Hereditary spastic paraplegia with amyotrophy and pes cavus.

The hereditary " ataxias " comprise a group of well recognized degenerative disorders of the central nervous system wherein the neurological syndromes are largely determined by genetic transmission. Clinical evidence of involvement of the pyramidal tracts is often present, as for example in Friedreich's ataxia, but from a study of the literature it would seem that degeneration ofthe pryamidal tracts alone, producing a spastic paraplegia, occurs much less frequently. This is certainly the conclusion reached by Bell and Carmichael (1939) following their exhaustive study of the literature, and they considered hereditary spastic paraplegia to be extremely rare in Great Britain. It seems that Gee (1889) was the first to report such an occurrence here, describing three cases in one pedigree showing dominant inheritance; Tooth (1891) published two pedigrees, each of two affected persons. The largest reported pedigree from this country however is that carefully described by Jones (1907). He observed a sibship of nine, eight boys and one girl; all the boys were affected to a greater or lesser extent but the girl was normal; both parents were normal, there was no consanguinity, and no relatives were affected. Jones held that mutation might have occurred, but since the parents were normal and unrelated, no conclusion is drawn as to the mode of inheritance. Varying degrees of disability were noted amongst these patients, although the age of onset was uniform throughout (one to two years approximately). The cardinal signs were also present to an unequal though symmetrical extent in the different persons: they were confined to the legs, which were regarded as being thinner than was normal, usually with some degree of pes cavus. Most of the affected members showed a spastic gait together with an increase in muscle tone and tendon reflexes, the plantar responses being always extensor. There was no evidence of impaired sensation. The abdominal reflexes were present and equal in all cases. Jones writes that the pcower in the legs was never grossly diminished and that the disability, after a time, appeared to become almost stationary. It will be seen that these features are all present in the pedigree we shall describe. Later, Ogilvie (1908) reported two affected persons in a family, but since that time there appear to be no further references from Great Britain. The largest number of cases of hereditary spastic paraplegia so far published from other countries are two pedigrees, both including 16 affected members, reported by Bayley (1897) and Bremer (1922), involving five and six generations respectively, with dominant inheritance. In both, the age of onset was in early childhood, probably under five years. In view of the apparent rarity of hereditary spastic paraplegia, we feel that the history of a family we saw recently should be recorded. We shall not describe each case in detail, so that following the account of Case I1.6, the first person to be examined, it may be assumed that the remainder are similarly affected unless otherwise stated. All members in generations IL and III have been examined by ourselves.