Astasia without abasia due to peripheral neuropathy.
OBJECTIVE
To describe an unusual symptom characterized by an inability to stand still despite the ability to walk in eight patients with paraparesis due to peripheral neuropathy.


METHODS
Case series during the past 18 years.


METHODS
Referral center.


METHODS
Six patients with acute or subacute polyneuropathies recovering from flaccid paralysis of the lower limbs and two patients with chronic progressive polyneuropathy for more than 10 years were studied. Weakness around the ankle joints was profound, while muscle strength around the hip joints was well recovered or preserved.


METHODS
Standing and walking were recorded and reviewed on videotape or motion pictures. Spectral content of postural sway was analyzed in three recent cases.


RESULTS
The symptom was transient in acute or subacute cases and was continual in chronic cases. The patients were compelled to take a series of steps forward and backward while standing until they initiated locomotion. They swayed rapidly around the hip joints before stepping. The anteroposterior component of postural sway in three patients had frequency peaks around 1 Hz.


CONCLUSIONS
We have termed this symptom astasia without abasia, or stilts phenomenon, in which maintenance of the body mass depends on a moving base of support. Both an abnormal pattern of postural movements and defective somatosensory feedback for postural stabilization may be responsible for the symptom.
Hirayama
K
K
Department of Neurology, School of Medicine, Chiba University, Japan.
Nakajima
M
M
Kawamura
M
M
Koguchi
Y
Y
D000293:Adolescent; D000328:Adult; D002648:Child; D003291:Conversion Disorder / Q000209:etiology*; D005260:Female; D005684:Gait; D006801:Humans; D008297:Male; D008875:Middle Aged; D009069:Movement Disorders / Q000209:etiology*; D010523:Peripheral Nervous System Diseases / Q000150:complications*; D011187:Posture