Infantile Spasms

Dr Rashmi Adiga

MBBS, D.C.H, M.R.C.P.C.H (U.K), C.C.T(U. K), F.R.C.P.C.H

Consultant Paediatric Neurologist 

Recently in my clinic , I came across a family who had a child with shaking of both upper limbs , they had a video of the episode and had done internet search of their child’s symptoms and were convinced that their child had infantile spasms. Video was typical of shuddering attacks and video EEG was normal, and I reassured parents who were relieved. Now a days parents have ready access to the Internet and they often do internet search of their infants symptoms and hence they are very worried that the symptoms of their babies might be infantile spasms .Hence I thought it would be a good idea to write an article on infantile spasms look alikes or in medical terms differential diagnosis of infantile spasms.

In 1841 the General practitioner Dr WJ West described infantile spasms in the journal , Lancet. He had described his son’s symptoms in detail and said that his son was remarkably fine healthy child when born continued to thrive until he was 4 months old it was at this time that he first observed slight bobbings of the head forward which he then regarded as a trick but were in fact the first indications of the disease for these bobbings increased in frequency and length and became so frequent and powerful as to cause a complete heaving of the head forward towards his knees and then immediately relaxing into upright position. 

Infantile spasms are a type of seizure which occurs in the first year of life. Even now we have a similar description of infantile spasms where the spasms look like a sudden stiffening of muscles, and the baby's arms, legs, or head may bend forward. The seizures occur in a series of short spasms, about one to two seconds in length usually with crying in between. The seizures usually occur immediately after waking up or just as the child is getting off to sleep.

Parents after doing an internet search should not make a diagnosis themselves and start treatment. If they note any symptoms they should consult a paediatric neurologist immediately. Accurate diagnosis of non-epileptic events is very important to prevent unnecessary use of anti-epileptic drugs and steroids in infants.

During the consultation ,the paediatric neurologist takes a detailed patient history from the parents. Birth history, past history (trauma, chronic illness, etc.) and family history need to be considered . The doctor will also check whether the child’s growth and development are normal for his or her age and will conduct an age-appropriate neurological examination. They’ll look at the video taken by the parents, if available, and, if not, may ask them to take a video recording the next time the symptoms develop. Using video recordings to verify the symptoms enhances not only the diagnostic accuracy but is also cost-effective. Basic tests may include a blood test (complete blood cell count, electrolyte, iron study, ionized/total calcium) and an EEG or video EEG. 

Some of the conditions which mimic infantile spasms are described below.

Videos of the episodes can help distinguish between normal baby movements and shuddering attacks and sometimes just this is enough.

Babies with colic and gastro-oesophageal reflux may be thought to have infantile spasms and vice-versa. Child may have episodes of crying with drawing the legs and this may usually happen in the evening. Videos of the episodes may be useful however awake/sleep EEG or video-EEG may help differentiate between colic and infantile spasms .

Benign myoclonus of early infancy can mimic infantile spasms. The infant may have a brief series of spasms with episodes characterised by myoclonic activity of the truncal or limb musculature. Myoclonic activity means a sudden jerk of the shoulders or the body or a part of the body. Usually child has a normal neurological examination and development. Video EEG can help delineate between this condition and infantile spasms. The myoclonus usually resolves by the time the child reaches 2 years of age and no other seizures develop.

Sleep Myoclonus is common. Benign neonatal sleep myoclonus usually present in the first week of life with sudden , synchronous and repetitive jerks of the fingers, wrists and elbows ,usually in sleep. Baby has a normal neurological examination and EEG. The disorder resolves spontaneously in the first year of life.

Shuddering attacks are often thought to be infantile spasms. Shuddering attacks are involuntary movements of the head and upper extremities that occur during normal activities and do not impair consciousness. Videos of the episodes can help distinguish between normal baby movements and shuddering attacks. Triggers of the attack usually include excitement. Child usually has a normal neurological examination and development . Video EEG is completely normal but not usually needed.Parents can be reassured that the attacks will reduce in frequency as the child grows older and will spontaneously stop with age.

There may be other infantile epilepsies which may look like infantile spasms. Video of the seizures and EEG can help differentiate them .

In summary there are many conditions which can mimic infantile spasms. Parents after doing an internet search should not make a diagnosis themselves and start treatment. It is important for parents to see a paediatric neurologist who can take a detailed history and perform a detailed examination including age appropriate neurological examination. With experienced practitioners, EEG may not always be necessary.  Video EEG and EEG capturing a full sleep wake cycle can help differentiate most of these conditions. 

It is very crucial to identify the mimics correctly so that unnecessary  investigations and treatment can be avoided in normal infants.