Babinski’s sign - The 'tickle' test.

As part of my trawl of the symptoms of HSP, today I'm exploring Babinski's Sign, which seems also to be called Babinski's Reflex.

1) Babinski reflex is one of the reflexes that occurs in infants. It occurs after the sole of the foot has been firmly stroked. The big toe then moves upward or toward the top surface of the foot. The other toes fan out. This reflex is normal in children up to 2 years old. It disappears as the child gets older. It may disappear as early as 12 months. From: http://www.nlm.nih.gov/medlineplus/ency/article/003294.htm

2) The Babinski sign is an important neurologic examination based upon what the big toe does when the sole of the foot is stimulated. The Babinski sign is obtained by stimulating the external portion (the outside) of the sole. The examiner begins the stimulation back at the heel and goes forward to the base of the toes. A useful way to elicit the response that requires no special equipment is with firm pressure from the examiner's thumb. Just stroke the sole firmly with the thumb from back to front along the outside edge.

Too vigorous stimulation may cause withdrawal of the foot or toe, which can be mistaken as a Babinski sign. Most newborn babies are not neurologically mature so they normally show a Babinski sign. Upon stimulation of the sole, they extend the great toe . Many young infants do this, too, and it is perfectly normal. However, in time during infancy the Babinski response vanishes and, under normal circumstances, should never return.

A Babinski sign in an older child or adult is abnormal. It is a sign of a problem in the central nervous system (CNS), most likely in a part of the CNS called the pyramidal tract. From http://answers.yahoo.com/question/index?qid=20090509083919AAiuHmw

The next part of my trawl is to see what pops up from the HSP research papers. There are various papers from 1989 and more recently which note that Babinski's Sign is present in a number of cases of HSP (and similar conditions). Of note, there's a paper from 2000 which described a new locus for HSP in a french family, and compared these patients with familys with SPG4 noted that there were significantly more patients without Babinskis signs, 

This suggests to me that Babinskis sign may not be present in everyone with HSP.  And, therefore, I shouldn't start making bold assertions after tickling the feet of my family....

Of note, when I was having my blood test to determine if I had HSP back in early 2009, one of the things the people at Genetics said was that they might be able to tell if I had HSP by tickling my feet. So, I'm quite pleased to have found out what that means.

The 2000 paper is: A new locus for autosomal dominant pure spastic paraplegia, on chromosome 2q24-q34. Fontaine B, Davoine CS, Dürr A, Paternotte C, Feki I, Weissenbach J, Hazan J, Brice A. Am J Hum Genet. 2000 Feb;66(2):702-7. http://www.ncbi.nlm.nih.gov/pubmed/10677329