Lennox-Gastaut syndrome is the most distressing of childhood epilepsies. The children suffer frequent fits of many different types, and experience gradual mental deterioration. Infantile spasms often evolve into Lennox-Gastaut syndrome, and the age of onset is from 1 to 8 years, peaking at 3 to 5 years. The prognosis for children with Lennox-Gastaut syndrome is bleak.
Clinically, neurologists define Lennox-Gastaut syndrome by three characteristics:
In Lennox-Gastaut syndrome the primary focus for the epilepsy appears to be the brain stem, that is, the area at the top of the spinal cord and below the cerebral cortex. Because of its central position and the fact that the "higher" brain functions evolved from the brain stem, epilepsies in this area are particularly harmful. A simplistic view is that epilepsies of the brain stem disrupt autonomic functions like reflexes, and that Lennox-Gastaut syndrome represents the disruption of the proper functioning of the higher areas of the brain because the basic functions in the brain stem are inadequate to support its proper operation.
How do I know if my child has Lennox-Gastaut syndrome?
The basic answer is that you know when your neurologist tells you. The symptoms are variable; the first manifestation of Lennox-Gastaut syndrome is often a head drop where the head suddenly drops because the muscles in the neck lose their tone. The head drop is usually brief and may be accompanied by a loss of consciousness. These head drops usually develop into full drop attacks where the child falls down because many of the muscles in the body lose their tone at the same time. The drop attacks are physically dangerous, because the child falls and hurts itself.
Lennox-Gastaut syndrome is characterised by multiple types of fit. As well as drop attacks, these are likely to include atypical absence fits and massive myoclonic jerks. Atypical absence fits may begin and end gradually, with consciousness only partially affected; the child may continue to be active, although mentally distant and abstracted. Myoclonic jerks are the violent jerking of one or more limbs.
Specific cases of Lennox-Gastaut syndrome may suffer from a wide variety of other forms of fits, and in particular from severe status epilepticus. In status, the child will lose consciousness, and may suffer from a sequence of atonic and myoclonic fits alternating between floppiness and rigidity. Status can persist for hours, days or weeks, and can cause severe mental damage. If you think your child is in status, you should call an ambulance immediately. If your child is at risk of status, you should always:
Lennox-Gastaut syndrome is refractive to treatment. Because of the variety of types of fit associated with Lennox-Gastaut syndrome, neurologists often resort to using multiple drugs in high quantities, which is almost certainly harmful in itself. Vigabatrin and felbamate are newer drug treatments which have shown some promise with Lennox-Gastaut syndrome. The ketogenic diet appears to be a useful treatment, although there are not any good statistics.
Sadly the prognosis is poor. Most (60%) children will be refractive to drug therapy. Mental retardation may be present at the onset of Lennox-Gastaut syndrome, and deterioration is likely to occur subsequently. Most (70% - 95%) children will be mentally retarded, and most of these severely. Some (5%) children will die of complications - physical damage or status epilepticus. Those that become adult will have continuing problems. Most (80%) will continue to have fits through their adult life. Some (25%) will have emotional disorders. Almost all (95%) will have continuing mental disabilities, ranging from language difficulties to learning arrest and impaired movement. About half (50%) will be completely dependent and only some (20%) will be able to lead independent lives. It is easy to quote the statistics, but remember that each represents a personal tragedy.
Lennox-Gastaut is an epileptic syndrome characterised by the triad of multiple fit types, diffuse spike slow waves (1-3Hz) and mental retardation.
First described by Tissot in 1770. Characteristic EEG described by Gibbs in 1938. Lennox established clinical correlation between EEG and physical symptoms in 1950.
About 1 in 10,000 – this represents 5% of childhood epilepsies.
Age of onset from 1 to 8 years, peaking at 3 to 5 years. More prevalent in boys than girls.
Prior risk factors are infantile spasms (30%) and family history of epilepsy. Known causes include hypoxic ischaemic encephalopathy (lack of oxygen at birth), intrauterine infections (CMV, rubella, toxoplasmosis), head trauma, meningitis, tuberous sclerosis, brain tumours and metabolic disorders (lipid storage disease, aminoacidopathies).
Fits very frequent - 25 a day or more - 50% during inactive wakefulness, 30% during drowsiness.
Wide variety of fit types:
Factors associated with worst prognosis include infantile spasms, onset before 3 years, high frequency of fits, frequent status epilepticus.
EEG shows abnormally slow background with diffuse interictal slow spike waves at leas than 3Hz during waking and bursts of fast (10Hz) waves during sleep. The maximal voltage area is usually anterior.
CT/MRI likely to show abnormalities, particularly subcortical cerebral atrophy.
There is disagreement as to whether polytherapy or monotherapy is better. The precise drugs used will depend on the types of fits for a particular child. Typical drugs used include valproic acid, clonazepam, vigabatrin , felbamate and topimirate. ACTH can be used successfully for short periods, but the child will usually regress afterwards. The ketogenic diet appears to work well with some children, although there are no useful clinical studies.
Information about Lennox-Gastaut syndrome
There is very little useful information about Lennox-Gastaut syndrome on the Web.
Lennox-Gastaut Support Group
9 South View
Burrough on the Hill
Tel 01664 454305
"The original Lennox-Gastaut Support Group went into abeyance in 1995 and was re-formed in 1996. It offers support and information by telephone and letter and linking families where possible. It publishes a newsletter and has information available, details on request. Over 100 families and health care professionals are in membership"
The LGS group is a parents support organisation with a newsletter and snail mail interchange. The contact is:
6443 Riggs Place
Los Angeles, CA. 90045
phone (310) 670-8279
Rob Evers’ Epilepsy in Young Children contains profiles of a number of children (40+ at November 2002) suffering from Lennox-Gastaut syndrome.
The Massachusetts General Hospital runs a bulletin board system Harvard neurology web forum for epilepsy which sometimes refers to Lennox-Gastaut
Many parents whose children have Lennox-Gastaut use the ketogenic diet and subscribe to the Ketogenic diet list or to the other ketogenic diet list .
There is one book published on the subject:
Niedermayer E, Degen R (eds), Lennox-Gastaut syndrome . New York: AR Liss Inc 1988 - ISBN 0471500380/5807-0382616-726789
Med line lists about 50 papers published since 1996 which refer to Lennox-Gastaut syndrome :
return to Infantile
spasms and other epilepsies
return to Symptomatic generalised epilepsies
(checked: 15 November 2002)
(update 1.3: 22 January 2003)
(issue 1: 12 January 1998)