SCN4A 유전자 Met1592Val 돌연변이를 가진 가족성 고칼륨혈증 주기마비의 전기진단검사소견과 임상적 특징
Electrodiagnostic Findings and Clinical Characteristics of Familial Hyperkalemic Periodic Paralysis With a SCN4A Met1592Val Mutation
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Background: Hyperkalemic periodic paralysis (HYPP) is characterized by episodic flaccid paralysis of skeletal muscles that is exacerbated by the consumption of potassium-containing foods, fasting, or rest following exercise. HYPP is largely diagnosed based on clinical features and electrodiagnostic findings. Methods: Seven patients from three families were assessed by interviews and clinical examinations. Standardized protocols comprising short and long exercise tests were applied to 15 unaffected control subjects and the 7 patients with familial HYPP. Results: Exercise of short duration induced an immediate increase in the amplitude of the compound motor action potential (CMAP) in the patients, and this was significantly larger and lasted longer than that observed in controls within 50 seconds (p<0.05). A long exercise test induced a large increase in the CMAP amplitude in patients immediately after exercise completion, which decreased to normal values with 1 minute. In contrast, controls showed a decreased CMAP amplitude immediately after exercise, which subsequently also returned to the normal value. Precipitants of attacks were vigorous exercise and hunger in all patients, and cold and potassium-rich foods in five patients. All patients experienced clinical myotonia at the eyelids or lips. Conclusions: We conclude that exercise tests may be helpful in confirming abnormal excitability of muscle membranes in patients with HYPP. We have described the clinical and electromyographic characteristics in familial HYPP with the Met1592Val mutation in the SCN4A gene.
Abstract
Background: Hyperkalemic periodic paralysis (HYPP) is characterized by episodic flaccid paralysis of skeletal muscles that is exacerbated by the consumption of potassium-containing foods, fasting, or rest following exercise. HYPP is largely diagnosed based on clinical features and electrodiagnostic findings. Methods: Seven patients from three families were assessed by interviews and clinical examinations. Standardized protocols comprising short and long exercise tests were applied to 15 unaffected control subjects and the 7 patients with familial HYPP. Results: Exercise of short duration induced an immediate increase in the amplitude of the compound motor action potential (CMAP) in the patients, and this was significantly larger and lasted longer than that observed in controls within 50 seconds (p<0.05). A long exercise test induced a large increase in the CMAP amplitude in patients immediately after exercise completion, which decreased to normal values with 1 minute. In contrast, controls showed a decreased CMAP amplitude immediately after exercise, which subsequently also returned to the normal value. Precipitants of attacks were vigorous exercise and hunger in all patients, and cold and potassium-rich foods in five patients. All patients experienced clinical myotonia at the eyelids or lips. Conclusions: We conclude that exercise tests may be helpful in confirming abnormal excitability of muscle membranes in patients with HYPP. We have described the clinical and electromyographic characteristics in familial HYPP with the Met1592Val mutation in the SCN4A gene.
참고문헌 (20)
- Lehmann-Horn F, "The periodic paralysis and paramyotonia congenita in Myology. 2nd ed.", pp.1303~1334 (1994), Mcgraw Hill
- Hudson AJ, "The skeletal muscle sodium and chloride channel diseases", Brain, 118, pp.547~563 (1995)
- Ptacek L, "The familial periodic paralyses and nondystrophic myotonias", Am J Med, 108, pp.58~70 (1998)
- Fournier E, "Electromyography guides towards subgroups of mutations in muscle channelopathies", Ann Neurol, 56, pp.650~661 (2004)
- Subramony SH, "Exercise and rest in hyperkalemic periodic paralysis", Neurology, 36, pp.173~177 (1986)
- de Silva SM, "Paramyotonia congenital or hyperkalemic periodic paralysis? Clinical and electrophysiological features of each entity in one family", Muscle Nerve, 13, pp.21~26 (1990)
- McManis PG, "The exercise test in periodic paralysis", Muscle Nerve, 9, pp.704~710 (1986)
- Cannon SC, "A sodium channel defect in hyperkalemic periodic paralysis: potassium-induced failure of inactivation", Neuron, 6, pp.619~626 (1991)
- Bradley WG, "Progressive myopathy in hyperkalemic periodic paralysis", Arch Neurol, 47, pp.1013~1017 (1990)
- "Hyperkalemic periodic paralysis. Gene reviews"[URL]
- Kim J, "A family with hyperkalemic periodic paralysis", J Korean Neurol Assoc, 15, pp.931~936 (1997)
- Barchi RL, "Ion channel mutations and disease of skeletal muscle", Neurobiol Dis, 4, pp.254~264 (1997)
- Wagner S, "A novel sodium channel mutation causing a hyperkalemic paralytic and paramyotonic syndrome with variable clinical expressivity", Neurology, 49, pp.1018~1025 (1997)
- Miller TM, "Correlating phenotype and genotype in the periodic paralyses", Neurology, 63, pp.1647~1655 (2004)
- Cleland JC, "Clinical evaluation of membrane excitability in muscle channel disorders: potential applications in clinical trials", Neurotherapeutics, 4, pp.205~215 (2007)
- Kim GS, "Electrophysiological Changes by Exercise and Cold Provocation Test in a Patient with Hyperkalemic Periodic Paralysis", J Korean Neurol Assoc, 18, pp.665~668 (2000)
- Tengan CM, "The exercise test as a monitor of disease status in hypokalemic periodic paralysis", J Neurol Neurosurg Psychiatry, 75, pp.497~499 (2004)
- Streib EW, "Transient paresis in myotonic syndromes: a simplified electrophysiologic approach", Muscle Nerve, 5, pp.719~723 (1982)
- Rojas CV, "Hyperkalemic periodic paralysis M1592V mutation modifies activation in human skeletal muscle Na+ channel", Am J Physiol, 276, pp.259~266 (1999)
- Yang N, "Sodium channel mutations in paramyotonia congenita exhibit similar biophysical phenotypes in vitro", Proc Natl Acad Sci USA, 91, pp.12785~12789 (1994)