Puusepp's sign--clinical significance of a forgotten pyramidal sign

The pyramidal signs in the lower extremity can be divided into three groups: (1) Babinski's group characterised by dorsoflexion of the great toe, (2) pyramidal signs marked by plantar flexion of the toes (e.g. Rossolimo's sign), and (3) synkinetic movements such as Strümpell's phenomenon. Puusepp's sign described by the Estonian neurologist and neurosurgeon Ludvig Puusepp belongs to none of these three groups. Its eliciting does not differ from that of Babinski's sign. The response, however, is different and consists of a tonic slow abduction of the little toe. We showed its relevance on the basis of clinical examination of six patients: four females aged 29, 50, 43 and 57 years and two males aged 42 and 49 years. The diagnoses were as follows: a new relapse of multiple sclerosis, a secondary progressive multiple sclerosis, a left middle cerebral artery stroke, a lumbago resulting in L3-L4 fusion surgery, an amyotrophic lateral sclerosis and a left intracerebral haemorrhage respectively. Puusepp's sign was the only elicitable pyramidal sign in all the patients but two. The 50-year-old female patient revealed on neurological examination Babinski's sign on the left side and Puusepp's sign on the right side. The testing of pyramidal signs in the 57-year-old woman displayed a bilateral Strümpell's sign and a left Puusepp's sign. These six cases showed that although rarely recognized in the clinical practice Puusepp's sign contributed to establishing the diagnosis of a central motor neuron involvement in the case of an absent Babinski's sign. Thus, its testing does not differ from that of Babinski's sign which requires only a little attention from the examiner, but provides an important piece of clinical information.