The Neurophysiological Basis of Myoclonus

2017 ◽  
Author(s):  
Phillip D. Thompson ◽  
Hiroshi Shibasaki ◽  
Mark Hallett
Keyword(s):  
Subacute Sclerosing Panencephalitis ◽  
Sensory Stimuli ◽  
Classification Schemes ◽  
Clinical Appearance ◽  
Cortical Myoclonus ◽  
Somatosensory Evoked Response ◽  
Spinal Myoclonus ◽  
Jakob Disease ◽  
Neurophysiological Assessment ◽  
Neurophysiological Basis

There are several types of myoclonus, with a variety of classification schemes, and the clinician must determine what type of myoclonus a patient has and what type of neurophysiological assessment can facilitate diagnosis. The electromyographic (EMG) correlate of the myoclonus should be examined, including the response to sensory stimuli (C-reflex). The electroencephalographic (EEG) correlate of the myoclonus should then be examined, possibly including back-averaging from the myoclonus or looking at corticomuscular (EEG–EMG) coherence. The somatosensory evoked response (SEP) should be obtained. Such studies will help determine the myoclonus origin, most commonly cortical or brainstem. One form of cortical myoclonus has the clinical appearance of a tremor (cortical tremor). Brainstem myoclonus includes exaggerated startle (hyperekplexia). Other forms of myoclonus include spinal myoclonus and functional myoclonus, which have their own distinct physiological signature. Several causes of myoclonus are reviewed, including rare types such as Creutzfeldt-Jakob disease and subacute sclerosing panencephalitis.

Myoclonus

2016 ◽  
Author(s):  
Hiroshi Shibasaki ◽  
Marina A J Koning-Tijssen
Keyword(s):  
Spinal Cord ◽  
Key Words ◽  
Loss Of Consciousness ◽  
Voluntary Movements ◽  
Involuntary Movements ◽  
Cortical Myoclonus ◽  
Progressive Myoclonus Epilepsy ◽  
Myoclonus Epilepsy ◽  
Jakob Disease

Myoclonus is defined as sudden, brief, jerky, shocklike, involuntary movements involving the extremities, face, and trunk, without loss of consciousness. Myoclonus is one of the most commonly encountered involuntary movements, and it can be seen in association with a variety of conditions. This review covers  the epidemiology, classification, and diagnosis of myoclonus, as well as a thorough discussion of cortical myoclonus, myoclonus of brainstem origin, myoclonus of spinal cord origin, and myoclonus of undetermined origin. Figures show the principle of jerk-locked back-averaging, example data of jerk-lock averaging, schematic diagrams of cortical reflex myoclonus and spontaneous cortical myoclonus, a polygraphic electromyogram (EMG) recorded from a patient with postanoxic, reticular reflex myoclonus, surface negative slow electroencephalographic (EEG) potentials recorded before psychogenic jerks and voluntary movements mimicking the jerks in a patient with a diagnosis of psychogenic truncal movements, and an EEG-EMG polygraph in a patient with Creutzfeldt-Jakob disease. Tables list the classification of myoclonus based on the estimated site of origin, causes of cortical myoclonus, and causes of progressive myoclonus epilepsy and gene abnormalities. Key words: cortical myoclonus, EEG-EMG polygraph, epilepsy syndromes, involuntary movements, myoclonus This review contains 6 highly rendered figures, 3 tables, and 63 references.

Myoclonus

2016 ◽  
Author(s):  
Hiroshi Shibasaki ◽  
Marina A J Koning-Tijssen
Keyword(s):  
Spinal Cord ◽  
Key Words ◽  
Loss Of Consciousness ◽  
Voluntary Movements ◽  
Involuntary Movements ◽  
Cortical Myoclonus ◽  
Progressive Myoclonus Epilepsy ◽  
Myoclonus Epilepsy ◽  
Jakob Disease

Myoclonus is defined as sudden, brief, jerky, shocklike, involuntary movements involving the extremities, face, and trunk, without loss of consciousness. Myoclonus is one of the most commonly encountered involuntary movements, and it can be seen in association with a variety of conditions. This review covers  the epidemiology, classification, and diagnosis of myoclonus, as well as a thorough discussion of cortical myoclonus, myoclonus of brainstem origin, myoclonus of spinal cord origin, and myoclonus of undetermined origin. Figures show the principle of jerk-locked back-averaging, example data of jerk-lock averaging, schematic diagrams of cortical reflex myoclonus and spontaneous cortical myoclonus, a polygraphic electromyogram (EMG) recorded from a patient with postanoxic, reticular reflex myoclonus, surface negative slow electroencephalographic (EEG) potentials recorded before psychogenic jerks and voluntary movements mimicking the jerks in a patient with a diagnosis of psychogenic truncal movements, and an EEG-EMG polygraph in a patient with Creutzfeldt-Jakob disease. Tables list the classification of myoclonus based on the estimated site of origin, causes of cortical myoclonus, and causes of progressive myoclonus epilepsy and gene abnormalities.   Key words: cortical myoclonus, EEG-EMG polygraph, epilepsy syndromes, involuntary movements, myoclonus   This review contains 6 highly rendered figures, 3 tables, and 63 references.

scholarly journals Post-anoxic myoclonus

2014 ◽  
Vol 2 (6) ◽  
pp. 8
Author(s):  
Pavis Laengvejkal ◽  
Parunyou Julayanont ◽  
Drew Payne
Keyword(s):  
Brain Injury ◽  
Clinical Presentation ◽  
Subacute Sclerosing Panencephalitis ◽  
Chronic Phase ◽  
Muscular Contraction ◽  
Comorbid Conditions ◽  
Anoxic Brain Injury ◽  
Hypoxic Event ◽  
Negative Myoclonus ◽  
Jakob Disease

Myoclonus is a movement disorder characterized by involuntary, sudden, brief muscle jerks caused by muscular contraction (positive myoclonus) or inhibition (negative myoclonus).1,2 Myoclonus is generally a medical sign and not a diagnosis. It can occur in multiple disorders. A short differential diagnosis list includes anoxic brain injury, multiple sclerosis, Parkinson's disease, subacute sclerosing panencephalitis, and Creutzfeldt-Jakob disease.  One way to classify the etiologies is through review of the clinical presentation and comorbid conditions. This article presents a review of anoxic brain injury related myoclonus. Post-anoxic myoclonus (PAM) can develop in either acute or chronic phase. Acute PAM occurs within hours after hypoxic event; chronic PAM (Lance-Adams syndrome) develops in survivors several days to weeks after the episodes of brain hypoxia.

Myoclonus

2020 ◽  
pp. 45-90
Author(s):  
Hiroshi Shibasaki ◽  
Mark Hallett ◽  
Kailash P. Bhatia ◽  
Stephen G. Reich ◽  
Bettina Balint
Keyword(s):  
Spinal Cord ◽  
Cognitive Impairment ◽  
Motor Cortex ◽  
Neurodegenerative Diseases ◽  
Motor Neurons ◽  
Cortical Myoclonus ◽  
Negative Myoclonus ◽  
Spinal Myoclonus ◽  
Nocturnal Myoclonus ◽  
Convulsive Seizures

Myoclonus is defined as brisk, shock-like, involuntary movements. Hiccup and nocturnal myoclonus are physiological myoclonus. Myoclonus is usually caused by abrupt, instantaneous contraction of muscles (positive myoclonus), but it can be also caused by transient interruption of the ongoing muscle contraction (negative myoclonus, asterixis). Myoclonus is usually irregular, but some myoclonus may occur at certain intervals (rhythmic or periodic myoclonus). Myoclonus is caused by excessive excitation of motor neurons in the motor cortex (cortical myoclonus, epileptic myoclonus), in the brainstem, or in the spinal cord (spinal myoclonus). Cortical myoclonus is commonly associated with convulsive seizures and is also called epileptic myoclonus. Syndromes characterized by myoclonus, generalized convulsion, and cognitive impairment are coined the progressive myoclonus epilepsies and are caused by multiple neurodegenerative diseases.

P22-14 Cortical and non-cortical myoclonus of Creutzfeldt-Jakob disease (CJD): Precious lesson learned from a patient

2010 ◽  
Vol 121 ◽  
pp. S236
Author(s):  
J. Chen ◽  
C.H. Tsai ◽  
M.K. Lu ◽  
Y.L. Liou ◽  
Y.T. Hsu
Keyword(s):  
Cortical Myoclonus ◽  
Jakob Disease

scholarly journals Syndromes of Rapidly Progressive Cognitive Decline-Our Experience

2017 ◽  
Vol 08 (S 01) ◽  
pp. S66-S71 ◽  
Author(s):  
Sadanandavalli Retnaswami Chandra ◽  
Lakshminarayanapuram Gopal Viswanathan ◽  
Anupama Ramakanth Pai ◽  
Rahul Wahatule ◽  
Suvarna Alladi
Keyword(s):  
Small Vessel Disease ◽  
Subacute Sclerosing Panencephalitis ◽  
Treatment Options ◽  
Vitamin B12 Deficiency ◽  
Autoimmune Encephalitis ◽  
Acid Decarboxylase ◽  
Thyroid Peroxidase ◽  
Immune Mediated ◽  
Thyroid Peroxidase Antibody ◽  
Jakob Disease

ABSTRACT Background: Dementias are fairly slowly progressive degenerative diseases of brain for which treatment options are very less and carry a lot of burden on family and society. A small percentage of them are rapidly progressive and mostly carry a different course outcome. However, there are no definite criteria other than the time line for these patients. Aims: The aim of this was to identify and categorize the causes and course of rapidly progressive dementias seen in our center. Settings and Design: Patients who presented with rapid deterioration of cognitive functions within weeks to 1 year between 2011 and December 2016 were evaluated. Patients and Methods: All patients underwent all mandatory tests for dementia including brain imaging. Complete vasculitis workup, autoimmune encephalitis profile including Voltage Gated Potassium Channel, N-methyl-D-aspartic acid receptor, glutamic acid-decarboxylase, thyroid-peroxidase antibody, cerebrospinal fluid, and other special tests such as duodenal biopsy and paraneoplastic workup were done based on clinical indications. Results and Conclusions: Out of 144 patients 42 had immune-mediated encephalopathy, 18 had Creutzfeldt-Jakob disease, 3 had Vitamin B12 deficiency, 63 had infection with neurocysticercosis, 7 had tuberculosis, 2 had HIV, 1 had herpes simplex encephalitis, 1 had neurosyphilis, 1 Whipples disease, 1 had Subacute Sclerosing Panencephalitis, 1 had Mass lesion, 3 had Frontotemporal dementia, and 3 had small vessel disease. Good majority of these patients have infective and immune-mediated causes and less number belong to degenerative group. Therefore, caution is needed to look for treatable cause as it carries a different treatment options and outcome.

Idiopathic spinal myoclonus: A clinical and neurophysiological assessment of a movement disorder of uncertain origin

2009 ◽  
Vol 24 (16) ◽  
pp. 2344-2349 ◽  
Author(s):  
Marcello Esposito ◽  
Mark J. Edwards ◽  
Kailash P. Bhatia ◽  
Peter Brown ◽  
Carla Cordivari
Keyword(s):  
Movement Disorder ◽  
Spinal Myoclonus ◽  
Neurophysiological Assessment

Viral infections of the nervous system

1984 ◽  
Vol 61 (2) ◽  
pp. 207-224 ◽  
Author(s):  
Leslie P. Weiner ◽  
John O. Fleming
Keyword(s):  
Viral Infections ◽  
Current Knowledge ◽  
Subacute Sclerosing Panencephalitis ◽  
Epidemic Encephalitis ◽  
Laboratory Findings ◽  
Spongiform Encephalopathies ◽  
Content Type ◽  
Neurotropic Viruses ◽  
Jakob Disease ◽  
Immunodeficiency Syndrome

✓ Neurotropic viruses cause a number of important infectious syndromes including encephalitis, myelitis, meningitis, and radiculopathy. In this review, the biology of conventional and unconventional viruses is examined. The host immune response to viruses is discussed, and patterns of viral pathogenesis are explained. The clinical features, laboratory findings, management of important viral infections, such as herpes simplex encephalitis and epidemic encephalitis, are presented. Post-infection syndromes, such as the Guillain-Barré syndrome, and chronic viral infections, such as those causing progressive multifocal leukoencephalopathy and subacute sclerosing panencephalitis, are discussed. Current knowledge concerning the nature of unconventional virus-like agents of the spongiform encephalopathies, including kuru and Creutzfeldt-Jakob disease, is summarized. Finally, viral infections of immunocompromised patients and the possible role of viruses in the newly described acquired immunodeficiency syndrome (AIDS) are examined.

Post-hypoxic cortical myoclonus mimicking spinal myoclonus - electrophysiological and functional MRI manifestations

2010 ◽  
Vol 18 (1) ◽  
pp. e4-e5 ◽  
Author(s):  
H.-C. Huang ◽  
J.-C. Chen ◽  
M.-K. Lu ◽  
J.-M. Chen ◽  
C.-H. Tsai
Keyword(s):  
Functional Mri ◽  
Cortical Myoclonus ◽  
Spinal Myoclonus
Sign in / Sign up

Export Citation Format

Share Document