524 LETTERS TO THE EDITOR choose from a list of choices. We therefore believe that our patients were appropriately classified as having locked-in syn- drome. Robin Ockey, MD Deb Mowry, DO George Varghese, MD University of Kansas Kansas City, KS 66160 References 1. Bauer G, Gerstenbrand F, Rumpl E. Varieties of the locked-in syn- drome. J Neurol 1979;221:77-91. 2. Rao N, Costa JL. Recovery in non-vascularlocked-in syndrome dur- ing treatment with Sinemet. Brain Inj 1989;3:207-11. 3. Patterson JR, Grabois M. Locked-in syndrome. A review of 139 cases. Stroke 1968;17:758-64. 4. Plum F, Posner JB. The diagnosis of stupor and coma. 3rd ed. Phila- delphia: FA Davis, 1980. Ipsilateral Pushing in Stroke The propensity of some patients with stroke to push forcefully away from their stronger side while sitting or standing is both intriguing and vexing. The article by Pedersen and coworkers ~ makes a much-needed contribution to our knowledge of this unusual behavior. What Pedersen calls the "pusher syndrome" has also been referred to as "listing"2 or "lateropulsion."3 Several investiga- tions, to which Pedersen makes no reference, have focused directly on the phenomenon. Other studies have provided mate- rial of potential relevance. Some of the findings of these studies and some personal observations may provide useful addi- tional information to clinicians working with patients who "push." 1. Although some authors concur with Pedersen that there is no association between side of stroke lesion and the incidence of pushing, 4 others have shown a significantly greater incidence among patients with right brain lesions.2 Regardless of the side of the lesion, the directional bias appears to be predominantly toward the contralateral side. 2'4'5 A concomitant but usually weaker tendency to fall posteriorly can also exist. 2'3'5 2. Contrary to Pedersen, investigators have consistently shown an association of neglect with balance impairments in general and pushing in particular.2'4'6 Also associated with pushing are sensory impairments z5'6 and errors in the perception of visual vertical.3 3. I suspect that whatever else underlies pushing, the patients who demonstrate the behavior have an egocentric percep- tual problem. That is, they misperceive their position in space. This can be confirmed with individual patients us- ing the following simple procedure. Stand the leftward pusher with his back against a wall. Attempt to push him to the right. He will resist you (ie, push toward the left). If you succeed in getting his body over his base of support, he will complain that he is going to fall. When asked which direction, he will indicate to the right. Of course he will fall instead to the left if you stop pushing him toward the right. As often as not, you will not even manage to get him over his feet; because as you begin to displace his body to where it belongs he will stagger to the right with his right foot. All of these behaviors are consistent 4. with the patient's believing that his appropriate position in space is somewhere to the left of true center. The stagger is a last ditch effort to keep the body over what he erro- neously perceives to be his safe base of support. Further evidence for the above posit is provided by the effectiveness of a motor relearning program. I have found that most pushers who are cognitively intact and participa- tory can "learn" within a half-hour session to balance in standing with their feet apart. After I have made their positional misperception apparent to them, introduced them to the appropriate position over their feet, and pro- vided them with practice and feedback, they typically achieve a short duration of independent static standing. This usually is realized first with their backs against a wall. Later they learn to stand without back support and to achieve the appropriate position in the context of move- ment. Richard W. Bohannon, EdD, PT University of Connecticut Storrs, CT 06269 References 1. Pedersen PM, Wandel A, Jergensen HS, Nakayama H, Raaschou HO, Olsen TS. Ipsilateral pushing in stroke: incidence, relation to neuropsychologicalsymptoms,and impact on rehabilitation.The Co- penhagen Stroke Study. Arch Phys Med Rehabil 1996;77:25-8. 2. BohannonRW, Cook AC, Larkin PA, Dubuc WE, Smith MB, Horton MG, et al. The listing phenomenonof hemiplegicpatients. Neurology Report 1986;10:43-4. 3. Dieterich M, Brandt T. Wallenberg's syndrome: lateropulsion, cyclorotation, and subjective visual vertical in thirty-six patients. Ann Neurol 1992; 31:399-408. 4. Taylor D, Ashburn A, Ward CD. Asymmetricaltrunk posture, unilat- eral neglect and motor performance following stroke. Clin Rehabil 1994;8:48-53. 5. Masdeu JC, Gorelick PB. Thalmic astasia: inability to stand after unilateral thalmic lesions. Ann Neurol 1988;23:596-603. 6. Gottlieb D, Levine DN. Unilateral neglect influences the postural adjustments after stroke. J Neurol Rehabil 1992;6:35-41. The authors reply Dr. Bohannon offers some interesting observations and pro- vides some new references. We did not find these references in our search in Medline (key words: pusher, pushing, balance, posture), which shows that a standard terminology is not estab- lished for this symptom. We have, unfortunately, not been able to obtain all the references noted by Dr. Bohannan in time for this response. The study by Taylor and coworkers concems the same symp- tom that we describe. The study comprises a selected group and there is no control for covariates. The outcome was assessed at a fixed time after stroke and not after finished rehabilitation, as was the case in our study. Thus, we do not find that it challenges our main conclusions: that there is no significant association with neglect, and that final ADL outcome need not be affected by ipsilateral pushing in spite of prolonged rehabilitation when adequate time for rehabilitation is allowed. The study by Bohannon and colleagues on postural problems with thalamic lesions and the study by Dieterich and Brand with brain stem lesions offer intriguing parallels to the ipsilateral pushing symptom. Whether any common mechanism exists can- not be establish by existing data, but these studies included only Arch Phys Med Rehabil Vol 77, May 1996