Make your own free website on Tripod.com






The Lazy Arm Sign
As Subtle Pyramidal Sign



Lea Pollak, MD Colin Klein, MD Jose-Martin Rabey, MD
Arch Neurol 1997;54:935
Assaf Harofeh Medical CenterDept of Neurology
Zerifin 70300,
Israel

We noticed that in patients with pyramidal lesion, the distance between the finger and nose on repeated finger-nose testing shortens progressively in the paretic hand. The shortening of distance is also present in those patients in whom, on routine neurological examination, no obvious weakness, pronation drift, or changes in tone and reflexes can be found.

The patients set the starting point of the finger at a progressively shorter distance from the nose, despite the efforts of the examiner to correct the shortening. This shortening or lazy arm phenomenon can be explained by primary affection of the extensor muscles in upper limbs by a corticospinal lesion, resulting in the tendency to flexion and pronation of the elbow.[ 1-4]

The increased tone of the elbow flexors and pronators acts as an agonist during finger-nose touching, and as an antagonist on rendering of the finger to its primary position, thus causing a gradual shortening of the finger-nose-tip distance.

NeuroPhysiology teaches us that a pyramidal lesion is not only characterized by weakness and awkwardness of movements but also by decreased range of movements, as demonstrated by the finger abduction test where thumb and index finger are abducted more on the healthy side than on the affected one.[1]

In summary, the routinely examined finger to nose testing can thus be helpful in revealing subtle pyramidal signs in addition to being a classic test for detection of a cerebellar lesion.


References

1. Wartenberg R. Diagnostic Tests in Neurology. Chicago, Ill: Year Book Medical Publishers Inc; 1953:101-120.

2. Clinical Examinations in Neurology by Members of the Dept of Neurology and the Dept of Physiology and Biophysics, Mayo Clinic, Univ of Minnesota, Rochester. 5th ed. Philadelphia, Pa: WB Saunders Co; 1981:103-108.

3. De Jong S. The Neurologic Examination. 5th ed. Philadelphia, Pa: JB Lippincott; 1992:316-319.

4. Adams RD, Victor M, Ropper AH. Principles of Neurology. 6th ed. New York, NY: McGraw-Hill Book Co; 1997:45-63.



Medical Texts
Anatomy | Immune System | Lymphocytes | Meds
MHC | Movement | Cranial Nerves | Physiology


MS Glossary ThJuland's MSers' Glen - Our CyberHome Page Top The Glen's Gallery: Come & Share Our Stories MS Files MS Abstracts Site Index


Abstracts
ANS | Bladder | Cognition | Fatigue | Fluid | Genetics
Interferons | IVIG | Nitric Oxide | Optic Neuritis | Pain
Physiology | Prions | Prognosis | ReMyelinate | Steroids
Stress | Treatments | TNF | Uric Acid | Viruses




Copyright 1997 - 2010:
Permission is hereby granted to MS Societies and all MSers to utilize information from these pages provided that no financial reward is gained and attribution is given to the author/s.