MRI should be considered in patients with myoclonus showing continuous or reactive EEGs.

Movement disorders after hypoxic brain injury following cardiac arrest in adults.

BACKGROUND AND PURPOSE: Post-hypoxic movement disorders and chronic post-hypoxic myoclonus are rare complications after cardiac arrest in adults. Our study investigates the clinical spectrum, neuroimaging results, therapy and prognosis of these debilitating post-hypoxic sequelae. METHODS: This retrospective study included 72 patients from the neurological intensive care unit at a university hospital, who were diagnosed with hypoxic-ischaemic encephalopathy after cardiac arrest between January 2007 and September 2018. Clinical records were screened for occurrence of post-hypoxic movement disorders and chronic post-hypoxic myoclonus. Affected patients were further analysed for applied neuroprognostic tests, administered therapy and treatment response, and the outcome of these movement disorders and neurological function. RESULTS: Nineteen out of 72 screened patients exhibited post-hypoxic motor symptoms. Basal ganglia injury was the most likely neuroanatomical correlate of movement disorders as indicated by T1 hyperintensities and hypometabolism of this region in magnetic resonance imaging and positron emission tomography computed tomography. Levomepromazine and intrathecal baclofen showed first promising and mostly prompt responses to control these post-hypoxic movement disorders and even hyperkinetic storms. In contrast, chronic post-hypoxic myoclonus best responded to co-application of clonazepam, levetiracetam and primidone. Remission rates of post-hypoxic movement disorders and chronic post-hypoxic myoclonus were 58% and 50%, respectively. Affected patients seemed to present a rather good recovery of cognitive functions in contrast to the often more severe physical deficits. CONCLUSIONS: Post-hypoxic movement disorders associated with pronounced basal ganglia dysfunction might be efficiently controlled by levomepromazine or intrathecal baclofen. Their occurrence might be an indicator for a more unfavourable, but often not devastating, neurological outcome.

Generalized myoclonus in COVID-19.

OBJECTIVE: To report 3 patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) who developed generalized myoclonus. METHODS: Patient data were obtained from medical records from the University Hospital "12 de Octubre," Madrid, Spain. RESULTS: Three patients (2 men and 1 woman, aged 63-88 years) presented with mild hypersomnia and generalized myoclonus following the onset of the so-called inflammatory phase of coronavirus disease 2019 (COVID-19). All of them had presented previously with anosmia. Myoclonus was generalized with both positive and negative jerks, predominantly involving the facial, trapezius, sternocleidomastoid, and upper extremities muscles. These myoclonic jerks occurred spontaneously and were extremely sensitive to multisensory stimuli (auditive and tactile) or voluntary movements, with an exaggerated startle response. Other causes of myoclonus were ruled out, and none of the patients had undergone respiratory arrest or significant prolonged hypoxia. All of them improved, at least partially, with immunotherapy. CONCLUSIONS: Our 3 cases highlight the occurrence of myoclonus during the COVID-19 pandemic as a post- or para-infectious immune-mediated disorder. However, we cannot rule out that SARS-CoV-2 may spread transneuronally to first- and second-order structures connected with the olfactory bulb. Further investigation is required to clarify the full clinical spectrum of neurologic symptoms and optimal treatment.

Cortical myoclonus and epilepsy in a family with a new SLC20A2 mutation.

Idiopathic basal ganglia calcification (IBGC) or primary familial brain calcification is a rare genetic condition characterized by an autosomal dominant inheritance pattern and the presence of bilateral calcifications in the basal ganglia, thalami, cerebellum and cerebral subcortical white matter. The syndrome is genetically and phenotypically heterogeneous. Causal mutations have been identified in four genes: SLC20A2, PDGFRB, PDGFB and XPR1. A variety of progressive neurological and psychiatric symptoms have been described, including cognitive impairment, movement disorders, bipolar disorder, chronic headaches and migraine, and epilepsy. Here we describe a family with a novel SLC20A2 mutation mainly presenting with neurological symptoms including cortical myoclonus and epilepsy. While epilepsy, although rare, has been reported in patients with IBGC associated with SLC20A2 mutations, cortical myoclonus seems to be a new manifestation.

Subacute Sclerosing Panencephalitis Causing Rapidly Progressive Dementia and Myoclonic Jerks in a Sexagenarian Woman.

Background: Subacute sclerosing panencephalitis (SSPE) is a disease of childhood and adolescence, but can affect adults. Rapidly progressive cognitive decline, seizures including myoclonic jerks, spasticity, ataxia, visual disturbances, and incontinence are typical manifestations. Case report: A 62-year-old woman who presented with rapidly progressive dementia and myoclonus was diagnosed with SSPE. There was resolution of the movement disorder with clonazepam and valproic acid treatment and some amelioration of cognitive decline after 3 months of therapy with interferon alfa and isoprinosine. Discussion: With the recent rise in measles cases worldwide, any increased incidence of SSPE would require vigilance for early interventions.

Infantile epilepsy with multifocal myoclonus caused by TBC1D24 mutations.

PURPOSE: To summarize the clinical features and neuroimaging changes of epilepsy associated with TBC1D24 mutations. METHODS: Genetic testing was conducted in all epilepsy patients without acquired risk factors for epilepsy. Epilepsy patients identified with TBC1D24 compound heterozygous mutations by next-generation sequencing (NGS) epilepsy panel or whole exome sequencing (WES) were enrolled. The enrolled patients were followed up to summarize the clinical features. RESULTS: Nineteen patients were identified with TBC1D24 compound heterozygous mutations. Nine patients carried the same pathogenic variant c.241_252del. The seizure onset age ranged from 1 day to 8 months of age (median age 75 days). The most prominent features were multifocal myoclonus and epilepsia partialis continua (EPC). Myoclonus could be triggered by fever or infection in 15 patients, and could be terminated by sleep or sedation drugs. Psychomotor developmental delay was presented in 11 patients. Six patients exhibited hearing loss. Brain MRIs were abnormal in eight patients. Twelve patients were diagnosed with epilepsy syndromes including one patient who was diagnosed with Dravet syndrome. Two patients died due to status epilepticus at 4 months and 19 months of age, respectively. CONCLUSION: TBC1D24 mutation related epilepsy was drug-resistant. Multifocal myoclonus, EPC, and fever-induced seizures were common clinical features. Most patients presented psychomotor developmental delay. The neuroimaging abnormality and hearing loss could exacerbate during follow-up.