Neuromuscular junction disorders: Pathology review
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Neuromuscular junction disorders: Pathology review
Pathology
Central and peripheral nervous system disorders
Amyotrophic lateral sclerosis
Neurofibromatosis
Sturge-Weber syndrome
Tuberous sclerosis
von Hippel-Lindau disease
Central nervous system disorders
Brain herniation
Broca aphasia
Kluver-Bucy syndrome
Wernicke aphasia
Wernicke-Korsakoff syndrome
Acoustic neuroma (schwannoma)
Adult brain tumors
Pediatric brain tumors
Pituitary adenoma
Ischemic stroke
Transient ischemic attack
Brain abscess
Cavernous sinus thrombosis
Creutzfeldt-Jakob disease
Encephalitis
Epidural abscess
Meningitis
Neonatal meningitis
Aqueductal stenosis
Cerebral palsy
Chiari malformation
Dandy-Walker malformation
Septo-optic dysplasia
Spina bifida
Spinocerebellar ataxia (NORD)
Syringomyelia
Tethered spinal cord syndrome
Alzheimer disease
Creutzfeldt-Jakob disease
Delirium
Frontotemporal dementia
Lewy body dementia
Normal pressure hydrocephalus
Vascular dementia
Acute disseminated encephalomyelitis
Central pontine myelinolysis
JC virus (Progressive multifocal leukoencephalopathy)
Multiple sclerosis
Transverse myelitis
Cavernous sinus thrombosis
Cluster headache
Idiopathic intracranial hypertension
Migraine
Tension headache
Trigeminal neuralgia
Arteriovenous malformation
Epidural hematoma
Intracerebral hemorrhage
Saccular aneurysm
Subarachnoid hemorrhage
Subdural hematoma
Essential tremor
Huntington disease
Opsoclonus myoclonus syndrome (NORD)
Parkinson disease
Restless legs syndrome
Torticollis
Early infantile epileptic encephalopathy (NORD)
Epilepsy
Febrile seizure
Brown-Sequard Syndrome
Cauda equina syndrome
Friedreich ataxia
Neurogenic bladder
Syringomyelia
Treponema pallidum (Syphilis)
Vitamin B12 deficiency
Concussion and traumatic brain injury
Peripheral nervous system disorders
Poliovirus
Spinal muscular atrophy
Charcot-Marie-Tooth disease
Guillain-Barre syndrome
Bell palsy
Trigeminal neuralgia
Carpal tunnel syndrome
Erb-Duchenne palsy
Klumpke paralysis
Sciatica
Thoracic outlet syndrome
Ulnar claw
Winged scapula
Lambert-Eaton myasthenic syndrome
Myasthenia gravis
Nervous system pathology review
Adult brain tumors: Pathology review
Central nervous system infections: Pathology review
Cerebral vascular disease: Pathology review
Congenital neurological disorders: Pathology review
Dementia: Pathology review
Demyelinating disorders: Pathology review
Headaches: Pathology review
Movement disorders: Pathology review
Neurocutaneous disorders: Pathology review
Neuromuscular junction disorders: Pathology review
Pediatric brain tumors: Pathology review
Seizures: Pathology review
Spinal cord disorders: Pathology review
Traumatic brain injury: Pathology review
Assessments
Neuromuscular junction disorders: Pathology review
USMLE® Step 1 questions
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Questions
USMLE® Step 1 style questions USMLE
of complete
Reproduced from: Radiopaedia.org
Laboratory testing reveals a creatinine kinase level of 75 U/L. Which of the following additional examination findings will most likely be present in this patient?
Transcript
Content Reviewers
While doing your rounds, you see Kira, a 23-year-old female who presents with a series of recurrent symptoms that get worse as the day progresses. These include slurring of speech, difficulty swallowing, and double vision. She also mentions that her head feels heavy and is hard to hold up. She also complained that her arms are so weak she can’t even brush her hair. Additionally, she reports severe fatigue and shortness of breath. On examination, sensation and reflexes are normal. Next, you see a 62-year-old man named Jonathan, who presents with a history of leg muscle weakness that prevents him from doing simple things like climbing stairs or standing up, which gets better the more he uses his legs. He also reports shortness of breath, fatigue, dry mouth, impotence, and unintentional weight loss. Examination reveals a severely underweight man with dilated pupils. Reflexes are initially absent, although these are obtainable after a brief period of exercise. Blood tests were obtained, detecting anti-acetylcholine receptor antibodies in Kira and anti-voltage-gated calcium channels antibodies in Jonathan.
Now, both seem to have some type of neuromuscular junction disease. But first, a bit of physiology. In normal neuromuscular function, a nerve impulse is carried down the axon from the spinal cord, to the nerve endings, in the neuromuscular junction, where the impulse is transferred to the muscle cell. Here, the nerve impulse leads to the opening of voltage-gated calcium channels, causing an influx of calcium ions into the nerve terminal, which triggers synaptic vesicle fusion with plasma membrane. These synaptic vesicles contain a neurotransmitter called acetylcholine, which is released into the synaptic cleft. The neurotransmitter then binds to nicotinic acetylcholine receptors on muscle cell membranes and activates a chain reaction in the muscles that ultimately results in their contraction.
Sources
- "Robbins Basic Pathology" Elsevier (2017)
- "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
- "Myasthenia Gravis: A Review" Autoimmune Diseases (2012)
- "Recent advances in understanding and managing myasthenia gravis" F1000Res (2018)
- "Clinical features, pathogenesis, and treatment of myasthenia gravis: a supplement to the Guidelines of the German Neurological Society" Journal of Neurology (2016)
- "Lambert-Eaton Myasthenic Syndrome; Pathogenesis, Diagnosis, and Therapy" Autoimmune Diseases (2011)
- "Lambert-Eaton Myasthenic Syndrome" Neurol Clin (2018)
- "Synaptic Pathophysiology and Treatment of Lambert-Eaton Myasthenic Syndrome" Molecular Neurobiology (2014)
- "Lambert-Eaton myasthenic syndrome (LEMS): a rare autoimmune presynaptic disorder often associated with cancer" J Neurol (2017)
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