Chronic Post-hypoxic Myoclonus Research Articles

Overnight response to levetiracetam in Lance–Adams syndrome presenting 3 years after cardiac arrest

BackgroundLance–Adams syndrome (LAS), also known as chronic post-hypoxic myoclonus manifests as myoclonic movements of the face, limbs, or trunk following hypoxic brain injury, which may occur during respiratory failure or cardiac arrest.Case presentationWe present a case and provide a video of a patient who developed LAS 3 years after experiencing cardiac arrest, presenting with action-induced generalized myoclonus upon standing. The patient exhibited a significant response to levetiracetam. To the best of our knowledge, this is the first reported case of LAS with such a delayed onset following the initial hypoxic event.ConclusionIt is crucial for clinicians to be aware of this treatable condition and recognize that its onset may be delayed, occurring years after a hypoxic brain insult. This improved understanding will facilitate prompt diagnosis and effective management of LAS, ultimately enhancing patient outcomes.

N°188 – A case of chronic post-hypoxic myoclonus

N°188 – A case of chronic post-hypoxic myoclonus

Long‐term changes of the neural network in case of improved post‐hypoxic myoclonus and gait

AbstractChronic post‐hypoxic myoclonus (PHM) is a rare complication after successful cardiopulmonary resuscitation that causes severe gait disability due to action myoclonus. We report a case of a 69‐year‐old male patient with chronic PHM who showed significant improvement in myoclonus and gait. The diffusion tensor imaging (DTI) was taken at initial admission and long‐term follow‐up (3 years) to find the changes in the diffusion matrices of the related neural correlate region of interest (ROI). There was a change in pedunculopontine nucleus and several subcortical networks.

Complete remission of symptoms in a case of Lance-Adams syndrome: A 17-year follow-up

To describe a case of Lance-Adams syndrome in a Movement Disorder Clinic in El Salvador. Background: Chronic post-hypoxic myoclonus, also known as Lance-Adams syndrome, is a rare complication of successful cardiopulmonary resuscitation.

Is deep brain stimulation useful in Lance–Adams syndrome?

Lance–Adams syndrome (LAS) is a chronic post-hypoxic myoclonus that occurs after successful cardiopulmonary resuscitation. Although many drugs are available to treat this condition, the underlying mechanism of the disease is yet to be understood. Deep brain stimulation (DBS) has been attempted and proven to be partially successful in treating LAS in several cases. Here, we present a 40-year-old woman who developed myoclonus subsequent to cardiopulmonary arrest (CPA) that occurred after her first cesarean delivery at the age of 26 years. The patient underwent implantation of bilateral globus pallidus interna (GPi)-DBS about 14 years after disease onset. Regarding Unified Myoclonus Rating Scale (UMRS), 8% and 20% improvements were observed in action and resting myoclonus, respectively, with high-frequency stimulation as a result of the 3-year follow-up study. In this case, neuromodulation therapy applied 14 years after hypoxia-causing LAS was not sufficiently beneficial.

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

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. 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. 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. 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.

Diagnosis of chronic post-hypoxic myoclonus in near hanging survivor: Case report

A 39-year-old male, who attempted suicide by hanging, developed chronic myoclonus with intact cognitive function. Chronic post-hypoxic myoclonus is a rare syndrome that may develop after a respiratory arrest and it presents as late onset and persistent purposeful myoclonus with preserved or slightly impaired cognitive function. Increasing critical care nurses’ awareness of chronic post-hypoxic myoclonus will lead to earlier diagnosis of this rare syndrome.

Editors' note: Clinical Reasoning: Prognostication after cardiac arrest: What do we really know?

In reference to “Clinical Reasoning: Prognostication after cardiac arrest: What do we really know?,” Drs. Freund and Kaplan comment on the difficulty of distinguishing Lance-Adams syndrome (“chronic posthypoxic myoclonus”) from myoclonic status epilepticus, based on postarrest onset or outcomes, as there is substantial variability in both. They suggest further study into clinical, neuroimaging, and neurophysiologic correlates of posthypoxic myoclonus. Authors Beekman et al. agree and add the need for a systematic characterization of postarrest myoclonus to better understand its utility as a prognostic tool. In reference to “Clinical Reasoning: Prognostication after cardiac arrest: What do we really know?,” Drs. Freund and Kaplan comment on the difficulty of distinguishing Lance-Adams syndrome (“chronic posthypoxic myoclonus”) from myoclonic status epilepticus, based on postarrest onset or outcomes, as there is substantial variability in both. They suggest further study into clinical, neuroimaging, and neurophysiologic correlates of posthypoxic myoclonus.

Poster 327: Dysphagia as an Unusual Presenting Symptom of Chronic Post-Hypoxic Myoclonus: A Case Report

Poster 327: Dysphagia as an Unusual Presenting Symptom of Chronic Post-Hypoxic Myoclonus: A Case Report

Improvement of Post Anoxic Myoclonus with Valproic Acid and Add on Levetiracetam Therapy

Myoclonus may be defined as sudden muscle contractions that are brief, involuntary, and shock-like. There are many conditions that can lead to myoclonus including spinal cord injury, stroke and as a side effect of certain drugs. Post hypoxic myoclonus is a recognized entity that develops post successful resuscitation of cardiac arrest and this is known in the literature as Lance Adams Syndrome. Often myoclonus is confused with an underlying seizure disorder. Myoclonic status epilepticus at any time after return of spontaneous circulation (ROSC) is even considered to reliably indicate a poor prognosis. Different treatments have been attempted to manage post hypoxic myoclonus including valproic acid and clonazepam and even Bilateral Pallidal Deep Brain Stimulation. The authors would like to present a case report of a 59-years-old male with chronic post hypoxic myoclonus who was successful treated with a combination medication regime of valproic acid and levetiracetam.

A rare case report of Lance-Adams Syndrome

Lance-Adams syndrome or chronic post-hypoxic myoclonus, is a rare complication of post-cardiopulmonary resuscitation, accompanied by action myoclonus and cerebellar ataxia. It manifests as diffuse action-triggered jerking movements resulting in significant morbidity. A case of Lance-Adams syndrome is presented here in a 60-year-old farmer admitted to the intensive care unit with history of cobra bite, in coma and respiratory failure, revived elsewhere. His EEG and CT brain was unremarkable. This patients myoclonus was poorly controlled by a variety of anti-epileptic medications. Over 75 days of rehabilitation there was improvement in ambulation and there were no cognitive deficits.

Relief of Intractable Posthypoxic Myoclonus After Administration of Agomelatine

Chronic posthypoxic myoclonus is characterized by myoclonic jerks that are specifically triggered by action. It is a rare but devastating sequela of hypoxic encephalopathy. We report a 42-year-old female patient with treatment-resistant chronic posthypoxic myoclonus, which improved with administration of the drug agomelatine. We suggest that agomelatine could represent a useful therapeutic option in the treatment of chronic posthypoxic myoclonus.

Lance-Adams Syndrome

It is not common for a patient who survives cardiac arrest to experience significant neurologic impairment such as acute and chronic post-hypoxic myoclonus, known as Lance-Adams syndrome. This syndrome is predominantly characterized by myoclonus that starts days to weeks after cardiopulmonary resuscitation in patients who regained consciousness. Although several cases of LAS were reported, the decisive treatment method has not been established. We report a 43 year old man with Lance-Adams syndrome who showed long-term improvement through treatment with anti-myoclonic agents and participation in a rehabilitation program.

Poster 18 Lance-Adams Syndrome: Rehabilitation of Chronic Posthypoxic Myoclonus

Poster 18 Lance-Adams Syndrome: Rehabilitation of Chronic Posthypoxic Myoclonus

Lance-adams syndrome: a report of two cases

Chronic post-hypoxic myoclonus, also known as Lance-Adams syndrome (LAS), is a rare complication of successful cardiopulmanry resuscitation often accompanied by action myoclonus and cerebellar ataxia. It is seen in patients who have undergone a cardiorespiratory arrest, regained consciousness afterwards, and then developed myoclonus days or weeks after the event. Worldwide, 122 cases have been reported in the literature so far, including 1 case of Chinese. Here we report 2 Chinese LAS patients with detailed neuroimagings. Cranial single photon emission computed tomography (SPECT) of patient 1, a 52-year-old woman, showed a mild hypoperfusion in her left temporal lobe, whereas patient 2, a 54-year-old woman, manifested a mild bilateral decrease of glucose metabolism in the frontal lobes and a mild to moderate decrease of the N-acetyl aspartate (NAA) peak in the bilateral hippocampi by cranial [(18)F]-fluorodeoxyglucose positron emission tomographic (PET) scan and cranial magnetic resonance spectroscopy (MRS), respectively. We also review the literature on the neuroimaging, pathogenesis, and treatment of LAS.

Physiology of human posthypoxic myoclonus.

There are two types of posthypoxic myoclonus, acute and chronic. The acute type has not been intensively studied but is likely to be brain stem in origin. Chronic posthypoxic myoclonus is most commonly cortical reflex myoclonus, but reticular reflex myoclonus and exaggerated startle may also occur. These three conditions have characteristic physiological features. In assessing the relevance of an animal model, it would be appropriate to identify the myoclonus with one of these three patterns.

The clinical features and prognosis of chronic posthypoxic myoclonus.

The clinical and neurophysiologic features of 14 patients with chronic posthypoxic myoclonus are presented. Patients were first seen a mean of 2.5 years (range, 2 to 105 months) after the hypoxic event and followed up for 3.7 years (range, 7 to 84 months) thereafter. All patients had had a cardiorespiratory arrest, most caused by an acute asthmatic attack (11 cases). All patients had multifocal action myoclonus. Eleven patients had additional stimulus-sensitive myoclonus. There was late improvement in the myoclonic syndrome and the level of disability in all but one patient. Three patients were eventually able to discontinue antimyoclonic medication, and five patients were able to walk unaided. Cognitive deficits were found in seven patients and were usually mild. Other neurologic deficits were rare. Electrophysiologic investigation confirmed cortical action myoclonus in every case, although this could be combined with cortical reflex myoclonus, an exaggerated startle response, or brainstem reticular reflex myoclonus. We conclude that posthypoxic myoclonus typically consists of multifocal cortical action myoclonus that improves with time. It is only rarely associated with severe additional neurologic deficit.