Tag Archives: Neuromuscular junction
Classification: Presynaptic: Choline Acetyltransferase Synaptic: Endplate acetylcholinesterase AChE deficiency Postsynaptic: AChR deficiencies AChR kinetic abnormalities (slow & fast channel syndromes) Rapsyn mutation Diagnosis: In general: AChR antibodies: negative Genetic testing confirms the diagnosis Clinical features: At birth or <2 y.o.: Respiratory and feeding difficulties Ocular symptoms (ptosis impaired movements) NCS/EMG: RNST: decrement in amplitude CMAP … Continue reading Congenital Myasthenic Syndromes
Neonatal Myasthenia
Diagnosis: Myasthenia in a new born to a mother with myasthenia gravis AChR antibodies: positive Clinical features: Weakness, hypotonia, dysphagia, weak cry and suck, Edraphonium/Tensilon test positive Mother with myasthenia gravis Treatment: Neostigmine Rarely plasma exchange Related articles: Approach to weakness, neuromuscular disease patterns, neuromuscular junction disorders,
Clostridium tetani (tetanus)
Diagnosis: This is a clinical diagnosis supported by electrophysiological features Clinical features: Tetany: lockjaw (trismus), wrinkled forehead (frontalis), closed eyes (orbicularis oculi), retracted lips (resus sardonicus), contracted bulbar muscles, neck, limbs, rigidity, board-like abdomen Spasms: opsotonos, paroxysms of contraction, pharyngeal/laryngeal spasms, Diaphoresis, BP swings Localised tetany: rigidity and spasms localised to one part of the … Continue reading Clostridium tetani (tetanus)
Clostridium botulinum neurotoxin (Botulism)
Diagnosis: The diagnosis is by clinical features supported by neurophysiology and confirmed by toxin testing Clinical features: Types: Wound botulism, infant botulism, food botulism, Descending weakness (ocular opthalmoplegia then pharyngeal then limbs) Loss of pupil accommodation, constipation, ileus Reflexes reduced or absent Normal sensation Findings on investigations: NCS/EMG: RNST at 20 and 50 Hz: incremental … Continue reading Clostridium botulinum neurotoxin (Botulism)
Lambert Eaton Myasthenic Syndrome LEMS
Synonyms: LEMS a.k.a. Myasthenic syndrome Diagnosis: The diagnosis is made by a combination of clinical features, autoantibodies and electrophysiology Clinical features: Proximal weakness (shoulder and pelvic) and neck muscle weakness Improve with exercise, sometimes this is not clinically detectable Reduced or absent reflexes Cholinergic autonomic failure (dry mouth, constipation, impotence, decreased sweating, blurred vision) Findings … Continue reading Lambert Eaton Myasthenic Syndrome LEMS
Neuromuscular Junction Disorders NMJ
Please start with the section on neuromuscular disease patterns for an introduction. Also see the section on the approach to weakness. Here are some notes on neuromuscular junction diseases that may be of interest prior to reading about the individual diseases. Clinical features of neuromuscular junction disorders: No atrophy Normal or reduced tone Weakness: … Continue reading Neuromuscular Junction Disorders NMJ
Myasthenia Gravis
Clinical features: Ptosis, Diplopia (extraoccular muscle weaknss), dysphagia & facial weakness, respiratory failure In some patients: no ocular or facial weakness occurs Fatigable weakness, worse after exertion Fixed proximal myopathy in end stage disease Findings on Investigations: Neurotransmitter related tests: Edraphonium test (Tensilon): 10 mg I.V. (2mg initially & 8mg after 30 seconds) or Neostigmine … Continue reading Myasthenia Gravis