Affiliations: Department of Neurology, University of Munich,
Klinikum Grosshadern, Munich, Germany
Note: [] Corresponding author: Klaus Jahn, MD, Department of Neurology,
University of Munich, Klinikum Grøhadern, Marchioninistr. 15, 81377
Munich, Germany. Tel.: +49 89 7095 3671; Fax: +49 89 7095 6671; E-mail:
klaus.jahn@med.uni-muenchen.de
Abstract: Patients with neurological gait disorders often present to their
doctor with the key symptoms of dizziness and gait unsteadiness (e.g.
cerebellar ataxia, progressive supranuclear palsy). In vestibular syndromes, on
the other hand, the gait disturbance is a leading sign and many aspects of the
syndrome can be recognized from the analysis of posture and gait (e.g.
direction of falls). For therapy in particular it is important to better
understand the physiological control of posture and gait to adapt
rehabilitation programs. We recently succeeded in visualizing the hierarchic
network for postural control in humans by means of functional imaging
techniques. Growing evidence suggests that so-called "locomotor regions",
groups of neurons able to initiate or modulate spinal stepping in the cat in
response to electrical or chemical stimulation, also exist in humans. The most
important locomotor regions are the mesencephalic, the subthalamic, and the
cerebellar locomotor regions. Locomotor signals are transmitted from the
midbrain to the spinal cord via the ponto-medullary reticular formation and
integrate multisensory input at different levels. Functional imaging also
demonstrated that the multisensory cortical areas are inhibited during
locomotion, which is relevant for physical therapy of vestibular disorders
which therefore should include exercises with different gait patterns and
different speeds. The supraspinal network for locomotion is just beginning to
be recognized as an important factor in the pathophysiology of common gait
disorders. In Parkinson's disease, for example, low-frequency stimulation of
the mesencephalic locomotor region (pedunculopontine nucleus) is already used
to treat freezing and gait disturbance in selected patients. In this review we
summarize different attempts to visualize human supraspinal locomotor control
using functional neuroimaging techniques, both in healthy subjects and in
patients suffering from balance disorders.
