Epilepsy with myoclonic absences
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《美国医学杂志》
Department of Pediatrics, Grant Medical College and Sir JJ Group of Hospital, Byculla, Mumbai, India
Abstract
Epilepsy with myoclonic absences is a rare seizure disorder with intellectual impairment and resistance to conventional anti-convulsants. It is essential to diagnose epilepsy with myoclonic absences earlier for a better outcome. The authors present a case report to highlight this fact.
Keywords: Epilepsy with myoclonic absences; Lamotrigine
Epilepsy with myoclonic absences (EMA) is a rare type of childhood epilepsy in which intellectual impairment and resistance to treatment are usual.[1] It is important to identify and differentiate EMA from typical absence epilepsy (Petit mal epilepsy) because EMA has poor response to conventional anti-convulsants and poor long-term prognosis.[2] A search of Indian medical literature failed to reveal any reports of this rare seizure disorder.
Case report
A 7-year-old-female presented with multiple episodes of tonic-clonic seizures without loss of consciousness since the past six months. At the onset, the frequency of convulsions was 1-2 episodes per day. However, since the last one month the frequency of convulsions had increased, manifesting with multiple episodes (6-8 episodes every hour). She used to perceive her epilepsy as distressing and sometimes used to control the movement of one hand with another hand while convulsing. She was born of non-consanguineous marriage, had no family history of convulsions, and was developmentally normal until the onset of seizures. However, parents noticed temper-tantrums, impulsiveness and difficulty to comply instructions after the onset of seizures. On observation she appeared to have tonic component with clonic seizures along with myoclonic jerks of the upper limb. Over the past six months she did not respond to various anti-convulsants (40 mg/kg/day of valproate, 18 mg/kg/day of carbamazepine, 0.5 mg/kg/day of clobazam). Investigations revealed normal biochemical profile (blood sugar, calcium, electrolytes) and normal MRI brain study. Video-electroencephalogram (Video-EEG) revealed focal as well as generalized epileptiform discharges (spike and wave pattern) of 3.0 cycles/second (c/sec) Figure1, similar to that seen in typical absence seizures along with rhythmic myoclonic jerks of the upper limb, suggestive of myoclonic absence seizures. The onset and end of spike and wave pattern were abrupt and were precipitated by hyperventilation. At last, follow-up with six months of combination therapy (25 mg/kg/day of valproate and 4 mg/kg/day of lamotrigine) produced a fair control with only one or two seizures per day.
Discussion
Epilepsy with myoclonic absences (EMA) constitutes a very rare seizure type accounting for 0.5 % - 1 % of all epilepsies observed.[1] EMA is recognized as an individual entity by Commission on Classification and Terminology of the International League Against Epilepsy in 1989.[3] t0 he mean age of onset of seizures is 7 years (range of 11 month to 12 years). EMA is characterized clinically by absence seizures accompanied by severe bilateral rhythmic myoclonias. The myoclonias constitute a constant feature which may involve the muscles of shoulder, arms and leg (muscles of face are less frequently involved). Rhythmic jerking of shoulder, head and arms is seen or the patient may show staggering when standing (rarely falling down). At times, the myoclonias are felt as very disturbing phenomenon by the patient, and the patient frequently holds his hand giving the impression of attempting to control the intensity of the jerks. These seizures have an abrupt onset and an abrupt end with duration lasting 10-60 seconds (greater than that observed in typical childhood absences).[1] Mental retardation or mental subnormality occurs before the onset of the seizures or during the evolution of the seizures. Behavioral problems, impulsiveness and difficulty in complying instructions are the main complaints[2] as seen in the present case. i0 n comparison, neurological and cognitive problems are rare in typical absence epilepsy of childhood.[2] i0 nter-ictal EEG shows a normal background in all cases, while ictal EEG demonstrates bilateral synchronous, symmetrical spike and wave discharges at 3 c/sec similar to that observed in typical childhood absences.[1] Video-EEG plays a vital role in the diagnosis of EMA to visualize the muscular movements during the epileptiform discharges. Polygraphic EEG and electromyogram ( emg0 ) of various muscles are an alternative for the diagnosis of EMA. [1]
EMA is usually resistant to conventional anticonvulsants; however combination therapy (20-40 mg/kg/day of valproate and 20-40 mg/kg/day of ethosuximide) helps to control the seizure.[2] Recently lamotrigine (1-5 mg/kg/day) alone or in combination with valproate (20 mg/kg/day) is proved to be effective in EMA. [2],[4],[5],[6] This patient had not responded to maximum doses of valproate (40 mg/kg/day) alone but had shown a fair control with combination therapy (lamotrigine and reduced doses of valproate). EMA has a poor prognosis especially in poorly controlled seizures.[2] It is therefore essential to diagnose EMA at the earliest for a better outcome.
In view of varied evolutionary manifestations of this epilepsy; EMA should be considered with high level of suspicion especially in all absence seizures which are resistant to therapy and/or associated with mental retardation.
Contributions
Dr. T. Y. Surve, Dr. g.0 m0 ittal, Dr. s.s0 . k0 hadse & Dr. S. a0 . Khanna were involved in the care of the patient, drafting the paper, revising the paper and final approval of the paper.
Dr. T. Y. Surve was involved in the search of the literature.
Source of support: None
Competing interest: None
References
1. Tassinari CA, Bureau M, Thomas P. e0 pilepsy with myoclonic absences. In Roger J, Bureau M, Dravet C, Dreifuss FE, Wolf P, eds. Epileptic syndromes in infancy, childhood, and adolescence. 2nd ed. London; John Libbey 1992; 151-160.
2. Manonmani V, Wallace SJ. Epilepsy with myoclonic absences. Arch Dis Child 1994; 70: 288-290.
3. Commission on Classification and Terminology of the International League Against Epilepsy. Proposal for revised classification of epilepsies and epileptic syndromes. Epilepsia 1989; 30: 389-399.
4. Gibbs J, Appleton RE, Rosenbloom L, Yuen WC. Lamotrigine for intractable childhood epilepsy: a preliminary communication. Dev Med Child Neurol 1992; 34: 369-371.
5. Wallace SJ. Management issues in severe childhood epilepsies. Seizure 1995; 4: 215-220.
6. Wallace SJ. Myoclonus and epilepsy in childhood: a review of treatment with valproate, ethosuximide, lamotrigine, and zonisamide. Epilepsy Res 1998; 29: 147-154.(Surve Talib Y, Mittal Gau)
Abstract
Epilepsy with myoclonic absences is a rare seizure disorder with intellectual impairment and resistance to conventional anti-convulsants. It is essential to diagnose epilepsy with myoclonic absences earlier for a better outcome. The authors present a case report to highlight this fact.
Keywords: Epilepsy with myoclonic absences; Lamotrigine
Epilepsy with myoclonic absences (EMA) is a rare type of childhood epilepsy in which intellectual impairment and resistance to treatment are usual.[1] It is important to identify and differentiate EMA from typical absence epilepsy (Petit mal epilepsy) because EMA has poor response to conventional anti-convulsants and poor long-term prognosis.[2] A search of Indian medical literature failed to reveal any reports of this rare seizure disorder.
Case report
A 7-year-old-female presented with multiple episodes of tonic-clonic seizures without loss of consciousness since the past six months. At the onset, the frequency of convulsions was 1-2 episodes per day. However, since the last one month the frequency of convulsions had increased, manifesting with multiple episodes (6-8 episodes every hour). She used to perceive her epilepsy as distressing and sometimes used to control the movement of one hand with another hand while convulsing. She was born of non-consanguineous marriage, had no family history of convulsions, and was developmentally normal until the onset of seizures. However, parents noticed temper-tantrums, impulsiveness and difficulty to comply instructions after the onset of seizures. On observation she appeared to have tonic component with clonic seizures along with myoclonic jerks of the upper limb. Over the past six months she did not respond to various anti-convulsants (40 mg/kg/day of valproate, 18 mg/kg/day of carbamazepine, 0.5 mg/kg/day of clobazam). Investigations revealed normal biochemical profile (blood sugar, calcium, electrolytes) and normal MRI brain study. Video-electroencephalogram (Video-EEG) revealed focal as well as generalized epileptiform discharges (spike and wave pattern) of 3.0 cycles/second (c/sec) Figure1, similar to that seen in typical absence seizures along with rhythmic myoclonic jerks of the upper limb, suggestive of myoclonic absence seizures. The onset and end of spike and wave pattern were abrupt and were precipitated by hyperventilation. At last, follow-up with six months of combination therapy (25 mg/kg/day of valproate and 4 mg/kg/day of lamotrigine) produced a fair control with only one or two seizures per day.
Discussion
Epilepsy with myoclonic absences (EMA) constitutes a very rare seizure type accounting for 0.5 % - 1 % of all epilepsies observed.[1] EMA is recognized as an individual entity by Commission on Classification and Terminology of the International League Against Epilepsy in 1989.[3] t0 he mean age of onset of seizures is 7 years (range of 11 month to 12 years). EMA is characterized clinically by absence seizures accompanied by severe bilateral rhythmic myoclonias. The myoclonias constitute a constant feature which may involve the muscles of shoulder, arms and leg (muscles of face are less frequently involved). Rhythmic jerking of shoulder, head and arms is seen or the patient may show staggering when standing (rarely falling down). At times, the myoclonias are felt as very disturbing phenomenon by the patient, and the patient frequently holds his hand giving the impression of attempting to control the intensity of the jerks. These seizures have an abrupt onset and an abrupt end with duration lasting 10-60 seconds (greater than that observed in typical childhood absences).[1] Mental retardation or mental subnormality occurs before the onset of the seizures or during the evolution of the seizures. Behavioral problems, impulsiveness and difficulty in complying instructions are the main complaints[2] as seen in the present case. i0 n comparison, neurological and cognitive problems are rare in typical absence epilepsy of childhood.[2] i0 nter-ictal EEG shows a normal background in all cases, while ictal EEG demonstrates bilateral synchronous, symmetrical spike and wave discharges at 3 c/sec similar to that observed in typical childhood absences.[1] Video-EEG plays a vital role in the diagnosis of EMA to visualize the muscular movements during the epileptiform discharges. Polygraphic EEG and electromyogram ( emg0 ) of various muscles are an alternative for the diagnosis of EMA. [1]
EMA is usually resistant to conventional anticonvulsants; however combination therapy (20-40 mg/kg/day of valproate and 20-40 mg/kg/day of ethosuximide) helps to control the seizure.[2] Recently lamotrigine (1-5 mg/kg/day) alone or in combination with valproate (20 mg/kg/day) is proved to be effective in EMA. [2],[4],[5],[6] This patient had not responded to maximum doses of valproate (40 mg/kg/day) alone but had shown a fair control with combination therapy (lamotrigine and reduced doses of valproate). EMA has a poor prognosis especially in poorly controlled seizures.[2] It is therefore essential to diagnose EMA at the earliest for a better outcome.
In view of varied evolutionary manifestations of this epilepsy; EMA should be considered with high level of suspicion especially in all absence seizures which are resistant to therapy and/or associated with mental retardation.
Contributions
Dr. T. Y. Surve, Dr. g.0 m0 ittal, Dr. s.s0 . k0 hadse & Dr. S. a0 . Khanna were involved in the care of the patient, drafting the paper, revising the paper and final approval of the paper.
Dr. T. Y. Surve was involved in the search of the literature.
Source of support: None
Competing interest: None
References
1. Tassinari CA, Bureau M, Thomas P. e0 pilepsy with myoclonic absences. In Roger J, Bureau M, Dravet C, Dreifuss FE, Wolf P, eds. Epileptic syndromes in infancy, childhood, and adolescence. 2nd ed. London; John Libbey 1992; 151-160.
2. Manonmani V, Wallace SJ. Epilepsy with myoclonic absences. Arch Dis Child 1994; 70: 288-290.
3. Commission on Classification and Terminology of the International League Against Epilepsy. Proposal for revised classification of epilepsies and epileptic syndromes. Epilepsia 1989; 30: 389-399.
4. Gibbs J, Appleton RE, Rosenbloom L, Yuen WC. Lamotrigine for intractable childhood epilepsy: a preliminary communication. Dev Med Child Neurol 1992; 34: 369-371.
5. Wallace SJ. Management issues in severe childhood epilepsies. Seizure 1995; 4: 215-220.
6. Wallace SJ. Myoclonus and epilepsy in childhood: a review of treatment with valproate, ethosuximide, lamotrigine, and zonisamide. Epilepsy Res 1998; 29: 147-154.(Surve Talib Y, Mittal Gau)