[Abstract+References] Combined Transcranial Direct Current Stimulation and Vision Restoration Training in Subacute Stroke Rehabilitation: A Pilot Study

Abstract

Background

Visual field defects after posterior cerebral artery stroke can be improved by vision restoration training (VRT), but when combined with transcranial direct current stimulation (tDCS), which alters brain excitability, vision recovery can be potentiated in the chronic stage. To date, the combination of VRT and tDCS has not been evaluated in postacute stroke rehabilitation.

Objectives

To determine whether combined tDCS and VRT can be effectively implemented in the early recovery phase following stroke, and to explore the feasibility, safety and efficacy of an early intervention.

Design

Open-label pilot study including a case series of 7 tDCS/VRT versus a convenience sample of 7 control patients (ClinicalTrials.gov ID: NCT02935413).

Setting

Rehabilitation center.

Subjects

Patients with homonymous visual field defects following a posterior cerebral artery stroke.

Methods

Seven homonymous hemianopia patients were prospectively treated with 10 sessions of combined tDCS (2.mA, 10 daily sessions of 20 minutes) and VRT at 66 (±50) days on average poststroke. Visual field recovery was compared with the retrospective data of 7 controls, whose defect sizes and age of lesions were matched to those of the experimental subjects and who had received standard rehabilitation with compensatory eye movement and exploration training.

Results

All 7 patients in the treatment group completed the treatment protocol. The safety and acceptance were excellent, and patients reported occasional skin itching beneath the electrodes as the only minor side effect. Irrespective of their treatment, both groups (treatment and control) showed improved visual fields as documented by an increased mean sensitivity threshold in decibels in standard static perimetry. Recovery was significantly greater (P < .05) in the tDCS/VRT patients (36.73% ± 37.0%) than in the controls (10.74% ± 8.86%).

Conclusion

In this open-label pilot study, tDCS/VRT in subacute stroke was demonstrated to be safe, with excellent applicability and acceptance of the treatment. Preliminary effectiveness calculations show that tDCS/VRT may be superior to standard vision training procedures. A confirmatory, larger-sample, controlled, randomized, and double-blind trial is now underway to compare real-tDCS− versus sham-tDCS−supported visual field training in the early vision rehabilitation phase.

References

  1. Roux, F. Perimetric visual field and functional MRI correlation: Implications for image-guided surgery in occipital brain tumours. J Neurol Neurosurg Psychiatry. 2001;71:505–514.
  2. Gray, C., French, J., Bates, D., Cartlidgen, Venables, G., James, O. Recovery of visual fields in acute stroke: Homonymous hemianopia associated with adverse prognosis. Age Ageing. 1989;18:419–421.
  3. Zhang, X., Kedar, S., Lynn, M., Newman, N., Biousse, V. Natural history of homonymous hemianopia. Neurology. 2006;66:901–905.
  4. Romano, J. Progress in rehabilitation of hemianopic visual field defects. Cerebrovasc Dis. 2009;27:187–190.
  5. Pöppel, E., Held, R., Frost, D. Residual visual function after brain wounds involving the central visual pathways in man. Nature. 1973;243:295–296.
  6. Weiskrantz, L., Warrington, E., Sanders, M., Marshall, J. Visual capacity in the hemianopic field following a restricted occipital ablation. Brain. 1974;97:709–728.
  7. Wüst, S., Kasten, E., Sabel, B. Blindsight after optic nerve injury indicates functionality of spared fibers. J Cogn Neurosci. 2002;14:243–253.
  8. Sabel, B.A., Fedorov, A., Naue, N., Borrmann, A., Herrmann, C., Gall, C. Non-invasive alternating current stimulation improves vision in optic neuropathy. Restor Neurol Neurosci. 2011;29:493–505.
  9. Sabel, B.A., Henrich-Noack, P., Fedorov, A., Gall, C. Vision restoration after brain and retina damage: The “residual vision activation theory”. Prog Brain Res. 2011;192:199–262.
  10. Bola, M., Gall, C., Sabel, B.A. “Sightblind”: Perceptual deficits in the “intact” visual field.Front Neurol. 2013;4:80.
  11. Bola, M., Gall, C., Moewes, C., Fedorov, A., Hinrichs, H., Sabel, B.A. Brain functional connectivity network breakdown and restoration in blindness. Neurology. 2014;83:542–551.
  12. Bola, M., Sabel, B.A. Dynamic reorganization of brain functional networks during cognition.NeuroImage. 2015;114:398–413.
  13. Bridge, H., Thomas, O., Jbabdi, S., Cowey, A. Changes in connectivity after visual cortical brain damage underlie altered visual function. Brain. 2008;131:1433–1444.
  14. Kasten, E., Wüst, S., Behrens-Baumann, W., Sabel, B.A. Computer-based training for the treatment of partial blindness. Nature Med. 1998;4:1083–1087.
  15. Gall, C., Antal, A., Sabel, B.A. Non-invasive electrical brain stimulation induces vision restoration in patients with visual pathway damage. Graefes Arch Clin Exp Ophthalmol. 2013;251:1041–1043.
  16. Eysel, U.T., Schweigart, G., Mittmann, T. et al, Reorganization in the visual cortex after retinal and cortical damage. Restor Neurol Neurosci. 1999;15:153–164.
  17. Poggel, D., Kasten, E., Sabel, B.A. Attentional cueing improves vision restoration therapy in patients with visual field defects. Neurology. 2004;63:2069–2076.
  18. Kasten, E., Bunzenthal, U., Sabel, B.A. Visual field recovery after vision restoration therapy (VRT) is independent of eye movements: An eye tracker study. Behav Brain Res. 2006;175:18–26.
  19. Nitsche, M.A., Schauenburg, A., Lang, N. et al, Facilitation of implicit motor learning by weak transcranial direct current stimulation of the primary motor cortex in the human. J Cogn Neurosci. 2003;15:619–626.
  20. Nitsche, M.A., Cohen, L.G., Wassermann, E.M. et al, Transcranial direct current stimulation: State of the art 2008. Brain Stimul. 2008;1:206–223.
  21. Antal, A., Kincses, T., Nitsche, M.A., Bartfai, O., Paulus, W. Excitability changes induced in the human primary visual cortex by transcranial direct current stimulation: Direct electrophysiological evidence. Invest Ophthalmol Vis Sci. 2004;45:702.
  22. Kraft, A., Roehmel, J., Olma, M., Schmidt, S., Irlbacher, K., Brandt, S. Transcranial direct current stimulation affects visual perception measured by threshold perimetry. Exp Brain Res. 2010;207:283–290.
  23. Plow, E.B., Obretenova, S.N., Halko, M.A. et al, Combining visual rehabilitative training and noninvasive brain stimulation to enhance visual function in patients with hemianopia: A comparative case study. PM R. 2011;3:825–835.
  24. Plow, E., Obretenova, S., Fregni, F., Pascual-Leone, A., Merabet, L.B. Comparison of visual field training for hemianopia with active versus sham transcranial direct cortical stimulation.Neurorehabil Neural Repair. 2012;26:616–626.
  25. Plow, E., Obretenova, S., Jackson, M., Merabet, L.B. Temporal profile of functional visual rehabilitative outcomes modulated by transcranial direct current stimulation.Neuromodulation. 2012;15:367–373.
  26. Hummel, F., Celnik, P., Pascual-Leone, A. et al, Controversy: Noninvasive and invasive cortical stimulation show efficacy in treating stroke patients. Brain Stimul. 2008;1:370–382.
  27. Alber, R., Cardoso, A.M., Nafee, T. Effects of non-invasive brain stimulation in cerebral stroke related vision loss. Princip Pract Clin Res. 2015;1:15–20.
  28. Rossi, S., Hallett, M., Rossini, P., Pascual-Leone, A. Safety, ethical considerations, and application guidelines for the use of transcranial magnetic stimulation in clinical practice and research. Clin Neurophysiol. 2009;120:2008–2039.
  29. Anops [computer program]. Version 2.9.6. Aachen, Germany: LinguAdapt.
  30. Bowen, D.J., Kreuter, M., Spring, B. et al, How we design feasibility studies. Am J Prev Med. 2009;36:452–457.

Source: Combined Transcranial Direct Current Stimulation and Vision Restoration Training in Subacute Stroke Rehabilitation: A Pilot Study – PM&R

Advertisements

, , , ,

  1. Leave a comment

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: